TILAPIA AUREA (STEINDACHNER) AND THE STATUS OF TILAPIA NILOTICA EXUL, T. MONODI AND T. LEMASSONI (PISCES, CICHLIDAE)

ABSTRACT

In West Africa from Senegal through the Middle Niger to the Chad basin, in the lower Nile and in Israel and beyond the Jordan River as far as the Asraq marshes, is found a species of Tilapia which, until 1951 (Jordan Valley) and 1954 (Middle Niger), was confused with T. nilotica. The earliest name for it is T. aurea (Steindachner) and the type locality is here designated as Senegal. In West Africa and the Nile, and in at least one of the coastal rivers of Israel, it coexists with T. nilotica, but there is no firm evidence for the existence of a natural population of T. nilotica in the Jordan Valley and beyond. Elsewhere, T. nilotica seems to be more abundant than T. aurea. The affinities of T. aurea may be with T. mossambica, which exists without T. nilotica in the eastward-flowing rivers of Africa, but this species has a finer dentition in jaws and pharynx and a characteristic hypertrophy of the jaws and snout in the breeding male.