Banded pygmy sunfish facts for kids
Quick facts for kids Banded pygmy sunfish |
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The banded pygmy sunfish (scientific name: Elassoma zonatum) is a tiny fish found only in the United States. It lives in slow-moving water with lots of plants, like ponds and swamps. This fish is quite small, usually less than 3.5 centimeters (about 1.4 inches) long.
Even when they are old enough to have babies, banded pygmy sunfish can keep some of their young features. Scientists first thought this fish was part of the cichlid family. But later, they realized it was special and put it in its own family called Elassomatidae. Some books now consider it a smaller group (subfamily) within the larger sunfish family, Centrarchidae.
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What's in a Name?
The scientific name for the banded pygmy sunfish is Elassoma zonatum. The word Elassoma means "small body," which makes sense because these fish are tiny! The word Zonatum means "banded," referring to the stripes on their bodies.
Where Do Banded Pygmy Sunfish Live?
The banded pygmy sunfish is a small fish that can live in many different watery places. You might find it in rivers, streams, lakes, ponds, and even swamps. These fish have always lived in the United States, mainly around the Mississippi River and the Gulf Coast.
Today, you can find them from North Carolina down to Florida. They also live west to Texas and north to Indiana and Illinois. These fish like calm or still water with lots of mud or dirt at the bottom. This is why they love swamps and ponds so much.
Sadly, people building homes and farms have drained many wetlands. This means the banded pygmy sunfish has lost some of its homes. Even though they can move to lakes or rivers, they really need wetlands to lay their eggs. When wetlands disappear, the fish can't breed, and their numbers go down in those areas.
What Do Pygmy Sunfish Eat?
Scientists have studied what banded pygmy sunfish eat by looking at their stomachs. They found that these fish mostly eat tiny insect larvae, small crustaceans (like tiny shrimp), and snail eggs. The crustaceans and snail eggs were their favorite foods. They also ate a few tiny bits of algae, probably by accident. They do not eat other fish or even their own babies.
Banded pygmy sunfish can live in water with very little oxygen, like swamps and ponds. Not many fish can survive in such low-oxygen places! Other fish that might affect them include live-bearers, grass pickerel, and bowfins. Bowfins sometimes eat pygmy sunfish. Grass pickerel and live-bearers might compete with them for food.
Besides fish, water snakes and birds that eat fish are also enemies of the banded pygmy sunfish. Water beetles and dragonfly babies (nymphs) compete with them for insect larvae. Wetlands are super important for these fish. They offer thick plants for hiding from predators and a safe place for snails to lay eggs. Wetlands are also full of insect eggs and larvae, which are great food sources. So, when wetlands are lost, it affects many other animals too, not just the pygmy sunfish.
How Do Pygmy Sunfish Grow?
Banded pygmy sunfish usually lay their eggs in the spring, often in March. They like to lay eggs on plants like Ceratophyllum if they can find them. If not, they scatter their eggs on rocky bottoms in calm water. The whole egg-laying process takes only about 5 to 6 minutes.
After the female lays her eggs, the male chases her away from the nest. This is because she might eat the eggs! A female can lay eggs two or three times a year. She might lay anywhere from 96 to 970 eggs, depending on her size. The eggs are tiny, about 3.7 to 3.8 millimeters (about 0.15 inches) wide.
It takes about 110 hours (a little over four days) for an egg to hatch. The newly hatched babies look like tiny tadpoles. They are very small, about 3.5 to 3.7 millimeters long. They don't have eyes or mouths yet. They get food from their yolk sac until their mouths grow. Young fish are about 8 to 8.5 millimeters long. It takes about 100 days for a baby fish to grow into an adult. Cooler temperatures (around 21–23°C or 70–73°F) are best for them to grow.
These fish become old enough to have their own babies when they are one year old. On average, a banded pygmy sunfish lives for about 2.5 years. The oldest one ever recorded lived for three years.
How Do Pygmy Sunfish Find Mates?
Male banded pygmy sunfish become very bright and colorful before and during the time they lay eggs. Females keep their normal colors.
Males have two main ways they act during this time:
- The "Sliding Threat Display": If another male swims into a male's territory, the male who owns the territory will swim close to the intruder. He will spread out his fins to look bigger and make his body colors much brighter. He will also quickly beat his tail. Then, he turns sideways to look even larger. If this doesn't scare the intruder away, the male will quickly strike at the other fish. It happens so fast that scientists can't even tell if they touch! Both fish usually swim away unharmed. The intruder leaves the territory, and the winner chases him away.
- The "Wiggle Waggle Display": This happens when a female that might be a mate swims into a male's territory. The male slowly swims toward her. If she stays, he starts to "dance" in a strange way. He swims up and down toward the plants where they might lay eggs. He also raises and lowers his top and bottom fins and opens and closes his side fins. This dance can last a few minutes. Then, the male might gently bite the female a few times to get her to join him at the egg-laying spot. Once the female is there, the male becomes very colorful, and the female gets into the best position to lay her eggs in the plants.
After the eggs are laid, the male usually guards the nest for the next 72 to 100 hours (about 3 to 4 days).
Protecting the Banded Pygmy Sunfish
Some types of pygmy sunfish are on the threatened species list, but the banded pygmy sunfish is not. It is found in enough places that it's not considered in danger by the government. No state has listed it as threatened either.
The biggest danger to this fish is losing its habitat. When wetlands are drained for buildings or farms, the places where they breed and find food disappear. Luckily, there are efforts to protect wetlands across the country. The USDA has rules to keep at least 2% of wetlands in every eastern state. Even though there isn't a special group just for this fish, protecting wetlands helps them and many other species.
This fish is tough! It can live in water with low oxygen and warmer temperatures. While some pygmy sunfish can mix and have babies with other types of pygmy sunfish, the banded pygmy sunfish cannot.
Scientists keep an eye on these fish by using nets to count them. They suggest that places with many banded pygmy sunfish should be protected. So far, no new species have been found that compete with or eat the banded pygmy sunfish.
