Heterandria formosa facts for kids
Quick facts for kids Heterandria formosa |
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The least killifish (also called the dwarf topminnow or midget livebearer) is a tiny fish. Its scientific name is Heterandria formosa. It belongs to the Poeciliidae family, which also includes popular aquarium fish like guppies and mollies. Even though it's called a "killifish," it's not actually part of the killifish family!
This little fish is one of the smallest fish species on Earth. In 1991, a book called Baensch Aquarium Atlas said it was the 7th smallest fish in the world. As of 2006, it was still the smallest fish found in North America.
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Where the Least Killifish Lives
The least killifish is the only fish of its kind (genus) found in the United States. You can find it in the southeastern parts of the U.S. This includes states like South Carolina, Georgia, and Florida. It also lives along the Gulf Coast of Florida and goes as far west as Louisiana. Recently, some have even been found in eastern Texas.
This fish mostly lives in freshwater that moves slowly or stands still, often where there are lots of plants. But it can also live in brackish water, which is a mix of fresh and salt water. It's one of the few aquarium fish that is endemic (meaning it's only found naturally) in North America.
What the Least Killifish Looks Like
The least killifish is one of the smallest fish and smallest vertebrates (animals with backbones) known to science.
- Male least killifish grow to be about 2 centimeters (0.8 inches) long.
- Female least killifish are a bit bigger, growing to about 3 centimeters (1.2 inches) long.
These fish are usually an olive-green color. They have a dark stripe that runs along the middle of their body. There's also a dark spot on their dorsal fin (the fin on their back). Female least killifish also have a dark spot on their anal fin (the fin on their underside, near the tail).
What the Least Killifish Eats
The least killifish mainly eats small creatures that live in the water. These include:
- Invertebrates like worms
- Crustaceans (like tiny shrimp)
They also eat plant matter, so they have a varied diet.
Reproduction and Life Cycle
Like many fish in the Poeciliidae family, the least killifish is a livebearer. This means the mother fish gives birth to live, free-swimming young, instead of laying eggs.
Here's how they reproduce:
- The male fish uses a special fin called a gonopodium (which is a changed anal fin) to give sperm to the female.
- The fertilized eggs grow inside the female's body until they hatch.
- Then, the baby fish are released into the water.
The least killifish has a unique way of having babies. Instead of releasing all the young at once, the female releases them over a period of time. She might release up to 40 baby fish over 10 to 14 days, or sometimes even longer!
See also
In Spanish: Heterandria formosa para niños
