Length-Weight Relationship and Condition Factor of African Mud Catfish (Clarias gariepinus (Burchell 1822) and Tilapia (Oreochromis nilotica Linnaeus 1758) in Orashi River of Ogba/Egbema/Ndoni Lga of Rivers State, Nigeria

Abstract

Length-weight relationship and condition factor are important in fishery assessment studies since it provide information about the growth of the fish, its general wellbeing and fitness in aquatic habitat. LWRs for 2 fish species –Clarias gariepinus (Burchell 1822) and Oreochromis nilotica (Linnaeus 1758) collected from Orashi River were established and their growth condition was evaluated. The study was carried out from September 2019 to August 2020. The biometric measurement (length/weight) shows that the weight of the fish increased in proportion to its length as indicated by the slope (b) of the relationship.  The mean value shows strong relationship because coefficient of determination (R2) is >0.5 and range from 0.795-0.985. Higher values of both length and weight were recorded for Catfish over Tilapia. The results indicated that almost all the fish sampled exhibited a positive allometric growth and trended to grow bigger. All relationship were statistically significant (p=0.05). The mean Fulton’s condition factor (K) of the fish range from Catfish (1.24-1.80) and Tilapia (1.5-3.7) in the 5 stations sampled. The result showed that Tilapia had a high mean range and therefore was in better conditions than the Catfish. This gives information on the food supply, timing and duration of breeding cycle. The indices may also be used in the general assessment of the “well being” of a fish [1]. Multiple comparison tests using Turkey Kramer showed that the condition factor of Catfish from Okwuzi (station 1) was significantly different from that of Ndoni and Omoku but Ebocha and Obrikom was not significantly different from each other. With regards to seasonal variation, dry season recorded higher values than rainy season.