Aspectos da biologia reprodutiva e alimentar de Elachistocleis ovalis e Ctenophryne geayi (Amphybia, Microhylidae)

Abstract

Elachistocleis ovalis (Schneider, 1799) and Ctenopbryne geayi Mocquard, 1904 are two species of anuran amphibians in the family Microhylidae, whose normally fossorial life habits make it difficult to capture them outside the reproductive period, when adults concentrate in puddles formed with the onset of rainfall. This study aimed to examine the characteristics of the reproductive and feeding biology, especially the variation between individuals in gonad development, dietary patterns, and fat accumulation in the two species. The specimens studied were collected from November 2000 to March 2001 in the volta grande area of the Xingu River, municipalities of Vitoria do Xingu and Senador José Porfírio, Pará. We examined 102 specimens of E. ovalis and 96 of C. geayi from which the fat bodies, stomachs and gonads were isolated. As for reproduction, 65 females of E. ovalis were examined, with only one with mature eggs, 29 males and 8 juveniles; and 57 females of C. geayi, where 40 had mature eggs, 18 in the immature stage, 23 males and 16 juveniles. The presence of ova at different stages of development at the same time of year may indicate the occurrence of more than one laying during the reproductive period in the rainy season. The fat bodies of males and females were correlated to animal size, gonadal development and food consumption. As for diet composition, stomach contents analyses indicated that E. ovalis feeds primarily on ants and termites, which appeared in 70% and 85% of the individuals examined, respectively, while for C. geayi, the most consumed prey items were ants and coleopterans, which occurred in 100% and 45% of individuals, respectively.