Ovarian histology in vitellogenic females of Leptodactylus latinasus (Anura, Leptodactylidae)

Abstract

Leptodactylus latinasus belongs to the L. fuscus group. Species belonging to this group build incubation chambers where they place a foam nest, after which the first larval stages start developping. The goal of this study was to describe the histology of vitellogenic ovaries in L. latinasus. Twenty–eight females were used. Some were processed immediately after they were collected, whereas others were placed in the presence of males, with artificially built incubation chambers, under lab conditions. The ovaries were fixed in buffered formalin and routine histological techniques were used to examine the samples. Different degrees of ovarian alterations in vitellogenic oocytes, which prevented the process of reproduction, were observed: 1) few non atresic vitellogenic oocytes; 2) peripheral atresia; 3) invasive atresia towards the center of oocytes with alteration of the vitellus; 4) almost complete lipid vacuolization, apoptotic bodies; 5) detachment of follicular cells in some oocytes; 6) decrease in oocyte size. Furthermore, the intromission of fat bodies in the oocytes, with vases, fibroblastic cells and macrophages was noticeable. The massive atresia of the ovocytes in vitellogenic females has not been previously reported in other anurans. This would indicate that the conditions for ovulation were not optimal. Amplexus and oviposition of this species occur inside incubation chambers of mud, which constitute a microhabitat where conditions would be appropriate for reproduction. Thus, these results suggest that if the environmental conditions are not favorable, reproduction does not occur, and the ovaries suffer massive atrophy.