JSARD: ISSN 1811-8976, Volume 11 Issue 2 August 2013 1063 J. Subtrop. Agric. Res. Dev.11 (2):1063-1069, August 2013, website: www.gscience.net or www.gurpukur.com SEASONAL VARIABILITY AND SPECIES COMPOSITION OF FISH IN SOME SELECTED AREA OF THE NORTH-EASTERN PART OF BANGLADESH M. S. HOSSAIN 1 *, S. MIAN 2 , T. DEY 1 , M. M. RAHMAN 3 and M. J. ISLAM 4 ABSTRACT The study was conducted at the Faculty of Fisheries, Department of Aquaculture, Sylhet Agricultural University, Sylhet, Bangladesh to know the seasonal variability and species composition of fish. The samples were collected from three upazila namely Sylhet sadar, Jaintapur and Fenchuganj upazilla under Sylhet district of Bangladesh during July, 2011 to April, 2012. These study area were located in a certain portions of the river Surma, Kushiara and Portions of the haor Baourbag and Hakaluki. Visits to the Lal bazaar, kazirbazar, tilaghor bazaar, Majortilla, Pirer bazaar, Cantonment, Haripur, Jaintapur and Fenchugonj fish markets were made almost fortnightly basis during the study period. Focus group discussions were conducted along with the fishermen and local residents, fish traders, Upazilla Fisheries Officers (UFO) to know the species availability in various seasons of the study area. A total of 99 species of fish and prawns belonging to 63 genera and 27 families were observed and identified through fish market survey from the study area. Among them, 88 were indigenous species and 11 were exotic species. Among the indigenous species, 24 species were belonging to the family Cyprinidae. Next to Cyprinidae, 10 species were belonging to family Bagridae. Five species were identified belonging to the family Cobitidae, four species belonged to the family of Channidae, Schilbeidae, Anabantidae, Ambassidae and Siluridae. Three species were belonged to family Clupeidae, Sisoridae and Mastacembelidae. Two species were belonged to family Tetraodontidae, Notopteridae and Palaemonidae. Only 1 species belonged to family Anguillidae, Pristolepidae, Belonidae, Claridae, Gobiidae, Nandidiae, Hemirhamphidae, Cyprinodontidae, Synbranchidae, Chacidae, Mugilidae, Ophichthidae and Heteropneustidae. Based on their abundance during the study period these indigenous species are categories into 5 types. Forty (40) species were not threatened, 12 were vulnerable, 20 were endangered, 10 were critically endangered and finally 6 species were treated as data deficient species Keywords: Biodiversity, Species composition and Conservation. INTRODUCTION Bangladesh is well known as the land of rivers where it bears a huge potential for fisheries sector. This fisheries sector has an important and potential contribution in the agro-based economic development (5- 6% in GDP), poverty alleviation, employment and supplying of animal protein (63%) and earning the foreign currency (DoF, 2005). Bangladesh is unique in having possibly the largest inland water resources with large rivers, their tributaries, canals, streams and beels. The country abounds in a large varieties of fish species that is 260 of fresh water fish species, 24 species that of prawns in Inland water bodies and 475 species of marine fish, 36 species of marine shrimps and 12 species of exotic fishes (DoF, 2005). Although, it is clear that the Inland water resources in the main source of fish production but unfortunately the total open water production is coming in a fixed cycle with the continuous decreasing of most common fish species. The people of Bangladesh are commonly referred to as Macche-Bhate Bangali (i.e., the people made of fish and rice) (Ahmed and Garnett, 2011), but now it is a rare talk. The fact is the unconsciousness for the open water fisheries has brought the poor situation of many delicious and nutritious fish species. In this context, it is highly essential to measure the fisheries diversity of the open water. Sylhet is located within the region where there are hills and basins which constitute one of the most distinctive regions in Bangladesh. Greater Sylhet is enriched with fisheries resources. It has a large open water bodies among them different rivers, haor and beels are most important. There are 197 haors in greater Sylhet region which covers 1384 sq km. Among them 42 haors are only in Sylhet district which covers an area of 101843.3 hectare (BBS, 2005). These hoar already kept the great attention in Govt., biologist, tourists as well as international scientists. These haor plays an important role in fish production and some of these are functions as a 'mother fishery' for the 1 Department of Aquaculture, Faculty of Fisheries, 2 Department of Fisheries Biology and Genetics, Faculty of Fisheries, Sylhet Agricultural University, Sylhet-3100, 3 Department of Agricultural Extension Education, Bangladesh Agricultural University, Mymensingh- 2202 and 4 Department of Fisheries Technology and Resource Utilization, Faculty of Fisheries, Sylhet Agricultural University, Sylhet-3100, Bangladesh. *Corresponding author’s Email: fishsakhawat@yahoo.com