International Research Journal of Biological Sciences ______ISSN 2278-3202 Vol. 7(7), 39-51, July (2018) Int. Res. J. Biological Sci.

Review Paper Review on freshwater fish diversity of Northern West , : status, threats and conservation measures Souraditya Chakraborty University of , Raja Rammohunpur, Dist Darjeeling, -734013, India [email protected] Available online at: www.isca.in, www.isca.me Received 3rd April 2018, revised 23 rd June 2018, accepted 5th July 2018

Abstract Fishes are the most diverse group of vertebrates and the most important aquatic fauna, directly or indirectly related to human well-being. West Bengal is a Nadimatrik state i.e., land nourished by rivers with a total freshwater area stretching about 272380 ha area. However, despite the huge water resource, the knowledge of fish diversity is very inadequate, especially in northern part of West Bengal, known as North Bengal. This dearth of information on ichthyofauna is a big obsta cle for promoting, resurrecting and conserving the fish variety present in the variety of freshwater habitats present here. This review is an attempt to provide a systematic catalog of fish species recorded so far in this area, along with thei r local names , economic importance and conservation status. Attempt has also been made to enlist the possible threats to survival of these fish varieties and their conservation strategies. As many as 177 species of freshwater fishes, belonging to 31 families have been found to be recorded in various freshwater habitats in this area.

Keywords : Fish, fresh water, fish diversity, North Bengal, ichthyofauna.

Introduction economic status and livelihood of local people depend largely on the diversity of fishes in these freshwater habitats. Fishes are the most important aquatic fauna which is directly related to human well-being. The diversity among fishes is very However, despite the huge water resource, the knowledge of 1 high and includes 33,900 species . The awareness of fish faunal fish diversity in this area is very inadequate and unorganized. diversity in tropical Asia is still in its primal phase notably in This lack of systematic information on the ichthyofauna in this 2 India where survey work is still fragmentary . region is a big obstacle for exploring the fish variety and strategizing any conservation mean. West Bengal is an eastern stat e of India having a total area of 88,551 square kilometers, ranging between the Himalayas in the The main objective of this review is to: i. highlight the rich north to the in the southern side. freshwater resource in North Bengal, the recently updated status of freshwater fish faunal diversity recorded, along with their West Bengal is traditionally referred to as Nadimatrik i.e., land local names and conservation status. ii. focus the local threats to nourished by rivers with a total freshwate r area stretching about fish diversity and iii. suggest some proposals for fish 3 332379 ha area . biodiversity management and conservation and in North Bengal.

The northern part of West Bengal, commonly called North These would definitely help in strategizing effective methods 0 0 0 0 Bengal, lies within 24 40'N/87 45'E to 27 03’N/88 26’E for their conservation, exploration, production, and exploitation including the districts of Darjeeling, Jalpaiguri, Alipurduar, in future. Coochbehar, North Dinajpur, South Dinajpur and Malda. This part of Bengal is unique as it bears a variety of freshwater District-Wise Freshwater Area in North Bengal habitats; some endowed with a huge amount of snow -fed water while others rain-fed and so on. Owing to the geographical and topographical differences, there is a huge variation in the extent of t he freshwater area in Documenting and characterizing different components of d