Fecundity and Gonadal Development of the Frillfin Goby, Bathygobius soporator (Valenciennes, 1837) from the Cross River Estuary, Nigeria

Abstract

Fecundity and gonadal development of the Frillfin Goby, Bathygobius soporator from the Cross River Estuary, Nigeria was studied from July 2012 to June 2013. A total of 210 gravid female fish were examined during this period. The results show that fecundity ranged between 5462 eggs for fish of Total Length (TL-cm) 12.4cm, Total Weight (TW-g) 25.0g, Gonad Weight (GW-g) 0.5g, and Mean Egg Diameter (MED-mm) 0.45mm to 63250 eggs for fish of Total Length (TL-cm) 12.9cm, Total Weight (TW-g) 45.0g, Gonad Weight (GW-g) 3.0g, and Mean Egg Diameter (MED-mm) 0.44mm. Gonadosomatic index (GSI) ranged between 1.22% for fish of Total Length (TL-cm) 14.4cm, Total Weight (TW-g) 41.0g and Gonad Weight (GW-g) 0.5g 13.48% for fish of Total Length (TL-cm) 12.3cm, Total Weight (TW-g) 23.0g and Gonad Weight (GW-g) 3.1g. there was a positive significant relationship between fecundity and Total length, total weight, Gonad weight and a positive non-significant relationship between fecundity and mean egg diameter as follows: F = 856.6TL1.1654 (r = 0.2938 and r2 = 0.0863, P<0.05), F = 4587.1TW1.1654 (r = 0.2960 and r2 = 0.0876, P<0.05), F = 13863MED1.1654 (r = 0.010 and r2 = 0.0001, P>0.05) and F = 13863MED1.1654 (r = 0.010 and r2 = 0.0001, P>0.05). Histological sections of the ovaries of B. soporator showed six stages of oocyte development (virgin, maturing virgin, developing, ripened, spawning and spent). This finding is useful in formulating management strategies for B. soporator fishery which is a valuable fish in the Cross River estuary.