Freshwater butterflyfish

The freshwater butterflyfish, also known as the African butterflyfish, is a unique species of fish. Its scientific name is Pantodon buchholzi. It belongs to a group of fish called osteoglossiforms. This fish is the only living member of the family Pantodontidae. Even though it shares a name with saltwater butterflyfish, they are not closely related. This fish is a specialist that lives in freshwater habitats. It is found in the Niger and Congo basins of Western and Central Africa.

This fish is a highly specialized surface hunter. It has an upturned mouth designed to catch small prey at the water's surface. Its eyes are constantly trained upward to watch for food. The butterflyfish is carnivorous and eats aquatic insects and smaller fishes. To help it breathe, it uses a large, well-vascularized swim bladder. This organ allows the fish to breathe air at the surface. This combination of features makes it perfectly suited for life at the very top of the water.

One of the most amazing things about this fish is its ability to glide. If it builds up enough speed in the water, it can jump out. It then glides for a short distance above the surface to escape predators. During this glide, it wiggles its large pectoral fins. It uses specialized, enlarged pectoral muscles to make this movement happen. This specific motion is why the fish is called a butterflyfish.

The history of this fish goes back millions of years. The family Pantodontidae was once very diverse. During the Late Cretaceous period, many different types of these fish existed. Scientists have found fossils of early pantodontids in the Sannine Formation of Lebanon. These ancient relatives actually lived in marine environments off the coast of northern Africa. This suggests that the ancestors of the modern freshwater butterflyfish moved into freshwater habitats independently. The closest relative to the modern genus is called Palaeopantodon.

Scientists have discovered something strange about the genetics of this species. There are populations in the Niger basin and the Congo basin. They look almost identical in their physical shape. However, their DNA shows they are extremely different from one another. This difference likely began in the Late Paleocene, about 57 million years ago. This is a rare example of morphological stasis. This happens when two separate populations stay looking the same even as their genes change significantly.

The freshwater butterflyfish also has a very interesting genetic structure. It has experienced one of the largest losses of Hox gene clusters in a teleost fish. Hox genes are important for helping an animal develop its body. This fish has only five Hox clusters left. It likely lost three clusters in the past. Even so, it still has a similar total number of Hox genes as other fish. This is because it has a high number of duplicated genes in certain clusters. Because of its small size and small genome, it may become a model organism for research.

In the wild, these fish live in specific environments. They prefer slightly acidic standing water with lots of surface foliage. This foliage provides important cover for them. They are commonly found in Lake Chad and the Congo Basin. They also live in the Niger, Cameroon, Ogooue, and upper Zambezi regions. They can also be seen in the Niger Delta and the lower Cross River. They require a steady water temperature between 25 and 28 degrees Celsius.

People can keep these fish in large aquariums, but they have special needs. You should only keep one specimen in a tank. This is because they can be aggressive toward other fish. They are also known to jump, so the tank must have a tight seal. They do best with live floating plants to reduce their stress. Their water should have a pH between 6.9 and 7.1. They also prefer a diet of live insects, such as crickets.