FOOD SHORTAGE DURING THE MEGALOPA STAGE REDUCES SIZE AT METAMORPHOSIS AND EARLY JUVENILE GROWTH IN SHORE CRAB, CARCINUS MAENAS

Environmental conditions experienced by larval stages can affect size, growth and survival during the juvenile life of marine invertebrates. We studied if food conditions experienced during the end of the larval development affect the size at metamorphosis and growth during the first five juvenile stages (J-I-V) of the shore crab, Carcinus maenas. Megalopae were collected from the field and maintained in the laboratory with or without food (Artemia sp nauplii) until metamorphosis to the first juvenile stage. The resulting juveniles were fed thereafter. Prolonged time to metamorphosis in the absence of food resulted in smaller size at metamorphosis, and juvenile growth rates were significantly reduced when megalopae were not fed. Effects of larval nutrition were still found at the J-V stage, in spite of 30-40 d of ad libitum food conditions after metamorphosis. The nutritional history during the larval phase may be important to explain variability in juvenile survival in C. maenas, if mortality by cannibalism and predation depends on juvenile size and growth rates.