The African lung fish, Protopterus annectens from Agenebode, in the Lower River Niger was investigated for aspects of its biology. Samples of the fish were collected from October 2016 to November 2017. Sex ratio of 1:1.4 (male to females) was obtained from the river. The results from the stomach analyses revealed that P. annectens consumed mud, detritus and sand (100%). Bird's foot was regarded as incident diet (0.01%)while grass was also observed to be part of the relevant diet (7.1%) of the fish, an indication that it is an omnivore.The Gonadosomatic Index (GSI) ranged from 12.34 to 13.33. The peak of GSI were observed during the months of September, October and November, coinciding with the end of wet season. Highly fecund fish were also observed in the months of October and November and then a decline in December, again these months experienced decline in rainfall thus suggesting the end of spawning periods. The changes in GSI revealed that Protopterus annectens has specific maturing, spawning and breeding periods. Protopterus annectens was found to be highly fecund with eggs range from 72,275 to 129,732 (mean value of   92,116 ± 743 eggs). This study also revealed that fecundity was more relative to body weight than length of fish.