DECAPOD CRAB ZOEAE AS FOOD FOR REARING CEPHALOPOD PARALARVAE

A simple method of providing a regular supply of live food for the experimental culture of paralarval cephalopods is described. The primary food source utilized was hatched zoeae of large laboratory populations of the hermit crab, Pagurus prideaux. Zoeal size, swimming behaviour, and distribution in the water column make these zoeae a suitable live prey for rearing early post-hatching planktonic stages of cephalopods and probably other marine zooplanktivores. Ovigerous P. prideaux females were collected from the sea throughout the year at depths between 10 and 90 m in the NW Mediterranean and maintained at densities of up to 500 specimens.m-2. One month after spawning in aquaria, 38% of the females of P. prideaux started to incubate a second clutch of eggs. Other decapod crustacean species, such as Liocarcinus depurator and Dardanus arrosor, were maintained to use their zoeae as a food source for cephalopod paralarvae. P. prideaux zoeae were used as the sole or main food resource for rearing Loligo vulgaris and Octopus vulgaris, during the first 2 months of life. First feeding and initial growth in L. vulgaris and O. vulgaris paralarvae can be successfully stimulated using decapod zoeae with a total length equivalent to 50-100% of the cephalopod's mantle length.