EFFECT OF VARIATIONS IN PREY ABUNDANCE ON GROWTH AND DEVELOPMENT OF CRAB LARVAE REARED IN THE LABORATORY AND IN LARGE FIELD-DEPLOYED ENCLOSURES

We reared larvae of the Atlantic mud crab Panopeus herbstii (Milne-Edw ards) in small laboratory bowls and in large field-deployed enclosures with varying prey abundances. Laboratory experiments used brine shrim p nauplii (Artemia sp.) as prey, with abundances ranging from 500 to 1 0 000 l(-1). Enclosure experiments used wild zooplankton as prey at na tural abundances ranging from 10 to 500 zooplankters l(-1). Results of laboratory experiments showed a strong response to low prey abundance . Dry-weight growth, survival, and development rates of larvae reared at low prey abundances all decreased significantly Increases in prey a bundances above standard culture conditions (5000 Artemia 1(-1)) had L ittle effect. Results of enclosure experiments showed no response to v ariations in prey abundance or larval density. No significant differen ces were found in dry-weight growth, survival, or development rates. T he results indicate that larvae can develop successfully at prey densi ties previously thought incapable of supporting growth. The data also corroborate earlier work suggesting that growth and development are se parate processes which can be decoupled.