Assessment of size structures, length-weight models and condition factors of Eleotridae (Pisces: Perciformes: Gobiodei) from the coastal waters of Benin (West Africa)

Abstract

The Eleotridae is one of the fish family widely distributed in the Benin coastal waters where the species constitute an important component of artisanal fisheries. The current study evaluates length frequency distributions, length-weight models and condition factors of Eleotrid fishes in order to assess their wellbeing in the degrading coastal waters of Benin. Fish samplings were made during eighteen (18) consecutive months and morphometric data were recorded and analyzed using SPSS computer software. Larger Eleotrids were Eleotris vittata, E. senegalensis, E. daganensis and Bostrychus africanus while Dormitator lebretonis, the most abundant species displayed small sizes (standard length) ranging between 1.2 - 11.30 cm. Overall, all the species showed unimodal size distributions except Eleotris daganensis that exhibited a bimodal size distribution in Lake Nokoué. Length-weight models showed allometric growth with slopes b ranging between 2.4725 and 3.7296 along with significant correlation coefficients (r) varying between 0.7695 and 0.9965. Condition factors (K) varied significantly across the four (4) coastal waters and ranged between 0.79 (Dormitator lebretonis) and 3.60 (Eleotris daganensis). The sustainable exploitation of Eleotrid fishes in the Benin coastal waters requires a holistic approach of ecosystem management including ecological follow-up, habitat restauration and species valorization.