Temporal variation of growth pattern and physiological status of hilsa shad, Tenualosa ilisha (hamilton, 1822) in the meghna river (Bangladesh)

Abstract

The current study was conducted on the temporal variation of the growth pattern and the physiological status of Tenualosa ilisha (Hamilton, 1822) from the Meghna River, Bangladesh for the period of July 2018 to June 2019. A sum of 1433 individuals were collected, where its body weight (BW), total length (TL), standard length (SL) and fork length (FL) were measured with 0.01 g and 0.01 cm accuracy. The growth pattern was estimated through length-weight relationship by the equation: BW = a×TLb, where BW was in g and TL in cm. The parameters a and b were estimated with linear regression analyses. Physiological status was determined using equation provided as follows: ā = W/Lb. If ā was close to the a value (a, LWR parameter) then the fish was in an ideal condition, where ā > a pointed to fatty fish and ā < a to lean fish. The TL ranged from 15.3cm to 57.8 cm while the BW was from 37.17-2250 g. The overall growth pattern for T. ilisha was positive allometric (b = 3.135) in the Meghna River. The maximum fatty fish was found in the month of December (44%) while the minimum was in October. The highest percentage of lean fish was found in the monthof February (41%) and the lowest was in September (22%). The present findings would add some beneficial data for consumer preference, meanwhile further studies are recommended to achieve a sustainable management of hilsa fishery and other water bodies in the Meghna River.