ONTOGENY AND BEHAVIORAL ASPECTS OF THE TADPOLES OF MEGAELOSIA GOELDII (BAUMANN, 1912) (AMPHIBIA, ANURA, HYLODIDAE)

Ana Maria Telles Carvalho-e-Silva

Abstract


The genus Megaelosia consists of large sized, diurnal species that live associated to rivers. Although the tadpole of M. goeldii was described, its ontogeny and behavior were never detailed. In this work, the development of the M. goeldii larvae is described, considering its behavioral aspects. Tadpoles were collected between 1983 and 2016 in the municipality of Teresópolis, RJ. Stages were determined based on the table of development. Ten groups were defined with size variations of 10mm, to search for possible relationships between larvae growth and depigmentation of mouthparts. Tadpoles present accentuated growth on stage 25, but small changes in size from stages 26 to 42. Changes in coloration were observed throughout its development. Larvae were found in rivers of running water, in approximately 1.0-1.2 m depth. During the day they shelter on dens in the margins, and at night are more easily spotted in shallower waters, foraging near the dens. Larvae are observed throughout the year, though the smaller ones are mostly found in August and September, indicating that reproduction occurs in the winter. The tadpoles showed emetic behavior when collected, probably by exposure to stress situations or to scare away the predator. Of the 208 specimens analyzed, 71% presented depigmentation in the oral disc, the phenomenon was more frequently visualized in larger tadpoles.  The oral depigmentation in tadpoles indicate the presence of the fungus Batrachochytrium dendrobatides causing chytridiomycosis, one of the main factors responsible for the worldwide decline of amphibians.


Full Text:

PDF

Refbacks

  • There are currently no refbacks.