Distribution and Ecology of the Recent Benthic Foraminifera from the sediments of Adyar River, Chennai, Tamilnadu, India

Micropalaeontological investigation has been carried out, for the first time to study the systematic of recent Benthic Foraminifera from the Adyar River, Chennai, Tamilnadu, India, Totally 20 sediment samples were collocted during March 2010. 46 benthic foraminiferal species belonging to 22 genus, 5 families and 3 sub orders are identified. Off which Miliolina (52%) occupies the dominant place followed by Rotallina (33%) Textularina (15%). From station no. 1 to 6 the foraminifeal species distribution shows decrease in order. The higher species are observed in the rivermouth area particularly in the sample no1. (254 species). The following species are abundantly distributed in this region namely Ammonia beccarii, Elpidiumcripsum, Spiroloculina communis and Textularia agglutinans followed by Ammobaculites exigus, Triloculina trigonula. In general the distribution of foraminifera is very low. The abundance of species in the river mount may be due to the mixing of marine and nearshore environment. All the species are illustrated with Scanning Electron Microscope Photographs. From the Zoogeographical distribution of the fauna of the study area, it is observed that the assemblage shows close affinity with the Indo- Pacific faunal Province