Life History Traits of Ambassidae Fish, Chanda nama (Hamilton, 1822) From the Old Brahmaputra River of Northeastern Bangladesh

The present study provides a comprehensive analysis of the population structure (length–frequency distributions), growth pattern (length–weight relationships [LWRs] and length–length relationships), physiological condition factors (allometric [K_A], Fulton's [K_F] and relative [K_R]), relative weight (W_R) and form factor (a_3.0) of Chanda nama. A total of 1200 specimens were collected from the Old Brahmaputra River, northeastern Bangladesh, for 12 months by traditional fishing gear, including seine net and cast net. The total length (TL) of several individuals varied from 2.3 to 7.2 cm. The highest percentage contributed to the population's 4.0–4.5-cm-sized group. The LWRs indicated a positive allometric growth pattern (b > 3.0). Fulton's condition factor significantly correlated with TL and body weight (p < 0.0001). The calculated W_R ranged from 67.38 to 137.64. No significant variations from 100 were found using the Wilcoxon rank test (p = 0.034), suggesting that C. nama might live there in a balanced predator–prey environment. Furthermore, the measured value for the form factor (a_3.0) was 0.0105. In addition, fish with a TL of 7–8 cm should be caught since they are in good condition and have enough meat. The study's findings will greatly contribute to the efficient and enduring management of C. nama in the Old Brahmaputra River and its adjacent ecosystems.