Daget (1949a; 1949b; 1954; 1956; 1957; 1959; 1961a; 1962), Blanc, Daget and d'Aubenton (1955) and Monod (1945, 1949) have reported extensively on Tilapia sampled from the Central Niger River delta near Timbuktu in Mali. Species reported as occurring include Tilapia galilaea, T. nilotica, T. melanopleura, T. heudelotii, T. monodi, and T. zillii. Daget and Stauch (1963) record T. galilaea, T. nilotica, T. monodi, T. zillii and T. melanopleura from the Cameroun section of the Benue River. Among these identifications, Thys van den Audenaerde (1968a) verifies those of T. galilaea, T. nilotica and T. zillii but indicates that T. monodi and T. heudelotii are mistaken for T. aurea. and that T. melanopleura is in several cases an unspecified Tilapia and in some oases may be this or T.zillii. Holden (1963) records T. galilaea, T. nilotica, T. zillii and an unidentified Tilapia from the Sokoto River, tributary to the Niger River in northern Nigeria. Leger and Leger (1914) as recorded in Thys van den Audenaerde (1968a) report T. lata from the Niger, probably Mistaken for T. Zillii.
Boeseman (1963) identified two Tilapia spp. collected from the Niger River delta mouth as T. melanopleura and T. heudelotii. Thys van den Audenaerde (1968a) corrects these to be T. guineensis and T. melanotheron respectively. Boulenger (1902a, 1902b) as reported in Thys van den Audenaerde (1968a) records T. mariae, T. lata, T. nilotica and T. galilaea from the Niger River delta; Thys van den Audenaerde indicates the identity of T. lata reported to be T. guineensis. Burchard (1967) reports T. mariae as occurring in clear water streams tributary to the Niger at least as far upstream as Lokoja.
Various preimpoundment surveys connected with the proposed Kainji Dam (Daget, 1961b; Banks, Holden and McConnell, 1966; FAO, 1970a; Motwani and Kanwai. 1970) report T. galilaea, T. nilotica, T. zillii, T. monodi and T. melanopleura as present in the Niger River. McConnell (1966) indicates that these are the species likely to occur in the proposed impoundment. Thys van den Audenaerde (1968a) corrects the identification by Daget (1961b) of T. monodi as T. aurea and T. melanopleura as an unnamed Tilapia.
Investigations of Tilapia in Kainjii Lake since filling (FAO, 1970b; FAO, 1972; Ita, 1972) have reported the presence of four species only: T. galilaea, T. nilotica, T. zillii, and T, melanopleura.
Trewavas (1966) describes the differences between T. aurea and T. nilotica, and concludes that T. aurea “… was recognized in the Middle Niger by Daget as T.monodi in 1954 …” T, aurea to date has not been positively recorded in Kainji Lake since its filling, although Dr. D. Lewis (personal communication) tentatively identified a T. monodi in 1970 which may have been T. aurea.
The four Tilapias presently recognized in Kainji Lake include T. galilaea, T. nilotica, T. zillii, and T. dageti. Two specimens of the latter have been identified by Dr. E, Trewavas (personal communication). T. dageti has hitherto been referred to as T. melanopleura in the papers of Daget; the type specimen of T. melanopleura is apparently T. zillii and the name is no longer valid (Thys van den Audenaerde, 1968b). T. dageti is now the unnamed Tilapia noted noted by Thys van den Audenaerde (1968a) as being confused as T. melanopleura in the Niger drainage.
A total of 12 species of Tilapia have been reported from the Niger river drainage by various authors (and one personal communication). Of these eight appear to be valid records, including T. guineensis. T. melanotheron, T. mariae. T. aurea. T. galilaea, T. nilotica. T. zillii, and T. dageti. The last four have been recorded from Kainji Lake.
