Diversity and Abundance of Donax Species at two Sandy Beaches of Karachi Coast

Abstract

Three species of family Donacidae, Donax cuneatus, D. denticulatus and D. scalpellum were recorded from Sandspit and Clifton. A total of 3446 organisms were reported from Clifton and 22 from Sandspit during studied period. A total of 32 samples were collected in duplicate from 04 stations at both sites in Pre-monsoon and during Southwest monsoon period. All the species of Donaxwere most abundant in Pre-monsoon season at both sites and scarce in late SW monsoon season. The total abundance of D. cuneatus, D. denticulatus and D. scalpellumis relatively higher at Clifton. Donax species was the most abundant species among macro benthic fauna at Clifton mainly at sea view which is relatively a disturbed site. The present study revealed the greater variability in relative abundance of Donax species at both sites and influenced by monsoon season rather than morphological characteristics of the sediment.