Determination of Length-Weight Relationship and Condition Factor of Labeo rohita in Jebba Lake, Niger State

Length-weight relationships and condition factor data for commercially harvested fish species are essential for fisheries stock assessment and management, yet such data for Labeo rohita in Jebba Lake, Niger State, North Central Nigeria, are not available in the recent literature. This study determines the length-weight relationship, condition factor, and basic population parameters of Labeo rohita sampled from artisanal fishers at three landing sites on Jebba Lake over four months. A total of 320 fish specimens were collected, measured to the nearest millimetre for total length, and weighed to the nearest gram. Length-weight relationship parameters (a and b) were estimated by log-log linear regression, and Fulton's condition factor was calculated for all specimens. The b-value computed from the length-weight regression was 2.94, indicating slight negative allometric growth, consistent with values reported for this species in comparable reservoir environments in West Africa. Condition factor values ranged from 0.88 to 1.23, with mean values significantly above unity, indicating generally good nutritional condition of the population. Sex-disaggregated analysis showed females to have slightly higher condition factors than males during the sampling period. Seasonal variation in condition factor was observed, with higher values recorded at the onset of the wet season. The data generated form a useful baseline for incorporating Labeo rohita into the stock assessment framework of the Jebba Lake fisheries under the Niger State Ministry of Agriculture and Rural Development.

Keywords: length-weight relationship, condition factor, Labeo rohita, Jebba Lake, Niger State