Nashville crayfish facts for kids
Quick facts for kids Nashville crayfish |
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|---|---|
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| Conservation status | |
| Scientific classification | |
| Genus: |
Faxonius
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| Species: |
shoupi
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| Synonyms | |
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Orconectes shoupi Hobbs, 1948 |
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The Nashville crayfish, also known as Faxonius shoupi, is a cool freshwater creature. It's a type of crustacean, like a tiny lobster! You can only find it naturally in the Mill Creek area near Nashville, Tennessee. Before 2017, it had a different scientific name, Orconectes shoupi.
This special crayfish is protected by the Endangered Species Act (ESA) because it was once in danger. However, thanks to conservation efforts, the United States Fish and Wildlife Service is now thinking about removing it from the endangered list!
Contents
What Does It Look Like?
The Nashville crayfish has a striking orange and black color. It has four pairs of legs, which it uses to move around. It also has two long pinchers with red tips, perfect for grabbing food or defending itself.
You might notice a lighter-colored "saddle" mark on its back. It also has lighter spots on the sides of its head. This crayfish is quite large for its kind, growing up to about 7 inches (18 cm) long!
Life Cycle and Reproduction
Scientists don't know a lot about the Nashville crayfish's full life cycle. Most of the studies have focused on the male crayfish. Male crayfish change between two forms during the mating season.
One form, called "form 1," is for reproduction. The other, "form 2," is for when they are not mating. The male's reproductive part, called a gonopod, has a special "short-curved" shape. This unique shape helps prevent them from mating with other crayfish species in the same group, a process called "lock and key" reproductive isolation.
Based on other crayfish species, reproduction usually starts in late summer and early fall. This is when males change into their "form 1" for mating. Females typically lay their eggs in late winter and early spring. Each female can lay hundreds of eggs! However, many of these eggs or young crayfish don't survive.
Where It Lives and What It Eats
Diet and Habitat
Crayfish are not picky eaters! They munch on things like algae, insects, worms, snails, and even fish eggs. They also eat leaves and mussels. They usually look for food at night, from sunset until midnight. During the day, they often hide in their burrows to stay safe.
Female Nashville crayfish carrying eggs or young can often be found hiding under large flat rocks.
Range
The Nashville crayfish is super tough and can live in many different kinds of creek conditions. You can find them in creeks with lots of sediment, gravel, flat rocks, or rounded stones. They can even live in cloudy water caused by oil or in areas with construction debris.
However, the Nashville crayfish lives in a very small area. They are only found in the Mill Creek Basin and its smaller streams in Davidson and Williamson Counties in Tennessee. Recently, a separate group was found in the Lower Tennessee River at the Pickwick Tailwater. This suggests they might have lived in a wider area long ago. They live in about 104 miles (167 km) of the 192 miles (309 km) of streams in the Mill Creek Watershed.
Behavior
Nashville crayfish can be quite feisty! They might chase, corner, or push their opponents backward if they feel threatened. Not much is known about how territorial Nashville crayfish are about their homes. But generally, most crayfish are very protective of their burrows and will fight to keep them safe.
Protecting the Nashville Crayfish
Main Challenges
The Nashville crayfish population faces several challenges. Poor water quality from local development is a big problem. Their homes are also being damaged, and they live in a very small area.
Another challenge comes from invasive crayfish, like Faxonius placidus and Faxonius durelli, which compete with them for food and space. Sometimes, people also catch too many for fun, education, science, or business.
The Nashville crayfish was first considered for protection in 1977. It was officially listed as "endangered" on September 26, 1986.
Population Size
When the Nashville crayfish was first listed as endangered in 1986, there were far fewer of them than in 1969. But since then, recent studies show their numbers are growing! This is thanks to efforts to restore their habitat. In places where their homes have been fixed up, they quickly move back in.
For a long time, people thought the Nashville crayfish only lived in Mill Creek and a few of its smaller streams. But then, a completely separate group was found in the Lower Tennessee River! This exciting discovery suggests that they used to live in a much larger area.
Recent Reviews
The U.S. Fish and Wildlife Service (USFWS) regularly checks on endangered species. Their most recent review for the Nashville crayfish was in 2017. They suggested that the species could be moved from "endangered" to "threatened" status. This means they are still at risk but are doing much better.
Even with a lot of new buildings and people in the Nashville area, the crayfish population in Mill Creek has stayed steady or even grown over the past 20 years. This shows that the crayfish are tough and can handle some changes in their environment. While they might still face some challenges, their population is expected to remain strong.
A detailed Species Status Assessment (SSA) was completed in 2018. It also found that even with issues like poor water quality and pollution from city growth, the Nashville crayfish numbers in Mill Creek have been stable or increasing since they were listed. The assessment suggests improving water quality, but even without major changes, the crayfish populations are predicted to survive for at least the next 40 years.
Recovery Plan
The plan to help the Nashville crayfish recover hasn't been updated since 1989. When the species was first listed in 1986, a special "critical habitat" area wasn't set aside. This was because officials worried that marking their habitat might make them more likely to be harmed or caught in the busy Nashville area. The 1989 plan mentioned that urban development, like the risk of chemical spills, was a big threat to the species.
