Diversity of amphipods in the continental shelf sediments of southeast coast of India

The diversity of amphipods in the continental shelf sediments of the southeast coast of India is dealt in the paper. Samples for the study were collected onboard FORV Sagar Sampada during Cruise Nos. 260, 275 and 290 conducted in December 2008, May 2010 and October 2011 respectively. Samples were collected at various depths (30 m, 50 m, 75 m, 100 m, 150 m and 200 m) along 6 transects namely Singarayakonda, Tammenapatanam, Chennai, Cheyyur, Cudallore-Parangipettai and Karaikkal besides Cuddalore-SIPCOT using Smith-McIntyre grab having a bite area of 0.2 m2. The total number of species of amphipods recorded was 44 belonging to 29 genera and 17 families. The number of species and abundance decreased from the shallower depths to the deeper depths. The abundance varied from 1 to 467 nos./0.2 m2. The maximum was found in Cheyyur transect at 30 m depth and the minimum in Cheyyur at 150 m and in Cuddalore-SIPCOT at 200 m depth. The number of species at various depths ranged from 1 to 17. While the maximum number of species was found in Cheyyur at 30 m depth, the minimum was found in Cheyyur at 150 m, CuddaloreSIPCOT at 200 m and Cuddalore-Parangipettai at 150 m depths. Ampelisca spp. was found to be dominant in the study area. Species estimators, especially Chao1 showed the chances of recording as many as 142 species of amphipods in the study area with intensive sampling. In view of this fact, further sampling in the study area will throw more light on the amphipod diversity.