Summary of Abstract Submission

Abstract Submission No. IO50-06-0006PresentationPoster

BIODIVERSITY OF BENTHIC POLYCHAETES FROM A SHALLOW TROPICAL BAY, BAY OF BENGAL, INDIA

Dr. Mosuru Srinivasa Rao*1, Dr. C. Annapurna1, K. Chandra Rao1, M. Sirisha1

1 Andhra University, India

ABSTRACT :

The aim of this study is to determine patterns of species richness and community structure along with the influence of environmental parameters on the diversity of polychaetes of a shallow tropical bay named Nizampatnam bay, Bay of Bengal. Four cruises were conducted during 2006 to 2008 covering 20 stations along the bay having depth of 40 m. Altogether 128 infaunal samples were collected represented by crustacea (61.4%), polychaeta (34%), ophiuroidea (1.5%), bivalvia (1.3%) and others (1.8%) includes nemertina, echiuroidea and pisces. Polychaete abundance varied from 140 nos.m-2 to 2420 nos.m-2 with mean 135.811.22. Bottom salinity ranged between 24.8 and 36.8 psu, temperature 25.0 and 34.1 0C, dissolved oxygen 1.34 and 5.82 ml.l-1. The predominant sediment texture in the Nizampatnam bay was characterized by clayey-silt and sandy with an average mean particle diameter (MPD) of 153.7μm. Overall, sediment organic matter (%) varied from 0.26 to 2.20 mean 1.160.06. During this investigation, 97 polychaetes species were identified from the infauna which were dominated by Prionospio cirrefera, Nephthys dibranchis, Diopatra neopolitana, Lumbrineris heteropoda and Cossura coasta. Polychaete diversity indices S, N, d and H were higher in the stations with depth <15m than the stations with depth >15m. Multivariate analyses were used to define assemblages named after the most important (determining) taxon. Two polychaete associations could be recognised namely Prionospio cirrefera assemblage (<15m) and Lumbrineris heteropoda assemblage (>15m).