Butterflyfish Facts

Michael Bryan

Michael Bryan

Published: 27 Aug 2021

Modified: 05 Nov 2021

underwater, coral reef, fish, butterfly fish

The butterflyfish has been traded by people for aquarium displays. Its body shape and distinctive color patterns have been an eye-catcher in a controlled environment together with other ornamental fishes. In its natural habitat, the butterflyfish is highly territorial and monogamous, meaning it only goes singly or in pairs, inhabiting shallow waters around coral reefs.

As adults, they are white with strong black vertical stripes and yellow highlights on their fins, while juveniles are distinctly darker colors and have an eyespot on their dorsal fins to confuse predators. Truly, butterflyfish are unique in terms of a lot of things compared to other fishes, and if you want to know more about them, then here are some facts that would surely satisfy your growing interest in them.

  1. The butterflyfish are a group of conspicuous tropical marine fish of the family Chaetodontidae.
  2. Butterflyfish look like smaller versions of angelfish, Pomacanthidae, but they lack preopercle spines at the gill covers.
  3. A butterflyfish mostly range from 12 to 22 cm (4.7 to 8.7 in) in length.
  4. The two largest of the species, the lined butterflyfish and the saddle butterflyfish, C. ephippium, grow up to 30 cm. The common name references the brightly colored and strikingly patterned bodies of many species, bearing shades of black, white, blue, red, orange, and yellow.
  5. Many have eyespots on their flanks and dark bands across their eyes, not unlike the patterns seen on butterfly wings.
  1. They have deep, laterally narrow bodies that can be noticed through the profusion of reef life.
  2. The butterflyfish has a conspicuous coloration intended for interspecies communication.
  3. These corallivores are especially territorial, forming pairs and staking claim to a specific coral head.
  4. Their coloration also makes them popular aquarium fishes.
  5. Most species feed on coral polyps and sea anemones.
  6. Butterflyfish are pelagic spawners. They release many buoyant eggs into the water, which become part of the plankton, floating with the currents until hatching.
  7. Hybrids are rare in nature, but butterflyfishes are the most likely reef fish to breed with other species.
  8. Butterflyfishes produce several sounds to ward off members of the same species or aid communication between a pair.
  9. Butterflyfishes that feed on coral polyps tend to be monogamous; the male defends the pair’s territory, allowing the female to feed.
  10. If you see a large number of butterflyfishes on a dive, that’s a good sign for the coral reef. These fishes require large areas of healthy coral for food, and changes in their populations can be indicative of wider issues.
  1. The butterflyfish can live up to 7 years in the wild and up to 10 years in a well-kept aquarium.
  2. The jaws of some butterflyfishes can measure more than 25% of their body length.
  3. Butterflyfishes generally stay in groups unless they are a particularly territorial species. A solitary butterflyfish is usually traveling in search of a mate. It is one of the very few fish that finds a mate who they hunt with, live, and travel together for life.
  4. Moray eels, snappers, and groupers are the main predators of butterflyfish.
  5. The family name “Chaetodontidae” derives from the Ancient Greek words χαιτέ, chaite (hair) and οδοντος, odontos (tooth).
Table of Contents

They are busybodies in the morning.

A lot of animals are classified as being diurnal, meaning active during day time, and would have an inactive period of rest during the nighttime. Butterflyfish are one of those animals. They stay active to feed during the day and hide in the corals during the night.

underwater, fishes, corals, butterfly fish
Image from pxhere

There are more than 100 different species of butterflyfish in oceans around the world.

Butterflyfishes belong to a large family of over 100 species. Their markings, patterns, and fin shape would vary greatly between species, but their overall body shape, coloration, and behavior are usually similar across the family.

They are famous for aquarium displays.

Traded primarily as aquarium ornamentals, butterflyfishes have been essential in some grand aquarium displays all over the world. People would prefer seeing them swimming around, displaying their body coloration and pattern. Their diet may make them somewhat of a problem to maintain, but the juveniles seem to thrive better in captivity than the adults.

Butterflyfishes have large fake eyes.

The butterflyfish has a large spot that looks like an eye on the tail end of its body. Their real eye is often much smaller or camouflaged within other body markings. This is to trick a predator into thinking the fish will move in the direction of the false eye, thereby giving the smaller fish a chance to escape capture.

underwater, yellow stripes
Image from Pixabay

People look at their abdomens and forewings to identify their gender.

Males tend to have a more slender abdomen and females tend to have larger rounded abdomens. Hairstreaks are a good example of this, males have triangular forewings, and the females’ forewings have a more rounded shape.

Some of them were almost goners.

As of 1994, there were five species of butterflyfish listed as vulnerable to extinction, all in the genus Chaetodon. These species of butterflyfish would have been long gone because of their limited habitats and how susceptible they were to human activities.

They have fins that resemble butterfly wings.

The African Butterfly Fish is a freshwater species that has been around for quite some time. While many fish can break the surface of the water if they want to, this species can actually glide. Their pectoral fins that resemble butterfly wings have made it possible for them to glide.

freshwater species, butterfly wings
Image from Wikimedia Commons

Butterflyfishes have a variety of food selections.

The Butterflyfish can eat a variety of food may it be zooplankton to tiny motile crustaceans and mollusks, soft and stony corals, anemones, tubeworms, and other soft and encrusting sessile invertebrates associated with live rock. They can also be opportunistic marine fish flesh-eaters.

The butterflyfish is one of the most common types of coral reef fish in the world.

Butterflyfishes have well adapted to life in narrow spaces of the vast coral reef systems, however few of their relatives also live in seagrass beds, lagoons, and mudflats. Only four species occur in the Eastern Pacific and 13 in the Atlantic Ocean. Their preferred habitat is shallow warm waters less than 65 ft deep near shores or estuaries, but a few species do reside in deep water habitats up to 650 ft.

The IUCN Red List has classified most of its species as least concerned.

While it is rather settling to know that this fish is not on the endangered list anymore, the effects of climate change still pose the greatest threat to its species. Make no mistake, though, the population of butterflyfish is in excellent health and requires no specific conservation efforts to survive.

The butterflyfish mates at a very specific time of the year.

In the tropics, the spawning season usually peaks in winter or early spring. In temperate climates, the spawning season takes place in the summer. The butterflyfish forms stable monogamous pairs for at least three years and sometimes their entire lives.

Once fertilized, the eggs hatch in a mere 28 to 30 hours later.

Parents likely play almost no role in raising and caring for their young, but to protect themselves, the butterflyfish has a unique larval stage in which it develops a plate of bony armor over the head. This plate eventually extends outwards along the back to form spines.

The Tear Drop Butterflyfish is a beautiful fish originating from the reefs of the Indo Pacific.

Suited for a larger fish-only aquarium, these fishes have a white base becoming yellow dorsally, median fins with large black eyespot on its upper side, and a black bar through the eyes. They also have a black vertical stripe which is present at the posterior end.

teardrop shape, underwater, yellow
Image from Wikimedia Commons

You can set them up in an aquarium.

If you plan to add a butterflyfish in your aquarium, then you should have a large tank of at least 70 gallons or perhaps as much as 150 gallons with plenty of reefs and other small hiding places. Butterflyfish can be fed on a standard diet of tropical fish food and flakes with a mixture of plants and meat.

They need to have the appropriate tankmates.

Tankmates can include gobies, parrotfish, and clownfish, but some species may be more territorial than others.  Also, the optimal pH for a Butterfly Fish is between 8.1 and 8.6.

An Iron Butterflyfish is expensive.

A peaceful species, their diet mainly consists of tubeworms and clams. It is expensive and worth $3,500. The Iron Butterflyfish, found only around the Izu Islands in Japan, is reportedly to sell for $3,800.

The freshwater butterflyfish is a specialized surface hunter.

These freshwater fishes are experts in capturing small prey along the water’s surface. They can jump and glide to avoid predation. Their eyes and mouth are well suited for accurately catching unwary prey.

Their youngs have armor.

Since they are very tiny and vulnerable at birth, babies develop armor plates that protect their bodies until they grow and become stronger. These bony plates extend backward from the head.

coral reef, tiny fishes, school of fish, yellow
Image from pxfuel

Released eggs become part of the plankton.

Actual spawning takes place at dusk, with the female releasing anywhere from 3,000 to 4,000 eggs. The eggs are small, pelagic, and hatch within a day. Most of the eggs released will be eaten by animals that feed on planktons.

Butterflyfish have different names in several countries.

Common English names include banded butterflyfish, banded mariposa, butterbum, butterflyfish, Portuguese butterfly, and schoolmistress. Other names are borboleta (Portuguese), chamba heel (Papiamento), demoiselle (French), gestreifter falterfisch (German), macamba kulu berde (Papiamento), mariposa (Spanish), parche (Spanish), parche rayado (Spanish), and paru-parong isda (Filipino).