Yellow-eyed Tang ~ Kole Tang

Habitat: Natural geographic location:
  The Yellow-eyed Tang or Kole Tang was described by Bennett in 1828, originally as Acanthurus strigosus but later renamed to Ctenochaetus strigosus. They are found in the eastern Central Pacific and are endemic to the Hawaiian Islands and Johnston Island.
   In their natural habitat they are found most commonly at depths down to about 40 feet (12 meters), but can be as deep as 69 feet (113 meters). They inhabit shallow to deep lagoons and outer reefs, areas saturated with highly oxygenated water from strong tides. They are generally seen singly though juveniles may be in loose groups.
   From 1955 until 2001 the Yellow-eyed Tang, along with three of its close relatives, were grouped together and identified by Randall as the Strigosus Complex. Also included in this complex were the Indian Gold Ring Bristletooth C. truncatus, the Bluelip Bristletooth C. cyanocheilus, and 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 Indian Gold Ring Bristletooth C. truncatus, being 'yellow-eyed' but with stripes instead of spots.

Status:
   These fish are not listed on the IUCN Red List.

Description:
   The Yellow-eyed Tang or Kole Tang is very similar to its Indian Ocean counterpart, the Indian Gold Ring Bristletooth or Spotted Yellow Eye Tang C. truncatus. The variation of this species is quite attractive with a light colored body and many blue horizontal stripes (20 or so). There are blue spots on much of the head and they can have elongated tail fin. There is a broad yellowish ring encircling much of the eye, and eye itself is edged with a blue ring.
   Its adult pattern is also quite similar to that of the Striped Bristletooth C. striatus. The Yellow-eyed Tang can be distinguished by its more truncated tail and the yellowish ring around the eye, both missing on the Striped Bristletooth. Juveniles are yellow and the top of the dorsal fin and the bottom of the anal fins are lined in blue, they also have a blue ring edging 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. In the aquarium you will often see little lip marks on the glass where algae used to be from this feeding behavior.

Length/Diameter of fish:
   Adults reach 7.1 inches (18 cm).

Maintenance difficulty:
      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. 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 rockwork 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. Being quite agile, it needs 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. It can be housed in a community reef environment as it will not harm corals or invertebrates. Live rock and live sand will lend themselves to natural algae growth and detritus build up which this fish will enjoy grazing on, and makes it a valuable addition to a reef environment.
   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. Consequently they will need vigorous filtration, protein skimming, and regular small water changes.
   Many of the Acanthuridae members are very colorful, active, and attractive to aquarists. But they 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. They can be treated successfully with medical care or copper drugs, but because they have an important microfauna in their digestive system, prolonged or continuous use of a copper treatment is not advisable.
   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.

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

Foods:
   Though the Yellow-eyed 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.

Maintenance:
   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.
   For more information see, Marine Aquarium Basics: Maintenance

Aquarium Parameters:
   These fish need a lot of water movement creating an oxygen rich environment rather than a placid aquarium. They are also quite agile and need plenty of swimming space along with corals/ rocks to provide crevices for retreat and sleeping at night. They will need a large aquarium with lots of live rock. They will benefit even more with the inclusion of live sand. Live rock and live sand will lend itself to a lot of good algae growth and detritus build up to help accommodate this constant feeder, which makes these fish a valuable addition to a reef environment.
Minimum Tank Length/Size:
   A minimum 75 gallon (284 liters).
Light: Recommended light levels
   It nature it is found in sunlit areas. It can be kept under normal lighting conditions in the aquarium, but can also be kept under very bright light as long as some dimly lit spaces are provided.
Temperature:
   This species lives in tropical areas. Temperatures between 73 -80° F (23 - 27° C) will serve them well.
Water Movement: Weak, Moderate, Strong
   All surgeonfish and 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.
Water Region: Top, Middle, Bottom
   It will 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.

Social Behaviors:
   The great thing about the Yellow-eyed Tang is that they are fine in a reef setting with inverts and corals, and they will graze on the algae. This is one of the more peaceful surgeonfish. Its moderate behavior makes it a good companion in a community tank.
   It should not be housed with aggressive species but rather more peaceful fish. Avoid fish of a similar body shape and those that eat the same natural diet. In the wild adults are solitary, and it should be kept singly in the aquarium as well. It can be kept with a variety of other tank mates including some of the other 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. If it is be kept with any tangs, add this fish first and let it get established before adding another tang. Always watch for compatibility as the Yellow-eyed Tang can be a target for aggressive tank mates and become stressed.
   Surgeonfish and tangs can be territorial, sometimes just with their own kind and sometimes with other species. 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.  

Sex: Sexual differences:
   Sexual differences for this species are extremely slight and almost impossible to detect. The male may demonstrate some color change during courtship.

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 Yellow-eyed Tang has not yet been bred in captivity, the Ctenochaetus genus has been observed performing pair spawning in the ocean.This is the only species from this genus that does not bond with a mate, though they too will spawn in pairs.
   For information on breeding and the development of the fry, see: Marine Fish Breeding: Tangs.

Buy Yellow-eyed or Kole Tang From LiveAquaria.com

Availability:
   The Yellow-eyed Tang or Kole Tang is often available at retailers and on the internet. They are priced starting at around $22.00 USD and up.