The butterfly fish are a group of tropical marine fish belonging to the family Chaetodontidae. There are approximately 129 species of butterfly fish that are mostly found on the reefs of the Atlantic, Indian, and Pacific Oceans. Butterflyfish look like smaller versions of angelfish (Pomacanthidae), but lack preopercle spines at the gill covers.
Thanks to their beautiful colors and patterns and docile personality, many butterfly fish are popular aquarium fish, and they are often found as pets. The name Chaetodontidae is a combination of two Ancient Greek words: chaite, meaning hair, and odontos, meaning tooth. This is probably a reference to the rows of brush-like teeth in these fishes’ mouths.
This Chaetodontidae family should not be confused with the freshwater butterfly fish (also known as the African butterfly fish). Endemic to the West African region, the freshwater butterfly fish belongs to an entirely different order. The freshwater butterfly fish is more closely related to other African fish in the order of Osteoglossiformes.
Butterfly Fish Characteristics
Butterfly fish are closely related to angelfish and both groups are collectively known as coralfish. Butterfly fish are small fish and most do not exceed 12 to 22 9.7 to 8.7 inches in length. The largest of the species is the lined butterfly fish (Chaetodon lineolatus) and the saddle butterfly fish (Chaetodon ephippium) which grows to 12 inches in length. Butterfly fish are, in general, sexually monomorphic (meaning males and females look alike), although occasionally males have been found to be larger than females.
These fish are named for their brightly colored and strikingly patterned bodies, in shades of black, white, blue, red, orange and yellow. Some species are dull in color. Like patterns seen on butterfly wings, many of the species have eyespots on their flanks and dark bands across their eyes. Their coloration makes them popular aquarium fish, and as they are relatively small, they don’t need a large fish tank to house them.
Butterfly fish have uninterrupted dorsal fins with tail fins that may be rounded or truncated, but are never forked. The dorsal fin on the back sometimes features sharp spines which provide a defense against potential predators.
Their bodies are deep and laterally compressed, which allows them to slip between rocky outcroppings and reef crevices. This, combined with their bright colors, has lead many to believe they are intended for interspecies communication.
These fish also have a protruding snout, varying in length depending on the species, that is tipped with a small mouth. This extended snout allows them to reach inside cracks and holes to feed small organisms hiding within.
Lifespan
Butterfly fish have an average lifespan of between 5 and 10 years.
Diet
Butterfly fish eat mostly small invertebrates such as sponges, worms and plankton.
They’ll also eat coral polyps, algae and sea anemones. They feed during the day, at the bottom layer of the seabed.
Behavior
Butterfly fish are diurnal animals, which means they are active and feed during the day
and rest on the coral during the night. At night, butterfly fish hide in reef
crevices and their colors can fade to blend and avoid predation.
The smaller species of butterfly fish tend to stay in groups, whereas the larger species
are usually solitary or swim with their mating partner, with whom they mate for
life. The butterfly fish relies on its sight to find prey and communicate with
others.
Reproduction
Butterfly fish are specific about the time of year that they mate; in the tropics, the spawning season usually peaks in winter or early spring, but in temperate climates, the spawning season takes place in the summer.
When the female is ready to mate, her stomach becomes swollen with eggs. The male will come up from behind and gently nudge her abdomen with its snout, and they will release the eggs and sperm together, creating a white cloud in the water. Some males without a mate may swim in and quickly add his sperm to the cloud!
Gestation is only 28 to 30 hours. Butterfly fish play no part in raising their young and instead, the young have a unique larval stage in which they develop a plate of bony armor over the head to protect themselves. This plate eventually extends outward along the back to form spines, which are eventually absorbed into the body.
The young butterfly fish enters a juvenile stage when it has reached the size of a coin, during which period it exhibits different color patterns from its adult form. Juveniles will live within small tidal pools or shallow areas temporarily before moving to the corals.
Butterfly fish form monogamous pairs for at least three years and sometimes even their entire lives. They reach sexual maturity at around a year old.
Location and Habitat
Butterfly fish are mostly found in the coral reefs of the Atlantic, Indian and Pacific Oceans, in temperate, tropical and subtropical waters. The greatest concentration of species is found in a stretch of Pacific territory between Australia and Taiwan. Only four species occur in the Eastern Pacific and 13 in the Atlantic Ocean.
Their preferred habitat is the shallow warm water less than 65 feet deep near shores or estuaries, but a few species reside in deep water habitats up to 650 feet. They are well adapted to life in coral reef systems, though a few species also inhabit seagrass beds, lagoons, and mudflats. Young butterfly fish may occupy different areas than adults, such as tidal pools, boulder reefs and shallow areas without coral.
Conservation Status
The exact population of the butterfly fish is unknown, but it is one of the most most common types of coral reef fish in the world. The species is listed as least concern on the IUCN Red List. That being said, they do face threats. The biggest threat to these fish is the destruction of the coral reefs.
The butterfly fish is never caught for food, but it is popular in the exotic pet trade. These animals can make good pets, but they have very specific requirements that can be demanding for the average fish owner.
Predators
The butterfly fish is preyed on by sharks, eels, snappers, and other large fish. Because they are very small, they have the ability to hide in small crevices around coral reefs. Many of the species have also evolved spines, armor, and toxins to deal with threats from predators.
SOURCE: ANIMALCORNER.ORG