The Reproductive Biology of Auchenoglanis biscutatus and Protopterus annectens from Lower River Benue Wadata, Makurdi-Nigeria

Abstract

Data on the reproductive biology of Auchenoglanis biscutatus and Protopterus annectens were collected between april 2019 to march 2020. Reproductive parameters including sex ratio was determined as number of males by number of females, gonadosomatic index as total gonad weight by body weight and expressed in percentage while fecundity was obtained via volumetric and gravimetric methods. There was a slight dominance of males over females of both species (1.1:1) with more immature individuals caught within the study period. Higher GSI, gonad length and gonad weight (0.87±0.06, 15.94±0.89 and 3.01±0.19) were recorded in Auchenoglanis biscutatus during dry season while GSI and gonad weight (4.06±0.62, 5.63±0.45) of Protopterus annectens and number of mature fishes (0.35) were higher during rainy season. The relative fecundity for Auchenoglanis biscutatus investigated had no significant difference in both seasons (7.99±0.94, 8.22±0.78) while the relative fecundity for Protopterus annectentens  differed significantly among the wet and dry seasons (3.43±0.94, 0.48±0.22). The relative fecundity of Protopterus annectens (11.59±2.04) was higher than that of Auchenoglanis biscutatus (8.04±0.75).it was concluded that the study of the sex ratio indicates that males were higher than females.