RELATIONSHIP BETWEEN FECUNDITY AND BIOMETRIC INDICES OF THE SILVER CATFISH Chrysichthys nigrodigitatus (Lacepede) IN THE CROSS RIVER ESTUARY, NIGERIA

Abstract

The relationship between fecundity and biometric parameters of silver catfish, Chrysichthys nigrodigitatus from the Cross River estuary was studied between July and October 2012. A total of 120 gravid female fish were examined. The results show that fecundity of C. nigrodigitatus ranged between 975 eggs for fish of total length 23.2 cm, total weight 99 g, ovary weight 15 g and mean egg diameter 2.43 mm to 11,280 eggs for fish of total length 50.0 cm, total weight 1420.0 g, ovary weight 80.0 g and mean egg diameter 3.44 mm. There was a positive significant relationship between fecundity (F) and total length (TL), total weight (TW), ovary weight (OW) and mean egg diameter (MED) as follows: F = 2.457TL1.9225 (r = 0.8457 and r2 = 0.7152, P<0.05), F = 61.51TW0.6098 (r = 0.890, r2 = 0.7921, P<0.05), F = 28.162OW1.2468 (r = 0.9457, r2 = 0.8943, P<0.05),F = 704.44MED1.0624 (r = 0.2128, r2 = 0.0453, P<0.05). Fecundity and mean egg diameter increases with total weight (TW). This finding is essential for evaluating the aquaculture strategies required to intensify commercial production and management of C. nigrodigitatus stock since it is a valuable source of protein in Nigeria.

Keywords

• fecundity
• c. nigrodigitatus
• cross river estuary
• biometric parameters
• ovary weight