Significance of feeding to the development of postlarval megalopae in the free-living crabs Lophopanopeus bellus and commensal crab Fabia subquadrata.

Crab megalopae, derived from wild caught terminal stage zoeae, were reared in ‘point of no return’ (PNR) diet treatments consisting of progressively extended initial periods of starvation followed by continuous feeding and ‘point of reserve saturation’ (PRS) treatments consisting of progressively extended periods of feeding followed by continuous starvation. No unfed megalopae of either the free-living Lophopanopeus bellus or the commensal Fabia subquadrata survived to Crab I, while megalopae fed continuously on brine shrimp Artemia sp. nauplii showed high survival. Extension of initial starvation produced increased mortality and delayed molting in both species, with a PNR of 9 d in L. bellus and 8 d in F. subquadrata. Megalopae thus must initiate feeding by approximately one-half of the mean stage duration of those continuously fed. L. bellus megalopae initially fed for only one-third of the mean stage duration showed the same survival as those continuously fed, while F. subquadrata