Fecundity, maturation and spawning frequency of Mormyrus rume (Cuvier And Valenciennes, 1894) from Epe Lagoon, Nigeria

This study aims at studying its reproductive biology of Mormyrus rume using Epe Lagoon as a case study during the period of August 2014 to July 2016. A total of 867 specimens were collected using gill and cast net. Standard techniques were used in the analysis of sex ratio, total length (TL), gonad weight (GW), body weight (BW), fecundity, stages of maturation and gonadosomatic index on the fish species. Sex ratio of 1 male to 1.13 females was observed. Six stages of maturity: Immature, resting, maturing, ripe, spawning and spent were observed in this study. The immature fishes occurred mostly in October to March and the spawning stage occurred mostly from May to August. Egg size ranged from 0.3mm to 1.86mm Fecundity estimates for this species ranged from 4,211 to 31,499 eggs and the gonadosomatic index ranged from 8.85% to 104% meaning a high percentage of fish body mass was converted to gonads for reproduction. It was observed that spawning was not synchronized in the fish species. Therefore this study provides information on some aspects of the reproductive biology of this commercially important fish species in Epe Lagoon for its optimum utilization, conservation and potential for aquaculture.