Westralunio carteri facts for kids
Quick facts for kids Westralunio carteri |
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|---|---|
| Conservation status | |
| Scientific classification | |
| Genus: |
Westralunio
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| Species: |
carteri
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Westralunio carteri is a special type of freshwater mussel. It belongs to the family Hyriidae. This mussel is found only in Western Australia, which means it is endemic there. People often call it Carter's freshwater mussel. It's the only species of its kind, Westralunio, living in Australia.
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How Mussels Make Babies
Most Westralunio carteri mussels have separate sexes. This means there are male mussels and female mussels. Sometimes, a mussel might be a hermaphrodite. This means it has both male and female parts.
Special cells called gametes develop inside the mussels. These are sperm in males and eggs in females. When it's time to reproduce, the female's eggs move. They go from her ovaries to special areas in her gills. These gill areas are called 'marsupia'. When a female has eggs in her marsupia, she is called 'gravid'.
The fertilised eggs of Westralunio carteri grow into embryos. These embryos then develop into tiny larvae. These larvae are called 'glochidia'.
Life Cycle: The Parasitic Stage
Most freshwater mussel larvae, or glochidia, need to live on fish. They are like tiny, temporary passengers. Sometimes, they can attach to amphibians too.
A mature Westralunio carteri glochidium is very small. It has two tiny 'larval teeth' that fit together. Its shell is a see-through brown colour. It also has a single muscle to close its shell. On average, these tiny larvae are about 306-309 micrometres long. That's super tiny!
Female mussels release these mature glochidia in spring. They come out on strands of mucus. They are still inside a thin 'egg sac' at first. Soon after they are released, they hatch from their sacs. Then, they start to 'wink' open and close. This helps them get ready to attach to a passing fish.
Once they touch a fish, the glochidia attach. They can stick to the fish's fins, eyes, mouth, or gills. After they attach, the fish's skin cells grow around them. This forms a protective cyst. The glochidia stay in this cyst for about 21 to 28 days.
During this time, they go through a big change called metamorphosis. They change into tiny juvenile mussels. They lose their single muscle and grow two separate muscles. They also grow a tiny foot with hairs on it. Once they are fully developed, they let go of the fish. They then start their life in the mud or sand at the bottom of the water. Here, they grow into adult mussels.
Growing Up: From Young to Adult
When young Westralunio carteri mussels first leave their fish host, they are still very small. They are about the same size as glochidia. But they grow quickly! They keep growing for several years.
These mussels become ready to reproduce when they are 2 to 3 years old. At this age, they are usually about 25–30 millimetres long. As they get older, their growth slows down. The biggest Westralunio carteri ever found was 101 millimetres long. However, most are less than 90 millimetres long.
How fast they grow and how old they get can be different. It depends on where they live. Some mussels can live for a very long time. They can reach between 40 and 50 years old! Mussels of the same size from different places can even be 10 years apart in age.
Find Out More
- The western Australia Mussel Watch website [1]
- ARKive website [2]
