Fungi associated with post-harvest deterioration of dried <i>Clarias gariepinus</i> vended in some markets in Uyo, Akwa Ibom state, Nigeria

Abstract

Mycoflora of dried Clarias gariepinus (Burchell, 1822) were studied on samples obtained from Afaha, Okpokpo and Itam markets in Uyo, Akwa Ibom State using standard methods. Potato dextrose agar was used for isolation process. This was done twice (first and seventh day). Fungi were identified according to their macroscopic and microscopic characteristics. Results revealed that fish samples from okpokpo market contained highest number (10) of fungal isolates while samples from Afaha and Itam markets recorded seven each. Species of Aspergillus, Fusarium, Candida, Epicoccum, Rhizopus, Absidia, Penicillium, Trichoderma, Mucor, Cladosporium and Alternaria were isolated. The most commonly isolated fungi were Aspergillus flavus, Aspergillus niger, Fusarium sp. and Rhizopus sp. The least isolated fungi from Afaha market were A. glaucus (10.0% and 13.1%) and Fusaruim sp. (5.5% and 15.3%) while Okpokpo market Penicillium was the least at 13.2% and 22.5% at initial and final isolation respectively. The highest frequencies of occurrence were: Afaha market, Rhizopus sp. (45.4%); Okpokpo market, A. flavus (56.1%) and Itam market, Alternaria sp. at 46.65%. Generally, incidence of A. flavus was highest and samples from Okpokpo market recorded highest frequency of occurrence of fungi at final isolation. This high frequency of occurrence of these fungi revealed reduction in value of dried catfish, subsequent spoilage and increase in economic loss.

Key Words: Mycoflora, isolation, fungi, Fusarium, C. gariepinus