This research was focused on the molluscan diversity along the coast of Damb, Balochistan. 3 classes (Gastropoda, Bivalvia, and Cephalopoda) of phylum Mollusca were collected, identified and counted from this site from June-2022 to November 2022. 3 classes 23 families and 61species were identified from this site. A total 4818 specimens of molluscs were collected, among them 3283 (68%) specimens of 38 species of 16 families of class Gastropoda, while 1531 (31.56%) specimens of 22 species of 6 families of class Bivalvia were reported from this site. 14 specimens of 2 species of two families of class Cephalopod were collected. Simpson’s Diversity Index (SDI) of gastropoda was about 0.1503 which shown the low diversity of gastropoda of this area. While Simpson’s Diversity Index (SDI) of bivalvia was about 0.2795 which shown the high diversity of bivalvia of this site as compared to gastropoda. 3025 specimens of 6 species of family Potamididae of gastropoda was found in highest % of abundence which about (92.14%) of total collection of gastropoda. Family Tellinidae of class bivalvia with 3 species was found in highest % of abundence which about (84.64%) of total collection of bivalvia.

This paper deals with relative growth of long carapace width (LCW) and carapace length (CL) with reference to short carapace width (SCW) in two species of edible crabs, namely Portunus pelagicus and P. sanguinolentus. The relationship between SCW and CL was found negatively co-related in both the species. Size-weight relationship showed that males are heavier than similar sized females in both species. Meat yield was found higher in P. pelagicus than P. sanguinolentus. Male P. pelagicus had 40.1 to 51.3% (average 44.5%