An Evaluation of Hepatosomatic Index, Gonadosomatic Index and Fecundity of Mystus gulio

The Tengra fish, M. gulio, often known as "nona tengra" in the local region, is a small euryhaline catfish belonging to the Bagridae family. It is generally referred to as the long-whiskered catfish and is commonly found in the coastal waters of Bangladesh and India. The tengra fish (Mystus gulio) is an important commercial species found in the coastal regions of West Bengal, India and Bangladesh. M. gulio is an important species within its ecosystem and has significance in local fisheries. Its adaptability to both freshwater and brackish environments makes it a resilient species. This study investigated the hepatosomatic index (HSI), gonadosomatic index (GSI), and fecundity of M. gulio to better understand its reproductive biology. Specimens were collected monthly from the Meghna River estuary between February and June 2023. The GSI was found to be highest in August (9.95±0.15%), indicating the peak spawning season. The hepatosomatic index (HSI) was computed to investigate the relationship between its fluctuations and the gonadosomatic index (GSI). The HSI showed an inverse relationship with GSI, being lowest in March. Fecundity ranged from 88,495 to 264,104 eggs, with a mean of 171,581±17,855. Fecundity was positively correlated with total length, body weight, and gonad weight. Statistical analysis revealed significant differences in GSI and HSI between sexes and age groups (virgin vs 1+ year). Regression models showed that fecundity was highly dependent on gonad weight (r2=0.809) compared to length (r2=0.047) and weight (r2=0.216). M. gulio is an important brackish water fish with good taste and nutritional value. While it is optimally exploited from the East Coast of India, its cultural potential is being explored through polyculture experiments and research on seed production and farming techniques. These findings provide valuable insights into the reproductive dynamics of M. gulio and can inform management strategies for sustainable fisheries. In conclusion, this study focuses on the statistical association and analysis of the hepatosomatic index (HSI), gonadosomatic index (GSI), and fecundity of tengra fish. The GSI and HSI readings are crucial for comprehending the reproductive and nutritional condition of Tengra fish. However, further research is needed to fully understand the reproductive biology of this catfish across its range to inform sustainable management strategies.