Ontogeny and behavioral aspects of the larva of Phasmahyla guttata (Lutz, 1924) (Amphibia, Anura, Hylidae)

Abstract

The genus Phasmahyla Cruz, 1990 is composed of small anurans, whose spawns are deposited on leaves above forested streams. Their tadpoles are neustonic and presents dorsal buccal funnel. In the city of Rio de Janeiro the genus is represented by P.guttata (Lutz 1924). Tadpoles of this species were collected in the Rio dos Macacos, Horto Florestal, Rio de Janeiro and their ontogenetical development were studied. Larvae hatch in the stage 25 (ca 16.5 mm), remaining in this stage until an average length of 18.4 mm. The buccal funnel grows from 1.9 mm (stage 25) to 7.1 mm (stage 40), been completely absorbed in the end of stage 42. The tail grows gradually until stage 41, when the tadpoles reach theirs biggest size (average length of 55.1 mm). In stage 41, tail start to be absorbed, disappearing completely in the stage 46. In the streams, the tadpoles are distributed in schools, constituted by tadpoles of several development stages. The composition of schools changed throughout the year. In the months of June and July the occurrence of newly hatched tadpoles was not observed, with the appearance of the first newly hatched in the month of August. A greater number of newly hatched tadpoles were observed in March, April and May. Five spawns were collected, all deposited in nests of leaves rolled into funnel shape. To make up the nests, the pair used only fresh leaves, which are longer than wide.