Population biology of Pachyurus bonariensis Steindachner, 1879 (Perciformes, Sciaenidae), an allochthonous species in the Laguna dos Patos hydrographic system, Brazil

Authors

  • Ana Paula Sassanovicz Dufech Universidade Federal do Rio Grande do Sul, Laboratório de Ictiologia, Departamento de Zoologia
  • Clarice Bernhardt Fialho Universidade Federal do Rio Grande do Sul, Laboratório de Ictiologia, Departamento de Zoologia

Keywords:

fish, Maria-Luiza, southern Brazil, introduction

Abstract

The genus Pachyurus is widely distributed in the large hydrographic systems of South America, being represented only by Pachyurus bonariensis in the southern portion of the continent, in the La Plata drainage (Uruguay, Parana and Paraguay rivers). The occurrence of this species is recent in the Laguna dos Patos system, and most aspects about population biology and distribution of P. bonariensis for this region are unknown. Abundance, constancy of occurrence, sexual dimorphism and sex ratio were analyzed for the species. The establishment of this species in the Laguna dos Patos system is discussed. One hundred and one specimens (82 females, 15 males and four immature) were captured in the Parque Estadual de Itapuã, Rio Grande do Sul State, at Praia das Pombas, Lago Guaíba. The species was constant during the studied period, from June 2002 to July 2003. The abundance was higher in January and April 2003. Females were larger and significantly more abundant than males (chi2 = 43.12; p < 0.05). These results and the identification of sexually mature females suggest reproductive activity and indicate that P. bonariensis is an allochthonous species that established a successful population in the Laguna do Patos hydrographic system.

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Published

2007-01-01

How to Cite

Dufech, A. P. S., & Fialho, C. B. (2007). Population biology of Pachyurus bonariensis Steindachner, 1879 (Perciformes, Sciaenidae), an allochthonous species in the Laguna dos Patos hydrographic system, Brazil. Biota Neotropica, 7(1). Retrieved from //www.biotaneotropica.org.br/BN/article/view/259

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