Crossing, Sex reversal and reproductive capacity of two populations of Sarotherodon Melanotheron (Cichlidae) from the Central Region of Ghana

Abstract

The study investigated whether progeny of Sarotherodon melanotheron from two different populations would have higher reproductive capacity and also exhibit desirable aquaculture traits. Broodstock of S. melanotheron were collected from Kakum Estuary and Benya lagoon and bred to the second filial generation stage. Reproduction was higher in the parents from the Estuary than those from the lagoon. Water quality parameters were within the acceptable range for fish culture. Three different concentrations; 30, 60 and 120 mg/kg feed of 17 α-methyltestosterone and the control were administered for 30 days. Fry fed 120 mgMT/kg feed produced the highest proportion (92.70 %) of males which differsignificantly (F = 266.22, p < 0.05) from 30 mg MT/kg feed and the control but was not significantly different (p > 0.05) from 60 mg MT/kg feed. A positive linear correlation was found between fecundity and total length, body weight, and ovary weight of S. melanotheron from Fosu lagoon with ‘r’ values as 0.58, 0.61 and 0.52 respectively. Relationship between brood size and fish length as well as body weight was also linear with ‘r’ as 0.85 and 0.86 respectively. The overall results indicated that none of the male hormone concentrations produced 100 % males and that the anabolic effect of the hormone was not significant in the growth of S. melanotheron fry in all the treatments.