Eel-tailed catfish

The eel-tailed catfish (Tandanus tandanus) is a species of catfish (order Siluriformes) of the family Plotosidae. This fish is also known as dewfish, freshwater catfish, jewfish, and tandan.

This species is a freshwater fish native to the Murray-Darling river system of eastern Australia. 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 recorded on his 1832 expedition.

Habitat

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 due to natural river capture events.

Juvenile eel-tailed catfish feed on zooplankton, and small insects, particularly chironomid larvae. Fish over about 100 mm also eat small fish while adults include shrimps, crayfish in the warmer months and midge larvae in winter. In addition, they eat mollusks and dragonfly, caddis and mayfly larvae. The eel-tailed catfish is host for a number of intestinal parasites including cestodes and nematodes.

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.