Alien Fish Species in the Mbô Floodplain Rivers in Cameroon

Abstract

The aim of this study was to identify different alien fish species introduced in the Mbô Floodplain (MF) Rivers in Cameroon and to study their life-history traits. For this purpose, a total number of 237 fishes with a total length (TL) of 24.50 ± 5.97 cm and total weight of 199.50 ± 106.78 g collected by traditional fishing gears were used for taxonomic identification. Four species grouped into three families were identified : Clariidae ( Clarias gariepinus ), Cichlidae ( Oreochromis niloticus and Tilapia cameronensis ), and Channidae ( Parachanna obscura ). There are two types of fish introduction: accidental introduction and intentional transfer. All fish species collected and examined were of large sizes (TL > 25 cm). The regression coefficient b of the length-weight relationship ranged from 3.00 ( C. gariepinus ) to 3.37 ( T. cameronensis ) (3.18 ± 0.17). Fish species showed a monthly and seasonal fluctuation in abundance in number of individuals. Alien fish species in the Mbô Floodplain showed two types of somatic growth: isometric and positive allometric. 75% of overall alien fish species were established and they recorded a mean K factor of 0.70 ± 0.40. Only 25.00% of the sampled species had more females than males.