The Female Reproductive System of the Australian Gastric Brooding Frog, Rheobatrachus silus (Anura: Leptodactylidae)

Abstract

The digestive tract of females of the Australian frog Rheobatrachus silus is highly modified to permit the stomach to become a brood sac, but the reproductive tract retains the basic anuran pattern and lacks major modifications. Its only unique feature is a tendency towards asymmetry in the lobes and egg complements of the ovaries. The oocytes are unpigmented and when mature have a mean diameter of up to 4.7 mm. The oocyte complement occasionally far exceeds the number of tadpoles or frogs observed to be carried in the stomach. Comparison with the tree frog Litoria rothii and the fossorial Neobatrachus centralis indicates that R. silus has far fewer ovarian lobes. larger and many fewer oocytes, and a much less convoluted oviduct.