THE ROLE OF SEAGRASS AS PREFERRED HABITAT FOR JUVENILE SILLAGINODES-PUNCTATA (CUV AND VAL) (SILLAGINIDAE, PISCES) - HABITAT SELECTION OR FEEDING

Previous experiments have shown that the relationship between abundanc e of juvenile fishes and seagrass density is the result of habitat sel ection rather than direct predation, but have not distinguished betwee n habitat selection and simple feeding. The simple feeding model, in w hich fish swim until they find food, eat it, and swim again, predicts that fish will be found where the most food is available regardless of the presence or density of seagrass. Food availability was manipulate d in tanks in which juvenile Sillaginodes punctata (Cuv. & Val.) (King George whiting) were offered the choice of two habitats, live eelgras s (Zostera muelleri Irmisch ex Aschers.) or unvegetated sand. When foo d was available, fish were initially distributed in a way that strongl y supported the feeding model, but once they were satiated, the distri bution of fish fitted the predictions of neither model. In the absence of food, fish selected eelgrass habitat. At night, the distribution o f fish showed that they took little account of food availability or ha bitat.