~ 19 ~ International Journal of Fauna and Biological Studies 2016; 3(6): 19-24 ISSN 2347-2677 IJFBS 2016; 3(6): 19-24 Received: 05-09-2016 Accepted: 06-10-2016 Sujit Kr. Ghosh Zoological Survey of India, M-Block, New Alipore, Kolkata, West Bengal, India Priyanka Das Zoological Survey of India, M-Block, New Alipore, Kolkata, West Bengal, India Bulganin Mitra Zoological Survey of India, M-Block, New Alipore, Kolkata, West Bengal, India Correspondence Bulganin Mitra Zoological Survey of India, M-Block, New Alipore, Kolkata, West Bengal, India Studies on the fresh water aquatic beetle fauna (Coleoptera: Insecta) of Chilika lake and its adjoining areas and their colonization in brackish water Sujit Kr. Ghosh, Priyanka Das and Bulganin Mitra Abstract Studies on the aquatic beetle fauna of 8 selected sites of Chilika Lake, the one of the Ramsar site in Odisha, situated in the east coast of India connecting the Bay of Bengal was carried out during the month of July to August, 2016. Present survey is the second survey exactly after the 100 years of the first survey made by Annandale and his team in the year 1915. Altogether, 42 species under four families of aquatic beetle fauna are reported here including the earlier reported species. Of them, 20 species are reported for the first time from the Chilika Lake and its adjoining areas. Moreover, 16 species are reported for the first time from the Indian brackish water. Keywords: Aquatic beetle, Chilika Lake, Ramsar site, Brackish water, new records 1. Introduction The first faunistic study on Chilika Lake was initiated by Annandale in the year 1915 and the results of these studies have been published in a series of papers from 1915 to 1924 [1] . In that series [2] it was being reported the occurrence of aquatic insects excluding beetles. The second attempt on the exploration of the faunal diversity of the Chilika Lake has been taken by the Estuarine Biological Station, Zoological Survey of India (presently EBRC) from 1985 to 1987 and the studies were carried out starting from limnology to faunal account from protozoa to mammals excluding insects [1] . Aquatic beetles are very integral part of the biotic component and the best indicator of any water body or wetland. So far knowledge goes, Arrow [3] was the first man who reported two species of aquatic beetles from Chilika Lake areas, each one from the family Dytiscidae and Hydrophilidae from the collection of Annandale in 1915. Afterwards, one new species was described [4] , Hydroglyphus regimbarti as Bidessius regimbarti Gschwendtner, 1936 of the family Dytiscidae. After that, initiative was taken [5] to report the dytiscid species of Chilika Lake collected by Annadale and his team in the year 1915. Vazirani has included all these species in his revisionary works on subfamilies Noterinae, Laccophilinae, Dytiscinae and Hydroporinae of family Dytiscidae. Present communication is the outcome of the recent survey (2016) exclusively on the insect faunal diversity of Chilika Lake and aquatic beetles in particular. This present survey was made exactly hundred years after the first collection made by Annadale in the year 1915 and his team. The present communication reports 42 species including earlier reported species which are distributed in 4 families, Noteridae (4 species), Dytiscidae (24 species), Hydrophilidae (13 species) and Hydrochidae (1 species). Of them, 20 species are reported for the first time from the lake and adjoining areas. All these collections were made from both fresh and brackish water of the lake and adjoining areas. Among the 42 species, 16 species were collected from both fresh and the brackish water of the Chilika Lake and its adjoining areas. 2. Material and Methods 2.1 Study area: Chilika lagoon (85º20′ E, 19º40′ N), situated in the east coast of India connecting the Bay of Bengal, is the largest brackish water wet land and one of the Ramsar sites in India [6] . It is spread over Puri, Khurda and Ganjam districts of Odisha state on the east coast of India, at the mouth of the Daya River, flowing into the Bay of Bengal, covering an area of over 1,100 Sq km (Map 1).