Evidence for a trophic paternal-larval relationship in the frog Rhinoderma darwinii

Larvae of Rhinoderma darwinii have a nonaquatic development inside the vocal sac of the male. Different authors have suggested the existence of a trophic relationship between the male and the larvae. In order to test this possibility, horseradish peroxidase, 3H valine and 3H leucine were injected into the paternal circulation and traced in the larvae at different postinjection intervals. The different tracers were demonstrated in several organs of the larvae thus indicating a possible paternal nourishment. Up to stage 10, the tracers were incorporated into the larvae through their skin and the cephalic and caudal parts of their digestive tract. At later stages, the intestines were the main route for the entry of tracers into the larvae.