Tandanus tandanus is a species of freshwater catfish, commonly known as the Eel-tailed catfish, that is found throughout Australia. It is an important food source for Indigenous Australians and is a popular sportfish among recreational anglers. In this article, we will explore the physical characteristics, distribution, habitat, diet, reproduction, and conservation status of Tandanus tandanus. Physical Characteristics: Tandanus tandanus has a long, slender body that is cylindrical in shape. It is characterized by a long, slender eel-like tail, which gives it its common name, the Eel-tailed catfish. The fish can grow up to 60 cm in length and can weigh up to 2 kg. Its coloration ranges from brownish-grey to dark brown, with a paler underside. Distribution: Tandanus tandanus is found throughout Australia, except for Tasmania and the northern parts of Western Australia. It is most commonly found in rivers, creeks, and billabongs in the eastern and southern parts of the country. Habitat: Tandanus tandanus prefers slow-moving, freshwater habitats, such as rivers, creeks, billabongs, and swamps. It is commonly found in areas with dense vegetation, submerged logs, and other debris, which provide cover and shelter. The fish is able to tolerate a wide range of water temperatures and pH levels, and can survive in both clear and murky water. Diet: Tandanus tandanus is an omnivorous fish, feeding on a wide range of aquatic invertebrates, crustaceans, small fish, and plant matter. It is known to scavenge on dead animals, and has been observed to eat the eggs and fry of other fish species. Reproduction: Tandanus tandanus is a long-lived species, with individuals living for up to 30 years. The fish reaches sexual maturity at around 5-7 years of age. Spawning occurs during the warmer months, between September and April, with peak spawning activity occurring in October and November. The fish is an egg-laying species, with females producing up to 15,000 eggs per season. The eggs are adhesive and are attached to submerged objects, such as logs and vegetation. Conservation Status: Tandanus tandanus is considered to be a species of least concern by the International Union for Conservation of Nature (IUCN). The fish is widespread and abundant throughout its range, and there are no major threats to its survival. However, habitat destruction, pollution, and overfishing are potential threats to the species, and ongoing monitoring and conservation efforts are necessary to ensure its long-term survival. Conclusion: Tandanus tandanus is an important freshwater catfish species in Australia, with ecological, cultural, and economic significance. Its long, slender body and eel-like tail make it a unique and interesting species, and its ability to tolerate a wide range of environmental conditions allows it to thrive in a variety of habitats. While the species is currently considered to be of least concern, ongoing conservation efforts are necessary to ensure its continued survival in the face of potential threats.