Tasmanian whitebait facts for kids

The Tasmanian whitebait (Lovettia sealii) is a small fish also known as the Australian whitebait or Derwent whitebait. It belongs to the Galaxiidae family. This fish is special because it lives in both fresh and salt water, moving between rivers and the ocean. You can only find it in Tasmania and southern Victoria, Australia.

How it Got its Name

A Scottish scientist named Robert Mackenzie Johnston first described this fish in 1883. He called it Haplochiton sealii and noticed many of them in the upper Derwent River in Tasmania during October and November. Later, in 1915, another scientist, Allan Riverstone McCulloch, moved it to a new group called Lovettia. He named this group after a Mr. Lovett, who collected fish from the Derwent River.

The fish was first called "Tasmanian whitebait." But in 1993, people found a group of these fish in southern Victoria on the Australian mainland. Because of this, its name was changed to "Australian whitebait." It is the only type of fish in its group, Lovettia.

What Does it Look Like?

The Australian whitebait is a thin, long fish without scales. It usually grows to about 65 millimeters (about 2.5 inches) long, but can reach up to 77 millimeters (about 3 inches). Its body is somewhat flat on the sides. It has a long, thin head with a large, shiny silver eye and a lower jaw that sticks out.

Its top fin (dorsal fin) is tall and starts near its belly fins. The tail fin is forked, like a "V" shape. The fin on its underside (anal fin) is longer than its top fin. The side fins (pectoral fins) are long and thin. This fish also has a clear, balloon-like organ called a swim bladder inside its body, which helps it float. It also has a small, fleshy fin on its back near its tail, called an adipose fin.

Young fish and adults living in the ocean are mostly see-through. Their side line (lateral line) is not very dark. Their fins are usually clear, except for small dark spots on the tail fin. Adult fish have a shiny silver stripe along their sides. When adults move into river mouths to lay eggs, their color gets much darker, sometimes almost completely black. Males are usually darker than females. Females ready to lay eggs have a yellowish belly.

Where Does it Live?

For a long time, people thought Australian whitebait only lived along the coasts of eastern, northern, and western Tasmania. But in 1993, a group of them was found in the Tarwin River in southern Victoria, Australia. Scientists are still studying how far these fish spread in the Tarwin River. However, they have confirmed the fish are still in Anderson Inlet (near the Tarwin River) in 2007 and 2014. This shows the group in Victoria has been there for a long time.

We don't know much about where Australian whitebait live. But because large groups of them have been seen several kilometers out at sea, scientists think adult fish mostly live in shallow ocean waters near the coast. Unlike other fish in the Galaxiidae family, this species does not seem to have a stage where it lives only in fresh water.

Life Cycle and Reproduction

Adult Australian whitebait swim from the ocean into river mouths (estuaries) and then upstream. They stop just before the river becomes completely fresh, where the tide no longer reaches. Here, they lay their eggs over several days, usually from August to December.

Most Australian whitebait live for about one year. After they lay their eggs, almost all of them die. Less than 1% live to be two years old and lay eggs a second time. Instead of dying right away, the adult fish slowly get weaker. In Tasmania, groups of these fish that have finished laying eggs have been seen further up rivers. This suggests that some adults might stay in the river systems if they survive their first spawning. Recent studies of their ear bones (otoliths) show that Australian whitebait depend on river mouths and the ocean. They don't seem to live in pure fresh water at any point in their lives.

Importance to People

Australian whitebait are part of the "whitebait" catch in Tasmania. People fish for them.

Conservation Status

The Australian government does not list Australian whitebait as a threatened species. However, the state of Victoria lists it as threatened under its Flora and Fauna Guarantee Act of 1988. In Victoria, it is considered "Critically Endangered" by the Department of Environment, Land, Water and Planning's list of threatened animals from 2013. This means it is at a very high risk of disappearing in Victoria.

• Froese, Rainer and Pauly, Daniel, eds. (2010). "Lovettia sealii" in FishBase. May 2010 version.