Publication Title : Resolution of Confusion of Two Major Clupeid Fishes from Bangladesh
Publicationed By : Motia Gulshan Ara
Publication Publication Date : 2014-12-10 00:00:00
Publication Online Link : https://www.researchgate.net/publication/328792654_Resolution_of_Confusion_of_Two_Major_Clupeid_Fishes_from_Bangladesh
Publication Description :
Hilsa shad, Tenualosa ilisha (Hamilton and Buchanan, 1822) and Indian River shad, Gudusia chapra (Hamilton and Buchanan, 1822) are two major clupeid ﬁsh species in Bangladesh. In spite of having enormous signiﬁcance of T. ilisha and G. chapra in ﬁsheries sector, these two clupeid ﬁsh species are under serious human exploitation for food, nutrition and income. The original concept and the principal impetus under the current study is that pre-juvenile hilsa shad (jatka) resemble Indian River shad (chapila) externally and this usually leads to social chaos which creates huge confusion and conﬂict. So to overcome this confusion, systematics study (morphometric measurements, meristic counts and external morphology) of hilsa shad and Indian river shad was conducted. Signiﬁcant differences were found between the systematics of hilsa shad and Indian River shad at one hand in the present study, and on the other, pre-juvenile hilsa shad (jatka) and Indian River shad were externally distinctly different. Pre-juvenile hilsa shad (jatka) differed morphmetrically from Indian river shad by having the ratios of ED: SL= 0.09 vs. 0.11, BD: SL= 0.32 vs. 0.33, HD: SL= 0.27 vs. 0.32, HL: SL=0.31 vs. 0.34, PvFL: SL= 0.50 vs. 0.52, ML: SL=0.14 vs. 0.16, and MW: SL= 0.04 vs. 0.06. Pre-juvenile hilsa shad (jatka) also differed meristically from Indian river shad by having dorsal ﬁn rays (18 to 19 vs. 14 to 16), pectoral ﬁn rays (15 to 16 vs. 12 to 14), anal ﬁn rays (20 to 24 vs. 22 to 24), caudal ﬁn rays (22 to 26 vs. 18 to 20), total number of scutes (30 to 31 vs. 28 to 29), pre-pelvic scutes (16 to 17 vs. 18 to 19), post-pelvic scutes (14 to 15 vs. 9 to 10), and vertebral segments (48 to 49 vs. 41 to 43). It was also found that pre-juvenile hilsa shad (jatka) differed externally from Indian river shad by having thicker body, big and upturned mouth, unequal jaws, homocercal caudal ﬁn and a number of small black spots (5-7) along the ﬂank behind gill opening. If these conﬂicts are solved then the ﬁshers will be unable to keep people in ﬁx by introducing jatka as chapila and the law enforcement authorities will be able to perform their duties properly without any confusion. By establishing the comparison key and making aware the fact of signiﬁcant differences between pre-juvenile hilsa shad (jatka) and Indian river shad, it will be possible to stop ﬁshers from catching and selling of prejuvenile hilsa shad (jatka). Through this the pre-juvenile hilsa shad (jatka) will be able to grow in, which ultimately sustain the total hilsa production in our country. Finally, the whole nation will be beneﬁted nutritionally as well as economically through sustaining hilsa population in Bangladesh waters.