Butterflyfish – A Complete Guide (Care, Diet, Facts)

There is no wonder why the butterfly fish is a fan-favorite among aquarists. With over 115 documented species, these fish come in an array of colors, shapes, and sizes. Some swim and hunt in groups, while others prefer solitude. Some species eat only coral, while others enjoy a variety of marine plant and animal delicacies. Despite so many differences, they all have one thing in common: a quiet, graceful, and vibrant beauty.

Butterfly fish are tropical, and sometimes temperate, commonly found in the shallow waters of the Atlantic, Pacific, and Indian Oceans. They can be seen playfully darting along coral reefs at tourist destinations during a snorkeling session.

Their inspiring good looks do, however, come with a delicate care regime. Bearing that in mind, if you intend to purchase a butterfly fish, you should undergo extensive research about the care and maintenance of your specific species.



The butterfly fish comes from the Chaetodontidae family of the Perciformes order. Perciformes are ray fish and they make up close to 40% of the world’s bony fish population. More than 6,000 species in over 150 different families are placed in the Perciformes order.

A number of large game fish harvested for human consumption, such as tunas, mackerels, and swordfish, fall into this placement. Sunfishes and perches are also popular freshwater and sport fishes in this order.

Many species in the Perciformes order are kept as aquarium pets. Perciform fish are commonly found amidst the coral reefs of the tropical, subtropical, and temperate regions. They can range in size, from the miniscule 1.2cm adult goby from the Philippines, to the 11 ft length of the bluefin tuna or black marlin. The general length of these fish are between 12 to 98 inches, our larger species of butterfly fish falling into the very beginning of that range.

The bannerfish and coralfish belong to the same family as the butterfly fish. They share the same habitat and are often mistaken for one another as they are all vividly beautiful reef fish. Another close relative is the angelfish, though they are generally larger than most species of butterfly fish, discounting the larger lined and saddle butterfly fishes.

Life Cycle

Butterfly fish lay eggs in clutches of 3 to 4 thousand at a time. They are round, transparent, and buoyant. A small speck of oil behind the yolk keeps the fish upside down in the sac, just below the surface of the water. After 28-30 hours, the eggs hatch, and the larvae emerges.

At this point, the larvae – called fry – form plates on their heads in an armored phase called tholichthys. Depending on the species, the bone-like armor will develop into different sized plates and spines across the fry’s body. The fry are generally a silver color during this phase. This protective growth is unique to the butterfly fish among other shallow water-dwelling fish.

The fry tend to remain floating among the plankton – where they were lain as eggs – for around two months. Once they reach a size of 20 mm, the fry will sink to the bottom of whatever waterscape they are occupying. As they settle, the fry absorb their plates and quickly develop into juveniles.

Juvenile butterfly fish occupy tidal pools, boulder reefs, and shallow areas without coral. They find habitats with a food source away from adults. At this stage, they are usually solitary creatures. In many species of butterfly fish, the juvenile will have different color and pattern variations than that of their adult counterparts. Juveniles will become sexually mature at about one year of age.

Butterfly fish typically live to be seven years old in the wild. In captivity, given the right tank and feeding conditions, adult butterfly fish can live up to ten years.


Once butterfly fish reach sexual maturation at or about the one year mark, they will mate with one fish for at least three years, if not for life. Courting is very active and energetic; females and males can be seen chasing each other in tight circles before breaking off. During this courtship, the couple will chase off any stragglers who come to view or interrupt their ritual.

Peak spawning season varies from region to region and by species. Butterfly fish in tropical regions take to the winter months. Midsummer is more suitable for fish in temperate regions. Other species will mate throughout the year, unhindered by the seasonal changes.

During mating season, females can easily be spotted with their swollen bellies full of eggs. As dusk arrives, she will rise above the normal swimming and hunting grounds for spawning. When the male spots her, he will swim below her and press on her belly with his trunk. Upon the release of her clutch, the male will release his cloud of sperm. This is an optimal time for other males to add to the mix, if they are fast enough. The clutch then rises to the plankton above, and the adults swim back to their normal depths below.

It is not very common for butterfly fish to successfully breed in captivity. It is also unclear as to whether butterfly fish care for their young. Due to the difference in their locations, however, it can be safe to say that fry and juveniles are mostly left to fend for themselves.


Colors and Patterns

As previously mentioned, these creatures come in a variety of colors. They are predominantly yellow, white, and black. You will, however, find many species sporting vivid blues, striking oranges, and radiant reds. The intensity of these hues have earned these fish the nickname “poster fish”. Other species still are more dull than their flamboyant family members, donning more grey tones.

Butterfly fish may change colors as a means of communication as well as camouflage. Yellows will become more prominent during displays of territorial aggression. At night, bright colors will fade to become less visible to predators.

Bands, stripes, and lattice patterns are common designs among the butterfly fish. The Pyramid Butterfly fish is seen with what appears to be a large white triangle on the bulk of its body, framed by bright yellows.

Most butterfly fish have bands across their eyes and dark spots near their tails. The spots greatly resemble eyes, thus helping to confuse predators about the location of the fish’s head. This may deter serious injury when a predator attempts to bite at its head. It will also prove difficult to determine which direction the butterfly fish will swim.


The bodies of the butterfly fish are round and very thin laterally, resembling a small disk or pancake. This compact shape allows easy access to the cracks and crevices of coral and boulder reefs. This keeps our fish friends safe from predators while also affording them an advantage during mealtimes.

They have an uninterrupted dorsal fin and rounded or truncated tail fins (known as caudal fins). The constant movement of their pectoral fins give them their quick, powerful movements. They can even swim sideways and upside down!

They have elongated jaws which vary by species and eating habits. Longer jaws are useful in gathering small invertebrates, while shorter jaws aid in the trimming of coral polyps. Butterfly fish have small, bristle-like teeth.

Adult butterfly fish range from 4 to 8 inches in size. The lined butterfly fish and the saddle butterfly fish are the largest at 12 inches. The smaller species are more likely to travel in groups, while the larger are generally solitary or mated-pair swimmers.


Depending on the species and the particular habitat of these fish, their diets can be rather diverse. While the majority of their food sources consist of corals, sea anemones, sponges, and algae, these omnivores will also snack on seaweed, small crustaceans, zooplankton, and worms.

In captivity, butterfly fish are also known to eat dried shrimp, brine shrimp, and possibly manufactured flakes. Consumption of the latter is based on the fish observing another fish in the tank eating it, thereby eating by example.

The most sought-after meal for the majority butterfly fish species is the coral polyp. Coral polyps are soft-bodied organisms similar to sea anemones or jellyfish. They have a hard limestone skeleton base called a calicle, which forms the structure of a reef. A coral reef is started when a polyp attaches to a rock and replicates, possibly hundreds of times.

Corallivores can maintain their simplistic diet of polyps alone, but other species must maintain a varied diet in order to remain healthy. Many fish owners buy prepared foods from reputable dealers. Some even make their own from fresh and frozen ingredients.


Butterfly fish live in the warm salt water of the tropical, subtropical, and temperate regions. Only four species are found in the east Pacific Ocean and thirteen in the Atlantic Ocean. The rest can be found in the West Pacific and Indian Oceans.

Coral reefs are the popular locale for the butterfly fish, but they can be found in other shallow waters. Tidal pools and boulder reefs are a favorite among  juveniles that want to stay out of the way of the more territorial adult corallivore fish.

Brackish estuaries – coastal bodies of water with a combination of fresh water and ocean water flowing into them – have an abundance of water and sediment nutrients. This makes it an ideal place for a plethora of marine life, the butterfly fish and its prey among them.

Mangrove swamps and mud flats prove to be great nurseries for fry with their nutrient rich soils and waters. The extremely shallow pools make it difficult for larger predator to get to the eggs and fry within.

Seagrass meadows can do a lot to satisfy the butterfly fish. There are lots of hiding places amidst the billowing plants to dodge predators as well as plenty of space to swim. Different types of algae, juicy worms, and, of course, an abundance of seagrass are all prime eats for the butterfly fish here.

Tank Requirements

The specifics of how a butterfly fish’s tank must be kept will vary from species to species. Tanks should be large enough to allow your butterfly fish to swim and play, mocking the reefs or pools they are naturally accustomed to.

Smaller fish will require at least 75 gallons of water while bigger fish will require 150 gallons or more. If you will have multiple creatures in your tank, aim for a large one to accommodate all the needs of your aquatic family members


Salinity levels, aeration, and temperature are all key elements to successfully keeping your butterfly fish. These creatures are very sensitive to even minor fluctuations. A small adjustment could wreak havoc to their system. This being said, you should do your research before your fish arrives, not after. Unstable tank conditions will lessen your fish’s quality, and possibly length, of life.

They should be kept in fish-only tanks, or those with only fish and live rocks. Raccoon butterfly fish and merten’s butterfly fish are two examples of species that may be kept in a live reef tank. If you are unwilling or unable to care for live coral, do not buy a species of butterfly fish that is corallivorous.

Due to their extreme sensitivity, you should undergo a gradual acclimation to the tank upon arrival. Juveniles are best at adaptation on all fronts, so it would be wise to attain one in lieu of an adult. Tanks should be cleaned regularly in a gradual fashion, so as not to upset the balance. It is wise to introduce cleaner fish to your tank to maintain stability and cleanliness.

Tank Mates

It is important to know which kinds of partner fish you can keep in the tank with your butterfly fish. If you intend to keep more than one butterfly fish together, be sure the species you have purchased are passive, non-territorial ones. The smaller species which don’t dine on coral will be more suitable for keeping together in large groups. For bigger or naturally solitary species, a male to female pair would be the best solution.

Aggressive breeds of fish should be avoided. Any signs of aggression between any fish in the same tank may warrant a  separation. This can be accomplished by placing a large net inside the tank to prevent the fish from physically reaching each other while still allowing them to see each other. If they still exhibit aggressive behavior after you have separated them in this capacity, a total tank separation may be necessary for both parties’ sake.

Clown fish, gobies, damselfish, tangs, parrotfish, and hogfish are all suitable friends to keep in a tank with your butterfly fish. Gobies are an especially good choice as they will promote overall health and cleanliness by consuming leftover waste. They are also known to eat parasites from the gills and scales for part if not all of their sustenance. Parasites are common among reef fish in the wild (the butterfly fish included), along with bacterial infections.

Keep in mind that your butterfly fish needs adequate space to swim and hide to remain happy.  Don’t overcrowd your tank with multitudes of creatures or exorbitant amounts of decorations. Tank diversity or aesthetic pleasure should not be held priority over the quality of life of the rest of your fish. Natural predators, such as sharks, eels or snapper fish, as well as other large or fresh water fish, should be avoided. Integration of these creatures will undoubtedly cause a short life span for your beautiful butterfly friend.

Acclimation Process

Your butterfly fish will likely be caught by a diver from its natural habitat and then shipped in its original water. When your specimen arrives, it may be wise to put it in a quarantine tank before introducing it to an established tank with other fish in it, as it may have a parasite or disease. This way you will be able to observe it before transferring it. This option may take a couple of weeks.

When your fish arrives, you will take the shipping bag and place it in the tank, letting the temperatures adjust. After an hour, cut the top of the bag off and pour a small amount of the tank water into the shipping bag. Do not let the shipping water empty out into the tank. If you need to let some water out of the bag to prevent it from overflowing, use a clean utensil to scoop some of out and dispose of it. Repeat this process several times, once every hour, over the course of about ten hours.

After you have gone through the water switch, take a net and scoop your new friend out of the bag and place him inside the tank. Live coral will need to be carefully transferred without air exposure. Again, do not dump the water into the tank. Some may get into the tank when transferring coral. Dispose of the shipping bag and its contents.

If purchasing from a pet store, ask to see your fish eating before you take him home to ensure he will eat for you. It can take a while for your butterfly fish to eat after the shock of transfer. It may only eat live food for a while. Some aquarists are reportedly successful introducing live clams on a half shell upon arrival.

Once they start eating, they can be switched to a frozen or dried food diet. It may take to flakes if another fish in the tank eats it. It is not very common for flakes to be a success with butterfly fish.

Things to Avoid Putting in your Tank

Protecting your fish from unsafe decor is an important step in your tank set up. While many cute and intriguing houses, rocks, and wood are found in your local pet store, they aren’t always safe for use in a live tank. A general rule of thumb for these objects is to keep food-safe and/or properly treated items in your tank.

Plastic castles, while charming to look at, can leech chemicals into the water after long-term exposure. Ask your pet store attendant if their plastic decor is food safe, or look for the universal wine glass and fork symbol. Do not put single-use food containers, like plastic water bottles, in your tank as these will also release pollutants over a long period of time.

Drift wood can be an attractive addition to your tank. Hardwoods are the best option, as they have a slow deterioration rate. They must be treated with a non-toxic seal to ensure the safety of your tank life.

Metals will leech harmful elements into your water. Clay is known to contain metal compounds. Due to the fact that clay can break, it is unwise to keep kiln-fired pottery in your tank. If you insist on adding them, however, make sure it contains no chemicals or metals and frequently check for chips.

Chipped clay and broken glass pose a significant risk. A cut gone unnoticed or unaddressed can prove fatal. Degradable materials should also be avoided, as your fish may nibble and ingest them. They can also upset the balance in your tank once the material dissolves into the water.

Sand should come from a reputable dealer and should be specifically designed for aquatic use. Beach or industrial sand could contain waste and toxins. If you want to use beach sand, it must be thoroughly rinsed repetitively before your fish arrives. Pebbles or rocks should be big enough that they can not be ingested.

If you need to put your hands inside your fish tank, make sure you have thoroughly cleaned them. Bacterial infections can ensue from improperly cleaned hands. Any residue from soaps, creams, perfumes, or lotions could drastically affect the sensitive creatures in your tank.


With their intense colors and eye-catching patterns, butterfly fish are a spectacular sight to behold. Tourists and aquarists from around the globe can all appreciate the diversity and attraction of this reef-dwelling fish.

For those who desire a butterfly fish pet, it is extremely important to do the research first. They are difficult to care for and require a lot of patience and adjustment. If you have the experience, time, and savings to care for these divine creatures, go for it! Otherwise, it may be best to leave it to the fishkeeping experts.

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