Collection, preservation, and identification of freshwater fish species in middle to north-east Bangladesh with special notes on phenotypic plasticity of few species

Abstract

A checklist of 110 species of fishes belonging to 10 orders, 31 families and 78 genera was recorded with their scientific, common and Bangla or local names. These fish specimens were collected from the rivers, beels, haors, ponds and swamps of middle to North-east Bangladesh (Jamalpur, Netrokona, Kishorganj, Munshiganj and Bogra Districts). The order Cypriniformes (37%) was recorded higher followed by Perciformes (24%), Siluriformes (23%), Clupeiformes (6%). The global and national IUCN categories of these species are also provided. Based on local IUCN criteria, around 23% fish species belongs to threatened level and 5, 8 and 10% are denoted as critically endangered (CR), endangered (EN) and vulnerable (VU), respectively. Although collection and preservation is comparatively hassle-free, however, due to mingle nature of few fish species; it seems difficult to error free identification of the collected fishes by morphological traits alone. Two individuals from Sanondabari, Jamalpur (MHBSFMSTU Fish 92 and Ghaglajur Bazar, Netrokona (MHBSFMSTU Fish 84), morphologically very similar but they are completely two separated species i.e. Gagata cenia and G. youssoufi, respectively. Phenotypic plasticity is a barrier to name the fish species accurately, suggesting the presence of putative candidate species or existence of hidden diversity in the collected specimens of Sisoridae family. Due to anthropological effects, the biodiversity and fishing grounds are losing their qualities, resulting the low number of freshwater fish species in these sampling sites. The systematic, ecology, distribution, habitats of these fish fauna need to be studied exclusively and a well-planned conservation strategy need to implement as early as possible for protecting our valuable freshwater tasty fishes. Further, the output of the current study will also guide the government and non-government organization to come forward and take necessary measure for the betterment of the country, its economy, and fisheries resources.