''Maccullochella'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of large

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

n predatory freshwater fish within the family Percichthyidae. The genus ''Maccullochella'' was named after an early Australian fish researcher with the surname ''McCulloch''. The ''Maccullochella'' species are called 'cod' in the vernacular. At the time of European settlement of Australia, members of the genus ''Maccullochella'' dominated the Murray-Darling river system (

Murray cod The Murray cod (''Maccullochella peelii'') is a large Australian predatory freshwater fish of the genus '' Maccullochella'' in the family Percichthyidae.Dianne J. Bray & Vanessa J. Thompson (2011Murray Cod, Maccullochella peelii Fishes of Au ...

, ''M. peelii'', and

trout cod The trout cod (''Maccullochella macquariensis'') or bluenose cod, is a large predatory freshwater fish of the genus '' Maccullochella'' and the family Percichthyidae, closely related to the Murray cod. It was originally widespread in the sout ...

, ''M. macquariensis'') and 4 East Coast river systems (

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 Ri ...

, ''M. ikei'', of the Clarence and Richmond Rivers,

Brisbane River cod The Brisbane River cod was a unique form of '' Maccullochella'' cod that occurred naturally in the Brisbane River system, an east coast river system in south east Queensland, Australia. The Brisbane River Cod was known as the Bumgur (meaning blue ...

, ''Maccullochella'' sp., and

Mary River cod The Mary River cod (''Maccullochella mariensis'') is a species of temperate perch native to the coastal Mary River system of southern Queensland, Australia. Mary River cod are one of Australia's most endangered freshwater fishes and are nota ...

, ''M. mariensis''). As large, long-lived, top-order predators with delayed sexual maturity and relatively low fecundity (fertility) ''Maccullochella'' species are extremely vulnerable to

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 stocks, fish stock), resu ...

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 o ...

and other forms of

habitat degradation Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

, and

river regulation River engineering is a discipline of civil engineering which studies human intervention in the course, characteristics, or flow of a river with the intention of producing some defined benefit. People have intervened in the natural course and b ...

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aqua ...

s and weirs that alter river environments and negatively affect spawning and recruitment (survival) of young fish. The ''Maccullochella'' species have not fared well since European settlement. All are endangered or critically endangered except for

, which are considered 'Threatened' and 'Vulnerable' under national and state legislation. There are grave concerns over the future of wild

now, just as much as there is for all the ''Maccullochella'' species.

Species

There are currently four recognized species in this genus: * '' Maccullochella ikei'' Rowland, 1986 (Eastern freshwater cod) * '' Maccullochella macquariensis'' ( G. Cuvier, 1829) (Trout cod) * '' Maccullochella mariensis'' Rowland, 1993 (Mary River cod) * '' Maccullochella peelii'' ( T. L. Mitchell, 1838) (Murray cod) Well-preserved fossil remains of small-sized ''Maccullochella'' (originally assigned to ''M. macquariensis'', but this was prior to the splitting of the genus) have been recovered from the

Middle Miocene The Middle Miocene is a sub-epoch of the Miocene epoch (geology), epoch made up of two Stage (stratigraphy), stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0. ...

-aged

diatomite Diatomaceous earth ( ), also known as diatomite ( ), celite, or kieselguhr, is a naturally occurring, soft, siliceous sedimentary rock that can be crumbled into a fine white to off-white powder. It has a particle size ranging from more than 3 ...

deposits of the Chalk Mountain Formation near

Coonabarabran Coonabarabran () is a town in Warrumbungle Shire that sits on the divide between the Central West and North West Slopes regions of New South Wales, Australia. At the 2021 census, the town had a population of 2,387, Material was copied from th ...

Etymology

The generic name honours the Australian zoologist

Allan Riverstone McCulloch Allan Riverstone McCulloch (20 June 1885 – 1 September 1925) was a prominent Australian ichthyologist. Born in Sydney, Australia, McCulloch began his scientific career at the age of 13 as an unpaid assistant to Edgar Ravenswood Waite in the ...

(1885-1925) who Whitley succeeded as the Curator of Fishes at the

Australian Museum The Australian Museum, originally known as the Colonial Museum or Sydney Museum. is a heritage-listed museum at 1 William Street, Sydney, William Street, Sydney central business district, Sydney CBD, New South Wales. It is the oldest natural ...

References

Freshwater fish genera Taxa named by Gilbert Percy Whitley Extant Miocene first appearances {{Centrarchiformes-stub