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The eel-tailed catfish, ''Tandanus tandanus'', is a
Freshwater Catfish, Tandanus tandanus.
Fishes of Australia. Retrieved 29 Aug 2014.
The eel-tailed catfish inhabits slow moving streams, lakes and ponds with fringing vegetation. It swims close to the sand or gravel bottoms. This species is more abundant in lakes than in flowing water. Though they are usually solitary, juveniles may form aggregations. The eel-tailed catfish is found in most freshwater habitats of the Murray-Darling river system except for the upland, sub-alpine and alpine headwaters of southern tributaries. It is also present in speciated but undescribed forms in several east coast systems in northern
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...
of catfish
Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, ...
(order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...
Siluriformes) of the family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Plotosidae. This fish is also known as dewfish, freshwater catfish, jewfish, and tandan.
This species is a freshwater
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does incl ...
fish
Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...
native to the Murray
Murray may refer to:
Businesses
* Murray (bicycle company), an American manufacturer of low-cost bicycles
* Murrays, an Australian bus company
* Murray International Trust, a Scottish investment trust
* D. & W. Murray Limited, an Australian who ...
- Darling river system of eastern Australia
Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...
. The scientific name for eel-tailed catfish comes from a name for the fish in an unidentified Aboriginal Australian language - ''Tandan'' - which Major Thomas Livingston Mitchell
Sir Thomas Livingstone Mitchell (15 June 1792 – 5 October 1855), surveyor and explorer of Southeastern Australia, was born at Grangemouth in Stirlingshire, Scotland. In 1827 he took up an appointment as Assistant Surveyor General of New South ...
recorded on his 1832 expedition.
Description
Eel-tailed catfish commonly grow to about 50.0 centimetres (19.7 in) and weigh about 1.8 kilograms (4.0 lb). Fish of this species may grow up to about 90.0 cm (35.4 in) and weigh up to 6.0 kg (13.2 lb). Eel-tailed catfish may live up to about 8 years. Eel-tailed catfish have large head with thick and fleshy lips and tubular nostrils. The skin is tough and smooth. Body coloration in adults vary from olive-green to brown, black or purplish on their backs and white on the underside. A downturned mouth with fleshy lips surrounded by a number ofbarbels
In fish anatomy and turtle anatomy, a barbel is a slender, whiskerlike sensory organ near the mouth. Fish that have barbels include the catfish, the carp, the goatfish, the hagfish, the sturgeon, the zebrafish, the black dragonfish and some s ...
assist them with feeding. They are a solid, almost cylindrical, elongate fish, with the posterior half of their body tapering into a pointed eel-like tail. A continuous fin margin surrounds this tapering posterior half of the body. Their eyes are small.
The eel-tail catfish has 4 pairs of barbels surrounding the mouth, and sharp serrated dorsal- and pectoral-fin spines which are venomous and can cause a very painful wound.Martin F. Gomon & Dianne J. Bray (2011Freshwater Catfish, Tandanus tandanus.
Fishes of Australia. Retrieved 29 Aug 2014.
Ecology
The eel-tailed catfish inhabits slow moving streams, lakes and ponds with fringing vegetation. It swims close to the sand or gravel bottoms. This species is more abundant in lakes than in flowing water. Though they are usually solitary, juveniles may form aggregations. The eel-tailed catfish is found in most freshwater habitats of the Murray-Darling river system except for the upland, sub-alpine and alpine headwaters of southern tributaries. It is also present in speciated but undescribed forms in several east coast systems in northern 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
, es ...
due to natural 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. T ...
events.
Juvenile eel-tailed catfish feed on zooplankton
Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...
, and small insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...
s, particularly chironomid
The Chironomidae (informally known as chironomids, nonbiting midges, or lake flies) comprise a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae. Many specie ...
larvae. Fish over about 100 mm also eat small fish while adults include shrimp
Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are ref ...
s, crayfish
Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, m ...
in the warmer months and midge larvae in winter. In addition, they eat mollusk
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...
s and dragonfly, caddis and mayfly larvae. The eel-tailed catfish is host for a number of intestinal parasite
An intestinal parasite infection is a condition in which a parasite infects the gastro-intestinal tract of humans and other animals. Such parasites can live anywhere in the body, but most prefer the intestinal wall.
Routes of exposure and inf ...
s including cestode
Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, known as tapeworms. Their bodies consist of ...
s and nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant- parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a bro ...
s.Couch, A.J.; 1983.
Eel-tailed catfish spawn in spring and midsummer, when the water temperature increases to between 20–24 °C (68–75 °F. The nest is built about one or two weeks before spawning. They build large nests up to a metre in diameter with small stones and gravel, within which the eggs are laid. One parent, sometimes both, guard the eggs until they hatch.
Conservation
Freshwater Catfish were once widespread in eastern Australia, however, populations have suffered severe declines in both distribution and abundance since the 1980s. The Murray-Darling populations of eel-tailed catfish has declined significantly over recent decades. Most populations in the southern half of the Murray-Darling river system are extinct or nearly so. The species remains relatively common in coastal catchments from the Hunter River (NSW) north. Numerous factors are thought to have contributed to the decline of Freshwater Catfish populations in the Murray-Darling Basin since the 1970s. These include habitat degradation and barriers to movement, and increased predation by and competition with introduced species such ascarp
Carp are various species of oily freshwater fish from the family Cyprinidae, a very large group of fish native to Europe and Asia. While carp is consumed in many parts of the world, they are generally considered an invasive species in parts of ...
(which has similar feeding habits) and Redfin. Severe siltation also probably severely impacts upon the species spawning by smothering the rocks and pebbles they use to build nests.
The Freshwater Catfish population in the Murray-Darling Basin is listed as:
New South Wales Fisheries Management Act 1994: Endangered
Victorian Flora and Fauna Guarantee Act 1988: Threatened
South Australian Fisheries Management Act 2007: Protected
Populations in several rivers and impoundments in the northern half of the Murray-Darling appear secure for now. The species does well in the upland reaches of these northern Murray-Darling rivers; this is in contrast to its absence from the upland reaches of southern Murray-Darling rivers, where water temperatures are cooler.
References