Growth Condition, Length-Weight Relationship and Morphological Diversity of Sarotherodon melanotheron and Tilapia guineensis inhabiting the Coastal Waters of Ondo State, Nigeria

Abstract

Sarotherodon melanotheron and Tilapia guineensis were studied in Mahin Lagoon and Idiogba in the coastal waters of Ondo State to determine their sizes, length-weight relationships, and condition factors. The mean total length and weight for S. melanotheron were 13.35±1.66 cm and 48.41±20.89 g in Mahin, and 13.44±1.72 cm and 49.96±20.80 g in Idiogba, respectively. Meanwhile, the values recorded for T. guineensis were 16.06±4.83 cm and 104.81±107.94 g in Mahin, and 15.00±3.74 cm and 78.98±81.51 g in Idiogba. This morphological similarity revealed an overlap of data between the populations of the two species in Mahin Lagoon and Idiogba. The regression coefficient (b) of length and weight revealed that S. melanotheron exhibited hypoallometry (b=2.55; a=-2.76; R2=0.78) in Mahin and (b=2.31; a=-2.13; R2=0.78) in Idiogba, while T. guineensis exhibited hyperallometry (b=3.04; a=-4.06; R2=0.96) in Mahin and (b=3.05; a=-4.11; R2=0.92) in Idiogba. The condition factor was greater than 2 for both species, although it was higher in T. guineensis (K=2.53 in Mahin and K=2.34 in Idiogba) than in S. melanotheron (K=2.04 in Mahin and K=2.06 in Idiogba). Therefore, this study revealed that both species were very fat and healthy despite anthropogenic activities in the study area.