Ichthyofauna of Okpara Stream, a Tributary of Oueme River, Benin, West-Africa

Abstract

In tropical Africa, and particularly in Benin, running waters dwell a high and valuable fish fauna that are almost unknown, but under severe degradation. The current study inventoried the fish biodiversity of the Okpara stream, the main tributary of the Oueme River (the largest in Benin), in order to fill the gap of ichthyological data and to improve habitat protection, species conservation and valorization. During 18 months, fish samplings were made monthly with various fishing gears on five (5) locations. A total of 53 fish species belonging to 30 genera, 14 families and 7 orders were recorded among a total of 9552 individual fish collected. The most representative families were Mormyridae with 9 species and Cichlidae with 8 species, then follow Mockokidae, Clariidae, Cyprinidae and Alestidae with 6, 6, 6, 4 species, respectively. Families such as Anabantidae, Bagridae, Claroteidae, Malapteruridae, Polypteridae and Schilbeidae were less represented and individually included 2 species. The Hepsetidae and Aplocheilidae were represented by one (1) species, respectively the African pike, Hepsetus odoe and Epiplatys bifasciatus. A holistic scheme of ecosystem management and species conservation requires a complete knowledge on the fish community structure, ecotoxicology and species ecological status.

Aspects of life history patterns of the cichlid fish Hemichromis fasciatus Peters, 1857 from Okpara Stream, Northern Benin, West Africa

“…Dissolved oxygen concentrations ranged between 0.44 and 5.66 mg/l and the percentages of saturation were moderate to low and varied from 6.37 to 75.3%. The water was acid or alkaline with pHs ranging between 6.4 to 8.1 (Sidi Imorou et al, 2019a). As results, and based on the physicochemical features recorded, the Okpara stream is relatively suitable for a high primary production and the prominence of the fish fauna.…”

“…Site 5 is also located around Okpara downstream at Sui village (Tchaourou Township). At the five collecting sites, samplings were done in the "aquatic vegetation habitat" at the edge of the stream and in the "open water habitat" exempt of vegetation, but characterized by a relatively high depth (Sidi Imorou et al, 2019a). Okpara Stream displayed a relatively adequate water quality with moderate temperatures ranging between 25 to 30.1°C, depths between 17 to 1080 cm and low transparencies varying between 10 and 78.1 cm.…”

“…Hemichromis fasciatus (Actinopterygii: Perciformes: Cichlidae) is a widespread African piscivorous cichlid dwelling most inland waters such as freshwater lakes, brackish waters, estuaries, rivers, streams floodplains etc. because of its high tolerance to environmental conditions (Leveque and , Kuela 2002, Paugy et al, 2003, Kantoussan 2007, Montchowui et al, 2007Sidi Imorou et al, 2019a. Like most African cichlids and despite its reduced abundance, the species showed great fisheries importance in the most water bodies.…”

“…In Benin, H. fasciatus is common and was recorded in almost all water bodies and running waters where this piscivorous cichlid showed reduced abundances varying between 0.37% and 6% of the fish community, but constituted an important fisheries resource (Jackson et al, 2013;Montchowui et al, 2007). However, recent fisheries survey by Sidi Imorou et al (2019a) in the Okpara stream (North Benin), a tributary of the Oueme River indicated that H. fasciatus dominated this stream making numerically 29.49% of the fish assemblages. Consequently, in the Okpara Stream, the species is intensively exploited and thus, displayed high commercial and economic values in this northern running water.…”

African Arowana Genome Provides Insights on Ancient Teleost Evolution

“…African arowana (or African bonytongue, Heterotis niloticus), pirarucu (Arapaima gigas), and Asian arowana (Scleropages formosus) are three representative species of Osteoglossidae in Osteoglossiformes with some morphological differences (Adite et al, 2017;Axelrod et al, 1986;saint-Paul, 1986). African arowana is the only omnivore in Osteoglossiformes (Adite et al, 2013;Oliveira et al, 2019), distributing majorly in Africa, compared to pirarucu mainly in South America and Asian arowana in Southeast Asia.…”