Journal of the Marine Biological Association of India

Volume 29 Issue 1&2

Ecology of meiobenthos of Rambha Bay in Chilka Lagoon, Bay of Bengal.

D. G.Rao

During 1978-80, the meiobenthos of the soft sediments of Rambha Bay in Chilka Lagoon was sampled. Apart from several qualitative samples, a total of as many as 26 quantitative samples (in triplicate) were analysed to study the relative abundance, density, composition and seasonal fluctuations of sedimentary meiofauna. The sediment nature and physico-chemical parameters of the ambient milieu was also studied to explain the spatial and temporal variations of the meiobenthos. The bottom sediment of Rambha Bay comprised of muddy sand and silty sand.

As many as 14 meiofaunal taxa were encountered. Of which nematodes, copepods, oligochaetes, ostracods, kinorhynchs and polychaetes were the dominant groups in the order of their abundance. The systematic study revealed as many as 76 species belonging to Foraminifera (7 species,), Polychaeta (10 species), Copepoda (34 species), Amphipoda (6 species), Isopoda (6 species), Tanaidacea (1 species), Cumaceae (2 species) and Mollusca (7 species). The kinorhynch species of undetermined identity viz. Echinoderes sp. and Pycnophyes sp. were discovered in the Rambha sediments for the first time.

The density of meiofauna ranged between 1128/10 cm' and 1583/10 cm^ and the biomass range between 7.719 mg/10 cm" and 10.528 mg/10 cm' in the Rambha Bay. Studies on the vertical distribution revealed that an average 71.67% of the total meiofauna were restricted to 0-5 cm of the sediment deposit; 21.56% to 6.10 cm and 6.74% to 11-15 cm depths respectively. In Rambha Bay, the macro-meiofaunal ratio was 1:129.

The significance of meiofauna as the food organisms to the higher tropic levels was also discussed

Date : 31-12-1987