Abstract

Lotic environments are subjected to the impacts of human activities in an intense way in urban regions and one of the ways to assist in the environmental diagnosis is through the knowledge of the composition of bioindicator organisms, including microalgae. The objective of this work was to qualitatively characterize the Chlorophyceae Class Wille, providing descriptions and meristic data of the specimens as well as the environmental conditions in which the taxa were recorded. Water and phytoplankton samplings were carried out quarterly in 2020, in nine supply rivers, distributed in three river basins in the western region of Paraná (Paraná III basin, Piquiri basin and Baixo Iguaçu basin). The studied rivers were classified as oligotrophic or mesotrophic and the taxa were mostly rare. Thirty-six taxa belonging to the Chlorophyceae class were recorded, distributed in five families: Hydrodictyaceae Dumortier, Neochloridaceae Ettl & Komárek, Radiococcaceae Fott ex P.C.Silva, Scenedesmaceae Oltmanns, Selenastraceae Blackman & Tansley. These taxa have mainly cenobial representatives, with about 70% of the individuals in this thallus configuration, followed by 22% colonies and 8% unicellular thallus. Among the identified species, five occurred only in mesotrophic sites, warning for environments with tendencies to elevate their trophic, since they are genera previously associated with these conditions. Ten new citations were recorded for the State of Paraná, namely: Pseudopediastrum boryanum var. longicorne (Reinsch) P.M.Tsarenko, Radiococcus skujae I.Kostikov, T.Darienko, A.Lukesová & L.Hoffmann, Desmodesmus perforatus (Lemmermann) E.Hegewald, Desmodesmus subspicatus (Chodat) E.Hegewald & A.W.F.Schmidt, Scenedesmus indicus Philipose ex Hegewald, Engelberg & Paschma, Ankistrodesmus bernardii Komárek, Monoraphidium capricornutum (Printz) Nygaard, Monoraphidium caribeum Hindák, Raphidocelis danubiana var. elegans (Playfair) Taşkin & Alp, Selenastrum rinoi Komárek & Comas. Taxonomic studies, such as this one, are an important tool for understanding the flora, and in addition to contributing to the registration of species in aquatic ecosystems, they serve as a basis for ecological studies and other approaches used to preserve biodiversity in these places.

Keywords
bioindicators; green algae; phytoplankton; rivers; taxonomy

Resumo

Ambientes lóticos são ecossistemas muito vulneráveis aos impactos das atividades humanas, especialmente em regiões urbanas, e uma das formas para auxiliar no diagnóstico ambiental é utilizando o conhecimento da composição dos organismos bioindicadores, dentre eles as microalgas. O objetivo foi caracterizar qualitativamente as microalgas enquadradas na Classe Chlorophyceae Wille, fornecendo descrições e dados merísticos dos espécimes bem como as condições ambientais em que os táxons foram registrados. Foram realizadas amostragens de água e de fitoplâncton trimestralmente no ano de 2020, em nove rios de abastecimento, distribuídos em três bacias hidrográficas da região oeste do Paraná (bacia do Paraná III, bacia do Piquiri e bacia do Baixo Iguaçu). Os rios estudados foram enquadrados como oligotróficos ou mesotróficos e os táxons apresentaram em sua maioria ocorrência rara. Foram registrados 36 táxons pertencentes a classe Chlorophyceae distribuídos em cinco famílias: Hydrodictyaceae Dumortier, Neochloridaceae Ettl & Komárek, Radiococcaceae Fott ex P.C.Silva, Scenedesmaceae Oltmanns, Selenastraceae Blackman & Tansley. Esses táxons possuem representantes principalmente cenobiais, apresentando cerca de 70% dos indivíduos nessa configuração de talo, seguido por 22% de colônias e 8% de talos unicelulares. Entre as espécies identificadas, cinco ocorreram somente em locais mesotróficos, advertindo para ambientes com tendências a elevar sua trofia, visto que são gêneros já associados anteriormente a essas condições. Foram registradas 10 novas citações para o Estado do Paraná, sendo estas: Pseudopediastrum boryanum var. longicorne (Reinsch) P.M.Tsarenko, Radiococcus skujae I.Kostikov, T.Darienko, A.Lukesová & L.Hoffmann, Desmodesmus perforatus (Lemmermann) E.Hegewald, Desmodesmus subspicatus (Chodat) E.Hegewald & A.W.F.Schmidt, Scenedesmus indicus Philipose ex Hegewald, Engelberg & Paschma, Ankistrodesmus bernardii Komárek, Monoraphidium capricornutum (Printz) Nygaard, Monoraphidium caribeum Hindák, Raphidocelis danubiana var. elegans (Playfair) Taşkin & Alp, Selenastrum rinoi Komárek & Comas. Trabalhos taxonômicos, como este, são uma importante ferramenta para o conhecimento da flora, e além de contribuir no registro das espécies nos ecossitemas aquáticos, servem como base para estudos ecológicos e demais abordagens utilizadas na preservação da biodiversidade nesses locais.

Palavras-chave
algas verdes; bioindicadores; fitoplâncton; rios; taxonomia

Introduction

The Chlorophyceae class is part of the “UTC clade” (Ulvophyceae, Trebouxiophyceae and Chlorophyceae) within the Chlorophyta division, and stands out for having its undeniable monophyly, supported by molecular and ultrastructural data (Fučíková et al. 2019FUČÍKOVÁ, K., LEWIS, P.O., NEUPANE, S., KAROL, K.G. & LEWIS, L.A. 2019. Order, please! Uncertainty in the ordinal-level classification of Chlorophyceae. PeerJ, 7, e.6899.). Owing to the high number of species, it is considered one of the most abundant and diverse group in Brazilian continental waters (Rodrigues et al. 2010RODRIGUES, L.L., SANT’ANNA, C.L. & TUCCI, A. 2010. Chlorophyceae das Represas Billings (Braço Taquacetuba) e Guarapiranga, SP, Brasil. Braz. J. Bot. 33:247–264.), grouping around 563 genera and 3.797species (Guiry & Guiry 2023M.D. GUIRY IN GUIRY, M.D. & GUIRY, G.M. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 17 de março de 2023.
https://www.algaebase.org... ). The morphology of these organisms ranges from flagellated unicellular to unicellular devoid of locomotion organelles, motile or non-motile colonies, filaments and pseudoparenchyma structures (Wehr et al. 2015WEHR, J.D., KOCIOLEK, P. & SHEATH, R. 2015. Freshwater Algae of North America: Ecology and Classification. 2 ed. Academic Press, Massachusetts, EUA.). The species of the Class Chlorophyceae present a wide morphometric and ecophysiological variability, being able to develop in different habitats, being influenced especially by the light exposure, availability of reactive soluble phosphorus and mixing of the water column (Happey-Wood 1988HAPPEY-WOOD, V.M. 1988. Ecology of freshwater planktonic green algae. In Sandgren (C.D. ed.), Growth and Reproductive Strategies of Freshwater Phytoplankton. Cambridge University Press, Cambridge, p.175–226.).

Increasingly, lotic environments are degraded due to urbanization and intense anthropic activities (Li et al. 2022LI, P., WANG, D., LI, W. & LIU, L. 2022. Sustainable water resources development and management in large river basins: an introduction. Environ. Earth. Sci. 81(6):1–11.). In this context the water for public supply is deteriorated, besides all aquatic biota that suffer the consequences of inadequate management of these environments (Peres et al. 2022PERES, K.K., GUICHO, R., MEDEIROS, G., AMARAL, M.W.W., DA SILVA, T.T., PILATTI, M.C., PRIOR, M. & BUENO, N.C. 2022. Environmental fragility as an indicator of the risk of contamination by human action in watersheds used for public supply in western Paraná, Brazil. Environ. Earth. Sci. 81:486.). In this sense the taxonomic composition of the Class Chlorophyceae is an important tool to assist in environmental diagnosis, since the species are often associated with environments with organic pollution and potential eutrophication (Wijeyaratne & Nanayakkara 2020WIJEYARATNE, W.M.D.N. & NANAYAKKARA, D.B.M. 2020. Monitoring of water quality variation trends in a tropical urban wetland system located within a Ramsar wetland city: A GIS and phytoplankton based assessment. Environ. Nanotechnol. Monit. Manag., 14:100323.). The literature for the State of Paraná, mainly studies in lotic environments, is scarce when compared to lentic environments, in addition to all the richness of species that have not yet been described. Among the main works referring to the Chlorophyceae Class in rivers, we can mention: Oliveira et al. (1994)OLIVEIRA, M.D., TRAIN, S. & RODRIGUES, L.C. 1994. Levantamento preliminar do fitoplâncton de rede (exceto Zygnemaphyceae) do Rio Paraná, no Município de Porto Rico, Paraná, Brasil. Rev. UNIMAR 16:155–173. with 46 taxa distributed in 25 genera in the Paraná River; Bittencourt-Oliveira (1997)BITTENCOURT-OLIVEIRA, M.C. 1997. Fitoplâncton do rio Tibagi, Estado do Paraná, Brasil: Nostocophyceae, Chlorophyceae, Euglenophyceae, Chrysophyceae e Tribophyceae. Hoehnea 24:1–20. with 24 taxa distributed in the Chlorococcales, Oedogoniales and Volvocales orders in the Tibagi River; Medri et al. (2002)MEDRI, M.E., BIANCHINI, E., SHIBATTA, O.A. & PIMENTA, J.A. 2002. A Bacia do rio Tibagi. Londrina, PR. with the flora of the Tibagi River; Biolo et al. (2009)BIOLO, S., SIQUEIRA, N.S. & BUENO, N.C. 2009. Chlorococcales (Chlorophyceae) de um tributário do Reservatório de Itaipu, Paraná, Brasil. Hoehnea 36:667–678. with the identification of 21 taxa distributed in six families in the São Francisco Falso River.

Among the most recent works we can still cite: Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330. with 28 taxa distributed in the families Hydrodictyaceae, Oocystaceae and Scenedesmaceae in the São João River; Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451. with thirty taxa, distributed in six families and 16 genera in the Cascavel River; Medeiros et al. (2021)MEDEIROS, Y., AQUINO, C.A.N., BORTOLINI, J.C., MEDEIROS, G., AMARAL, M.W., FAVARETTO, C.C.R. & BUENO, N.C. 2021. Plnktonic chlorophyceans of a Brazilian subtropical river: Taxonomy and ecological aspects. Rodriguésia 72:02192019. recorded 26 taxa in a subtropical river in the State of Paraná and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222. with a book chapter that synthesizes the taxa of green microalgae described in the works for western Paraná.

Thus, our study aimed to carry out a taxonomic survey of phytoplanktonic chlorophyceans in lotic environments with different physical and chemical conditions of the water of the western region of Paraná; Provide descriptions, illustrations, morphometric and meristic data of the species found along the environments; Contribute to the registration of species found on the UNOPA (herbarium of UNIOESTE – Universidade Estadual do Oeste do Paraná) species Link platform.

Material and Methods

1. Selection, location and characterization of study sites

We selected nine rivers used to capture water for public supply in the western region of Paraná, along the Lower Iguaçu River, Paraná III and Piquiri river basins (Table 1), which were distributed in nine municipalities: Guaraniaçu, Catanduvas, Três Barras do Paraná, Boa Vista Aparecida, Foz do Iguaçu, Medianeira, Santa Tereza do Oeste, Cascavel and Toledo (Figure 1).

The water sampling for physicochemical and biological analyses was performed in two sites in each river. These sites are similar in terms of flow, riparian vegetation and human influence, however, they were selected taking into consideration the characteristic of lotic systems, where the water flow carries dissolved materials including pollutants, making a comparison between the two possible (Vannote et al. 1980VANNOTE, R.L., MINSHALL, G.W., CUMMINS, K.W., SEDELL, J.R. & CUSHING, C.E. 1980. The river continuum concept. Can. J. Fish. Aquat. Sci. 37(1):130–137.). Sampling was carried out during the year 2020 in all four seasons. All samples were deposited in the herbarium of UNIOESTE – Universidade Estadual do Oeste do Paraná – UNOPA, Campus Cascavel, connected to the Brazilian Network of Herbaria and the data were computerized and made available on speciesLink (www.splink.cria.org.br).

2. Sampling and analysis of environmental variables in rivers

Data were obtained on water temperature (Temp – °C), dissolved oxygen (DO – mg L^–1), pH, electrical conductivity (Condut – mS/cm^–1) and turbidity (Turb – NTU), measured at the moment of the samples through the multiparameter probe Horiba U-5000. The data referring to the flow (m³ s) and maximum depth were collected with the aid of a ruler, measuring tape and a floating object, considering the multiplication between the average speed resulting from the displacement of the object and the cross-sectional area at the site to calculate the flow, measured in situ.

For chemical analysis, water samples were collected by subsurface immersion of polyethylene bottles, being kept properly refrigerated and in the dark until their destination. Estimates of concentrations of nitrate (NO₃ – mg L^–1), ammonia nitrogen (N-NH3 – mg L^–1), total phosphorus (TP- mg L^–1), chlorophyll a (CLa – mg L^–1), were performed following the standardized methods in Standard Methods (APHA 2017AMERICAN PUBLIC HEALTH ASSOCIATION (APHA). 2017. Standart Methods for the Examination of Water and Wastewater. 23 th Edition. Washington, D.C. 1796.).

3. Phytoplankton community

For the qualitative analysis, phytoplankton samples were obtained using a 25 µm mesh size plankton, were preserved in Transeau solution (Bicudo & Menezes 2017BICUDO, C.E.M. & MENEZES, M. 2017. Gêneros de Algas de Águas continentais do Brasil: chave para identificação e descrições. 3 ed. RiMa, São Carlos.) in order to concentrate the phytoplanktonic material. The qualitative study of phytoplankton was carried out using an Olympus CX41 photomicroscope, coupled with an Olympus SC30 camera, and the morphometry of the taxa was performed at 40× and 100× magnification. The taxa were identified based on specialized literature, classification used follows Krienitz & Bock (2012)KRIENITZ, L. & BOCK, C. 2012. Present state of the systematics of planktonic coccoid green algae of inland waters. Hydrobiologia, 698(1):295–326.. In order to verify the occurrence of taxa in the Paraná State, we considered only taxonomic studies with description, measures and/or illustrations, in lotic and lentic environments. The measurements (in μm) are represented by L – length; W – width; T – thorn; D – diameter; De – dent; Co – coenobium; P – process. Constancy is a measure of species occurrence (C) and was expressed as follows: constant (C ≥ 70%), common (30% ≥ C ≤ 70%), sporadic (10% ≥ C ≤ 30%) and rare (C ≤ 10%) (Dajoz 2005DAJOZ, R. 2005. Princípios de Ecologia. Artmed, Porto Alegre.).

4. TSI – Trophic State Index

The Trophic State Index presented and used in the calculation of VAT (Index of Preservation of Aquatic Life), was composed by the Trophic State Index for phosphorus – TSI(PT) and the Trophic State Index for chlorophyll a – TSI(CL), modified by Lamparelli (2004)LAMPARELLI, M.C. 2004. Grau de trofia em corpos d’água do estado de São Paulo: avaliação dos métodos de monitoramento. São Paulo: USP/ Departamento de Ecologia., 2004. 235 f. Tese de doutorado, Universidade de São Paulo., being established to lotic environments, according to the equations:

Rivers

$$\begin{array}{l}\text{TSI (CL) = 10}\times \text{(6}-\text{((}-\text{0,7}-\text{0,6}\times \text{(ln CL)) / ln 2))}-\text{20}\\ \text{TSI (PT) = 10}\times \text{(6}-\text{((0,42}-\text{0,36}\times \text{(ln PT)) / ln 2))}-\text{20}\end{array}$$

Where: PT: total phosphorus concentration measured at the water surface, in µg L^–1; CL: chlorophyll a concentration measured at the water surface, in µg L^–1; ln: natural logarithm. To classify the Trophic State for rivers, the Carlson Index (1977)CARLSON, R.E. 1977. A trophic state index for lakes. Limnology and Oceanography. March, V22 (2):361–369. modified by Toledo et al. (1983)TOLEDO, A.P., TALARICO, M., CHINEZ, S.J. & AGUDO, D. 1983. Aplicação de modelos simplificados para a avaliação de processos de eutrofização em lagos e reservatórios tropicais. In: Congresso Brasileiro de Engenharia Sanitária. Anais. Camboriú, Congresso Brasileiro de Engenharia Sanitária 1–34..

Results

Were registered 36 taxa belonging to the class Chlorophyceae Wille, distributed in five families: Hydrodictyaceae Dumortier, Neochloridaceae Ettl & Komárek, Radiococcaceae Fott ex P.C.Silva, Scenedesmaceae Oltmanns, Selenastraceae Blackman & Tansley and 16 genera: Ankistrodesmus Corda, Coelastrum Nägeli, Comasiella E.Hegewald, M.Wolf, A.Keller, Friedl & Krienitz, Desmodesmus (R.Chodat) S.S.An, T.Friedl & E.Hegewald, Golenkinia Chodat, Kirchneriella Schmidle, Lacunastrum H.A.McManus, Monoraphidium Komárková-Legnerová, Pediastrum Meyen, Pseudopediastrum E.Hegewald, Radiococcus Schmidle, Scenedesmus Meyen, Stauridium Corda, Selenastrum Reinsch, Tetrallantos Teiling, Westella De Wildeman (Figures 2–4).

FAMILY HYDRODICTYACEAE

Lacunastrum gracillimum

(West & G.S.West) H.A.McManus., J. Phycol., 47(1): 123-130, 2011. Basionym: Pediastrum duplex var. gracillimum West & G.S.West, J. Bot., 33:52, 1895.

Figure 2: A

Flat coenobium, with circular to oval shape; formed by 16 cells, clathrated; marginal cells in an asymmetrical “H” shape, concave base, two slender, long processes of equal length, ending in a slightly rectused papilla, deeply excavated “U” incision; inner cells similar to outer ones; chloroplast with the shape of the cell, one central pyrenoid.

Morphometric data: Co = 32.5-62.5 μm; L = 12.5-15.0 μm; W = 5.0-10.0 μm.

Paraná State citation: Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451. as Pediastrum duplex var. gracillimum West & G.S.West, Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Taxonomic remarks: molecular studies, associated with cell wall scan data, considering the differential characteristics of the coenobium, elongated cell lobes and smooth cell wall, made it possible to transfer the species Pediastrum gracillimum (West & G.S.West) Thunmark to the genus Lacunastrum H.A.McManus (McManus et al. 2011MCMANUS, H.A., LEWIS, L. & SCHULTZ, E. 2011. Distinguindo múltiplas linhagens de Pediastrum duplex com morfometria e uma proposta para Lacunastrum gen. nov. J. Phycol. 47(1):123–130.). Some specimens in this work presented larger dimensions than those recorded in Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451., however they are in agreement with their description and illustration.

Occurrence in samples: UNOPA 6985, 6987, 6995, 7001

Frequency of occurrence: rare

Pediastrum duplex

Meyen, Nova Acta Phys.-Med. Acad. Caes. Leop.-Carol. Nat., 14: 768-778, 1829.

Figure 2: B

Circular coenobium; formed by 16 to 32 cells (sometimes four, eight or 64 cells) arranged concentrically; intercellular spaces present; polygonal marginal cells joined at the base; square to angled inner cells; chloroplast with the shape of the cell; pyrenoid not observed.

Morphometric data: Co = 32.5-50.0 μm; L = 7.5-15.0 μm; W = 7.5-15.0 μm.

Paraná State citation: Picelli-Vicentim (1987)PICELLI-VICENTIM, M.M. 1987. Chlorococcales planctônicas do Parque Regional do Iguaçu, Curitiba, Estado do Paraná. Rev. Bras. Biol. 47:57–85., Rodrigues & Train (1993)RODRIGUES, L.C. & TRAIN, S. 1993. Chlorococcales planctônicas do Lago Municipal do Parque Alfredo Nyffeler, Paraná, Brasil. Rev. UNIMAR. 15:19–35., Oliveira et al. (1994)OLIVEIRA, M.D., TRAIN, S. & RODRIGUES, L.C. 1994. Levantamento preliminar do fitoplâncton de rede (exceto Zygnemaphyceae) do Rio Paraná, no Município de Porto Rico, Paraná, Brasil. Rev. UNIMAR 16:155–173., Bittencourt-Oliveira (1997)BITTENCOURT-OLIVEIRA, M.C. 1997. Fitoplâncton do rio Tibagi, Estado do Paraná, Brasil: Nostocophyceae, Chlorophyceae, Euglenophyceae, Chrysophyceae e Tribophyceae. Hoehnea 24:1–20., Picelli-Vicentim et al. (2001)PICELLI-VICENTIM, M.M., TREUERSCH, M. & DOMINGUES, L.L. 2001. Fitoplâncton da Represa do Passaúna, Estado do Paraná, Brasil. Hoehnea 28:53–76., Train et al. (2001)TRAIN, S., RODRIGUES, L.C., BORGES, A.F., UEDA, A.T., NACAGAVA, M.M. & BOVO, E.M. 2001. Fitoplâncton. PELD, UEM. 87–99., Borges et al. (2003)BORGES, P.A.F., PAGIORO, T.A. & TRAIN, S. 2003. Spatial variation of phytoplankton and some abiotic variables in the Pirapó River-PR (Brazil) in August 1999: a preliminary study. Acta Sci. Biol. Sci. 25(1):1–8., Biolo et al. (2009)BIOLO, S., SIQUEIRA, N.S. & BUENO, N.C. 2009. Chlorococcales (Chlorophyceae) de um tributário do Reservatório de Itaipu, Paraná, Brasil. Hoehnea 36:667–678., Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330., Felisberto & Rodrigues (2010FELISBERTO, S.A. & RODRIGUES, L. 2010. Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil). Acta Sci. Biol. Sci. 32:373–385., 2012FELISBERTO, S.A. & RODRIGUES, L. 2012. Dinâmica sucessional de comunidade de algas perifíticas em um ecossistema lótico subtropical. Rodriguésia 63:463–473.), Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451., Medeiros et al. (2021)MEDEIROS, Y., AQUINO, C.A.N., BORTOLINI, J.C., MEDEIROS, G., AMARAL, M.W., FAVARETTO, C.C.R. & BUENO, N.C. 2021. Plnktonic chlorophyceans of a Brazilian subtropical river: Taxonomy and ecological aspects. Rodriguésia 72:02192019. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Occurrence in samples: UNOPA 6983, 6985, 6987, 7094

Frequency of occurrence: rare

Pseudopediastrum boryanum var. longicorne

(Reinsch) P.M.Tsarenko, Algae of Ukraine: diversity, nomenclature, taxonomy, ecology and geography, 3: 280-355, 2011.

Basionym: Pediastrum boryanum f. longicorne Reinsch, Algenfl. Franken, 96, 1866.

Figure 2: C

Circular to oval coenobium; formed by 16 to 32 cells arranged in concentric rings without intercellular space; marginal cells extended into two longer processes, ending in swollen, stubby spines; polygonal inner cells with straight sides; cell wall usually granulated or smooth; parietal chloroplast, with one pyrenoid.

Morphometric data: Co = 32.5-41.0 μm; L = 7.5-18.0 μm; W = 5.0-13.0 μm; P = 7.0-10.0 μm.

Paraná State citation: first record.

Taxonomic remarks: the lineage of Pseudopediastrum boryanum (Turpin) E.Hegewald is divided into varieties through a set of morphological characters, such as the number of coenobium cells, the size and shape of the marginal cells, the absence of perforations between the cells and the density of the granules from the surface (Lenarczyk & Saluga 2018LENARCZYK, J. & SAŁUGA, M. 2018. Evolutionary relationships between the varieties of green algae Pediastrum boryanum and P. duplex s.l. (Chlorophyceae, Hydrodictyaceae). Fottea, 18(2):170–188.). The specimens of this work were identified as P. boryanum var. longicorne (due to the size of the marginal cells, which are longer than the type species, resembling a “U” shape, and are in agreement with the specialized literature (Rai & Misra 2013RAI, S. & MISRA, P. 2013. Taxonomy and Diversity of Genus Pediastrum Meyen (Chlorophyceae, Algae) in East Nepal. Our Nature, 10(1):167–175.).

Occurrence in samples: UNOPA 6805, 6815, 6995

Frequency of occurrence: rare

Stauridium tetras

(Ehrenberg) E.Hegewald, J. Phycol., 41: 1039-1054, 2005.

Basionym: Micrasterias tetras Ehrenberg, Infus., 155, 1838.

Figure 2: D-F

Rectangular, oval or circular coenobium; formed by four, eight or 16 cells without intercellular spaces; marginal cells divided into two lobes, by a deep linear incision, from the outside reaching the middle of the cell; internal cells formed by four to six sides with a single linear incision; smooth cell wall, parietal chloroplast; pyrenoid not observed.

Morphometric data: D = 22.5-35.0 μm; L = 7.5-12.5; W = 7.5-13.5 μm.

Paraná State citation: Cited as Pediastrum tetras (Ehrenberg) Ralfs in Lozovei & Luz (1976)LOZOVEI, A.L. & LUZ, E. 1976. Diptera Culicidae em Curitiba e arredores, 2: alimentação. Arq. Biol. Tecnol. 19:43–83., Lozovei & Hohmann (1977)LOZOVEI, A.L. & HOHMANN, E. 1977. Principais gêneros de microalgas em biótopos de larvas e mosquitos de Curitiba, Estado do Paraná, Brasil, 3: levantamento e constatação da ecologia. Acta. Biol. 6 (1,2,3,4):123–51., Picelli-Vicentim (1986)PICELLI-VICENTIM, M.M. 1986. Catálogo das Chlorophyta de águas continentais e marinhas do estado do Paraná, Brasil. Braz. J. Biol.14:2–27., Rodrigues & Train (1993)RODRIGUES, L.C. & TRAIN, S. 1993. Chlorococcales planctônicas do Lago Municipal do Parque Alfredo Nyffeler, Paraná, Brasil. Rev. UNIMAR. 15:19–35., Oliveira et al. (1994)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451., Train et al. (2001)TRAIN, S., RODRIGUES, L.C., BORGES, A.F., UEDA, A.T., NACAGAVA, M.M. & BOVO, E.M. 2001. Fitoplâncton. PELD, UEM. 87–99., Train et al. (2003)TRAIN, S., RODRIGUES, L.C., BORGES, A.F., ZANDONADI, A.P., PIVATO, B.M., BOVO, V.M., UEDA, A. T. & NACAGAVA, M.M. 2003. Fitoplâncton. PELD, UEM. 75–87., Algarte et al. (2006)ALGARTE, V.M., MORESCO, C. & RODRIGUES, L. 2006. Algas do perifíton de distintos ambientes na planície de inundação do alto Rio Paraná. Acta Sci Biol Sci. 28:243–251., Borges et al. (2008)BORGES, P.A.F., TRAIN, S. & RODRIGUES, L.C. 2008. Estrutura do fitoplâncton, em curto período de tempo, em um braço do reservatório de Rosana (ribeirão do Corvo, Paraná, Brasil). Acta Sci. Biol. Sci. 30:57–65. and Felisberto & Rodrigues (2012)FELISBERTO, S.A. & RODRIGUES, L. 2012. Dinâmica sucessional de comunidade de algas perifíticas em um ecossistema lótico subtropical. Rodriguésia 63:463–473., Biolo et al. (2009)BIOLO, S., SIQUEIRA, N.S. & BUENO, N.C. 2009. Chlorococcales (Chlorophyceae) de um tributário do Reservatório de Itaipu, Paraná, Brasil. Hoehnea 36:667–678., Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330., and as Stauridium tetras in Menezes et al. (2011)MENEZES, V.C., BUENO, N.C., BORTOLINI, J.C. & GODINHO, L.R. 2011. Chlorococcales sensu lato (Chlorophyceae) em um lago artificial urbano, Paraná, Brasil. Iheringia Ser. Bot. 66:227–240., Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451., Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Taxonomic remarks: in the species proposition, some specimens from the sampling had been identified as Pediastrum tetras, however, Buchheim et al. (2005)BUCHHEIM, M., BUCHHEIM, J., CARLSON, T., BRABAND, A., HEPPERLE, D., KRIENITZ, L. & HEGEWALD, E. 2005. Phylogeny of the Hydrodictyaceae (Chlorophyceae): inferences from rDNA data 1. J. Phycol. 41(5):1039–1054. proposed the transference of Pediastrum tetras to the genus Stauridium Corda from molecular analyses. Despite being a well-defined species, it can present considerable morphological variation (Ramos et al. 2016RAMOS, G.J., BICUDO, C.E.M., GÓES-NETO, A. & MOURA, C.W.N. 2016. Hydrodictyaceae (Chlorophyceae, Chlorophyta) do Pantanal dos Marimbus, Chapada Diamantina, Bahia, Brasil. Iheringia Ser. Bot. 71(1):13–21.), and therefore the dimensions of the specimens also vary, as verified in Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Occurrence in samples: UNOPA 6799, 6981, 6983, 6995, 7072, 7096, 7272

Frequency of occurrence: rare

FAMILY NEOCHLORIDACEAE

Golenkinia radiata

Chodat, J. Bot., 8: 305-308, 1894.

Figure 2: G

Spherical cells, isolated; with numerous long and delicate spines (12-14); parietal and single chloroplast; an elliptical to reniform pyrenoid.

Morphometric data: D = 13 .5- 15.0 μm; T = 19.0-25.0 μm.

Paraná State citation:Cecy et al. (1976)CECY, I.I.T., MOREIRA, I.M.V. & HOHMANN, E. 1976. Estudo ficológico e químico-bacteriológico da água do tanque do Passeio Público de Curitiba, Estado do Paraná, Brasil. Bol. Mus. Bot. Munic. 25:1–37., Lozovei & Luz (1976)LOZOVEI, A.L. & LUZ, E. 1976. Diptera Culicidae em Curitiba e arredores, 2: alimentação. Arq. Biol. Tecnol. 19:43–83., Stankiewicz et al. (1981)STANKIEWICZ, E.H., ANDRADE, L.F. & DOMINGUES, L.L. 1981. Levantamento ficológico do Rio Iguaçu: algas unicelulares, I. Surehma 1:1–76., Oliveira et al. (1994)OLIVEIRA, M.D., TRAIN, S. & RODRIGUES, L.C. 1994. Levantamento preliminar do fitoplâncton de rede (exceto Zygnemaphyceae) do Rio Paraná, no Município de Porto Rico, Paraná, Brasil. Rev. UNIMAR 16:155–173., Train et al. (2000)TRAIN, S., OLIVEIRA, M.D. & QUEVEDO, M.T. 2000. Dinâmica sazonal da comunidade fitoplanctônica de um canal lateral (Canal Cortado) do Alto Rio Paraná (PR, Brasil). Acta Sci. Biol. Sci. 22:389–395., Bittencourt-Oliveira (2002)BITTENCOURT-OLIVEIRA, M.C. 1997. Fitoplâncton do rio Tibagi, Estado do Paraná, Brasil: Nostocophyceae, Chlorophyceae, Euglenophyceae, Chrysophyceae e Tribophyceae. Hoehnea 24:1–20., Train et al. (2003)TRAIN, S., RODRIGUES, L.C., BORGES, A.F., ZANDONADI, A.P., PIVATO, B.M., BOVO, V.M., UEDA, A. T. & NACAGAVA, M.M. 2003. Fitoplâncton. PELD, UEM. 75–87., Perbiche-Neves et al. (2007)PERBICHE-NEVES, G., FERRAREZE, M., GHIDINI, A.R., BRITO, L. & SHIRATA, M.T. 2007. Assembléias micro fitoplanctônicas num lago urbano da cidade de Curitiba: Estado do Paraná, Brasil. Braz. J. Biol. 29(66): 43–51., Borges et al. (2008)BORGES, P.A.F., TRAIN, S. & RODRIGUES, L.C. 2008. Estrutura do fitoplâncton, em curto período de tempo, em um braço do reservatório de Rosana (ribeirão do Corvo, Paraná, Brasil). Acta Sci. Biol. Sci. 30:57–65., Felisberto & Rodrigues (2010)FELISBERTO, S.A. & RODRIGUES, L. 2010. Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil). Acta Sci. Biol. Sci. 32:373–385., Menezes et al. (2011)MENEZES, V.C., BUENO, N.C., BORTOLINI, J.C. & GODINHO, L.R. 2011. Chlorococcales sensu lato (Chlorophyceae) em um lago artificial urbano, Paraná, Brasil. Iheringia Ser. Bot. 66:227–240., Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451., Riediger et al. (2014)RIEDIGER, W., BUENO, N.C., JATI, S. & SEBASTIEN, N.Y. 2014. Fitoplâncton de lagoas de estabilização da Estação de Tratamento de Esgoto (ETE) no oeste do Paraná, Brasil: classes Chlorophyceae e Euglenophyceae. Iheringia Sér. Bot. 69:329–340., Medeiros et al. (2021)MEDEIROS, Y., AQUINO, C.A.N., BORTOLINI, J.C., MEDEIROS, G., AMARAL, M.W., FAVARETTO, C.C.R. & BUENO, N.C. 2021. Plnktonic chlorophyceans of a Brazilian subtropical river: Taxonomy and ecological aspects. Rodriguésia 72:02192019. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Taxonomic remarks: the dimensions analyzed in this study are smaller than in Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222., however they are in agreement with the specimens by Tucci et al. (2014)TUCCI, A., BENTO, N.D.R.M., ROSAL, C. & BICUDO, C.E.M. 2014. Criptógamos do Parque Estadual das Fontes do Ipiranga, São Paulo, SP. Algas 34: Chlorophyceae (Golenkiniaceae e Micractiniaceae). Hoehnea, 41:307–314., and in both works the description and illustration are also in agreement.

Occurrence in samples: UNOPA 6805, 6821, 6991, 6995

Frequency of occurrence: rare

FAMILY RADIOCOCCACEAE

Radiococcus skujae

I.Kostikov, T.Darienko, A.Lukešová & L.Hoffmann, Algol. Stud., 104:40, 2002.

Figure 2: H

Spherical colonies; tetrahedrally or octahedrally arranged cells; sporangial cell wall fragments at the periphery of the mucilage; pyrenoid not observed.

Morphometric data: D = 4.0 – 6.0 μm.

Paraná State citation: first record.

Taxonomic remarks: in the specialized literature, some authors identified R. skujae as Thorakochloris nygaardii Komárek, however this taxon was transferred to the genus Hindakochloris nygaardii (Komárek) Comas. Kostikov et al. (2002)KOSTIKOV, I., DARIENKO, T., LUKEŠOVÁ, A. & HOFFMANN, L. 2002. Revision of the classification system of Radiococcaceae Fott ex Komárek (except the subfamily Dictyochlorelloideae) (Chlorophyta). Arch. Hydrobiol. Suppl. Algol. Stud. 23–58. considered this genus as a synonym of R. skujae, due to the cell shape and reproductive behavior, with Radiococcus being the most used nowadays.

Occurrence in samples: UNOPA 6981

Frequency of occurrence: rare

FAMILY SCENEDESMACEAE

Coelastrum astroideum

De Notaris, Desmidacée delle Val Itrasca, pp. 1-84,1867.

Figure 2: I

Spherical coenobium; formed by eight to 32 ovoid-shaped cells; intercellular spaces present, quadrangular; smooth cell wall, often with apical thickening; parietal chloroplast, with one pyrenoid.

Morphometric data: Co = 15.0-25.0 μm; D = 5.0-7.0 μm.

Paraná State citation:Biolo et al. (2009)BIOLO, S., SIQUEIRA, N.S. & BUENO, N.C. 2009. Chlorococcales (Chlorophyceae) de um tributário do Reservatório de Itaipu, Paraná, Brasil. Hoehnea 36:667–678. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Taxonomic remarks:Coelastrum astroideum De Notaris can be confused with other species, such as Coelastrum microporum Nägeli, however it differs in that its cells are ovoid in lateral view.

Occurrence in samples: UNOPA 6805, 6809, 6981

Frequency of occurrence: rare

Coelastrum microporum

Nägeli, Algarum unicellularium genera nova et minus cognita praemissis verificationibus de algis unicellularibus in genere, p.70, fig. 6, 1855.

Figure 2: J

Spherical coenobium; formed by eight to 32 cells joined directly by the cell wall; spherical cells, without connective processes; small triangular or rectangular intercellular spaces; smooth cell wall, without apical thickening; parietal chloroplast, one central pyrenoid.

Morphometric data: Co = 22.5-25 μm; D = 4-6 μm.

Paraná State citation:Picelli-Vicentim (1987)PICELLI-VICENTIM, M.M. 1987. Chlorococcales planctônicas do Parque Regional do Iguaçu, Curitiba, Estado do Paraná. Rev. Bras. Biol. 47:57–85. and Picelli-Vicentim et al. (2001)PICELLI-VICENTIM, M.M., TREUERSCH, M. & DOMINGUES, L.L. 2001. Fitoplâncton da Represa do Passaúna, Estado do Paraná, Brasil. Hoehnea 28:53–76..

Taxonomic remarks: Coelastrum microporum can be confused with Coelastrum astroideum, however, it differs in that its cells are spherical in both lateral and apical views. The specimens in this study have relatively smaller dimensions than those analyzed by Ramos et al. (2015)RAMOS, G.J.P., BICUDO, C.E.M. & MOURA, C.W.N. 2015. Scenedesmaceae (Chlorophyta, Chlorophyceae) de duas áreas do Pantanal dos Marimbus (Baiano e Remanso), Chapada Diamantina, Estado da Bahia, Brasil. Hoehnea 42(3):549–566., in comparison with Tucci et al. (2019)TUCCI, A., SANT’ANNA, C.L., AZEVEDO, M.T.P., MALONE, C.F.S., WERNER, V.R., ROSINI, E.F., GAMA, W.A., HENTSCHKE, G.S., OSTI, J.A.S., DIAS, A.S., JACINAVICIUS, F.R. & SANTOS, K.R. 2019. Atlas de Cianobactérias e Microalgas de Águas Continentais Brasileiras. 2 ed. Instituto de Botânica, São Paulo. the dimensions are larger, however, the description and morphology are in agreement with both works.

Occurrence in samples: UNOPA 6805, 6829, 7096

Frequency of occurrence: rare

Coelastrum proboscideum

Bohlin, Algae aquae dulcis exsiccatae praecipue scandinavicae quas adjectis algis marinis chlorophyllaceis et phycochromaceis, 1201-1400, 1896.

Figure 2: K-L

Tetrahedral coenobium; formed by four to 32 triangular cells, in lateral view; outer poles with crown-like thickening; quadratic intercellular spaces; single parietal chloroplast.

Morphometric data: Co = 15.5 μm; L = 4.0-8.0 μm.

Paraná State citation:Lozovei & Luz (1976)LOZOVEI, A.L. & LUZ, E. 1976. Diptera Culicidae em Curitiba e arredores, 2: alimentação. Arq. Biol. Tecnol. 19:43–83., Lozovei & Hohmann (1977)LOZOVEI, A.L. & HOHMANN, E. 1977. Principais gêneros de microalgas em biótopos de larvas e mosquitos de Curitiba, Estado do Paraná, Brasil, 3: levantamento e constatação da ecologia. Acta. Biol. 6 (1,2,3,4):123–51., Picelli-Vicentim (1986)PICELLI-VICENTIM, M.M. 1986. Catálogo das Chlorophyta de águas continentais e marinhas do estado do Paraná, Brasil. Braz. J. Biol.14:2–27., Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222.

Taxonomic remarks: the specimens in this study have smaller dimensions than those analyzed by Tucci et al. (2019)TUCCI, A., SANT’ANNA, C.L., AZEVEDO, M.T.P., MALONE, C.F.S., WERNER, V.R., ROSINI, E.F., GAMA, W.A., HENTSCHKE, G.S., OSTI, J.A.S., DIAS, A.S., JACINAVICIUS, F.R. & SANTOS, K.R. 2019. Atlas de Cianobactérias e Microalgas de Águas Continentais Brasileiras. 2 ed. Instituto de Botânica, São Paulo., but they are in agreement with other studies as in Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222., in addition to having illustration and description according to these works.

Occurrence in samples: UNOPA 6995, 7274

Frequency of occurrence: rare

Coelastrum pulchrum

Schmidle, Ber. Deutsch. Bot. Ges., 10: 206-211, 1892.

Figure 3: A-B

Spherical coenobium; formed by eight to 32 cells; intercellular spaces present; octagonal cells, joined by conical-truncated processes, facing the periphery of the coenobium; thickened apices; parietal chloroplast with one pyrenoid.

Morphometric data: Co = 30.0-62.5 μm; D = 5.0 -7.5 μm.

Paraná State citation:Oliveira et al. (1994)OLIVEIRA, M.D., TRAIN, S. & RODRIGUES, L.C. 1994. Levantamento preliminar do fitoplâncton de rede (exceto Zygnemaphyceae) do Rio Paraná, no Município de Porto Rico, Paraná, Brasil. Rev. UNIMAR 16:155–173., Picelli-Vicentim et al. (2001)PICELLI-VICENTIM, M.M., TREUERSCH, M. & DOMINGUES, L.L. 2001. Fitoplâncton da Represa do Passaúna, Estado do Paraná, Brasil. Hoehnea 28:53–76., Biolo et al. (2009)BIOLO, S., SIQUEIRA, N.S. & BUENO, N.C. 2009. Chlorococcales (Chlorophyceae) de um tributário do Reservatório de Itaipu, Paraná, Brasil. Hoehnea 36:667–678., Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330., Menezes et al. (2011)MENEZES, V.C., BUENO, N.C., BORTOLINI, J.C. & GODINHO, L.R. 2011. Chlorococcales sensu lato (Chlorophyceae) em um lago artificial urbano, Paraná, Brasil. Iheringia Ser. Bot. 66:227–240., Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451., Medeiros et al. (2021)MEDEIROS, Y., AQUINO, C.A.N., BORTOLINI, J.C., MEDEIROS, G., AMARAL, M.W., FAVARETTO, C.C.R. & BUENO, N.C. 2021. Plnktonic chlorophyceans of a Brazilian subtropical river: Taxonomy and ecological aspects. Rodriguésia 72:02192019. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Occurrence in samples: UNOPA 6827, 6829, 6981, 6983, 7094, 7270

Frequency of occurrence: rare

Coelastrum reticulatum var. cubanum

Komárek, Preslia, 47: 277, 1975.

Figure 3: C

Spherical coenobium found singly or in multiples; formed by 16 to 32 spherical cells connected to each other by cylindrical processes; intercellular spaces present; parietal chloroplast with one pyrenoid.

Morphometric data: Co = 10.0-35.0 μm; D = 4.0-7.5 μm.

Paraná State citation:Rodrigues & Train (1993)RODRIGUES, L.C. & TRAIN, S. 1993. Chlorococcales planctônicas do Lago Municipal do Parque Alfredo Nyffeler, Paraná, Brasil. Rev. UNIMAR. 15:19–35., Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451., Medeiros et al. (2021)MEDEIROS, Y., AQUINO, C.A.N., BORTOLINI, J.C., MEDEIROS, G., AMARAL, M.W., FAVARETTO, C.C.R. & BUENO, N.C. 2021. Plnktonic chlorophyceans of a Brazilian subtropical river: Taxonomy and ecological aspects. Rodriguésia 72:02192019. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Occurrence in samples: UNOPA 6805, 6827, 6829, 6833, 6981, 6983, 7005, 7094, 7096

Frequency of occurrence: sporadic

Comasiella arcuata var. platydisca

(G.M.Smith) E.Hegewald & M.Wolf, Phycologia, 49 (4): 325-335, 2010.

Basionym: Scenedesmus arcuatus var. platydiscus G.M.Smith, Trans. Wis. Acad. Sci. Arts Lett., 18: 451, 1916.

Figure 3: D-E

Flat coenobium; formed by four to eight reniform cells with rounded poles; cells arranged in double, alternating series, sheathed with inconspicuous mucilage; outer cells not fully aligned; parietal chloroplast with one pyrenoid.

Morphometric data: Co = 14.0-23.0; L = 9.0-13.0 μm; W = 4.0-5.0 μm.

Paraná State citation:Menezes et al. (2011)MENEZES, V.C., BUENO, N.C., BORTOLINI, J.C. & GODINHO, L.R. 2011. Chlorococcales sensu lato (Chlorophyceae) em um lago artificial urbano, Paraná, Brasil. Iheringia Ser. Bot. 66:227–240. cited as Scenedesmus arcuatus var. platydiscus, Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Occurrence in samples: UNOPA 6981, 6983 7072, 7094

Frequency of occurrence: rare

Desmodesmus armatus

(Chodat) E.H.Hegewald, Algol. Stud., 96: 1-18, 2000.

Basionym: Scenedesmus hystrix var. armatus Chodat, Algues vertes de la Suisse, p.25, 1902.

Figure 3: G

Flat coenobium; formed by two to four cells arranged linearly; ellipsoid inner cells; ellipsoid to arcuate outer cells, often with frontal ribs; main spines in linear arrangement; parietal chloroplast with one pyrenoid.

Morphometric data: L = 9.0-13.0 μm; W = 3.0-4.0; De = 0.8-1.2 μm; T = 13.0-14.0 μm.

Paraná State citation: in the work of Lozovei & Luz (1976)ANDRADE, R.M. & RACHOU, R.G. 1954. Levantamento preliminar de organismos planctônicos em alguns criadouros do Anopheles darlingi no sul do Brasil. Rev. bras. malariol. doenças trop. 6:481–496. still cited as Scenedesmus quadricauda Chod., Moresco & Bueno (2007)MORESCO, C. & BUENO, N.C. 2007. Scenedesmaceae (Chlorophyceae – Chlorococcales) de um lago artificial urbano: Desmodesmus e Scenedesmus. Acta Sci. Biol. Sci. 29:289–296., Biolo et al. (2009)BIOLO, S., SIQUEIRA, N.S. & BUENO, N.C. 2009. Chlorococcales (Chlorophyceae) de um tributário do Reservatório de Itaipu, Paraná, Brasil. Hoehnea 36:667–678., Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330., Felisberto & Rodrigues (2010)FELISBERTO, S.A. & RODRIGUES, L. 2010. Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil). Acta Sci. Biol. Sci. 32:373–385., Menezes et al. (2011)MENEZES, V.C., BUENO, N.C., BORTOLINI, J.C. & GODINHO, L.R. 2011. Chlorococcales sensu lato (Chlorophyceae) em um lago artificial urbano, Paraná, Brasil. Iheringia Ser. Bot. 66:227–240., Felisberto & Rodrigues (2012)FELISBERTO, S.A. & RODRIGUES, L. 2012. Dinâmica sucessional de comunidade de algas perifíticas em um ecossistema lótico subtropical. Rodriguésia 63:463–473., Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Taxonomic remarks: some specimens have smaller cell dimensions than those reported by Tucci et al. (2019)TUCCI, A., SANT’ANNA, C.L., AZEVEDO, M.T.P., MALONE, C.F.S., WERNER, V.R., ROSINI, E.F., GAMA, W.A., HENTSCHKE, G.S., OSTI, J.A.S., DIAS, A.S., JACINAVICIUS, F.R. & SANTOS, K.R. 2019. Atlas de Cianobactérias e Microalgas de Águas Continentais Brasileiras. 2 ed. Instituto de Botânica, São Paulo., however they are in agreement with those found in Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Occurrence in samples: UNOPA 6805, 6995, 7005

Frequency of occurrence: rare

Desmodesmus brasiliensis

(Bohlin) E.Hegewald, Algol. Stud., 96: 1-18, 2000.

Basionym: Scenedesmus brasiliensis Bohlin, Die Algen der ersten Regnell’schen Expedition, p.22, 1897.

Figure 3: H

Flat coenobium; formed by four cells arranged linearly; elliptical or oblong cells, up to cylindrical; attenuated ends with slightly rounded poles; ribs present in all cells, which can unite and form one to three teeth at the poles of the cells; parietal chloroplast with one pyrenoid.

Morphometric data: L = 15.0 μm; W = 7.9 μm; De = 2.0 μm.

Paraná State citation:Moresco & Bueno (2007)MORESCO, C. & BUENO, N.C. 2007. Scenedesmaceae (Chlorophyceae – Chlorococcales) de um lago artificial urbano: Desmodesmus e Scenedesmus. Acta Sci. Biol. Sci. 29:289–296.; Biolo et al. (2009)BIOLO, S., SIQUEIRA, N.S. & BUENO, N.C. 2009. Chlorococcales (Chlorophyceae) de um tributário do Reservatório de Itaipu, Paraná, Brasil. Hoehnea 36:667–678.; Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Taxonomic remarks: according to Biolo et al. (2009)BIOLO, S., SIQUEIRA, N.S. & BUENO, N.C. 2009. Chlorococcales (Chlorophyceae) de um tributário do Reservatório de Itaipu, Paraná, Brasil. Hoehnea 36:667–678. and Tucci et al. (2019)TUCCI, A., SANT’ANNA, C.L., AZEVEDO, M.T.P., MALONE, C.F.S., WERNER, V.R., ROSINI, E.F., GAMA, W.A., HENTSCHKE, G.S., OSTI, J.A.S., DIAS, A.S., JACINAVICIUS, F.R. & SANTOS, K.R. 2019. Atlas de Cianobactérias e Microalgas de Águas Continentais Brasileiras. 2 ed. Instituto de Botânica, São Paulo. the lateral projections are called teeth already in Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222. are called thorns, concluding that both denominations are correct.

Occurrence in samples: UNOPA 6831

Frequency of occurrence: rare

Desmodesmus communis

(E.Hegewald) E.Hegewald, Algol. Stud., 96:1-18, 2000.

Basionym: Scenedesmus communis E.Hegewald, Algol. Stud., 151, 1977.

Figure 3: I

Flat coenobium; formed by four to eight cells arranged linearly; internal cells oblong, with rounded poles, without ornamentation; trapezoidal outer cells, with a slightly convex outer margin and a long spine at each pole; smooth cell wall; parietal chloroplast with one pyrenoid.

Morphometric data: L = 10.0-22.5 μm; W= 5.0-12.5 μm; T = 7.5-15.0 μm.

Paraná State citation:Picelli-Vicentim (1986PICELLI-VICENTIM, M.M. 1986. Catálogo das Chlorophyta de águas continentais e marinhas do estado do Paraná, Brasil. Braz. J. Biol.14:2–27., 1987PICELLI-VICENTIM, M.M. 1987. Chlorococcales planctônicas do Parque Regional do Iguaçu, Curitiba, Estado do Paraná. Rev. Bras. Biol. 47:57–85.), Rodrigues & Train (1993)RODRIGUES, L.C. & TRAIN, S. 1993. Chlorococcales planctônicas do Lago Municipal do Parque Alfredo Nyffeler, Paraná, Brasil. Rev. UNIMAR. 15:19–35., Oliveira et al. (1994)OLIVEIRA, M.D., TRAIN, S. & RODRIGUES, L.C. 1994. Levantamento preliminar do fitoplâncton de rede (exceto Zygnemaphyceae) do Rio Paraná, no Município de Porto Rico, Paraná, Brasil. Rev. UNIMAR 16:155–173., Picelli-Vicentim, (2001)PICELLI-VICENTIM, M.M., TREUERSCH, M. & DOMINGUES, L.L. 2001. Fitoplâncton da Represa do Passaúna, Estado do Paraná, Brasil. Hoehnea 28:53–76., Moresco & Bueno (2007)MORESCO, C. & BUENO, N.C. 2007. Scenedesmaceae (Chlorophyceae – Chlorococcales) de um lago artificial urbano: Desmodesmus e Scenedesmus. Acta Sci. Biol. Sci. 29:289–296., Biolo et al. (2009)BIOLO, S., SIQUEIRA, N.S. & BUENO, N.C. 2009. Chlorococcales (Chlorophyceae) de um tributário do Reservatório de Itaipu, Paraná, Brasil. Hoehnea 36:667–678., Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330., Felisberto & Rodrigues (2010)FELISBERTO, S.A. & RODRIGUES, L. 2010. Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil). Acta Sci. Biol. Sci. 32:373–385., Menezes et al. (2011)MENEZES, V.C., BUENO, N.C., BORTOLINI, J.C. & GODINHO, L.R. 2011. Chlorococcales sensu lato (Chlorophyceae) em um lago artificial urbano, Paraná, Brasil. Iheringia Ser. Bot. 66:227–240., Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451., Medeiros et al. (2021)MEDEIROS, Y., AQUINO, C.A.N., BORTOLINI, J.C., MEDEIROS, G., AMARAL, M.W., FAVARETTO, C.C.R. & BUENO, N.C. 2021. Plnktonic chlorophyceans of a Brazilian subtropical river: Taxonomy and ecological aspects. Rodriguésia 72:02192019. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Occurrence in samples: UNOPA 6819, 6829, 6831, 6833, 6987, 6995, 6997, 7001, 7074, 7094

Frequency of occurrence: sporadic

Desmodesmus denticulatus

(Lagerheim) S.S.An, T.Friedl & E.Hegewald, Plant Biol., 1:427, 1999.

Basionym: Scenedesmus denticulatus Lagerheim, Öfversigt af Kongl. Vetenskaps-Akademiens Förhandlingar Arg., 39(2): 47-81, 1882.

Figure 3: J

Flat coenobium; formed by four cells arranged alternately; oval inner cells, without ornamentation; outer cells elliptical, with one or two short spines at each pole; parietal chloroplast with one pyrenoid.

Morphometric data: L = 7.5-22.5 μm; W = 7.5-12.5 μm; De = 2.5 μm.

Paraná State citation:Moresco & Bueno (2007)MORESCO, C. & BUENO, N.C. 2007. Scenedesmaceae (Chlorophyceae – Chlorococcales) de um lago artificial urbano: Desmodesmus e Scenedesmus. Acta Sci. Biol. Sci. 29:289–296., Biolo et al. (2009)BIOLO, S., SIQUEIRA, N.S. & BUENO, N.C. 2009. Chlorococcales (Chlorophyceae) de um tributário do Reservatório de Itaipu, Paraná, Brasil. Hoehnea 36:667–678., Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330., Felisberto & Rodrigues (2010)FELISBERTO, S.A. & RODRIGUES, L. 2010. Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil). Acta Sci. Biol. Sci. 32:373–385., Menezes et al. (2011)MENEZES, V.C., BUENO, N.C., BORTOLINI, J.C. & GODINHO, L.R. 2011. Chlorococcales sensu lato (Chlorophyceae) em um lago artificial urbano, Paraná, Brasil. Iheringia Ser. Bot. 66:227–240., Felisberto & Rodrigues (2012)FELISBERTO, S.A. & RODRIGUES, L. 2012. Dinâmica sucessional de comunidade de algas perifíticas em um ecossistema lótico subtropical. Rodriguésia 63:463–473., Aquino (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222., still cited as Scenedesmus denticulatus (Lagerh) in the studies of Picelli-Vicentim (1987)PICELLI-VICENTIM, M.M. 1987. Chlorococcales planctônicas do Parque Regional do Iguaçu, Curitiba, Estado do Paraná. Rev. Bras. Biol. 47:57–85., Oliveira et al. (1994)OLIVEIRA, M.D., TRAIN, S. & RODRIGUES, L.C. 1994. Levantamento preliminar do fitoplâncton de rede (exceto Zygnemaphyceae) do Rio Paraná, no Município de Porto Rico, Paraná, Brasil. Rev. UNIMAR 16:155–173., Train et al. (2001)TRAIN, S., RODRIGUES, L.C., BORGES, A.F., UEDA, A.T., NACAGAVA, M.M. & BOVO, E.M. 2001. Fitoplâncton. PELD, UEM. 87–99., Train et al. (2003)TRAIN, S., RODRIGUES, L.C., BORGES, A.F., ZANDONADI, A.P., PIVATO, B.M., BOVO, V.M., UEDA, A. T. & NACAGAVA, M.M. 2003. Fitoplâncton. PELD, UEM. 75–87. and Algarte et al. (2006)ALGARTE, V.M., MORESCO, C. & RODRIGUES, L. 2006. Algas do perifíton de distintos ambientes na planície de inundação do alto Rio Paraná. Acta Sci Biol Sci. 28:243–251..

Occurrence in samples: UNOPA 6833, 6995, 7072

Frequency of occurrence: rare

Desmodesmus intermedius var. acutispinus

(Roll) E.Hegewald, Algol. Stud., 96: 1-18, 2000.

Basionym: Scenedesmus quadricauda var. acutispinus Roll, Russkii Arkhiv Protistologii 4(3-4): 137-152, 1925.

Figure 4: B

Flat coenobium; formed by two to four oblong cells, arranged linearly; outer cells with a long spine on only one of the apices, distributed diagonally in the coenobium, parietal chloroplast with one pyrenoid.

Morphometric data: L = 6.6-7.0 μm; W = 2.5-3.0 μm; T = 6.0-8.0 μm.

Paraná State citation:Moresco & Bueno (2007)MORESCO, C. & BUENO, N.C. 2007. Scenedesmaceae (Chlorophyceae – Chlorococcales) de um lago artificial urbano: Desmodesmus e Scenedesmus. Acta Sci. Biol. Sci. 29:289–296. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Taxonomic remarks: the variety acutispinus differs from the type species in terms of the number and diagonal arrangement of spines at the apices of the outer cells. In the variety there are only two spines, and in the type species there are four spines.

Occurrence in samples: UNOPA 6981, 6983

Frequency of occurrence: rare

Desmodesmus opoliensis

(P.G.Richter) E.Hegewald, Algol. Stud., 96: 1-18, 2000.

Basionym: Scenedesmus opoliensis P.G.Richter, Scenedesmus opoliensis P. Richt, nov. sp. Zeitschrift für angewandte Mikroskopie, 1: 3-7, 1895.

Figure 3: K

Flat coenobium; formed by four cells arranged linearly; internal fusiform cells, with attenuated and rounded poles, without ornamentation; trapezoidal outer cells, with truncated poles at the base of spine insertion and slightly convex outer margin; parietal chloroplast with one pyrenoid.

Morphometric data: L = 15.0-17.0 μm; W = 6.0 μm; T = 14.0-16.0 μm.

Paraná State citation:Moresco & Bueno (2007)MORESCO, C. & BUENO, N.C. 2007. Scenedesmaceae (Chlorophyceae – Chlorococcales) de um lago artificial urbano: Desmodesmus e Scenedesmus. Acta Sci. Biol. Sci. 29:289–296., Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222., and still cited as Scendesmus opoliensis in the works of Rodrigues & Train (1993)RODRIGUES, L.C. & TRAIN, S. 1993. Chlorococcales planctônicas do Lago Municipal do Parque Alfredo Nyffeler, Paraná, Brasil. Rev. UNIMAR. 15:19–35. and Picelli-Vicentim (2001)PICELLI-VICENTIM, M.M., TREUERSCH, M. & DOMINGUES, L.L. 2001. Fitoplâncton da Represa do Passaúna, Estado do Paraná, Brasil. Hoehnea 28:53–76..

Taxonomic remarks: the dimensions recorded in the specimens of this study are relatively smaller than those of Tucci et al. (2019)TUCCI, A., SANT’ANNA, C.L., AZEVEDO, M.T.P., MALONE, C.F.S., WERNER, V.R., ROSINI, E.F., GAMA, W.A., HENTSCHKE, G.S., OSTI, J.A.S., DIAS, A.S., JACINAVICIUS, F.R. & SANTOS, K.R. 2019. Atlas de Cianobactérias e Microalgas de Águas Continentais Brasileiras. 2 ed. Instituto de Botânica, São Paulo., however they are in agreement with other works as in Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Occurrence in samples: UNOPA 6805

Frequency of occurrence: rare

Desmodesmus perforatus

(Lemmermann) E.Hegewald, Algol. Stud., 96: 1-18, 2000.

Basionym: Scenedesmus perforatus Lemmermann, Zeitschrift für Fischerei und deren Hilfswissenschaften 11: 73-123, 1903.

Figure 3: L

Flat coenobium; formed by four biconcave cells in a linear arrangement; external cells with concave internal face and convex external face; curved spines, presence of microtubules and sometimes presence of frontal ribs; parietal chloroplast with one pyrenoid.

Morphometric data: L = 14.5-16.0 μm; W = 5.5-6.0 μm; T = 6.0-10.0 μm.

Paraná State citation: first record.

Taxonomic remarks: Tucci et al. (2019)TUCCI, A., SANT’ANNA, C.L., AZEVEDO, M.T.P., MALONE, C.F.S., WERNER, V.R., ROSINI, E.F., GAMA, W.A., HENTSCHKE, G.S., OSTI, J.A.S., DIAS, A.S., JACINAVICIUS, F.R. & SANTOS, K.R. 2019. Atlas de Cianobactérias e Microalgas de Águas Continentais Brasileiras. 2 ed. Instituto de Botânica, São Paulo. have larger dimensions than those recorded in this study, but in Souza & Felisberto (2014)SOUZA, D.B.D.S. & FELISBERTO, S.A. 2014. Comasiella, Desmodesmus, Pectinodesmus e Scenedesmus na comunidade perifítica em ecossistema lêntico tropical, Brasil Central. Hoehnea 41:109-120. the specimens are also small, thus being in agreement with the population observed in our work.

Occurrence in samples: UNOPA 6827, 6829, 6981, 6983, 7094, 7270

Frequency of occurrence: rare

Desmodesmus serratus

(Corda) S.S.An, Friedl & E.Hegewald, Plant Biol., 1: 418-428, 1999.

Basionym: Arthrodesmus serratus Corda, Almanach de Carlsbad, 9: 213-244, 1839.

Figure 4: A

Flat coenobium; formed by four cells arranged linearly, without main spines; oblong cells, punctuated rib running through each cell; frequent presence of one to three teeth at the cell poles; outer cells with a row of spinules along their entire length; parietal chloroplast with one pyrenoid.

Morphometric data: L = 7.0-15.0 μm; W = 2.5-5.0 μm T = 2.0-3.0 μm.

Paraná State citation:Moresco & Bueno (2007)MORESCO, C. & BUENO, N.C. 2007. Scenedesmaceae (Chlorophyceae – Chlorococcales) de um lago artificial urbano: Desmodesmus e Scenedesmus. Acta Sci. Biol. Sci. 29:289–296., Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Occurrence in samples: UNOPA 6831, 6833, 7094

Frequency of occurrence: rare

Desmodesmus subspicatus

(Chodat) E.Hegewald & A.W.F.Schmidt, Algol. Stud., 96: 1-18, 2000.

Basionym: Scenedesmus subspicatus Chodat, Schweizerische Zeitschrift für Hydrologie, 3: 71-258, 1926.

Figure 4: C

Flat coenobium; formed by two or four oblong cells arranged linearly; frequent presence of secondary spine on inner cells and one or two lateral spines on outer cells; main spines in linear arrangement; parietal chloroplast with one pyrenoid.

Morphometric data: L = 7.0 μm; W = 2.0 μm; T = 4.0-6.0 μm.

Paraná State citation: first record.

Taxonomic remarks: D. subspicatus can be found in older literature (Rosini et al. 2013ROSINI, E.F., SANT’ANNA, C.L. & TUCCI, A. 2013. Scenedesmaceae (Chlorococcales, Chlorophyceae) de pesqueiros da Região Metropolitana de São Paulo, SP, Brasil: levantamento florístico. Hoehnea, 40:661–678.), as Scenedesmus quadricauda (Turpin) Brébisson, which refers to its holotype, however, currently the current name is Desmodesmus subspicatus as seen in Tucci et al. (2019)TUCCI, A., SANT’ANNA, C.L., AZEVEDO, M.T.P., MALONE, C.F.S., WERNER, V.R., ROSINI, E.F., GAMA, W.A., HENTSCHKE, G.S., OSTI, J.A.S., DIAS, A.S., JACINAVICIUS, F.R. & SANTOS, K.R. 2019. Atlas de Cianobactérias e Microalgas de Águas Continentais Brasileiras. 2 ed. Instituto de Botânica, São Paulo..

Occurrence in samples: UNOPA 6833

Frequency of occurrence: rare

Scenedesmus indicus

Philipose ex Hegewald, Engelberg & Paschma, Nova Hedwig., 47 (3/4): 497-533, 1988.

Figure 4: I

Flat and linear coenobium; formed by four cells arranged alternately; outer cells arcuate with rounded, dilated or swollen poles; oblong inner cells with swollen poles; parietal chloroplast with one pyrenoid.

Morphometric data: L = 11.0 – 15.0 μm; W = 3.5 – 4.0 μm.

Paraná State citation: first record.

Taxonomic remarks: Scenedesmus indicus is easily differentiated from the other species due to the morphology of the coenobium, in which the cells are arranged in an alternating manner.

Occurrence in samples: UNOPA 6805, 6995, 7276

Frequency of occurrence: rare

Scenedesmus obtusus

Meyen, Nova Acta Phys.-Med. Acad. Caes. Leop. -Carol. Nat., 14: 768-778, 1829.

Figure 3: F

Flat coenobium; formed by four or eight alternating cells; ovate-cylindrical cells with rounded poles; outer cells usually oblique; straight inner cells; slightly thickened cell wall; parietal chloroplast with one pyrenoid.

Morphometric data: L = 11.0-13.0 μm; W = 7.0 μm.

Paraná State citation:Picelli-Vicentim (1987)PICELLI-VICENTIM, M.M. 1987. Chlorococcales planctônicas do Parque Regional do Iguaçu, Curitiba, Estado do Paraná. Rev. Bras. Biol. 47:57–85.; Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330. and cited as Scenedesmus graevenitzii in Moresco & Bueno (2007)MORESCO, C. & BUENO, N.C. 2007. Scenedesmaceae (Chlorophyceae – Chlorococcales) de um lago artificial urbano: Desmodesmus e Scenedesmus. Acta Sci. Biol. Sci. 29:289–296..

Occurrence in samples: UNOPA 7082

Frequency of occurrence: rare

Tetradesmus dimorphus

(Turpin) M.J.Wynne, Feddes Repert., 126: 83-86, 2016.

Basionym: Achnanthes dimorpha Turpin, Mém. Mus. natl. hist. nat., 16: 313, 1828.

Figure 4: D

Flat coenobium; formed by four to eight fusiform cells with acute poles; arranged in a linear or alternating manner; external cells markedly concave, reaching straight or slightly convex; almost straight inner cells; parietal chloroplast; pyrenoid not observed.

Morphometric data: L = 19.0-22.0 μm; W= 3.0-5.0 μm; Co = 18.0 – 22.0 μm.

Paraná State citation: cited as Tetradesmus dimorphus in Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222., cited as Scenedesmus obliquus var. dimorphus (Turpin) Hansgirg in Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330., Menezes et al. (2011)MENEZES, V.C., BUENO, N.C., BORTOLINI, J.C. & GODINHO, L.R. 2011. Chlorococcales sensu lato (Chlorophyceae) em um lago artificial urbano, Paraná, Brasil. Iheringia Ser. Bot. 66:227–240., Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451., and cited as Scenedesmus acuminatus (Lagerh.) and/or Scenedesmus acutus (Meyen) in Picelli-Vicentim (1987)PICELLI-VICENTIM, M.M. 1987. Chlorococcales planctônicas do Parque Regional do Iguaçu, Curitiba, Estado do Paraná. Rev. Bras. Biol. 47:57–85., Rodrigues & Train (1993)RODRIGUES, L.C. & TRAIN, S. 1993. Chlorococcales planctônicas do Lago Municipal do Parque Alfredo Nyffeler, Paraná, Brasil. Rev. UNIMAR. 15:19–35., Oliveira et al. (1994)OLIVEIRA, M.D., TRAIN, S. & RODRIGUES, L.C. 1994. Levantamento preliminar do fitoplâncton de rede (exceto Zygnemaphyceae) do Rio Paraná, no Município de Porto Rico, Paraná, Brasil. Rev. UNIMAR 16:155–173., Bittencourt-Oliveira (1997)BITTENCOURT-OLIVEIRA, M.C. 1997. Fitoplâncton do rio Tibagi, Estado do Paraná, Brasil: Nostocophyceae, Chlorophyceae, Euglenophyceae, Chrysophyceae e Tribophyceae. Hoehnea 24:1–20., Train et al. (2001)TRAIN, S., RODRIGUES, L.C., BORGES, A.F., UEDA, A.T., NACAGAVA, M.M. & BOVO, E.M. 2001. Fitoplâncton. PELD, UEM. 87–99., Borges et al. (2003)BORGES, P.A.F., PAGIORO, T.A. & TRAIN, S. 2003. Spatial variation of phytoplankton and some abiotic variables in the Pirapó River-PR (Brazil) in August 1999: a preliminary study. Acta Sci. Biol. Sci. 25(1):1–8., Train et al. (2003)TRAIN, S., RODRIGUES, L.C., BORGES, A.F., ZANDONADI, A.P., PIVATO, B.M., BOVO, V.M., UEDA, A. T. & NACAGAVA, M.M. 2003. Fitoplâncton. PELD, UEM. 75–87., Algarte et al. (2006)ALGARTE, V.M., MORESCO, C. & RODRIGUES, L. 2006. Algas do perifíton de distintos ambientes na planície de inundação do alto Rio Paraná. Acta Sci Biol Sci. 28:243–251., Moresco & Bueno (2007)MORESCO, C. & BUENO, N.C. 2007. Scenedesmaceae (Chlorophyceae – Chlorococcales) de um lago artificial urbano: Desmodesmus e Scenedesmus. Acta Sci. Biol. Sci. 29:289–296., Borges et al. (2008)BORGES, P.A.F., TRAIN, S. & RODRIGUES, L.C. 2008. Estrutura do fitoplâncton, em curto período de tempo, em um braço do reservatório de Rosana (ribeirão do Corvo, Paraná, Brasil). Acta Sci. Biol. Sci. 30:57–65., Felisberto & Rodrigues (2010)FELISBERTO, S.A. & RODRIGUES, L. 2010. Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil). Acta Sci. Biol. Sci. 32:373–385. and Felisberto & Rodrigues (2012)FELISBERTO, S.A. & RODRIGUES, L. 2012. Dinâmica sucessional de comunidade de algas perifíticas em um ecossistema lótico subtropical. Rodriguésia 63:463–473..

Occurrence in samples: UNOPA 6827, 6981, 7272

Frequency of occurrence: rare

Tetrallantos lagerheimii

Teiling, Svensk Bot. Tidskr., 10 (1):59-66, 1916.

Figure 4: K

Coenobium formed by up to four cells; two are in the same plane and two are arranged vertically, joined by the poles; lunate or approximately reniform cells with rounded apices; parietal chloroplast with one pyrenoid.

Morphometric data: L = 10.0-12.5 μm; W = 5.0-7.5 μm.

Paraná State citation:Rodrigues & Train (1993)RODRIGUES, L.C. & TRAIN, S. 1993. Chlorococcales planctônicas do Lago Municipal do Parque Alfredo Nyffeler, Paraná, Brasil. Rev. UNIMAR. 15:19–35..

Occurrence in samples: UNOPA 7015, 7274, 7276

Frequency of occurrence: rare

Westella botryoides

(West) De Wildeman, Bull. Herb. Boissier., 5:532, 1897.

Basionym: Tetracoccus botryoides West, J. R. Microsc. Soc., 735, 1892.

Figure 4: J

Quadrangular coenobium; formed by four cells arranged in a cruciate manner; these cells form sincenobia with eight or 16 cells joined by the rest of the maternal cell wall by threads of mucilage; globular to subtriangular cells; parietal chloroplast with one pyrenoid.

Morphometric data: Co = 15.0 μm; D = 5.0 -7.5 μm.

Paraná State citation:Picelli-Vicentim (1987)PICELLI-VICENTIM, M.M. 1987. Chlorococcales planctônicas do Parque Regional do Iguaçu, Curitiba, Estado do Paraná. Rev. Bras. Biol. 47:57–85..

Occurrence in samples: UNOPA 6991, 6995

Frequency of occurrence: rare

FAMILY SELENASTRACEAE

Ankistrodesmus bernardii

Komárek, Nova Hedwigia 37: 65-180, 1983.

Figure 4: E

Fasciculate colony; formed by approximately eight to 10 spindle cells with a sigmoid curve in the median region; longer than wide; united and intertwined in the middle region of the colony, tapering gradually towards the apex; pyrenoid not observed.

Morphometric data: L = 60.0 μm; W = 1.8-2.6 μm.

Paraná State citation: first record.

Taxonomic remarks: Ankistrodesmus bernardii Komárek can be confused with Ankistrodesmus densus Korshikov, as both form colonies with many cells that are variable in length but differ in that A. densus has curved or sigmoid cells throughout.

Occurrence in samples: UNOPA 6827

Frequency of occurrence: rare

Ankistrodesmus densus

Korshikov, The Freshwater Algae of the Ukrainian SSR. p. 300, 1953.

Figure 4: F

Colony with many fasciculate cells; usually formed by 16 densely packed cells; cells longer than wide, fusiform, curved or sigmoid throughout their length; gradually taper towards the apex; superimposed on each other; parietal chloroplast without pyrenoids.

Morphometric data: L = 35.0-55.0 μm; W = 2.5 μm.

Paraná State citation:Picelli-Vicentim (1987)PICELLI-VICENTIM, M.M. 1987. Chlorococcales planctônicas do Parque Regional do Iguaçu, Curitiba, Estado do Paraná. Rev. Bras. Biol. 47:57–85., Rodrigues & Train (1993)RODRIGUES, L.C. & TRAIN, S. 1993. Chlorococcales planctônicas do Lago Municipal do Parque Alfredo Nyffeler, Paraná, Brasil. Rev. UNIMAR. 15:19–35., Oliveira et al. (1994)OLIVEIRA, M.D., TRAIN, S. & RODRIGUES, L.C. 1994. Levantamento preliminar do fitoplâncton de rede (exceto Zygnemaphyceae) do Rio Paraná, no Município de Porto Rico, Paraná, Brasil. Rev. UNIMAR 16:155–173., Biolo et al. (2009)BIOLO, S., SIQUEIRA, N.S. & BUENO, N.C. 2009. Chlorococcales (Chlorophyceae) de um tributário do Reservatório de Itaipu, Paraná, Brasil. Hoehnea 36:667–678., Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Occurrence in samples: UNOPA 6829, 7082

Frequency of occurrence: rare

Ankistrodesmus falcatus

(Corda) Ralfs, The British Desmidieae, p. 180, 1848.

Basionym: Micrasterias falcatus Corda, Almanach de Carlsbad, 5: 206, 1835.

Figure 4: G

Starry colony formed by one to four fascicles; cells arranged irregularly; cells are long, fusiform, slightly curved, falcate, longer than wide, joined by the medial convex region, gradually tapering towards the apex; parietal chloroplast without pyrenoids.

Morphometric data: L = 37.5-50.0 μm; W = 2.5μm.

Paraná State citation:Andrade & Rachou (1954)ANDRADE, R.M. & RACHOU, R.G. 1954. Levantamento preliminar de organismos planctônicos em alguns criadouros do Anopheles darlingi no sul do Brasil. Rev. bras. malariol. doenças trop. 6:481–496., Picelli-Vicentim (1986)PICELLI-VICENTIM, M.M. 1986. Catálogo das Chlorophyta de águas continentais e marinhas do estado do Paraná, Brasil. Braz. J. Biol.14:2–27., Rodrigues & Train (1993)RODRIGUES, L.C. & TRAIN, S. 1993. Chlorococcales planctônicas do Lago Municipal do Parque Alfredo Nyffeler, Paraná, Brasil. Rev. UNIMAR. 15:19–35., Oliveira et al. (1994)OLIVEIRA, M.D., TRAIN, S. & RODRIGUES, L.C. 1994. Levantamento preliminar do fitoplâncton de rede (exceto Zygnemaphyceae) do Rio Paraná, no Município de Porto Rico, Paraná, Brasil. Rev. UNIMAR 16:155–173., Bittencourt-Oliveira (1997)BITTENCOURT-OLIVEIRA, M.C. 1997. Fitoplâncton do rio Tibagi, Estado do Paraná, Brasil: Nostocophyceae, Chlorophyceae, Euglenophyceae, Chrysophyceae e Tribophyceae. Hoehnea 24:1–20., Train et al. (2001)TRAIN, S., RODRIGUES, L.C., BORGES, A.F., UEDA, A.T., NACAGAVA, M.M. & BOVO, E.M. 2001. Fitoplâncton. PELD, UEM. 87–99., Bittencourt-Oliveira (2002)BITTENCOURT-OLIVEIRA, M.C. 2002. A comunidade fitoplanctônica do rio Tibagi: uma abordagem preliminar de sua diversidade. In: M.M. Medri, E. Bianchini, O.A. Shibatta & J.A. Pimenta (orgs.). A Bacia do rio Tibagi. FUEL, Londrina., Algarte et al. (2006)ALGARTE, V.M., MORESCO, C. & RODRIGUES, L. 2006. Algas do perifíton de distintos ambientes na planície de inundação do alto Rio Paraná. Acta Sci Biol Sci. 28:243–251., Felisberto & Rodrigues (2010)FELISBERTO, S.A. & RODRIGUES, L. 2010. Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil). Acta Sci. Biol. Sci. 32:373–385., Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Taxonomic remarks: the specimens in this work have larger dimensions than those recorded in Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222., however they are in agreement with the specimens observed in Ramos et al. (2012)RAMOS, G.J.P., BICUDO, C.E.M., GOÉS NETO, A. & MOURA, C.W.D.N. 2012. Monoraphidium e Ankistrodesmus (Chlorophyceae, Chlorophyta) do Pantanal dos Marimbus, Chapada Diamantina, BA, Brasil, Hoehnea 39(3):421–434..

Occurrence in samples: UNOPA 6829, 6981

Frequency of occurrence: rare

Ankistrodesmus fusiformis

Corda, Almanach de Carlsbad, 8: 179- 198, 1838.

Figure 4: H

Starry colony formed by two to four cells; cells cruciate, fusiform, from straight to arcuate; tapered towards the apex, crossing over each other; pointed poles, longer than wide; pyrenoid not observed.

Morphometric data: L = 30.0 μm; W = 1.4-2.5 μm.

Paraná State citation:Picelli-Vicentim (1987)PICELLI-VICENTIM, M.M. 1987. Chlorococcales planctônicas do Parque Regional do Iguaçu, Curitiba, Estado do Paraná. Rev. Bras. Biol. 47:57–85., Rodrigues & Train (1993)RODRIGUES, L.C. & TRAIN, S. 1993. Chlorococcales planctônicas do Lago Municipal do Parque Alfredo Nyffeler, Paraná, Brasil. Rev. UNIMAR. 15:19–35., Train et al. (2001)TRAIN, S., RODRIGUES, L.C., BORGES, A.F., UEDA, A.T., NACAGAVA, M.M. & BOVO, E.M. 2001. Fitoplâncton. PELD, UEM. 87–99., Algarte et al. (2006)ALGARTE, V.M., MORESCO, C. & RODRIGUES, L. 2006. Algas do perifíton de distintos ambientes na planície de inundação do alto Rio Paraná. Acta Sci Biol Sci. 28:243–251., Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330., Felisberto & Rodrigues (2010)FELISBERTO, S.A. & RODRIGUES, L. 2010. Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil). Acta Sci. Biol. Sci. 32:373–385., Menezes et al. (2011)MENEZES, V.C., BUENO, N.C., BORTOLINI, J.C. & GODINHO, L.R. 2011. Chlorococcales sensu lato (Chlorophyceae) em um lago artificial urbano, Paraná, Brasil. Iheringia Ser. Bot. 66:227–240., Felisberto & Rodrigues (2012)FELISBERTO, S.A. & RODRIGUES, L. 2012. Dinâmica sucessional de comunidade de algas perifíticas em um ecossistema lótico subtropical. Rodriguésia 63:463–473., Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451. and Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222..

Taxonomic remarks: in Aquino et al. (2022)AQUINO, C.A.N., BORTOLINI, J.C., RIBEIRO, V.C.M. & BIOLO, S. 2022. CHLOROPHYTA: Chlorophyceae e Trebouxiophyceae. In Ficoflora: Bacillariophyta, Chlorophyta, Streptophyta e Euglenophyceae de ambientes aquáticos continentais do oeste do Paraná, sul do Brasil (BUENO, N.C., BORTOLINI, J.C., NARDELLI, S.M., BIOLO, S. eds.). Edunioeste – Editora da Universidade Estadual do Oeste do Paraná, Cascavel, PR, p.157–222. the registered specimens with four cells, whereas those observed in this study have only two, but they are in agreement with Ramos et al. (2012)RAMOS, G.J.P., BICUDO, C.E.M., GOÉS NETO, A. & MOURA, C.W.D.N. 2012. Monoraphidium e Ankistrodesmus (Chlorophyceae, Chlorophyta) do Pantanal dos Marimbus, Chapada Diamantina, BA, Brasil, Hoehnea 39(3):421–434. who also recorded this morphological variation in their population.

Occurrence in samples: UNOPA 7082, 7268

Frequency of occurrence: rare

Kirchneriella lunaris

(Kirchner) Möbius, Abh. Senckenb. Nat. Gesell., 18: 309-350, 1894.

Basionym: Rhaphidium convolutum var. lunare Kirchner, Kryptogamen-Flora von Schlesien, 114, 1878.

Figure 4: L

Colonies formed by four to 16 cells, sickle-shaped lunate; wrapped in a mucilaginous sheath; sometimes lonely; parietal chloroplasts close to the cell wall; pyrenoid not observed.

Morphometric data: L = 5.0-10.0 μm.

Paraná State citation:Picelli-Vicentim (1987)PICELLI-VICENTIM, M.M. 1987. Chlorococcales planctônicas do Parque Regional do Iguaçu, Curitiba, Estado do Paraná. Rev. Bras. Biol. 47:57–85., Rodrigues & Train (1993)RODRIGUES, L.C. & TRAIN, S. 1993. Chlorococcales planctônicas do Lago Municipal do Parque Alfredo Nyffeler, Paraná, Brasil. Rev. UNIMAR. 15:19–35. and Oliveira et al. (1994)OLIVEIRA, M.D., TRAIN, S. & RODRIGUES, L.C. 1994. Levantamento preliminar do fitoplâncton de rede (exceto Zygnemaphyceae) do Rio Paraná, no Município de Porto Rico, Paraná, Brasil. Rev. UNIMAR 16:155–173..

Occurrence in samples: UNOPA 6981, 6995, 7005, 7082

Frequency of occurrence: rare

Monoraphidium capricornutum

(Printz) Nygaard, Biol. Skr., 21(1): 1-107, 1977.

Basionym: Selenastrum capricornutum Printz, Skr. Norske Vidensk. -Akad. Oslo, Mat. -Naturvidensk. Kl., 6:92, 1914.

Figure 4: N

Spindle cells; arched in semicircles, slightly tapered at the ends; parietal chloroplast without pyrenoids.

Morphometric data: L = 10.0-12.5 μm; W = 2.5 μm.

Paraná State citation: first record.

Taxonomic remarks: the specimens in this study have relatively larger dimensions than those recorded in Ramos et al. (2012)RAMOS, G.J.P., BICUDO, C.E.M., GOÉS NETO, A. & MOURA, C.W.D.N. 2012. Monoraphidium e Ankistrodesmus (Chlorophyceae, Chlorophyta) do Pantanal dos Marimbus, Chapada Diamantina, BA, Brasil, Hoehnea 39(3):421–434. and Nandi et al. (2017)NANDI, C., BASU, P. & PAL, R. 2017. New insights into the diversity of planktonic Chlorophytes and Charophytes from West Bengal with reports of three novel taxa from India. Phykos. 47(2):135–149. with regard to the length of the cells, however the width, description and illustration are in agreement with the works.

Occurrence in samples: UNOPA 6827

Frequency of occurrence: rare

Monoraphidium caribeum

Hindák, Algol. Stud., 1:7-32, 1970.

Figure 4: O

Solitary cells, arcuate in a semicircle, slightly tapering at the ends; parietal chloroplast without pyrenoids.

Morphometric data: L = 17.5 μm; W = 2.5 μm.

Paraná State citation: first record.

Taxonomic remarks: M. caribeum can be confused with Ankistrodesmus arcuatus Korshikov, however the species differ by the size of the cells, where A. arcuatus has larger dimensions.

Occurrence in samples: UNOPA 7100

Frequency of occurrence: rare

Raphidocelis danubiana var. elegans

(Playfair) Taşkin & Alp, Türkiye suyosunlari listei [Turkey algae list]. p.804, 2019.

Basionym: Kirchneriella elegans Playfair, Proc. Linn. Soc., 41: 838, 1917.

Figure 4: M

Colony formed by four cells irregularly arranged in mucilage; curved cylindrical cells with rounded apices, in the same plane; parietal chloroplast without pyrenoid.

Morphometric data: L = 4.0 μm (distance between apexes); W = 2.0 μm.

Paraná State citation: first record.

Taxonomic remarks: recently the genus Kirchneriella contorta var. elegans (Playfair) Komárek changed to the taxon Raphidocelis danubiana var. elegans, which can be found in the literature in the first way.

Occurrence in samples: UNOPA 7005

Frequency of occurrence: rare

Selenastrum bibraianum

Reinsch, Abh. Senckenb. Nat. Gesell., 3(2): 1- 238, 1866.

Figure 4: P

Coenobium formed by four to 16 lunate or semicircular cells; ventral margins strongly convex towards the center of the colony, tapering towards the cell apex; single parietal chloroplast occupying the entire intercellular space; pyrenoid not observed.

Morphometric data: L = 15.0 μm; W = 4.0 μm.

Paraná State citation: Cited as Ankistrodesmus bibraianus (Reinsch) Koršikov in Bortolini et al. (2010)BORTOLINI, J.C., MEURER, T., GODINHO, L.R. & BUENO, N.C. 2010. Chlorococcales planctônicas do rio São João, Parque Nacional do Iguaçu, Paraná, Brasil. Hoehnea 37:315–330.; Aquino et al. (2014)AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451..

Occurrence in samples: UNOPA 6827

Frequency of occurrence: rare

Selenastrum rinoi

Komárek & Comas, 272, 276, figure 10, 1982.

Figure 4: Q

Colonies formed by four moon cells; convex side of cells oriented towards the center; apexes tapered; chloroplast without pyrenoid.

Morphometric data: L= 16.0 μm; W = 5.0 μm.

Paraná State citation: first record.

Taxonomic remarks: Selenastrum rinoi can be confused with Monoraphidium capricornutum, however, it differs in that it has smaller cells, with more distant apices, in addition to having an irregular arrangement of cells in the colony.

Occurrence in samples: UNOPA 6827

Frequency of occurrence: rare

The trophic state index indicated that seven of the nine sampled municipalities fall into oligotrophic conditions, while the remaining two are considered mesotrophic. Regarding the limnological conditions we observed a variation in the flow of the sampled rivers, where the lowest flow recorded is in Rio Tamanduá (0.09 m³ s) and the highest is in Rio Toledo (1.39 m³ s). Water temperature varied from 15°C to 20°C in Baú and Jacutinga Rivers respectively. The pH value in all sampled rivers was considered neutral (6). The electrical conductivity varied from (0.02 mS cm^–1) in the Toledo River to (0.08 mS cm^–1) in the Baú River. As for turbidity, the lowest value recorded was in Rio Baú (6.41 NTU) and the highest in Rio Jacutinga (23.35 NTU). Dissolved oxygen varied from (6.39 mg L^–1) in Gonçalves Dias River to (14.95 mg L^–1) in Baú River. The lowest value of ammonia nitrogen (0.01 mg L^–1) was constant in four rivers, namely Baú, Itaguaçu, Gonçalves Dias, and Jacutinga, while the highest value (0.14 mg L^–1) was registered in the Cascavel River. The values of total phosphorous were similar in all sampled rivers. Nitrate varied from (0.53 mg L^–1) at Gonçalves Dias to (1.83 mg L^–1) at Toledo River (Table 2). All sampled rivers had at least two species recorded, however, approximately 70% of the occurrences were in oligotrophic environments. The rivers with higher occurrences recorded were Cascavel (31%), Passo Liso (23%) and Toledo (17%), the first two being oligotrophic and the third mesotrophic.

Discussion

In our study we recorded 36 taxa of chlorophyceans belonging to the order Sphaeropleales. The Scenedesmaceae family was the most representative with 20 taxa (55%), followed by Selenastraceae with 10 taxa (27.7%) and Hydrodictyaceae with 4 taxa (11%). We also highlight the record of 10 new citations for the State of Paraná, thus expanding the knowledge of the flora of Chlorophyceae for lotic environments: Ankistrodesmus bernardii, Desmodesmus perforatus, Desmodesmus subspicatus, Monoraphidium capricornutum, Monoraphidium caribeum, Pseudopediastrum boryanum var. longicorne, Raphidocelis danubiana var. elegans, Radiococcus skujae, Scenedesmus indicus and Selenastrum rinoi. The class Chorophyceae develops in wide environmental variation, but they are important in oligotrophic aquatic environments and described as cosmopolitan, being bioindicators of water quality (D’Alessandro & Nogueira 2017D’ALESSANDRO, E.B. & NOGUEIRA, I.D.S. 2017. Algas planctônicas flageladas e cocoides verdes de um lago no Parque Beija-Flor, Goiânia, GO, Brasil. Hoehnea, 44:415–430.).

The genus with the highest number of taxa was Desmodesmus with 9 species (25%), followed by Coelastrum with 5 species (13%) and Ankistrodesmus with 4 species (11%). The higher occurrence of Desmodesmus compared to the others may be associated with the fact that this genus is common in most aquatic environments, from eutrophic to oligotrophic (Borges et al. 2008BORGES, P.A.F., TRAIN, S. & RODRIGUES, L.C. 2008. Estrutura do fitoplâncton, em curto período de tempo, em um braço do reservatório de Rosana (ribeirão do Corvo, Paraná, Brasil). Acta Sci. Biol. Sci. 30:57–65., Hentschke & Torgan 2010HENTSCHKE, G.S. & TORGAN, L.C. 2010. Desmodesmus e Scenedesmus (Scenedesmaceae, Sphaeropleales, Chlorophyceae) em ambientes aquáticos na Planície Costeira do Rio Grande do Sul, Brasil. Rodriguésia, 61:585–601., Domingues & Torgan 2012DOMINGUES, C.D. & TORGAN, L.C. 2012. Chlorophyta de um lago artificial hipereutrófico no sul do Brasil. Iheringia Ser. Bot. 67(1):75–91., Rosini et al. 2012ROSINI, E.F., SANT’ANNA, C.L. & TUCCI, A. 2012. Chlorococcales (exceto Scenedesmaceae) de pesqueiros da Região Metropolitana de São Paulo, SP, Brasil: levantamento florístico. Hoehnea, 39:11–38., Aquino et al. 2014AQUINO, C.A.N., BUENO, N.C. & MENEZES, V.C. 2014. Chlorococcales sensu latu (Chlorophyceae) de um ecossistema lótico subtropical, Estado do Paraná, Brasil. Hoehnea 41(3):431–451.), which can be observed in the Cascavel (Municipality of Cascavel) and Arroio Passo Liso (Municipality of Catanduvas) rivers, both in the watershed of the lower Iguaçu River, considered oligotrophic where high contributions of the genera Coelastrum sp. and Desmodesmus sp. were observed.

Among the 36 taxa identified in this study, five species occurred only under mesotrophic conditions, namely: Desmodesmus brasiliensis, Desmodesmus subspicatus, Scenedesmus obtusus, Monoraphidium caribeum, and Raphidocelis denubiana var. elegans. The occurrence of Desmodesmus in nutrient-rich environments, as mentioned earlier, is due to it being a genus adaptable to diverse environmental conditions, being common at all trophic levels (Phinyo et al. 2017PHINYO, K., PEKKOH, J. & PEERAPORNPISAL, Y. 2017. Distribution and ecological habitat of Scenedesmus and related genera in some freshwater resources of Northern and North-Eastern Thailand. Biodivers. J. of Biological Diversity, 18(3):1092–1099.). The genus Scenedesmus has already been associated with sites with mild to moderate organic pollution, warning for environments with tendencies to elevate their trophy (Sabkie et al. 2020SABKIE, N.S.M., ZULKIFLY, S.H.A.H.R.I.Z.I.M., LAZIM, N.N.F.M., ROSLI, N.S. & YONG, C.S. 2020. Physico-chemical influence on the diversity of phytoplankton at Putrajaya Lake and Wetlands, Putrajaya, Malaysia. Malay. Nat. J. 7(2):153–163.). We can also mention Monoraphidium caribeum, which, although cosmopolitan, is found mostly in eutrophic aquatic environments. The other occurrences were in oligo to mesotrophic conditions, which is in accordance with what is expected for the group (Comas 1996COMAS, A. 1996. Las Chlorococcales dulciacuícolas de Cuba. Biblioteca Phycologica 99:1–265.).

The Cascavel River showed the highest species richness (21 taxa). This environment was related to one of the lowest values of turbidity (8.29 NTU) in the area sampled. The Jacutinga River had the highest value for this variable (23.35 NTU), represented by only two species. The correlation of turbidity with Chlorophyceae representatives has been reported previously, where this variable negatively influenced the diversity of the group (Gogoi et al. 2019GOGOI, P., SINHA, A., DAS SARKAR, S., CHANU, T.N., YADAV, A.K., KOUSHLESH, S.K., BORAH, S., DAS, S.K. & DAS, B.K. 2019. Seasonal influence of physicochemical parameters on phytoplankton diversity and assemblage pattern in Kailash Khal, a tropical wetland, Sundarbans, India. Appl. Water. Sci. 9:156.; Kumar et al. 2020KUMAR, R., KUMARI, R., PRASAD, C. TIWARI, V., SINGH, N., MOHAPATRA, S., MERUGU, R., NAMTAK, S. & DEEP, A. 2020. Phytoplankton diversity in relation to physicochemical attributes and water quality of Mandakini River, Garhwal Himalaya. Environ. Monit. Assess. 192:799.). This relationship is due to the limitation of light penetration into the water, which reduces phytoplankton photosynthesis, in addition to altering the other limnological conditions (Nunes et al. 2022NUNES, P., ROLAND, F., AMADO, A.M., RESENDE, N.D.S. & CARDOSO, S.J. 2022. Responses of Phytoplanktonic Chlorophyll-A Composition to Inorganic Turbidity Caused by Mine Tailings. Front. Environ. Sci. 9:735.).

In our study, 94% of the taxa found had a rare frequency of occurrence, and only 6% were classified as sporadic. The rarity of the species in lotic environments may be related to the local hydrodynamics, where the greater flow of water prevents the establishment and development of potamoplankton, promoting a constant transport of taxa downstream (Medeiros et al. 2020MEDEIROS, G., PADIAL, A.A., AMARAL, M.W.W., LUDWIG, T.A.V. & BUENO, N.C. 2020. Environmental variables likely influence the periphytic diatom community in a subtropical lotic environment. Limnologica, 80:125718.). Phytoplankton is considered a group of key organisms to indicate changes in aquatic environments due to changes in the structure of biota, in response to physical and chemical factors in water bodies (Wojciechowski et al. 2017WOJCIECHOWSKI, J., HEINO, J., BINI, L.M. & PADIAL, A.A. 2017. Temporal variation in phytoplankton beta diversity patterns and metacommunity structures across subtropical reservoirs. Freshw. Biol., 62:751–766.).

Since 2007, 91 taxa have been recorded for the Chlorophyceae class in the State of Paraná, and according to the flora of Brazil (2020)FLORA DO BRASIL 2020. Jardim Botânico do Rio de Janeiro. Disponível em: < http://floradobrasil.jbrj.gov.br/ >.(Acesso em: 17 mar. 2022)
http://floradobrasil.jbrj.gov.br/... , 362 species were recorded throughout the country, with publications in São Paulo and Rio de Janeiro predominating, thus showing the need for further studies in Paraná. In conclusion, we can emphasize the importance of taxonomic studies, which serve as a basis for knowledge of biodiversity, providing essential information for ecological, bioindicator and conservation approaches.

Acknowledgments

The authors would like to thank Fundação Araucária/Companhia de Saneamento do Paraná for the scientific initiation grant to Maria Clara Pilatti, Fundação Araucária/Companhia de Saneamento do Paraná for a master’s grant to Thais Tagliati da Silva, the Coordination for the Improvement of Higher Education Personnel for the doctoral scholarship of Dra. Gabriela Medeiros, to Fundação Araucária/Coordination for the Improvement of Higher Education Personnel for the master’s scholarship to Mailor Wellinton Wedig Amaral,) Dra. Norma Catarina Bueno thanks Fundação Araucária/Companhia de Saneamento do Paraná for funding the research through the call public 26/2018 – Paraná Environmental Sanitation Research Program (PPPSA).

Data Availability

The data used in our analysis is available at https://collectory.sibbr.gov.br/collectory/public/show/co468?lang=pt_B

References

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