The Length-Weight Relationship (LWR), Condition factor (K) and feeding habits of Synodontis clarias (Linnaeus, 1758) were investigated over a 24 month period from January, 2009 - December, 2010. A total number of 163 specimens comprising of 74 females and 89 males with the size range of 7.60 – 20.00cm and the mean of 12.72± 0.258cm were investigated. The weight ranged from 13.12 – 607.30g with the mean of 65.83± 0.897g. The LWRs for the females, males and combined sexes had the r values of 0. 8415, 0.9463 and 0.8703 respectively. The mean condition factor K was 3.3667, 2.6868 and 2.9954 for the females, males and combined sexes respectively. The regression coefficient b was 1.9408, 1.8799 and 2.1359 for the females, males and combined sexes respectively indicating negative allometric growth pattern for the species. Out of the 163 stomachs examined for food items, 88 (53.99%) were empty while 75 (46.01%) contained a wide range and varying quantities of food items indicating that S.clarias in River Benue is omnivorous.

The growth parameters and mortalities of five species of Synodontis in the lower river Benue at Makurdi, Benue State were studied from January,2016 to December, 2018. The asymptotic length (L∞) calculated for the five species ranged from 18.80cm in S.clarias females to 37.04cm in S.membranaceus females. The t0 values were all negative in the combined sexes of S.clarias, S.omias, S.gambiensis and S.membranaceus. In both combined sexes of S.membranaceus and S.schall, the t0 values were positive. The growth rate (K) was low in S.clarias and S.omias (0.301- 0.497, 0.171 - 0.310) respectively and higher in S.membranaceus (0.310 - 0.640), S.schall females (0.430 - 0.580); S.schall males (0.573),S.gambiensis (0.500 - 0.571). Growth performance index (Ø’) was 2.212 in S.gambiensis and 2.946 in S.schall combined. Natural Mortality (M) ranged from 0.5422 in S.omias females to 1.3340 in S.membranaceus males. Fishing Mortality (F) was 0.8214 in S.omias combined and 3.0934 in S.membranaceus females. Total mortality (Z) ranged from 1.52 in S.omias combined to 4.078 in S.membranaceus combined. Mean Exploitation (E) ratios was 0.61 in S.clarias, 0.64 in S.omias, 0.53 in S.gambiences, 0.70 in S.membranaceus, and 0.66 in S.schall. The rate at which these species survived in the River was low (from 0.147, in S.omias combined, to 1.482 in S.membranaceus combined).