Two Spot Bristletooth Tang

Quick facts

Handling caution: Sharp caudal peduncle scalpel spine can cause lacerations when handled

Identity

Also known as

Twospot Surgeonfish; Twospot Tang; Two-spot Bristletooth

Synonyms

Ctenochaetus cyanocheilus (misapplied in some older trade references)

Environment

Saltwater

Native to

Indo-Pacific: East Africa, Red Sea, Mascarene Islands, Indonesia, Australia, Central and West Pacific, southern Japan

Habitat

Outer reef slopes and deep lagoons with mixed coral rubble, from about 15 to 300 feet, grazing detritus and microalgae off rock and rubble.

Sourcing

Wild-caught

Conservation

Not Evaluated

Care

Care level

Moderate

Temperament

Semi-Aggressive

Adult size

3 – 8.5 in (7.6 – 22 cm)

Lifespan

10 – 20 yrs

Min tank

75 gal (284 L)

Growth rate

Moderate

Placement

Rock & glass

Water

Temperature

72 – 82 °F (22 – 28 °C)

pH

8.1 – 8.4

dKH

8 – 12 dKH

Salinity

1.020 – 1.025 SG

Flow

Moderate-High

Behavior & compatibility

Social

Solitary

Aggression to own kind

High

Active

Daytime

Reef safe

Yes

Shrimp safe

Yes

Feeding & breeding

Diet

Herbivore

Foods

Flakes, Pellets, Frozen, Algae, Vegetables, Freeze-dried

Breeding type

Broadcast spawner

Breeding difficulty

Not bred in captivity

Sexing

No reliable external sexual dimorphism; visual sexing is essentially impossible in this species.

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Care guide

Overview

A brown-to-orange body traced with fine blue lines identifies this fish, along with the twin black spots marking the dorsal and anal fin bases that give it its common name. It grazes constantly across live rock and glass, needing mature, algae-rich surfaces to stay healthy. Best housed alone among tangs, it suits a spacious reef system with strong flow and a secure lid.

Care

A well matured system with abundant algae-covered live rock is essential, since this tang spends most of its time grazing biofilm and diatoms off rock and glass surfaces. It does best with strong, well-oxygenated water flow and plenty of open swimming space, as it is a fairly active swimmer despite being smaller and calmer than many other surgeonfish. A tight-fitting lid is recommended, since like most tangs it can startle and jump. Ich and other parasitic outbreaks are more common if the fish is stressed by cramped quarters or poor water quality.

Feeding

Most of its nutrition should come from grazing on natural algae and biofilm in the tank, supplemented with dried nori, spirulina flakes, and algae-based pellets offered several times a week. Occasional frozen mysis or brine shrimp can round out the diet, but vegetable matter should remain the bulk of what it eats. Feeding it too little algae-based food can weaken its immune response and increase aggression toward other tangs.

Tank mates

Generally peaceful toward non-tang species such as clownfish, gobies, blennies, and smaller angelfish, but it can be territorial and aggressive toward other tangs, especially other Ctenochaetus. Best kept as the only bristletooth in the tank unless the aquarium is very large and all tangs are introduced simultaneously. It rarely bothers corals or sessile invertebrates, making it a solid reef tank candidate as long as it has enough algae to graze.

Breeding

Like other surgeonfish, it is a broadcast spawner that releases eggs and sperm into open water, a behavior essentially impossible to replicate in home aquariums. Pairing and sexing are not practical for hobbyists, and there are no verified captive breeding accounts for this species. All specimens in the trade are wild-caught.

Health

Newly imported specimens are prone to marine ich and other parasitic infections, particularly if stressed during shipping or held in tanks lacking sufficient grazing surface. A slow acclimation and a quarantine period are advisable before introducing it to a display tank. Maintaining stable water chemistry and consistent access to algae helps prevent the emaciation sometimes seen in tangs deprived of a proper herbivorous diet.

Sources

1. Two Spot Bristletooth Tang (Ctenochaetu binotatus)
2. Ctenochaetus binotatus (Twospot surgeonfish)
3. Two-spot bristletooth Aquarium Care | Atlarium
4. Two Spot Bristletooth Tang – LiveAquaria