Histological development of the stomach and hepatopancreas of two laboratory-reared sesarmid crabs, Episesarma species (Decapoda: sesarmidae)

The objective of this study was to histologically record the ontogenetic changes in the stomach and hepatopancreas of two sesarmid species, Episesarma singaporense and E. versicolor , studied from the zoeal stage 1 to the crab stage. Specimens of ovigerous females were collected from a hatchery site and all stages (zoea 1 to crab) were processed using the morphology and histological method through semithin section. The results of histological analysis of the digestive system were largely organized within the body and showed a complex organization. The distinction between cardiac and pyloric stomachs in both species was unclear in the zoeal 1 and 2 stages but became evident in zoeal stages 3 and 4. All stomach structures in the megalopa and crab stages, especially the well-developed lateral teeth in the cardiac stomach, were clearer than they were in the zoeal stages. The same development was observed in the hepatopancreas that was fully developed by the zoeal 3 stage and became more intricately branched and larger in later stages. This development is an indicator of larval and later feeding activity, which provides information for aquaculture of two sesarmid species.