Taxonomy
In the 1800s and early 1900s, commercial fishermen, recreational fishermen, riverside residents and some fisheries scientists (e.g. Anderson, Stead, Langtry) distinctly recognised two species of cod in the southern Murray-Darling basin, Murray cod and trout cod or "blue nose cod". Taxonomically however, confusion abounded. Only one species of cod was taxonomically recognised, the Murray cod (then named Maccullochella macquariensis, after an early Australian fish researcher with the surname McCulloch and the Macquarie River in New South Wales where the holotype was captured) and as trout cod declined into near extinction over the 1900s the distinction between the two species was eroded and finally questioned. In the 1970s early genetic techniques confirmed forever that trout cod were a separate species and further showed that the original "Murray cod" specimen was in fact a trout cod. Following the rules of scientific classification, the name M. macquariensis remained with the original specimen, now known to be the trout cod, and a new name, M. peelii, for the Peel River where the new holotype was captured, was coined for the Murray cod. Subsequently, two further cod were identified as separate species, the eastern freshwater cod (M. ikei) and the Mary River cod (M. mariensis).
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