Length–weight Relationship and Relative Condition Factor of the Minor Carp Labeo gonius (Hamilton, 1822) from the Burhi Gandak River, Bihar, India

The present study evaluated the length–weight relationship (LWR) and relative condition factor (Kn) of minor carp Labeo gonius (Hamilton, 1822) from the Burhi Gandak River, Bihar, India, to assess its growth pattern and physiological condition. A total of 120 specimens were collected monthly from August 2022 to July 2023. The LWR was estimated using the length–weight relationship equation (W = aLᵇ). Males exhibited negative allometric growth (b = 2.4604; R² = 0.9704), whereas females showed positive allometric growth (b = 3.1808; R² = 0.962), due to reproductive development. The mean Kn values were 1.0083 for males and 1.0168 for females, indicating good physiological condition and favourable environmental conditions. The distribution of Kn across size classes suggested stable ecological parameters with minor variations linked to reproductive cycles. The findings provide baseline biometric data useful for fisheries management and conservation of this species in the Burhi Gandak River.