European fingernailclam facts for kids
Quick facts for kids European fingernailclam |
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The European fingernailclam, also known by its scientific name Sphaerium corneum, is a tiny clam that lives in fresh water. It's a type of mollusk called a bivalve, which means it has two shells. This little creature belongs to the Sphaeriidae family, often called "fingernail clams" because of their small size.
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What Does It Look Like?
The European fingernailclam has a round-ish shell. It can grow to be about 9 to 13.5 millimeters long. That's roughly the size of your pinky fingernail! The shells are usually brown or gray. Younger clams, called juveniles, often have yellow shells. If you look closely, you might see thin, raised lines on their shells. These lines are called striae.
Where Do They Live?
These small clams live in shallow, fresh water. You can find them in places like lakes, rivers, and creeks where the water moves slowly. They prefer habitats with a steady, gentle current. This helps bring them a constant supply of food.
What Do They Eat?
Like many bivalves, Sphaerium corneum mostly eats by filtering tiny bits of food from the water. They prefer water that has a lot of nutrients, as this means more food for them. They mainly eat tiny water plants called diatoms and other phytoplankton.
These clams can also climb plants and other things in their habitat. They do this to find better spots to feed. If the water current is very slow or there isn't much food, they can also eat by picking up food from the bottom. This is called deposit feeding.
How Do They Survive?
S. corneum clams are sensitive to high levels of pollution, especially organic waste. This kind of pollution can make the water dirty and stop them from feeding well. Because of this, they are known as a bioindicator species. If you find these clams in the water, it often means the water is quite clean.
They are also very good at surviving in places with low oxygen. They can live without oxygen for up to 400 days if the water is very cold (0°C). If the water is warmer (20°C), they can survive for about 9 days without oxygen. This special ability lets them burrow into sand, mud, or gravel. They do this to hide from predators and find new food sources. It also helps them survive when water levels drop and oxygen quickly disappears. However, they cannot survive if they dry out, so they need water to live.
Life Cycle
These clams can live for up to three years. However, how long they live often depends on where they are. In their native homes, they might live their full lifespan. But in places like the United States, where they are not native, they usually only live for 1 to 1.5 years. They become adults when their shell reaches about 4 millimeters in size. This can happen as early as three months old in their native areas.
Where Are They Found?
The European fingernailclam is originally from the Palearctic realm. This is a large area that includes Europe, Asia, and parts of North Africa.
You can find them in many countries, including:
- Czech Republic
- Finland
- Germany (though they are considered endangered in Thuringia)
- Netherlands
- Norway
- Sweden
- United States (where they are not native)
They live in both still water and slow-moving rivers. However, they are not found in places like the Faroe Islands or Iceland.
