Fertility and food biology of Hemichromis fasciatus Peters: 1857 (Perciformes, Cichlidae) in the lower zone of the Tshopo river in Kisangani (Democratic Republic of the Congo)

This article analyzes the fertility and food biology of H. fasciatus Peters, 1857 from the lower zone of the Tshopo river in Kisangani (DR Congo) so as to highlight, on the one hand, the fertility rate of this species, the length-weight relationship and the growth of gonads during the reproductive cycle at all the sites considered; on the other hand, determine the quality and quantity of the diet of this species according to size and sex. Sampling took place in November 2016, and from March 2017 to May 2018 In total, 100 specimens (85 upstream and 15 downstream of the hydroelectric dam) of size varying between 55.7-188.8 cm were captured at using two batteries of eight monofilament gillnets of 8, 10, 12, 15, 20, 25, 30 and mm between nodes. Analysis of the results obtained leads to the conclusion that the H. fasciatus species from the Tshopo River is invertivorous (intestinal coefficient = 0.46) with an opportunistic tendency, feeding mainly on animal and plant debris. This diet varied according to the sampling sites, the season, the sex and the stage of development of the individuals examined. The evolution of the gonado-somatic ratio upstream of the hydroelectric dam of the Tshopo river showed a peak for females 3.45 (n = 46) and for males 0.66 (n = 39); and downstream a peak is observed in females 5.86 (n = 8) and for males 0.52 (n = 7). The estimated absolute fertility ranged from 506 to 1,430 oocytes with an average of 817.18 oocytes and the relative fertility ranged from 20,440.95 to 131,433.82 kg-1 oocytes with an average of 48,932.30 kg-1.