Not only is it one of the most beautiful of all the surgeonfish, the Chevron Tang eats a different kind of algae than the other surgeonfish, making it one of the most desirable as well!
The Chevron Tang is very beautiful and striking as a juvenile. It has a bright orange colored body and head with variegated bright blue lines, radiating in somewhat of a herringbone type pattern. The fins are violet tinged becoming bright blue posteriorly, just above and below the caudal peduncle. The adult has a dark orangish red coloration overall with multiple thin dark green-blue lines. When seen from a distance the adult appears a uniform black and are known as the Black Surgeon in Hawaii. Only up close can you see the lined color patterning. These fish grow up to 11,” and will grow up to 80% of their total length within the first 4 to 5 years, reaching almost 9” by then. A typical tang life span is 30 to 45 years (Choat and Axe, 1996)
Called ‘bristle tooth’ or ‘Comb tooth’ tangs due to their nature of feeding. They primarily eat detritus which contains minute algae and diatoms rather than the filamentous algae eaten by other tangs. The Ctenochaetus species, referred to as both the Bristletooth or Combtooth Tangs, have several rows of small flexible comb like teeth described as little spatulas that are curved inward and can number up to 30 teeth. They have a protrusive pouting mouth which helps them get into crevices. They use their teeth to lift and sift through various types of algae and detrital material off of rocks, sand, and other surfaces. They do this by throwing their lower jaw upward as their upper jaw stays fixed, thus vacuuming this food into their mouth. In the aquarium you will often see little lip marks on the glass.
Like the others members of the Ctenochaetus genus, the Chevron Tang or Hawaiian Bristletooth has a moderate demeanor and is generally a good companion in a community tank. It can be kept with a variety of tank mates including some of the other genus’ of surgeonfish. It should not be housed with aggressive fish or those with a similar body shape or diet. Its diet makes it a great complimentary companion for other peaceful surgeonfish such as the Yellow Tang or the Pacific Sailfin Tang in the Zebrasoma genus, though you need to keep an eye on compatibility. Their defensive scalpel is not as developed and cannot defend against more aggressive tangs. Convict Tangs and Lavender Tangs are more chill and may make the best companions, but adding other tangs together should be done in tanks that are hundreds of gallons.
They are moderately easy to care for and would need just as much rock work as other tangs to provide them with plenty of food to much on during the day. These foods are slightly different than what other tangs need, making them the perfect “first tang” into your main display! It is when diatoms, detritus, blue-green algae and green algae appear and become abundant that you add your Chevron Tang. They do not like filamentous algae and will promptly spit it out if they get it in their mouths! For long term success in keeping these fish, providing for their dietary needs is of primary importance, and like all tangs, this include lots of algae crops. Most importantly is that their mouth is undamaged in shipping and they are feeding, so be sure to have the store feed the fish you want to buy.
Being among the smallest and least active of the surgeonfish, one would think a smaller aquarium would suit the Ctenochaetus. They still need a tank that is minimum 180 gallons with crevices within the live rock to hide and sleep in at night. They need plenty of naturally growing food and accumulated detritus, so provide plenty of rock work, yet keep in mind they need open areas to swim. They will benefit even more with the inclusion of live sand. The live rock and live sand along with surfaces of the aquarium glass will provide a lot of areas for good algae growth and detritus build up to help accommodate this constant feeder. Provide strong water movement and temperatures from 72 to 78˚F and a pH of 8.1 to 8.4. They will swim in all areas of the tank and will hide within the rock work at night.
For more Information on keeping marine fish see:
Guide to a Happy, Healthy Marine Aquarium
- Kingdom: Animalia
- Phylum: Chordata
- Class: Actinopterygii
- Order: Perciformes
- Family: Acanthuridae
- Genus: Ctenochaetus
- Species: hawaiiensis
- Aquarist Experience Level: Intermediate
- Aquarium Hardiness: Moderately hardy
- Minimum Tank Size: 180 gal (681 L)
- Size of fish – inches: 11.0 inches (27.94 cm)
- Temperament: Semi-aggressive
- Temperature: 72.0 to 78.0° F (22.2 to 25.6° C)
- Range ph: 8.1-8.4
- Diet Type: Herbivore
- My Aquarium – Enter your aquarium to see if this fish is compatible!
Habitat: Distribution / Background
The Chevron Tang, Ctenochaetus hawaiiensis, was described by Randall in 1955. Their common names have to do with their coloring such as the Black Surgeonfish, which is descriptive of the adult coloring; Chevron or Chevron Tang which describes the “V” or inverted “V” pattern; Hawaiian Surgeonfish or Hawaiian Kole, describing their location; and Hawaiian Bristletooth, describing their spatula, comblike teeth.
They are found in the Central Pacific (the Pacific Plate) from the Hawaiian Islands to Palau and south to Samoa and Marquesas Islands. Adults enjoy seaward rock reefs and coral reefs in shallower, highly oxygenated surge areas, feeding in areas of rock that have a lot of crevices. Juveniles are often found in much deeper reefs that are abundant in coral. In their natural habitat they are found at depths between 16 to 131 feet (5 – 40 meters) feeding on detritus, diatoms, blue-green and green algae.
Chevrons Tangs are on the IUCN Red List of Threatened Species under least concerned.
- Scientific Name: Ctenochaetus hawaiiensis
- Social Grouping: Pairs – Found in pairs and small groups in the wild, however one per tank.
- IUCN Red List: LC – Least Concern
The Chevron Tang is very beautiful and striking as a juvenile. It has a bright orange colored body and head with variegated bright blue lines, radiating in somewhat of a herringbone type pattern. The fins are violet tinged becoming bright blue posteriorly, just above and below the caudal peduncle.
The adult has a dark orangish red coloration overall with multiple thin dark green-blue lines. When seen from a distance the adult appears a uniform black and are known as the Black Surgeon in Hawaii. Only up close can you see the lined color patterning.
On each side of the caudal peduncle is a single spine or “scalpel” used for defense or dominance. When not in use the spine is folded down into a groove. This single spine is what places the Ctenochaetus genus in the subfamily Ancanturinae, along with the other single spine genera Acanthurus, Zebrasoma, and Paracanthurus. Though unlike these others, the spine on the Ctenochaetus is quite small. Even so, caution needs to be exercised when handling surgeonfish as a cut from its scalpel can cause discoloration and swelling of the skin with a high risk of infection. The pain lasts for hours then still ends up having a dull ache.
Unlike most of the other tangs of the Acanthuridae family who posses 9 dorsal spines, the Ctenochaetus have only 8 dorsal spines (the first one being very small). The Ctenochaetus species are often referred to as the Bristletooth or Combtooth Tangs, due to their nature of feeding. They have several rows of small flexible comb like teeth (up to 30 teeth) along with a protrusive pouting mouth. These teeth are adapted for lifting and sifting various types of algae and detrital material off of rocks, sand, and other surfaces and then they use their mouth to suck the food up. In the aquarium you will often see little lip marks on the glass where algae used to be from this feeding behavior. These fish grow up to 11,” and will grow up to 80% of their total length, or 9,” within the first 4 to 5 years. A typical tang life span is 30 to 45 years (Choat and Axe 1996)
Photo courtesy: John Rice
- Size of fish – inches: 11.0 inches (27.94 cm) – Will reach about 9″ in the first 4 to 5 years.
- Lifespan: 30 years – 30 to 45 years (Choat and Axe 1996), possibly less in captivity.
Fish Keeping Difficulty
Typically, Bristletooth or Combtooth Tangs are generally considered more difficult to keep, but with some knowledge of what to look for when obtaining a specimen and by providing for its needs, you can have a successful experience. The Chevron Tang will be moderately hardy as long as they are acquired with an undamaged mouth, undamaged fins, healthy appetite (eating before it leaves the store), and if they will have plenty of natural foods in their new home.
They need clean water parameters to stay healthy. Consequently they will need vigorous filtration, protein skimming, and regular small water changes.
Surgeonfish and tangs are continuous feeders and they need to be provided a proper diet. They are susceptible to nutritional disorders which may cause color loss and LLD (lateral line disease). Supplementing their diet with the addition of vitamin C to their food or adding a vitamin supplement directly to their water can help to avoid or aid in reducing these ailments. They are also susceptible to bacteria resulting from organic buildup which deteriorates water quality.
- Aquarium Hardiness: Moderately hardy
- Aquarist Experience Level: Intermediate
Foods and Feeding
Though the Chevron Tangs are considered herbivores, in the wild they feed on detritus, a thin film on the substrate containing many nutrients including dinoflagellates (minute marine protozoans), diatoms (unicellular algae), and large amounts of other organic material. In the aquarium a large portion of their diet will be obtained from grazing on the naturally growing minute algae and the detritus. However this food source will not be sufficient to maintain them, so they must also be offered supplemental foods.
The majority of their intake will be vegetable matter but they do need some meaty foods as well. Provide lots of marine algae, prepared frozen formulas containing algae or spirulina, frozen brine and mysid shrimp, and flake foods. Japanese Nori or other seaweed can be adhered to the aquarium glass with a vegetable clip. Feed 3 times a day in smaller amounts instead of a large quantity once a day. As continuous grazers, they will benefit from this and it will also keep the water quality higher over a longer period of time.
Providing a vitamin supplement (including vitamin C) can help provide for their nutritional needs, and vitamin C can help prevent or reduce Lateral Line Erosion (LLE). This can be done by soaking dried pellets with liquid vitamins, adding vitamins to the food, or adding a liquid vitamin into the water. It is also said that pellets soaked in garlic may help fend off Marine Ich. Some hobbyists also report success with supplemental foods such as previously boiled or frozen zucchini, broccoli, spinach, and leaf lettuce.
- Diet Type: Herbivore
- Flake Food: Yes
- Tablet / Pellet: Yes
- Vegetable Food: Most of Diet – 90%
- Meaty Food: Some of Diet – 10%
- Feeding Frequency: Several feedings per day – 3 times daily plus natural foods in the aquarium.
An agile swimmer and constant grazer it will spend a good deal of its time picking at the rock and sand as well as the aquarium glass, removing algae and detritus. Frequent water changes are not necessary, rather normal water changes at 10% biweekly or 20% monthly are fine.
-Medium sized up to 90 gallons, perform 15% bi-weekly.
-Large Tanks 100 gallons and over, once water is aged and stable can be changed 10% bi-weekly to 20% monthly, depending on bioload.
Fish only tanks:*
-Medium sized up to 90 gallons, perform 20% to 30% monthly depending on bioload.
-Large Tanks 100 gallons and over, once water is aged and stable can be changed 20% to 30% every 6 weeks depending on bioload.
For more information on maintaining a saltwater aquarium see: Saltwater Aquarium Basics: Maintenance. A reef tank will require specialized filtration and lighting equipment. Regular water changes done bi-weekly will help replace the trace elements that the fish and corals use up.
*Note: If this is the ONLY fish in the tank, with no corals or other fish you can get away 20% monthly.
- Water Changes: Bi-weekly
This fish needs a lot of water movement creating an oxygen rich environment rather than a placid aquarium which should be at least 180 gallons. Chevron Tangs need plenty of swimming space along with corals/ rocks to provide crevices for retreat and sleeping at night. It will do best in an environment that provides consistency, not only in water conditions and quality, but also in decor and fellow inhabitants. They will benefit even more with the inclusion of live rock and sand, since it lends itself to a lot of good algae growth and detritus build up to help accommodate this constant feeder. Cleaning up detritus and diatoms in the tank makes these fish a valuable addition to a reef environment. Light should be strong enough to provide them with blue-green and green algae they eat in the wild. Keeping stable temperatures from 72 – 78˚F will provide the deeper concentration of oxygen (higher temps have less oxygen) and a pH of 8.1 to 8.4 is best.
These fish need a lot of water movement creating an oxygen rich environment rather than a placid aquarium. Chevron Tangs thrive with good water movement, need lots of oxygen, and love to have the water rushing over their gills at times. Provide strong movement in at least one area of the tank. These tangs spend time primarily in the middle and bottom of the aquarium, picking at the rock and sand as well as the aquarium glass. It will sleep in crevices at night.
- Minimum Tank Size: 180 gal (681 L) – May be kept in a 125 gallon tank until 9″ long.
- Suitable for Nano Tank: No
- Live Rock Requirement: Typical Plus Hiding Places
- Substrate Type: Sand – Best substrate to build up diatoms and detritus, their natural foods.
- Lighting Needs: Moderate – normal lighting – Enough to support natural algae growth.
- Temperature: 72.0 to 78.0° F (22.2 to 25.6° C)
- Breeding Temperature: – unknown
- Specific gravity: 1.023-1.025 SG
- Range ph: 8.1-8.4
- Brackish: No
- Water Movement: Strong – Provide at least one area of strong water movement.
- Water Region: All – Mostly middle and bottom.
This is one of the more peaceful surgeonfish. Its moderate behavior makes it a good companion in a community tank. The Chevron Tang, will however, fight with other Chevron Tangs and will not get along with others of their same genus unless the tank is crazy huge, like a public aquarium. In the wild, yes, adults maintain pair bonds; however, as it is almost impossible to sex these fish they are best kept singly unless they are a proven mated pair.
Chevron Tangs should not be housed with more aggressive genus of tangs either, since they are the most docile of tangs. Housing with calmer tangs like Convict Tangs and the more peaceful tangs of the Zebrasoma genus can all be a good choices, since they eat a different kind of algae. This should be done in tanks that are hundreds of gallons, and should all be added at the same time as juveniles to an established tank. If adding a tang after another one is established, just mix up the rock work. Do not aggressive species but rather more peaceful fish. Do not house with predatorial fish who will eat your Chevron Tang, especially if it is a juvenile! Watch for compatibility as the Chevron can be a target for aggressive tank mates and become stressed. These problems arise when all the tangs are adults.
The great thing about the Chevron Tang is that they are fine in a reef setting and can be housed in a community reef environment. They will not harm corals, although their fast swimming can dislodge the coral, so glue them down. Because Chevron Tangs eat natural algae growth, diatoms and detritus build up around corals, having this fish will be beneficial to both!
Inverts are also quite safe with Chevron Tangs too!
- Venomous: No
- Temperament: Semi-aggressive – Peaceful to non-tangs
- Compatible with:
- Same species – conspecifics: Sometimes – Unless it is a known male and female bonded pair
- Peaceful fish (gobies, dartfish, assessors, fairy wrasses): Safe
- Semi-Aggressive (anthias, clownfish, dwarf angels): Safe
- Large Semi-Aggressive (tangs, large angels, large wrasses): Monitor – Only with mellow tangs from different genus and in a tank that is hundreds of gallons.
- Large Aggressive, Predatory (lionfish, groupers, soapfish): Threat – Larger predators will eat your tang even if it is the same size.
- Monitor – Will not bother mandarins, and seahorses and pipefish need their own tank.
- Anemones: Safe
- Mushroom Anemones – Corallimorphs: Safe
- LPS corals: Safe
- SPS corals: Safe
- Gorgonians, Sea Fans: Safe
- Leather Corals: Safe
- Soft Corals (xenias, tree corals): Safe
- Star Polyps, Organ Pipe Coral: Safe
- Zoanthids – Button Polyps, Sea Mats: Safe
- Sponges, Tunicates: Safe
- Shrimps, Crabs, Snails: Safe
- Starfish: Safe
- Feather Dusters, Bristle Worms, Flatworms: Safe
- Clams, Scallops, Oysters: Safe
- Copepods, Amphipods, Mini Brittle Stars: Safe
Sex: Sexual differences
Similar to others in their genus, females are smaller than males once full grown, however, in the beginning, females grow faster!
Breeding / Reproduction
Some species of surgeonfish have spawned in public aquariums and there have been a few scattered reports of spawning in home aquariums, but regular spawning and the rearing of the young has not yet been reported.
Though the Chevron Tang has not yet been bred in captivity, this species has been observed performing pair spawning in the ocean. Adults maintain bonded pairs in the wild. The only species from the Ctenochaetus genus that does not bond is the Yellow-eyed or Kole Tang C. strigosus, though they too will spawn in pairs.
For information on breeding and the development of the fry, see: Marine Fish Breeding: Tangs.
- Ease of Breeding: Unknown
Tangs produce less body slime than other saltwater fish and have been termed “dry skinned” fish by some. This makes them very susceptible to Cryptocaryon (saltwater ich) and other diseases. The most common ailments are bacterial diseases, Hole-in-the-Head Disease, Lateral Line Disease, and parasitic infections such as protozoas (including Cryptocaryon), worms, etc.
For Crypt, in the wild a cleaner wrasse (Labroides sp.) will help them by taking parasites from their bodies, however these wrasses are extremely difficult to sustain in captivity. Alternative fish such as Neon Gobies (Gobiosoma spp.) or cleaner shrimp can help them by providing this cleaning service in the home aquarium. As for treatment, some tangs are sensitive to copper because they have an important microfauna in their digestive system, soprolonged or continuous use of a copper treatment is not advisable. It is also said that pellets soaked in garlic may help fend off Marine Ich.
Providing a vitamin supplement (including vitamin C) can help provide for their nutritional needs, and vitamin C can help reduce Lateral Line Erosion (LLE) which may be caused by activated carbon. Enriching foods can be done by soaking dried pellets with liquid vitamins, adding vitamins to the food, or adding a liquid vitamin into the water. . Some hobbyists also report success with supplemental foods such as previously boiled or frozen zucchini, broccoli, spinach, and leaf lettuce.
The best routine is a quarantine tank and a stress free environment with good quality veggie foods, places to hide and a quiet area for the aquarium.
For more information see Fish diseases.
When available, a small 1 to 2″ baby will set you back at least $180.00 USD! (2014) Seems to be available in the late summer as babies.
Animal-World References – Marine and Reef
-Hawaii Division of Aquatic Resources
By Langston, Longenecker, and Claisse
Reproduction, growth, and mortality of kole, Ctenochaetus strigosus