Development and Growth of Larvae of the Volute, Cymbiola nobilis Lightfoot.

The volutid, Cymbiola nobilis Lightfoot, 1786, is a gastropods molluscs that inhabit deep seas and traditionally harvested by locals for food and hence fetch a high market value. The objective is to study the development of volutid and larval production as an effort to restore depleted natural population of this species. Egg masses used in this study was collected while still underneath spawning females, and embryonic and post-hatching larval development was observed in the laboratory. The larvae were reared in 50 x 100 cm aquarium with 0.22 µm filtered seawater medium at a salinity of 30 ± 1 PSU. Fecundity was estimated at 29 eggs/egg mass (n=10). The juvenile hatching was exactly the same as the adult. Base on this study the morphological features of Cymbiola nobilis can be assigned to eight different development stages beginning from egg described in this paper. The metamorphosis stage were took place in the egg and it is about 7 days before become pre-hatching juvenile. They showed a short period of metamorphic competence and morphological changes also described. [ABSTRACT FROM AUTHOR]