Phylogenetics and revised taxonomy of the Australian freshwater cod genus, Maccullochella (Percichthyidae)
Nock, C.J., Elphinstone, M.S., Rowland, S.J. and Baverstock, P.R., 2010. Phylogenetics and revised taxonomy of the Australian freshwater cod genus, Maccullochella (Percichthyidae). Marine & Freshwater Research, 61: 980–991.
Freshwater cod of the genus, Macullochella, are found in the inland Murray-Darling River System and coastal drainages in northern NSW and southern Queensland. Previously, three species and one sub-species were recognised, and all have important historical, social, conservation and fisheries values. Murray cod is Australia’s largest freshwater fish, and is found throughout most of the Murray-Darling River System. Trout cod is sympatric with Murray cod in the southern Murray and Murrumbidgee rivers, whereas eastern freshwater cod and Mary River cod are found naturally in the Clarence and Mary river systems, respectively. All cod are classified as threatened species at state and/or Commonwealth levels. Correct taxonomy is fundamental to good fisheries management. Research was done to clarify some uncertainty about the evolutionary history and taxonomy of these cod. It was determined that there are four separate species; Murray cod M. peeli, trout cod M. macquariensis, and two sister species, eastern freshwater cod M. ikei, and Mary River cod M. mariensis. The findings also suggest that Murray cod is the ancestral stock which crossed the Great Dividing Range in the Pleistocene Period around 1 million years ago; the eastern species diverged from each other around 300,000 years ago. These findings will ensure appropriate fisheries management and conservation in the future.