Neosho mucket facts for kids
Quick facts for kids Neosho mucket |
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|---|---|
| Conservation status | |
| Scientific classification | |
| Genus: |
Lampsilis
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| Species: |
rafinesqueana
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The Neosho mucket (also called the Neosho pearly mussel) is a special kind of freshwater mussel. It lives only in certain rivers in Arkansas, Oklahoma, Illinois, Missouri, and Kansas in North America. Its scientific name is Lampsilis rafinesqueana.
Contents
Meet the Neosho Mucket: Description
The Neosho mucket was first described in 1927 by a scientist named Frierson. He found them in the Illinois River in Oklahoma. These mussels are quite large compared to other freshwater mussels in their area. They can grow to be over 100 millimeters (about 4 inches) long!
Male mussels are usually a little bigger than females. For example, males might be 93mm long, while females are about 86mm. The top part of their shell, called the umbo, doesn't stick out much.
Shell Appearance and Features
The outside of the shell is usually smooth. It can be brown or a dull yellowish-green. Sometimes, you can see faint, broken, green zigzag lines on the shell. These lines are a good way to identify younger mussels. Older mussels often don't have these lines, or they are very hard to see.
The inside of the shell is bluish-white or creamy. On the left side of the shell, there are two strong, triangle-shaped teeth. There are also two shorter, curved teeth. On the right side, there is one strong tooth and a smaller one in front of it. These teeth help the mussel's shell close tightly.
Male vs. Female Mussels
If you look at the mussel from the side, its shape can be different depending on if it's a male or a female. This difference is called sexual dimorphism.
Males have a more oval-shaped shell. The back end points downwards. Females have a wider, more rounded shell at the back. This is because they have special pouches, called marsupial gills, where they carry their babies. This makes the female's shell taller at the back than the male's.
Sometimes, male Neosho muckets can look like another mussel species called A. ligamentina, especially if they don't have the green zigzag lines.
Shell Variations in Different Rivers
The Neosho mucket's look can change a bit depending on where it lives. For example, mussels from the Spring River in Missouri are often longer than those from Shoal Creek. Mussels from Shoal Creek also tend to have thinner shells, while those from other rivers have thicker, heavier shells.
Before 1927, people often confused the Neosho mucket with other similar mussels. It was sometimes thought to be Lampsilis ligamentina. But now, scientists know they are different species and usually live in different places.
Life of the Neosho Mucket: Ecology
Where They Live: Geographic Range
The Neosho mucket lives in the Arkansas River System. This includes the Neosho, Spring, Verdigris, Illinois, and Elk River basins. These rivers are found in southeast Kansas, northeast Oklahoma, southwest Missouri, and northwest Arkansas.
Sadly, the areas where this mussel lives are shrinking. It might not live in the Elk River basin anymore. It is now mostly found in the other four river basins.
Historically, they lived in many more places. For example, in Kansas, they were once found in the Cottonwood River. Now, they are mostly gone from there. They are still found in parts of the Verdigris, Neosho, and Spring Rivers. In the Spring River, there are many Neosho muckets. This might be because they can hold on tightly to the riverbed in the fast currents there.
In Oklahoma, live Neosho muckets are now only found in a 55-mile stretch of the Illinois River. The populations that are left are often separated from each other by large dams or polluted river sections. This means they can't easily mix, which makes them more vulnerable.
Their Home: Habitat
Neosho muckets usually live in shallow, fast-flowing water. They like riverbeds made of fine to medium-sized gravel. However, they can also be found in sandy-gravel areas or even cracks in bedrock.
For example, in the Spring River, where the water flows quickly, many Neosho muckets live there. They are often the most common mussel species in these fast-moving spots. But in Shoal Creek and parts of the Illinois River in Oklahoma, they are found in calmer, backwater areas. Even in slow currents, they seem to prefer loose gravel where they can bury themselves. So, their best home seems to be fast water with lots of loose gravel.
The type of habitat can even affect how the mussel looks. In the Illinois River in Oklahoma, mussels found in muddy, slow-moving water are often large and dark. They might even have algae growing on their shells. But mussels found in fast water over rocks or gravel are usually smaller, lighter in color, and more likely to have those green zigzag lines.
Making More Mussels: Reproduction
It seems that not many young Neosho muckets survive to become adults. This might be because young mussels often bury themselves deep in the riverbed. This makes them hard to find during surveys.
Like other mussels in the Lampsilis group, female Neosho muckets have a clever way to attract fish. They have special flaps on their mantle (the soft body part inside the shell) that look like small fish. These flaps act as a lure!
When a fish, like a smallmouth bass or largemouth bass, tries to eat the lure, it touches the mussel's gills. This causes the mussel to release its tiny baby mussels, called glochidia, into the water. The glochidia then attach themselves to the fish's gills, where they grow for a short time. The only known fish hosts for the Neosho mucket are smallmouth bass and largemouth bass.
Neosho muckets are "short-term breeders." This means they lay and care for their eggs from May to August. The baby mussels are released within a few weeks after the eggs are fertilized. This is different from many other mussels that keep their eggs over the winter. Breeding for a shorter time might help them avoid dangers like bacteria or predators.
Neosho muckets can live for a long time, sometimes over 30 years!
Other Behaviors
The Neosho mucket is very good at digging its foot into gravel. This helps it stay put in fast-moving water. This ability might be why it does so well in places like the Spring River, where currents are strong.
Scientists think that the Neosho mucket might have first developed in rivers like the Spring River. These rivers have strong currents and clear water, which would be good for its foot-anchoring ability and its colorful lure.
Challenges for the Neosho Mucket: Status and Threats
The Neosho mucket is listed as an Endangered species by the IUCN. This means it's at high risk of disappearing forever. Its habitat has shrunk by 70% in the last 25-50 years, and its numbers are still going down.
Main Threats
Many things threaten the Neosho mucket, mostly caused by humans:
- Dams and reservoirs: Building dams creates large lakes (reservoirs) that change the river flow and habitat.
- Pollution: Muddy water (siltation) and pollution from farms, lead, zinc, and gravel mining harm their freshwater homes.
- Deforestation: Cutting down trees can lead to more soil washing into rivers, making the water muddy.
Scientists have known since the 1960s that these mussels are sensitive to pollution and muddy water. Also, the low number of young mussels surviving makes the problem worse.
Most of the decline has happened in Oklahoma and Kansas. In Oklahoma, the Neosho mucket is now only found in a small part of the Illinois River. Even in Arkansas, the number of places where they live in the Illinois River dropped by 53% between 1998 and 2008. Many of the remaining groups of mussels in Arkansas seem to be struggling.
The Neosho mucket has always been considered rare. Its total population is estimated to be around 100,000 adult mussels. This natural rarity might make it more vulnerable to disappearing from local areas.
Because of these ongoing problems, the U.S. Fish and Wildlife Service considered adding the Neosho mucket to the Federal List of Endangered and Threatened Wildlife in 2000. More research is needed to help protect this species effectively.
Natural Threats and Invasive Species
Besides human impacts, there are also natural threats:
- Predators: Young mussels can be eaten by flatworms. Raccoons also eat mussels, especially when water levels are low in winter.
- Diseases: Sometimes, parasites called trematodes can infect adult mussels and cause them to die.
- Invasive species: Non-native species like zebra mussels and Asian clams compete with the Neosho mucket for food and space.
Neosho Mucket and People: In Relation with Humans
The Neosho mucket is a good choice for projects that try to breed mussels in captivity and then release them into the wild. This is because they are large, grow relatively fast, produce many babies, and their host fish (largemouth bass) are also commonly raised in fish farms. People have been trying to raise these mussels in captivity since the 1920s.
Raising Neosho muckets has been successful at fish farms in Chesapeake, Missouri. Young mussels raised in captivity have survived for 16 months after being released into rivers in Kansas. These released mussels were the first young Neosho muckets found in the wild in Kansas. Breeding these mussels in captivity will be very important for helping wild populations recover.
In 2001, the Neosho mucket was given a special "candidate status" by the U.S. Fish and Wildlife Service. This led to the creation of the Neosho Mucket Recovery Working Group. This group helps organize efforts to protect the species.
In the past, before the Neosho mucket was identified as its own species, it was likely used by people. It might have been popular for making pearl buttons. This use could have contributed to the decline in its population that we see today.
See also
In Spanish: Lampsilis rafinesqueana para niños
