Length-weight relationship and relative condition factor of Bombay duck (Harpadon nehereus, Hamilton, 1822) from the north-east coast of India

Abstract

Harpadon nehereus (Hamilton, 1822), commonly known as Bombay ducks, were collected from the North-East Coast of India for 1-year period (2024-2025) to analyse their Length-Weight (L-W) relationship and the Relative Condition factors (Kn). A total of 217 specimens, 169 males and 48 females, were used for this study. The result showed isometric growth for both males, females, and for combined at a significant level of 5% (p>0.05). Therefore, it maintains the Cube’s Law. The linear regression model of L-W Relationship for combined [LogW=2.966332LogTL-2.35996, R2=0.725, r=0.852], for male [LogW=3.204787LogTL-2.65817, R2=0.768, r=0.876], for female [LogW=2.926169LogTL-2.33932, R2=0.644, r=0.802]. Relative Condition Factors (Kn) were also calculated, for combined Kn=1.110474± 1.129, for male Kn=1.11472±1.129, for female Kn=1.176585±1.214, indicating that the specimens belong to a moderate environmental condition, as all the Kn=1 (p>0.05). Sex ratio was obtained, Female/Male=0.284, (p<0.05); which was not equal to one. The total length range (17.7 - 19.3 cm) was predominantly observed among the analysed specimens.