A Comparative Study on the Length-Weight Relationships of Two Freshwater Fish Families, Nandidae and Channidae, from Kawadighi Haor in North-eastern Bangladesh

Abstract Length-weight relationships (LWRs) were determined for two fish species from the Kawadighi Haor, Moulvibazar District, Bangladesh. Fish specimens were collected across the Haor region from March to July 2024 using multi-mesh gill nets (approximately 1 cm) and conical and box-shaped traps. Additional specimens were obtained from local fish markets and small-scale fishermen in the Haor region. Statistical analysis was done by linear regression model and confidence interval using rstudio 4.3.2. The relationships between length and weight were found to fit well, with R² values of 0.931 for Nandus nandus and 0.708 for Channa punctatus. The b values of the LWR equations ranged from 2.976 for N. nandus to 3.231 for C. punctatus.