The Cichlidae Fishes of Otamiri River, Imo State Nigeria: A Model System of Adaptation Evolution

The adaptative evolutionary trend of the fishes – Cichlidae was evaluated using the body morphometric, the feeding ecology and environmental factors controlling the distribution of the fishes in Otamiri River, Imo State in relation to the growth biology and adaptation to aquatic life were studied between February and April 2021. Two hundred and twenty-two (220) samples were collected and identified. The fish identified were Tilapia zilli, Tilapia mariae, Oreochromis niloticus, Tilapia guineensis, Sarotherodon melanotheron, Pehiachromis taeniatus,Tilapia aurea, Tilapia melaontheron, Sarotherodan galibeeas,Tilapiadigati, Hemicronus fasciatus, Hemicronus elongates. The standard length felled between the range of 13.35cm and 16.40cm, average of 14.55 cm. Body weight between153.00g and 168.50g, average of 163.76g. Length ratio ranged between 1.1:1 to 10.20:1 which showed omnivorosity. The fishes fed mainly on detritus and plant materials. Detritus constituted about 23%, Spirogyra 7%, Diatoms 10%, higher plant materials about 17% and unidentified 17%. The fishes are omnivorous feeders and with availability of food and nutrient the fishes display sustenance growth and abundant fishery production in Otamiri River. Keywords: Species, Cichliformes, Mouth-brooding, Egg, Frys