The Richmond River cod was a form of ''

Maccullochella ''Maccullochella'' is a genus of large Australian predatory freshwater fish within the family Percichthyidae. The genus ''Maccullochella'' was named after an early Australian fish researcher with the surname ''McCulloch''. The ''Maccullochella' ...

'' cod, now believed to have been

eastern freshwater cod The eastern freshwater cod (''Maccullochella ikei''), also known as the eastern cod or Clarence River cod, is a large predatory freshwater fish of the genus '' Maccullochella'' and the family Percichthyidae, that occur in the coastal Clarence Riv ...

, ''Maccullochella ikei'', that occurred naturally in the

Richmond River The Richmond River is a river situated in the Northern Rivers region of New South Wales, Australia. Course and features The river rises at the northern end of the Richmond Range, near its junction with the McPherson Range, on the Queensl ...

system, an east coast river system in north-east

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , e ...

, Australia. Eastern freshwater cod in turn are a species of ''Maccullochella'' cod found in east coast drainages and originating from Murray cod, ''Maccullochella peelii'', that crossed the

Great Dividing Range The Great Dividing Range, also known as the East Australian Cordillera or the Eastern Highlands, is a cordillera system in eastern Australia consisting of an expansive collection of mountain ranges, plateaus and rolling hills, that runs roug ...

and entered east coast drainages from a

river capture Stream capture, river capture, river piracy or stream piracy is a geomorphological phenomenon occurring when a stream or river drainage system or watershed is diverted from its own bed, and flows instead down the bed of a neighbouring stream. ...

event between 0.62 and 1.62 million years ago (mean estimate 1.1 million years ago). Richmond River cod are extinct, from

overfishing Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in the ...

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

including gross

siltation Siltation, is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary or ...

, and whole-of-catchment scale bushfires and

fish kill The term fish kill, known also as fish die-off, refers to a localized die-off of fish populations which may also be associated with more generalized mortality of aquatic life.University of Florida. Gainesville, FL (2005) ''Plant Management in Fl ...

s in the 1930s. The Richmond River system has now been restocked with small numbers of eastern freshwater cod from the Clarence River system, but these appear to have been insufficient to re-establish populations; there is no evidence of these stocked fish reproducing.

References

Further reading