LENGTH-WEIGHT RELATIONSHIP AND CONDITION FACTOR OF FISH SPECIES IN ERO RESERVOIR, IKUN EKITI, NIGERIA

Reservoirs are one of the freshwater environments that support a diverse array of fish species, contributing to food security as a vital source of protein and economic sustenance. Understanding fish population dynamics, including the length-weight relationship, is crucial for effective sustainable fisheries management. Recently, limited studies have explored the growth patterns and health status of fish species in Ero Reservoir, despite its ecological and economic significance. This study investigated the length-weight relationship (LWR) and condition factor (K) of fish species in Ero Reservoir to assess their growth patterns, health status, and environmental adaptability. A total of 110 fish samples, representing seven species from four families, were collected using standard fishing techniques. Biometric parameters, including total length and body weight, were measured, and the LWR and condition factor were analyzed using established formulas. The results showed that Chrysichthys nigrodigitatus was the most abundant species (35.5% of the total catch), while Heterobranchus bidorsalis was the least abundant (2.7%). LWR analysis revealed that most species exhibited negative allometric growth (b < 3.0), indicating that length increased at a rate greater than weight. However, Clarias gariepinus displayed positive allometric growth (b = 6.98), suggesting rapid weight gain relative to length. The condition factor (K) varied among species, with Coptodon zilli exhibiting the highest mean K-value (1.64 ± 0.09), indicating good health. At the same time, Heterobranchus bidorsalis recorded the lowest K-value (0.34 ± 0.05), suggesting possible environmental stress or food limitations. These findings further indicate that the growth conditions of fish resources in the Reservoir vary with fish species, regardless of the Reservoir's environmental factors.