SPECIES COMPOSITION AND ABUNDANCE OF MOLLUSCS ALONG KARACHI SHORES: Molluscan species composition and abundance along four rocky shores of Karachi

Ninety seven species of macro-molluscs were collected from four rocky beaches viz. Manora, Buleji, Nathiagali and Cape Monze along the Karachi coast from December 1993 to December 1995. More species were recorded from Buleji (68) and Manora (63) compared to Nathiagali (55) and Cape Monze (57). Gastropods dominated on all the four sites studied. Four species were commonly abundant on all the four sites viz.: Turbo coronatus, Nerita albicilla, Morula granulata and Cerithium rubus. The average number of species decreased with increase in the tidal heights at Manora, Buleji and Nathiagali whereas this was greater in the high tidal zone at Cape Monz rocky shore. The average number of individuals of molluscs was greater in mid tidal zone at Manora and Buleji rocky shore whereas it was greater in low tidal zone at Nathiagali and Cape Monz.