Indian Gold Ring Bristletooth

   Check out those kissy marks on the glass!  No, your bristletooth is not in love with you, but it is in love with the algae it’s eating!

   The Indian Gold Ring Bristletooth or Spotted Yellow Eye Tang has a unique coloration. It closely resembles the Yellow-eyed or Kole Tang, C. strigosus, being ‘yellow-eyed’ but with spots instead of stripes.  The adult Indian Gold Ring Bristletooth’s body is a light reddish brown with tiny white spots all over.  Their fins are yellow and the outermost margins, especially the dorsal and anal fins, are edged in a bright electric blue!   Their eye is surrounded by a yellow circle and their chin and belly area lacks spots.  They are all yellow as juveniles.  The Spotted Yellow Eye Tang male grows up to 6.3″ (16 cm), however they grow up to 5″ in the first 4 years, and then much slower after that.  Females are smaller and this genus only lives for 35 years.  (Choat and Axe, 1996).  They are best kept by intermediate aquarists.

   This fish is one of nine surgeonfish described as members of the Ctenochaetus genus.  The Ctenochaetus genus is 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. They use their teeth to lift and sift through various types of algae and detrital material from the rocks, sand, and other surfaces and then use their mouths to vacuum this food in. In the aquarium, you will often see little lip marks on the glass where algae used to be.  The Yellow-eyed or Kole Tang, C. strigosus is the most similar, however that tang has stripes and is darker. 

   When purchasing your bristletooth, closely examine their mouth area, and pass on any tang that has redness or swelling on their mouth.  They should be swimming around, eating, and curious about their surroundings.  Buying one from a store is best, since they do not ship well and can arrive with a damaged mouth.  Being among the smallest and least active of the surgeonfish, one would think a smaller aquarium would suit the Ctenochaetus. However, because they need plenty of naturally growing food and accumulated detritus, a small tank with enough live rock to help provide for their diet greatly reduces their necessary swimming space.  Conversely, when trying to offer more swimming space in a smaller tank, if one were to under stock live rock, then the environment becomes too sterile and reduces their necessary food source. For long term success in keeping these fish, providing for their dietary needs is of primary importance. 

   The Indian Gold Ring Bristletooth is peaceful and can be housed in a peaceful community reef tank or a fish only tank.  In a reef, it will not harm corals or invertebrates, making them a valuable addition to a reef environment.  Do not house with other bristletooth tangs or fish that also eat detritus.  House with other peaceful tangs in a tank that is much larger than the minimum tank size and add them first.  When adding to a peaceful community tank, then add the bristletooth last. Depending on the individual, it may get along with some of the other genus’ of peaceful surgeonfish but will have trouble with other aggressive tangs, often becoming the victim. Do not house with aggressive fish, since they will stress and become ill.  Avoid frogfish and other predatorial fish that can swallow them whole.

   Provide a tank that is at least 75 gallons, mature and has plenty of light to provide algae growth. To meet their dietary needs they will need a large aquarium with lots of live rock and 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.  They do better in lower temperatures from 72 to 78˚F (23 to 26˚F), pH that is also constant from 8.1 to 8.4, and good water quality made possible by a good quality skimmer!  Provide some crevices or caves for them to sleep in at night.   

For more Information on keeping marine fish see:
Guide to a Happy, Healthy Marine Aquarium

Habitat: Distribution / Background

   The Indian Gold Ring Bristletooth or Spotted Yellow Eye Tang, Ctenochaetus truncatus, was described by Randall & Clements in 2001.  They have several common names such as Indian Gold Ring Bristletooth, Spotted Yellow Eye Tang, Spotted Kole Tang, Truncate Bristletooth and Yelloweye Bristletooth.  The genus Ctenochaetus is Greek for “comb hair” and this is one thing that separated them from the Acanthurus genus.  The species name, truncatus comes from the adult’s truncated or shortened tail fin.  Those “comb hair” teeth gain them the name “bristletooth” because they have several rows of comblike, small, flexible teeth that they use to scrape algae rocks and flat surfaces.  The species name truncatus, refers to their truncate or shortened tail fin.  The other names are descriptive of location and physical features.

   They are found widespread in the Indian Ocean from the east coast of Africa to West Java and north to the Andaman Sea.   They inhabit clear inner reef crests and slopes, and prefer those areas that are saturated with highly oxygenated water from strong tides. In their natural habitat. they are found at depths down to about 69 feet (21 meters).  They mainly feed on detritus, however they will eat other benthic algae and weeds as well.  Juveniles are often seen in loose groups while adults generally form bonded pairs.  

   They are on the IUCN Red List for Least Concerned.

   From 1955 until 2001 the Indian Gold Ring Bristletooth, along with three of its close relatives, were grouped together and identified by Randall as the Strigosus Complex. Also included in this complex:

• The Yellow-eyed or Kole Tang, C. strigosus
• The Bluelip Bristletooth, C. cyanocheilus
• The Red-spotted Tang, C. flavicauda

   All four of these fish are extremely similar, differing primarily by slight variations in their color patterns and originating from different regions. Each of these is now described as its own species The Indian Gold Ring Bristletooth most closely resembles the Yellow-eyed or Kole Tang, C. strigosus, being ‘yellow-eyed’ but with spots instead of stripes.

• Scientific Name: Ctenochaetus truncatus
• Social Grouping: Varies – Known male and female pairs only, otherwise one per tank.
• IUCN Red List: LC – Least Concern

Description

   The Indian Gold Ring Bristletooth or Spotted Yellow Eye Tang is very similar to its Pacific counterpart, the Yellow-eyed or Kole Tang, C. strigosus. The variation of this species is quite attractive with a light colored body and small blue to yellow spots. Juveniles are pale with yellow dorsal, anal, and caudal fins. The top of the dorsal fin and the bottom of the anal fins are lined in blue, and there is a blue ring around the eye.

   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 scraping 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.  The males grow to 5″ within the first 4 years then will grow to a maximum of 6.3″ (16 cm) slowly after that, and females are smaller.  This genus lives a shorter life span than some other tangs, only reaching about 35 years. (Choat and Axe, 1996)

• Size of fish – inches: 6.3 inches (16.00 cm) – Males are larger, reaching 5″ at 4 years, then growth slows.
• Lifespan: 35 years – Up to 35 years (Choat and Axe, 1996)

Fish Keeping Difficulty

      Bristletooth 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. Some guidelines for selecting a healthy fish include avoiding those with damaged fins and more importantly those with a damaged mouth. Also be sure the fish is eating.  If it grazes on the rock work and the sand of the aquarium it can be a good specimen, and also if it accepts prepared foods.

   This fish needs a lot of water movement creating an oxygen rich environment rather than a placid aquarium.  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 are continuous feeders and they need to be provided a proper diet with plenty of live rock to provide detritus build up and algae growth, thus the tank should be mature.  Tangs are susceptible to nutritional disorders which may cause color loss and LLD (lateral line disease) and to bacteria resulting from organic buildup which deteriorates water quality. Consequently they will need vigorous filtration, protein skimming, and regular small water changes.  Tangs do not produce as much skin mucus on their bodies as other fish and can be susceptible to diseases such as Marine Ich and Marine Velvet. Surgeonfish are definitely a candidate for quarantine when you first receive them.

• Aquarium Hardiness: Moderately Difficult – Due to damaged mouth during shipping or lack of rock work and proper tank size.
• Aquarist Experience Level: Intermediate

Foods and Feeding

   The Indian Gold Ring Bristletooth are considered herbivores.  In the wild, they feed on on detritus, a thin film on the substrate containing many nutrients including dinoflagellates (minute marine protozoans), diatoms (unicellular algae), benthic weeds and algae, as well as 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
• Meaty Food: Some of Diet
• Feeding Frequency: Several feedings per day

Aquarium Care

   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.

Reef tanks:
-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:*
-Large Tanks 100 gallons and over, once water is aged and stable can be changed 15% bi-weekly to 30% monthly, 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.  

• Water Changes: Bi-weekly

Aquarium Setup

   Minimum tank size is 75 gallons.  Provide lots of live rock rock arranged so there is plenty of surface space for algae to grow and for detritus to collect.  Do not house in a nano tank, as they will outgrow it too fast and it will cause aggression.  Provide a mature tank with a sandy substrate and stable water parameters.  Light should be high enough to provide algae growth.  They do better in lower temperatures from 72 to 78˚F (23 to 26˚F), because lower temperatures in water provides higher oxygen saturation.  Indian Gold Ring Bristletooth do well at the normal ocean salinity of 1.023 and pH between 8.1 and 8.4, however both of these qualities, especially the pH should be stable.  They  appreciate at least an open area above to swim openly when they feel the urge and good water movement along with a good skimmer.  They swim at all levels of the tank and wedge themselves in between rocks or in a crevice at night.  

• Minimum Tank Size: 75 gal (284 L)
• Suitable for Nano Tank: No
• Live Rock Requirement: Typical Plus Hiding Places
• Substrate Type: Sand – Allows better access to detritus.
• Lighting Needs: Moderate – normal lighting – Enough to provide algae growth.
• Temperature: 72.0 to 79.0° F (22.2 to 26.1&deg C)
• Breeding Temperature: – Unknown
• Specific gravity: 1.023-1.025 SG
• Range ph: 8.1-8.4
• Brackish: No
• Water Movement: Strong
• Water Region: All

Social Behaviors

   The Indian Gold Ring Bristletooth is probably one of the most peaceful of all tangs towards other fish that are not tangs!  They can be housed as a proven mated pair, otherwise do not house your Bristletooth with others from their same genus/species or even genus.  This is due to their territorial nature however it may be done in a 10 foot long tank.

  It should not be housed with aggressive species of fish, but rather with more peaceful fish, yet should be added last in a peaceful community or reef environment.  If housing in a larger tank that is hundreds of gallons, other tangs can be added, however in this case, add your Indian Gold Ring Bristletooth first.  A few pointers are to avoid tangs of a similar body shape and those that eat the same natural diet and from different genus’ of surgeonfish. The peaceful sailfin tangs of the Zebrasoma genus can be a good choice as they eat a different kind of algae, so these two tend to compliment each other.  Always watch for compatibility as the Indian Gold Ring can be a target for aggressive tank mates and become stressed.  Introducing a new surgeonfish into an aquarium that already houses one or more is usually a problem. It is best to initially introduce several species together rather than adding a new one later on. Though a large aquarium can help alleviate many problems, be aware of the social behaviors of any species you are considering to prevent compatibility problems.

  The great thing about the Indian Gold Ring Bristletooth is that they are fine in a reef setting with corals, and they will graze on the algae.  This makes them a great janitor!

  Inverts are also safe from predation, although a copepod or two may be ingested if they are scurrying along an area of algae that your tang just happens to be eating!

• Venomous: No
• Temperament: Semi-aggressive – Peaceful toward non-tangs, yet the most peaceful of tangs.
• Compatible with:
  • Same species – conspecifics: Sometimes – Known male/female pairs.
  • Peaceful fish (gobies, dartfish, assessors, fairy wrasses): Safe – Add your tang last to this type of community tank.
  • Semi-Aggressive (anthias, clownfish, dwarf angels): Safe
  • Monitor – Large dottybacks may be too aggressive. Damsels are too aggressive. Line wrasses should be okay.
  • Large Semi-Aggressive (tangs, large angels, large wrasses): Monitor – Avoid more aggressive for the genus tangs. Add this tang first if housing with other peaceful tangs.
  • Large Aggressive, Predatory (lionfish, groupers, soapfish): Threat
  • Monitor – Mandarins should be fine.
  • 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

   The male of the two will be larger and may demonstrate some color change during courtship.  Females initially grow faster, however, males catch up and pass them as they become adults.

Breeding / Reproduction

    Similar to the are considered herbivores, the Indian Gold Ring Bristletooth male reaches sexual maturity at 15 months and the females at 9 months.  Males are larger than females and like other tangs, they are open water spawners and form bonded pairs.  They form bonds with each other, with the male exhibiting color changes during spawning to attract female.  A pair will break away and rise upward toward the surface and release their gametes. These little floating fertilized eggs are spherical and have a single oil globule to aid in their buoyancy and dispersal.  Once the egg hatches, the larvae look like little kites with a long snout with a small mouth, and they stay in this state for up to 68 days, being the genus with the longest larval stage.  During this time, they fall prey to fish and other marine animals.  Once they reach around 1 inch, give or take (23 to 33 mm), the  larvae are then changed into the juvenile stage.  When they are ready to join the reef, the larvae settle out of the water column and develop into these 1” juveniles, seeking the protection and food sources of the reef and seagrass habitats.  

   The Indian Gold Ring Bristletooth has not yet been bred in captivity.

   For information on breeding and the development of the fry, see: Marine Fish Breeding: Tangs.

• Ease of Breeding: Unknown

Fish Diseases

   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.  

   Diseases that Surgeonfish and Tangs are susceptible to:
Marine Ich (white spot disease), Marine Velvet and Lateral Line Erosion (LLE)

   For more information see Fish diseases.

Availability

   The Indian Gold Ring Bristletooth or Spotted Yellow Eye Tang is not often available at retailers but is more readily available on the internet.  Even then, they are seasonal and not available in the winter.  They range in price from $50.00 to $80.00 (Dec 2015).  

References

Animal-World References – Marine and Reef