STRUCTURAL-CHANGES IN THE HEPATOPANCREAS OF THE ROCK LOBSTER, JASUS-EDWARDSII (CRUSTACEA, PALINURIDAE) DURING DEVELOPMENT FROM THE PUERULUSTO POST-PUERULUS

There is evidence for non-feeding in pueruli of palinurid lobsters dur ing their long-distance swim to the coast and the succeeding post-sett lement phase until they molt to the juveniles. For a better understand ing of the nutritional supply during the puerulus stage, structural ch anges in the hepatopancreas were studied in post-settlement pueruli an d first-molt, post-pueruli of the rock lobster, Jasus edwardsii, colle cted on the southeast coast of the North Island, New Zealand between 1 989 and 1990. In newly settled (transparent) pueruli, the epithelium o f the hepatopancreas is dominated by presumed ''young R-(resorptive) c ells'', which are devoid of lipid droplets, but show active uptake of material from the hemolymph through pinocytosis at the basal region. I n the fully pigmented puerulus, the hepatopancreas is dominated by R-c ells containing massive lipid droplets; also present are small numbers of F-(fibrillar) and B-(blister-like) cells. This increase of lipid i nclusion in the R-cells corresponds to the reduction in size of the fa t bodies as the lobster develops from the transparent to the pigmented puerulus. After the molt to the post-puerulus, the R-cells are compre ssed, and the lipid droplets almost disappear, while the B-cells incre ase both in size and number.