Summary of Abstract Submission

Abstract Submission No. IO50-09-0073PresentationPoster

FREE-LIVING MARINE NEMATODES A COMPARISON BETWEEN TWO EXTREME ECOSYSTEMS

Kapuli Gani Mohamed Thameemul Ansari*1, Punyasloke Bhadury1

1 LITME Research Group, Dept. Biological Sciences, IISER Kolkata, India

ABSTRACT :

Free-living marine nematodes are widely used as indicator for monitoring aquatic ecosystem health. The present study investigated distribution and diversity of marine nematode community from two ecosystems (lagoon and mangrove creek) located along the North-East coast of India facing the Bay of Bengal of Indian Ocean. Sediment samples were collected from four stations in each ecosystem to systematically document the dynamics of free-living marine nematode community in relation to measured in-situ abiotic variables. PCA ordination showed significant variation in abiotic variables across both the ecosystems. A total of 97 marine nematode species have been identified as part of this study. Nematode species composition showed significant differences between the two targeted ecosystems; among them 30 species were found to be common in both ecosystems. RDA ordination clearly explained that species distributions in both ecosystems were controlled by silt/clay nature of sediment along with higher concentration of TOC, while ecosystem specific unique nematode species were mainly due to prevalence local environmental conditions. In this study 30 species were found to be lagoon specific while 32 species were specific to mangrove creek. This habitat specificity of nematode species composition was clearly explained by species-environment relationship of RDA ordination where first two axes accounted for 80.9% in lagoon and 94.8% in mangrove creek. The results were also supported by Monte Carlo significant test at the level of P=0.76 in lagoon and P=1 in mangrove creek. The study concluded that marine nematodes are very good ecological indicator for monitoring ecosystem health because of species specificity and prevalence explains their ecosystem dynamics including functioning.