Community Structure and Abundance of Tintinnids in the Bay of Bengal During the Spring

The Bay of Bengal (BoB) locates in eastern part of the northern Indian Ocean, with a unique inter-related oceanographic system due to the monsoon and enormous runoffs’ supply. microbial food web often dominated the stratified Tropical Ocean, while few studies have been taken up to the tintinnids ciliates. Community structure and abundance of tintinnids were investigated in transact 10° N of the BoB during April 23 to May 2 of 2010. Discrete samples (for tintinnids and environment parameter analysis) were collected at various depths of 0, 25, 50, 75, 100, 150 and 200 m at each station. The tintinnids abundance vertically increased from surface water to maximal at the 75 m, decreased thereafter to the 200 m layer. A total of 20 tintinnids species that belong to 16 genera. Undella ostenfedi was dominant species, followed by Eutintinnus fraknoii and Amphorella quadrilineata. Tintinnids abundance was positively correlated to chlorophyll a concentration (p<0.01), indicating the vertical distribution of the tintinnids community was regulated by available food resource.