POPULATION ABUNDANCE AND SPECIES COMPOSITION OF CHAETOGNATHS IN THE BOMBAY HARBOR - THANA AND BASSEIN CREEK ESTUARINE COMPLEX

Detailed study on the abundance, distribution and species composition of chaetognaths from the Bombay harbour-Thana and Bassein creek estuar ine complex was carried out from October 1985 to September 1986. Perce ntage contribution of chaetognaths to total zooplankton biomass varied from as low as 0.01 to as high as 25.78%. Unlike earlier studies in t he same area, the present study recorded the presence of only 4 specie s viz. Sagitta bedoti, S. oceania, S. enflata and S. robusta, S. bedot i being the most common, dominant and tolerant of them. Total absence of S. enflata in the interior stations receiving large quantities of s ewage and industrial effluents signifies a highly sensitive nature of this species. The present study shows a general decrease in the specie s diversity but an overall increase in the population density of chaet ognaths. S. bedoti and S. oceania dominated the complex indicating ada ptation of these hardy species to the prevailing water quality.