One-spot Butterflyfish

Facts about the One-spot Butterflyfish, it is a common name for several types of butterfly fish.

All in a Name

The One-spot Butterflyfish is also called the teardrop butterfly fish, Pacific Teardrop Butterflyfish, and limespot butterfly fish. Its scientific name is Chaetodon unimaculatus.
A related species, Chaetodon speculum, is also called the one spot butterfly fish, speculum butterfly fish, oval spotted coral fish and oval spot butterfly fish. Chaetodon speculum is also called the mirror butterfly fish.

Physical Description

This One-Spot Butterflyfish, species name Chaetodon unimaculatus, can reach almost eight inches or 20 centimeters in length. The One-spot Butterflyfish has a protruding snout and strong jaws. The dorsal fin in this species is continous. The One-spot Butterflyfish has a rounded tail fin.
The Chaetodon speculum or one spot butterfly fish also feeds on coral along with Christmas-tree worms. It is similar in size to Chaetodon unimaculatus. However, Chaetodon speculum is flat, bright yellow all over with the single black spot on the top of its body. The Chaetodon unimaculatus has a mostly yellow body and a black spot on top, but it has a large white patch on the lower half of its flat body, a black stripe near the tail, a vertical black stripe that includes the eye, and a white snout. The Chaetodon unimaculatus has a tearing eye spot most noticeable as a juvenile that fades somewhat with adulthood.

Behavior

Either species of this One-spot Butterflyfish will eat hard corals and soft corals as well as invertebrates. The One-spot Butterflyfish will eat part of the skeleton of the coral as it eats the living polyps. The One-spot Butterflyfish eat algae, sponges, marine worms, and most fish foods. Those kept in a tank should be offered meaty foods like diced table shrimp, mysis shrimp, Japanese Nori, angel formula, spirulina, dried flakes, and perhaps sponge based foods. Adults should be fed twice a day, while juveniles eat three or four times a day.
Juveniles of Chaetodon unimaculatus are solitary but adults are seen in pairs or small groups. Given their size of eight or so inches fully brown, it is best if the one spot butterfly fish of either species is the only fish of its size in the tank. If the tank is large enough, it can be kept with others of its species and even other species of butterfly fish. The One-spot Butterflyfish gets along with gobies, basslets, wrasses, cardinal fish, and angel fish. The One-spot Butterflyfish will not be aggressive toward clownfish or anthias. It can be aggressive with damselfish and dottybacks. The One-spot Butterflyfish are a threat to starfish, sponges, crabs, snails, shrimps, tunicates, sea fans, and polyps.

Habitat

Both species of One-spot Butterflyfish live in the tropical reef in the wild. However, it is not recommended that they be put in a reef aquarium. The One-spot Butterflyfish eat all types of coral, anemones, and invertebrates, destroying the man-made reef faster than it could possibly regenerate.
Because of their size, these fish need at least 75 gallons for a single one. Provide both rocks for places to retreat and open water for swimming. Their ideal water temperature is 74 F to 81 F or 23 C to 27 C.

Range

The One-spot Butterflyfish of either species is found throughout the Indian Ocean from Christmas Island to the Keeling Islands of Australia. It is found throughout the Pacific up to Hawaii.

Trivia

The common name of the One-spot Butterflyfish is applied to several different species. If shopping for a One-spot Butterflyfish, specify the species you are looking for since they in reality look quite different.