International Journal of Fisheries and Aquatic Research

Authors
Mahunan Tobias Césaire Azon, Diane Nathalie Kpogue, Juste Vital Vodounnou, Edmond Sossoukpe, Emile Didier Fiogbe

Abstract
Parachanna obscura is a fresh water teleost that presents some difficulties in sex identification. The current study aims to evaluate the sexual dimorphism in specimens of P. obscura of Lake Nokoué (Benin) through morphometric parameters, particularly the technic of Sexual Dimorphism Coefficient (SDC). This evaluation has been carried out based on parameters such as total length (TL), standard length (SL), tail length (TaL), weight (W), body circumference (BC), head length (HL), head circumference (HC), eye diameter (ED), length of the dorsal fin (L. Dors.) and the length of the anal fin (L. An.). Our results showed that mean and range values of the different parameters measured didn’t vary significantly (p ≥ 0.05) in males and females of P. obscura. The SDC₁ varied from 0.16 to 0.23 though SDC₂ varied from 0.34 to 0.48 all sexes included. Comparison of SDC values to standard values (0.20 for SDC₁ and 0.40 for SDC₂) has revealed significant differences (p ≤ 0.05). Results also showed that 68.42% of males of P. obscura were characterized by SDC₁ ≥ 0.20 and 69.7% of females by SDC₁ ˂ 0.20. By the same way, 73.68% of males of P. obscura have SDC₂ ˂ 0.40 though 60.60% of females were characterized by SDC₂ ≥ 0.40.