Distribution, genetics, ecology and status of the introduced cichlid, Oreochromis mossambicus, in Australia

Abstract

The African cichlid, Oreochromis mossambicus (Peters), has established breeding populations in a variety of water bodies in Queensland and in one Western Australian river system. The origin of all stocks is the aquarium trade. This paper reviews the distribution, genetic differentiation, somatic characteristics and ecological relationships of O. mossambicus (Tilapia) in Australia and the evidence of adverse ecological effects in terms of competition for food and space, predation, and the importation of parasites and diseases. We also discuss the implications of there being two different genetic strains of Tilapia in Australia, one relatively pure form of O. mossambicus and one based on this species but with hybrid introgression from one or more of O. niloticus, O. honorum and O. aureus. The paper describes Federal and State legal and informal prohibitions on the importation and translocation of Tilapias, existing management policies and practices, and options for the management of Tilapias in different habitats and circumstances. Finally, we examine the ways in which research directed towards understanding the ecology of O. mossambicus in Australia could be of benefit to other countries as well as to the needs of Australian management agencies.