Agassiz's perchlet facts for kids
Quick facts for kids Agassiz's perchlet |
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Agassiz's perchlet (Ambassis agassizii) is a small, see-through fish that lives in freshwaters in Australia. It's also known as Agassiz's glass fish or the olive perchlet. This fish has dark edges on its scales, which create a cool pattern on its body. It can grow up to about 7.5 centimeters long. It lays sticky eggs on water plants.
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What Does Agassiz's Perchlet Look Like?
Agassiz's perchlet has a body shaped like an oval, flattened from side to side. It has a mouth that points upwards and very large eyes. Its tail is forked, like a "V" shape.
Color and Size
These fish are usually semi-transparent, meaning you can almost see through them. They might also be a light olive color. Their scales have dark edges, which make a clear net-like pattern over most of their body. There's also a thin black line along their sides, which gets clearer near the tail.
Their fins are mostly clear. However, the fins on their belly and near their tail often have a wide, dark band along the edges. Agassiz's perchlets can grow to about 7 to 8 centimeters (around 3 inches). But most of them are about 4 centimeters (1.5 inches) long.
Special Features
This fish has small, cone-shaped teeth in its jaws. It also has a special line along its side called a lateral line. This line helps the fish sense movements in the water. For Agassiz's perchlet, this line is not complete and is often split into two parts. Its top fin (dorsal fin) has a deep notch and starts in front of its belly fins.
Where Does Agassiz's Perchlet Live?
Agassiz's perchlet is found only in Australia. It used to live in many places, including South Australia and Victoria. But now, it is mostly found in Queensland and New South Wales.
Past and Present Homes
These fish were once common in the Murray-Darling Basin, a large river system in Australia. However, their numbers have gone down a lot. Their living areas have become much smaller. Today, they are found in only a few spots in the Darling River area. There is also a separate group living in the central Lachlan River area. In 2008, a large group was found in a small river that flows into the Lachlan River.
What is the Habitat and Life of Agassiz's Perchlet?
Agassiz's perchlet likes to live in rivers, creeks, ponds, and swamps. They prefer water that flows slowly or is still. They often hide in places with overhanging plants, thick beds of water plants (called macrophytes), logs, dead branches, and rocks. These spots offer good places to hide during the day.
Daily Life and Food
These fish are nocturnal, meaning they are active at night. They leave their hiding spots to find food after the sun goes down. However, they sometimes feed during the day too. They eat tiny animals floating in the water, called zooplankton. They also eat insects that live in the water and insects that fall into the water from land.
Life Cycle
Agassiz's perchlets become adults and can have babies after about one year. They usually live for 2 to 4 years. They lay their eggs from October to December. This happens when the water temperature gets to about 23 degrees Celsius (73 degrees Fahrenheit).
A female fish lays between 200 and 700 small, sticky, round eggs. These eggs are very tiny, about 0.7 millimeters (0.03 inches) wide. They stick to water plants and rocks at the bottom of streams. The baby fish, called larvae, hatch from the eggs after 5 to 7 days. They are only 3 millimeters long when they hatch. They start swimming and eating 4 to 9 days after hatching. For about a month, the baby fish swim together in groups near the water's surface.
Why is Agassiz's Perchlet in Danger?
Agassiz's perchlet faces several threats that make it harder for them to survive.
New Fish and Habitat Loss
One big problem is new types of fish that have been brought into their areas. These include the Gambusia holbrooki and the European perch. These new fish often eat the Agassiz's perchlet or compete with them for food.
Their homes are also being damaged. People sometimes remove plants, logs, and branches from the rivers. These are the places where the perchlets hide and find food. Also, changes in water levels from dams can hurt their breeding. For example, cold water released from dams can stop the fish from laying eggs. The plants they use for shelter are also lost because of water changes and because of grazing by the introduced common carp.
How Agassiz's Perchlet Got Its Name
The name agassizii was given to this fish by Franz Steindachner in 1866. He didn't explain why he chose the name. However, it is almost certain that he named it after Louis Agassiz. Louis Agassiz was a famous Swiss-American biologist and geologist who lived from 1807 to 1873.
- Pusey, B. Kennard, M Arthington, A (2004) Freshwater Fishes of North-eastern Australia, CSIRO Publishing. (Available from CSIRO Publishing)
