Larval rearing of mud crab, Scylla tranquebarica (Fabricius, 1798) and feeding requirements of its zoea

Abstract

Feeding experiments were conducted with zooplankton to find out the suitable food for zoea1 of the mud crab Scylla tranquebarica. Zoeae1 from seven berried females, three from wild and four from rematured specimens were the source material for the present study. The veliger larvae (50-55μm) of pearl oyster and two species (Pseudodiaptomus spp. and Labidocera spp.) of pelagic copepods (500-1000 μm) were tested as feed. However, the zoea1 accepted only the former. The feeding activity could be resolved into 5 stages. Significant role of the serrated caudal setae in prey abrasion into required size suitable to mandibles for mastication and the size preference of the items of diet in relation to the growth of the mandibles with the advancement of zoeal stage also have been discussed. In all the 7 feeding experiments that were conducted by providing rotifer, Brachionus rotundiformis (<100 μm), the zoea1 advanced to zoea3/zoea4 or the first crab stage. The present study is a significant development in narrating the feeding behaviour of zoea1.