Length-weight relationships of some fish species from the Bandiala River in Saloum Delta, Senegal

This study describes the length-weight relationships (LWRs) of some fish species of ecological and economic importance found in Saloum Delta area, Senegal (October - December 2014). Specimens were caught with gillnets with one mesh size (36). They were sorted to the lowest taxonomy level and identified using identification manuals. The morphometric data such as fish’s total length (TL) was determined using measuring board and measuring total weight (TW) from a digital balance to an accuracy of 0.01 g. The growth coefficients of the LWRs were determined using Microsoft office Excel software. The fish assemblages consisted of 3684 individuals belonging to 15 families, 22 genera and 31 species of freshwater and marine origins. The fish size varied between 9.7 cm TL in Gerres nigri and 67.3 cm TL in Strongylura senegalensis and the weight ranged from 10.9 g TW for Gerres nigri to 578.3 g TW for Ephippion guttifer. The allometric coefficient b ranged from 1.23 (Trachurus trecae) to 3.60 (Pseudotolithus typus). The thirty (30) species exhibited allometric (b < 3 < b) and one (1) isometric (b = 3) growth patterns. These values of “b” shows that most of the fishes collected from the Saloum Delta area displayed negative allometric growth pattern. The results further indicated that LWRs were highly correlated (r2 > 0.92; p = 0.001). There were variations in the species morphometry. This information provides important tool in fishery management and modeling of aquatic ecosystem.