A Natural Hybrid of Tilapia nigra and Tilapia leucosticta from Lake Naivasha, Kenya Colony

Abstract

CICHLID fish of the genus Tilapia are of considerable importance in both natural fisheries and pond culture in many tropical and subtropical climates, particularly throughout Africa. Certain species have proved to be adaptable to varied environmental conditions, and consequently there has been a considerable artificial dispersion of species beyond their natural geographical range, as far afield as Malaya and Pacificislands, and including high-altitude waters in several parts of Africa. This transportation has brought into contact species which were hitherto geographically isolated, and due, at least in part, to this, there is an increasing number of records of hybridization. Lowe¹ first directed attention to possible hybridization between T. nilotica (Linné) and T. nigra (Günther), and between T. nilotica and T. esculenta Graham in Uganda. Yashouv and Chervinsky² have crossed T. nilotica and T. galilea (Artédi) in Israel, and Bard³ reports a hybrid between T. nilotica and T. machrochir Boulenger in culture ponds in the Cameroons. More recently, Hickling^4,5 crossed a Malayan strain of T. mossambica Peters with another of the T. mossambica group from Zanzibar, and Mortimer⁶ has hybridized T. mossambica and T. andersoni (Castelnau) in culture ponds in Northern Rhodesia.