Sickle darter facts for kids
Quick facts for kids Sickle darter |
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The sickle darter (Percina williamsi) is a small freshwater fish. It belongs to a group of fish called darters. These fish are part of the larger family that includes perches. The sickle darter was first officially named in 2007.
This fish is closely related to another darter called the longhead darter (Percina macrocephala). Sickle darters are usually about 90.5 mm (3.56 in) long. They have a slender body and a long snout. Scientists believe they eat small crayfish and mayflies, just like their close relatives.
You can find sickle darters in the upper parts of the Tennessee River system. This area covers parts of Tennessee, North Carolina, and Virginia. They like clear creeks and small rivers in the Appalachian Mountains. They prefer places with rocky, sandy, or silty bottoms.
Sickle darters have a dark bar under their eyes. They also have a black spot at the base of their tail fin. These marks help tell them apart from other darters. They also have larger scales than the longhead darter.
Sadly, the sickle darter has disappeared from many places where it used to live. This is mainly because of farming activities. These activities can cause dirt and mud (called silt) to get into the water. This makes the water cloudy (turbidity), which is bad for the fish. Even so, where they are found, you can often see them regularly.
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Where They Live
The sickle darter is mostly found in the upper Tennessee River system. This includes parts of Tennessee, Virginia, and North Carolina. They have also been seen in other rivers. These include the French Broad System, the Emory River, and the Holston and Clinch Rivers. A few have been found in the Little River in Blount County, Tennessee.
The biggest sickle darter ever found was 90.5 mm long. It was caught in the Holston River. Because of where they live, these fish are considered a type of subtropical fish. Before 2007, people thought the sickle darter was the same as the longhead darter. Since it's a new species, scientists are still learning a lot about it.
You can often see these darters in the rivers they live in. However, it's hard to find them in between these areas. This is likely because of human activities. Farming, city growth, and factories can cause water to become cloudy and muddy. This harms the darter's home.
Their Environment
The sickle darter is a bit bigger than its close relative, the longhead darter. This suggests it lives in larger, flowing pools, often a meter or more deep. It is a bottom-dwelling fish. This means it swims close to the riverbed. They often hide near wood or plants to catch their food.
Sickle darters like clear creeks and small rivers. They prefer rocky, sandy, or silty bottoms. They swim in the water currents. It's hard to measure exact water conditions for such a small fish. So, we don't have exact numbers for things like water speed or how much dirt is in the water.
Scientists think sickle darters eat crayfish and mayflies. This is what their close relative, the longhead darter, eats. Larger fish that eat other fish might prey on sickle darters. However, not many animals hunt them because of where they live in the water.
Other darters, like the tangerine darter and the logperch, compete with the sickle darter for food and space. Human activities are making the water cloudy and muddy. Sickle darters do not do well in these conditions. Because of this, their homes are shrinking, and their numbers are going down.
Life Cycle and Reproduction
Sickle darters lay their eggs in late winter. They choose shallow areas with gravel. They are polyandrous, meaning one female mates with several males. They breed once a year. The parents dig a shallow hole, lay eggs and sperm, and then cover them up. This protects the eggs.
A female sickle darter can lay about 350 eggs at a time. One female caught had 355 eggs. After laying the eggs, both parents leave the nest. The eggs hatch later. Male darters usually become ready to reproduce at 11 to 13 months old. Females are ready at 22 to 25 months old.
Sickle darters usually live for about three years. Some can live up to four years. Compared to smaller darters, sickle darters lay more eggs. They also have a longer time for laying eggs and grow faster. This is because they are larger.
The sickle darter has a long, thin body and a long snout. It has a straight black line along its side. It also has a spot between its two back fins. As mentioned, it has bigger scales than the longhead darter. Mud and cloudy water from human activities are very harmful. They can smother eggs and young fish, stopping new generations from growing.
Protecting the Sickle Darter
The sickle darter is seen often in some streams. But it is very spread out between these areas. It has disappeared from North Carolina. It is rare in Virginia. In Tennessee, it is considered a threatened species. Even with this information, the sickle darter is not yet on any state or federal protection list. Other darters, like the ashy darter, are on these lists.
Since the sickle darter was only named a new species in 2007, not much has been done to protect it. This is because scientists are still learning about it. Research is ongoing to find out more about the sickle darter. Until then, it's hard to make a clear plan to help its numbers stay steady. Also, no non-government groups are actively working to protect this fish. This makes it harder to help its shrinking populations and habitats.
The biggest problems for the sickle darter come from farming, factories, and city activities. These cause the water to become cloudy and muddy. This destroys both the fish's nests and their living spaces. Other dangers include pollution from coal mining and other industries. Dams and other barriers in rivers also hurt them. These things reduce where they can lay eggs and cause their numbers to drop.
Muddy water is the most damaging problem. It destroys many darter nests. This stops future generations of fish from growing up. Better farming methods should be used near streams and rivers. These methods can help control how much dirt gets into the water.
About Its Name
The sickle darter was first officially described in 2007. This was done by two American fish scientists, Lawrence M. Page and Thomas J. Near. They found the first official specimen near Broadford, Virginia. The fish's specific name, williamsi, honors another fish scientist named James David Williams.
