Presence and absence of the cement gland in foamnesting leptodactylids (Anura: Leptodactylidae): implications for the transition to terrestrial development

Reproduction and early development are compared in three foam-nesting leptodactylids: Leptodactylus fuscus, L. validus and Physalaemus pustulosus. Physalaemus pustulosus and L. validus produce floating foam nests containing large numbers of small eggs which hatch early and soon leave the nest as larvae, attaching to solid surfaces by their cement glands until the stage of independent feeding. Leptodactylus fuscus foam nests are deposited in terrestrial burrows and contain small numbers of large eggs which hatch early, but remain in the foam nest until the yolk is resorbed and the larva has developed its tail for effective locomotion. The lack of a cement gland in L. fuscus suggests that the post-hatching period in the nest is a normal part of development. L. fuscus eggs and hatchlings transferred prematurely to water displayed low survival. The results are discussed in the context of evolutionary reproductive transitions within the leptodactylids.