The comet or marine betta (''Calloplesiops altivelis'') is a species of reef-associated tropical

marine fish Saltwater fish, also called marine fish or sea fish, are fish that live in seawater. Saltwater fish can swim and live alone or in a large group called a school. Saltwater fish are very commonly kept in aquariums for entertainment. Many saltwater f ...

in the longfin family

Plesiopidae The longfins, also known as roundheads or spiny basslets, are a family, Plesiopidae, which were formerly placed in the order Perciformes but are now regarded as being ''incertae sedis'' in the subseries Ovalentaria in the clade Percomorpha. They ...

, most commonly found between 3 and 50 m deep. It is native to the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

Ocean. It can reach a maximum length of 20 cm.

Behaviour

Adults are usually found near reefs, and in caves and crevices along drop-offs. The comet is nocturnal by nature, and will hide under ledges and in holes by day. During night time, it leaves its hiding place and swims along the reef searching for food. They possess an eye-like shape which is actually the dorsal fin. When in danger, this fish will poke its head into a hole and expose its tail end, which mimics the head of the

moray eel Moray eels, or Muraenidae (), are a family of eels whose members are found worldwide. There are approximately 200 species in 15 genera which are almost exclusively marine, but several species are regularly seen in brackish water, and a few are ...

Feeding

Comets are predators, feeding on crustaceans and small fish. They catch their prey by approaching it swimming sideways and then waiting for the prey to try to escape. As the prey tries to escape on the side of the fish, it will escape towards the fish's mouth half the time.

In the aquarium

Comets are known to be difficult to feed in captivity, as they will generally only accept live foods. Moreover, they require time to stalk their prey. Therefore, if they are in an aquarium with other predatory fish (e.g. lions and groupers), they might starve, as they are not fast enough to get a good share of the food. Comets have been successfully bred in captivity.

References

External links

* {{Taxonbar, from=Q2573484 Plesiopidae Fish described in 1903