Journal of the Marine Biological Association of India

Demecology of kinorhyncha of chilka lagoon (Bay of Bengal)

Volume 38 Issue 1&2

D. G. Rao and S. Satapathy

Abstract

During 1978-80, the meiobenthic kinorhynchs of the soft sediments and phytal of Chilka lagoon was sampled. Apart from several qualitative samples, a total of 300 pain of core samples of sediment and 100 pairs of samples of Halophyla ovata were analysed to study the relative abundances, density and seasonal fluctuation of two kinorhynchs viz., Echinoderes sp. and Pycnophyes sp. The sediment nature and physiwchemical parameters of the ambient milieu was also studied to explain the spatial and temporal variations of the kinorhynchs. The lagoonal sediments in general comprised of soft sandy silt, muddy sands, silty sands excepting at outer channel where sand and clayey sand prevail. The kinorhynch species of undetermined identy viz., Echinoderes sp. and Pycnophyes sp. were discovered in the Chilka lagoon for the first time. Maximum abundance of the kinorhynchs corroborated with the salinity distribution than any other physicochemical parameters. Kinorhynchs were virtually absent in the northern sector stations (KG and GP). A maximum density of 73 indl10 cm2 was encountered in PK. On an average about 80-100% of the kinorhynchs were present in 0-5 cm depth. When the kinorhyncha population census data.of both the sedimentary and phytal biotopes of Chilka were pooled and the emergent pattern scrutinised, the kinorhyncha registered their peak densities during January-April period. It was observed that the abundance or distribution of kinorhynchs related with salinity, sediment nature and vegetation wver of the bottom. Fine grained sediments with a detrital surface layer was more congenial for the organisms.

Keywords

meiobenthic kinorhyncha, density, ecology, chilka lagoon

Date : 30-12-1996