Lake salmon facts for kids
Quick facts for kids Lake salmon |
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| Conservation status | |
| Scientific classification | |
| Genus: |
Opsaridium
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| Species: |
microlepis
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| Synonyms | |
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The lake salmon or mpasa (Opsaridium microlepis) is a type of freshwater fish. It lives only in Lake Malawi in Africa. You can find this fish in Malawi, Mozambique, and Tanzania. It belongs to the Cyprinidae family, which includes carps and minnows. Its natural homes are rivers and freshwater lakes.
What Lake Salmon Look Like
The lake salmon is a shiny, silver fish. It looks a bit like a trout, but its fins are not pink or orange. These fish can grow quite big. They can reach up to 4 kilograms (about 9 pounds) in weight. They can also be as long as 47 centimeters (about 1.5 feet).
Adult lake salmon are plain silver. But young fish look different. They have dark stripes on their sides. These stripes disappear as the fish get older.
Where Lake Salmon Live and Their Life Cycle
Lake salmon live in the open waters of Lake Malawi. They prefer areas with sandy bottoms. Young fish stay closer to the shore. They like to be near where rivers flow into the lake.
Adult lake salmon eat smaller fish that swim in open water. One of their favorite foods is a fish called Engraulicypris sardella. Young lake salmon eat tiny living things in the water called plankton. They also eat insects and other small bits of food.
During the rainy season, adult lake salmon swim from the lake up into the rivers. They do this to lay their eggs, which is called spawning. This usually happens at night. They choose shallow parts of the river with fast-moving, clean water. The riverbed needs to be gravelly and free of mud.
Lake salmon have a long spawning period. It starts when the rains begin and continues even after the rains stop. This can be from May to October. The young fish stay in the rivers until they are big enough. Then they swim back to the lake.
Protecting Lake Salmon
The lake salmon is in danger because too many are being caught. Many adult fish die during the spawning season. This happens because people often block the rivers. They use fences called weirs or nets to stop the fish from swimming upstream. This is especially bad when there isn't much rain.
Other problems threaten the lake salmon too. Sometimes, people deliberately poison the water. Also, the places where fish lay eggs are getting worse. This is due to soil washing into the rivers from farms and cut-down forests. This mud makes it hard for the fish to lay eggs. Taking too much water from the rivers for farming also makes it hard for young fish to return to the lake.
There are some efforts to protect these fish. The Bua River flows through the Nkhotakota Wildlife Reserve in Malawi. This is the only river where the spawning grounds are safe. The forests around it are protected. The headwaters of another river, the North Rukuru, are protected inside Nyika National Park. However, more trees are being cut down between the park and the spawning areas. The Linthipe River is a very important spawning river. But it is not protected and gets polluted by dirty water from the city of Lilongwe. We don't know much about the condition of the spawning rivers in Tanzania and Mozambique.
