FEEDING-BEHAVIOR AND GROWTH OF HERMISSENDA-CRASSICORNIS (MOLLUSCA, NUDIBRANCHIA) IN THE LABORATORY

The feeding behavior and growth of the nudibranch mollusc Hermissenda crassicornis, a generalist carnivore, has been studied; this species i s widely used as a biomedical and neurobiological model. Relative to t he stalks, polyps of the hydroid prey, Tubularia crocea, were preferen tially consumed by adults of H. crassicornis at a fast rate. Starved s lugs did not distinguish between reproductive and unreproductive polyp s, but unstarved slugs did select unreproductive polyps of T. crocea. Experiments with diets based on different parts of T. crocea (polyps, stalks, or whole) showed no obvious differences in juvenile growth amo ng treatments, but survival of juveniles was low. Juveniles of H. cras sicornis grew better on a diet of the small anemone Haliplanella lucia e than on T. crocea or the anemone Metridium senile. The relationship between body length and wet weight of H. crassicornis was similar for animals grown in the laboratory on a T. crocea diet and specimens from the field.