Mary River Cod (Maccullochella peelii mariensis) are a Maccullochella cod found in the coastal Mary River system of central Queensland, Australia. Mary River Cod are significant because they are the most northerly of the four Maccullochella cods found or once found in coastal river systems of eastern Australia. Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria Placozoa Subregnum Bilateria  Acoelomorpha  Orthonectida  Rhombozoa  Myxozoa  Superphylum Deuterostomia     Chordata (vertebrates, etc. ... Typical Classes Subphylum Urochordata - Tunicates Ascideiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... Orders See text The Actinopterygii are the ray-finned fish. ... Families many, see text The Perciformes, also called the Percomorphi or Acanthopteri, include about 40% of all fish and are the largest order of vertebrates. ... Genera Bathysphyraenops (disputed) Bostockia Coreoperca Edelia Gadopsis Guyu Howella Lateolabrax Maccullochella Macquaria Nannatherina Nannoperca Percichthys Siniperca The Family Percichthyidae are known as the Temperate perches. ... Binomial name Maccullochella peelii The Murray Cod (Maccullochella peelii) is the largest freshwater fish in Australia. ... Trinomial nomenclature is a taxonomic naming system that extends the standard system of binomial nomenclature by adding a third taxon. ... Motto: Audax at Fidelis (Bold but Faithful) Nickname: Sunshine State/Smart State Other Australian states and territories Capital Brisbane Government Governor Premier Const. ...

Description

A large fish, reliably recorded to at least 27 kilograms in the early years of European settlement. Very similar in appearance to Murray Cod and Eastern Freshwater Cod. Curiously, Mary River Cod have a slightly shorter, thicker caudal peduncle (tail wrist) than the other cod species. Trinomial name Maccullochella peelii peelii (Mitchell, 1838) The Murray Cod (Maccullochella peelii peelii) is the largest freshwater fish in Australia. ... Binomial name Maccullochella ikei Rowland, 1986 Eastern Freshwater Cod (Maccullochella ikei), also known as Eastern Cod, are a freshwater fish belonging to the family Percichthyidae; they are not a true cod. ...

Conservation

Mary River Cod are subject to the usual story of woe. Incredibly abundant at the time of first European settlement, they were grossly overfished with nets, lines and explosives by the early European settlers and, as with other Maccullochella cods, were used as pig feed. Such overfishing, combined with the massive siltation of their habitats by land-clearing; the destruction of riparian vegetation; cattle trampling river banks; dams and weirs blocking migration, rapidly caught up with this large, slow-growing, long-lived Maccullochella cod species, as it has with all its close relatives.

Mary River Cod are now critically endangered. A survey in the mid to late 1990s estimated only around 600 wild fish existed. Those fish were present in a number of fragmented, isolated populations, some already below minimum viability and in terminal decline.

Mary River Cod continue to be the victim of political games; serious protection or restoration of their habitat by the Queensland Government has not occurred and the only captive breeding of them has been done by private individuals without Government funding.

Classification

Taxonomically, Mary River Cod are designated as "Maccullochella peelii mariensis", which denotes that they are a sub-species of the Murray Cod, Maccullochella peelii peelii. This was done on the basis of examination of muscle proteins and enzymes. (This designation of Mary River Cod as a sub-species of Murray Cod was actually the cause of the Murray Cod's recent name change from Maccullochella peeli to Maccullochella peelii peelii.) Trinomial name Maccullochella peelii peelii (Mitchell, 1838) The Murray Cod (Maccullochella peelii peelii) is the largest freshwater fish in Australia. ... Trinomial name Maccullochella peelii peelii (Mitchell, 1838) The Murray Cod (Maccullochella peelii peelii) is the largest freshwater fish in Australia. ...

A recent genetic research project using using mitochondrial DNA, which offers far more resolution, indicated that Mary River Cod were in fact more closely related to Eastern Freshwater Cod, Maccullochella ikei, of the Clarence River (the most southerly of the four coastal cod populations) than they are to Murray Cod. If this finding is correct then it suggests that Mary River Cod should be renamed Maccullochella ikei mariensis to denote that they are a sub-species of Eastern Freshwater Cod. If this finding is correct it also, logically, suggests that Murray Cod only crossed the Great Dividing Range via a natural river capture event once, into the Clarence River system, and that the four coastal cod populations (Clarence, Richmond, Brisbane and Mary Rivers) were all sub-species of Eastern Freshwater Cod of the Clarence River. Dramatic drops in sea-level during Ice Ages and/or "lateral" river capture events could easily have seen these four coastal river systems linked at times and Eastern Freshwater Cod gaining access to each one. Mitochondrial DNA (mtDNA, or less popularly, mDNA) is DNA which is not located in the nucleus of the cell but in the mitochondria. ... Binomial name Maccullochella ikei Rowland, 1986 Eastern Freshwater Cod (Maccullochella ikei), also known as Eastern Cod, are a freshwater fish belonging to the family Percichthyidae; they are not a true cod. ... At least three rivers called the Clarence River: Australia The Clarence River flows through Australia Canada/USA The Clarence River rises in the Yukon Territory of Canada and crosses back and forth across the border several times into the U.S. state of Alaska. ... Trinomial name Maccullochella peelii peelii (Mitchell, 1838) The Murray Cod (Maccullochella peelii peelii) is the largest freshwater fish in Australia. ... Binomial name Maccullochella ikei Rowland, 1986 Eastern Freshwater Cod (Maccullochella ikei), also known as Eastern Cod, are a freshwater fish belonging to the family Percichthyidae; they are not a true cod. ... Trinomial name Maccullochella peelii peelii (Mitchell, 1838) The Murray Cod (Maccullochella peelii peelii) is the largest freshwater fish in Australia. ... The Great Divide runs around the entire eastern and south-eastern edge of Australia The Great Dividing Range (a. ... Binomial name Maccullochella ikei Rowland, 1986 Eastern Freshwater Cod (Maccullochella ikei), also known as Eastern Cod, are a freshwater fish belonging to the family Percichthyidae; they are not a true cod. ... Variations in CO2, temperature and dust from the Vostok ice core over the last 400 000 years For the animated movie, see Ice Age (movie). ... Binomial name Maccullochella ikei Rowland, 1986 Eastern Freshwater Cod (Maccullochella ikei), also known as Eastern Cod, are a freshwater fish belonging to the family Percichthyidae; they are not a true cod. ...

Confusing the situation further is a calamitous bottleneck a couple of thousand years ago in the population of the Eastern Freshwater Cod of the Clarence river system (as revealed by DNA analysis), in which the majority of the population perished and presumably much genetic diversity was lost (probably due to a combination of catastrophic drought, whole-of-catchment scale bushfires and ash-induced fish kills) as well as a poorly executed "privatised" stocking program where many inbred fish of very limited genetic diversity were stocked. Binomial name Maccullochella ikei Rowland, 1986 Eastern Freshwater Cod (Maccullochella ikei), also known as Eastern Cod, are a freshwater fish belonging to the family Percichthyidae; they are not a true cod. ...

With the new resolution that DNA technologies are providing us with, many questions are being asked about Eastern Freshwater Cod and the other coastal cod populations (though the original Richmond and Brisbane River Cod strains are extinct). Some are suggesting their origin, or least their isolation from Murray Cod, is much more recent than previously though. It is too early to speculate on these aspects but we look forward to the insights that future, high resolution DNA studies will provide us on the origin of the coastal cod populations. Binomial name Maccullochella ikei Rowland, 1986 Eastern Freshwater Cod (Maccullochella ikei), also known as Eastern Cod, are a freshwater fish belonging to the family Percichthyidae; they are not a true cod. ... Trinomial name Maccullochella peelii peelii (Mitchell, 1838) The Murray Cod (Maccullochella peelii peelii) is the largest freshwater fish in Australia. ...