Current ichthyofaunal survey of Otamiri River, Imo State, Nigeria

Abstract

Study on the Ichthyofaunal composition of Otamiri River, Imo State was carried out from June 2016 to March 2017. A total of 2,453 fishes belonging to 5 orders, 18 families, 46 genera, and 79 species were sampled from 5 landing sites by artisanal fishermen using different fishing gears. Mormyridae had the highest percentage in terms of species (20.6%) while Pantodontidae had the least percentage (0.9%). Mormyridae also recorded the highest percentage weight (18.2%) while Pantodontidae had the least fish weight (0.2%). Mormyridae was the most abundant with 19 species and 505 samples. Pantodontidae, Gymnarchidae, Arapaimidae and Hepsetidae were the least families having a single species and 21, 34, 38 and 41 fish samples respectively. Hemichromis fasciatus was the most dominant fish species (2.5%) while Petrocephalus banebane was the least with 0.3%. Parachanna obscura had the highest index of preponderance value of 11.8% while Ctenopoma kingsleyae, Petrocephalus bane bane, Petrocephalus soudanensis, Pollimyrus isidori isidori, Bryconaethiops quiquesquamae and Rhabdalestes septentrionalis had the least value (0.1%). The values of Simpson dominant and index were 0.01 and 0.99 respectively. Monthly catch records revealed the highest fish catch in the month of January with 12.7% of total catch while the months of October and March had the least percentage at 7.8% each. Key Words: Ichthyofaunal, order, family, genera and species.