Figure 2: (A) Shell, Nerita albicilla (B) Dissected Nerita albicilla. Dorsal view of animal after shell and mantle (a fold of body wall) removed. (C) Live specimen Perna viridis kept in aquarium. (D and E) Perna viridis was differentiated into male (white) and female (Red to Orange) on the basis of gonadal tissue color.