Distribution and Abundance of Gelatinous Zooplankton in Coastal Waters of Port Blair, South Andaman

Abstract

Study on gelatinous zooplankton distribution, abundance and species composition was undertaken during March’13, April’13, August’13, December’13 and February’14. A total of 16 species belonging to 10 taxa were recorded of which 8 taxa belonged to Station1 and 9 taxa to Station2 respectively. Hydromedusae (6.01 ind/m3) was found to be the most dominant taxa recorded followed by Chaetognaths (1.64 ind/m3), Larvaceans and Siphonophores showed a similar abundance (1.21 ind/m3). Station1 had high species richness (d=15) than Station2 (d= 9). Distribution and abundance of gelatinous zooplankton was regulated by hydro-biogeographic parameters. Gelatinous zooplankton taxa were found to be influenced by single or multiple abiotic and biotic factors. The absence or lower limit of required factors was responsible for restricted distribution of species such as Pleurobranchiapileus, Bassiabassensis, Eireneceylonensis, Eirenehexanemalis, Helgicirrahamalayensis and Octophialuciumindicum. Clustering of Station1 and Station2 samples (similarity value 23.01%) was observed due to occurrence of similar taxa in both stations. Cluster with least similarity and highest similarity found in Station1 indicating periodic blooming of gelatinous zooplankton taxa. Lack of literature on this ignored taxa and their noxious effect reported all over the world point out necessity of this study;