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The Kole Tang

Tangs are one of the most popular aquarium fish and several hundred thousand are sold annually. The problem is, most aquarists who buy a tang, shouldn’t. There is a constant debate in the hobby over just what size of tank is required to keep a tang, for most tangs the answer is (half-joking here)¬†larger than the one you have. A yellow tang for example needs at the very least a 6′ long aquarium and others like the Regal Tang (Paracanthurus hepatus or Dory from Finding Nemo) require 8′ to thrive.

There is one tang however, that feels at home in a 4′ long tang, the Kole¬†(pronounced “coal-e”) tang (Ctenochaetus strigosus) is a perfect fit for many aquarists who want a tang but have limited aquarium space.

General Information

  • Up to 6″
  • Lives 12-18 years
  • Algae eater (grazer)
  • 4′ long tank required minimum.
  • Sensitive to some activated carbons (HLLED)
  • Peaceful to most take mates
  • Requires clean water and plenty of hiding spaces
  • Brown when juvenile but takes on a navy blue as an adult
  • Bristlemouth tang (rasps algae with specialized “teeth”


Tangs in general are sensitive fish so acclimation should be a slow drip acclimation of about an hour. Once the fish is introduced into the tank it is recommended you turn the lights off for the rest of the day to give the fish time to settle in. Keeping the stress level low will help this fish’s natural immunities and thus prevent ich, a common issue with tangs.

Environment and Care

Because the kole is a heavy grazing fish and smaller than most tangs (6″ max) it can be housed in a smaller tank than most tangs. 4′ is the recommended minimum. Of course it will take advantage of a larger tank to expand grazing.

The tank should have plenty of rocks with caves and places to hide. The kole will dart to the rocks when frightened and sleep there at night.

They like plenty of flow in a tank and will often be seen playing in the current of powerheads or wavemakers.

This fish is reef safe and can be kept with all kinds of corals and invertebrates without worry.


It eats readily and grazes the day through on micro and macro algae. It’s wise to leave the back glass uncleaned of algae to give the tang something to eat. It will rasp algae off the glass all day long and to a lesser extent off the rock and sand. This tank also will rasp diatoms from the sand when present.

When first introduced into a tank it is advisable to keep a clip of seaweed (nori) in the tank for the kole to eat. After travel and life in a fish store the kole may not be at full health. Once your kole is at full health you will be startled by the difference. This is a fish that can get down right fat!

The kole will readily eat flake food high in algae content, such as Formula II. This is recommended as it will provide the algae as well as meat-based nutrition for optimal health. Feeding the occasional meaty food is acceptable as well as the kole will eat mysis and daphnia with relish as well as several other smaller meaty food items.


This is a very active fish. It will always be out swimming around. It is a shy fish though and will take several weeks to get used to you and it runs and hides when there is fast movement outside the tank. Maybe not the right fish for a room used by little kids or with heavy foot traffic. It will get used to the aquarist and take food from the hand and not run when known persons gaze at the tank.

They get along well with most other fish but may chase competitors, similar looking fish, or fish that compete for their hiding places. Normally this chasing is not violent and does not result in injury.

If the aquarist wishes to keep a kole with another tang it is best to have the tankmate be from another family of tang. For example a yellow tang and a kole tang could be housed with each other but other bristlemouth tangs should be avoided.


Overall this is a fine fish and one of the best tangs to begin with. While it might not have the striking color of a yellow tang it is beautiful and behaviorally interesting to watch. Care is easy, the fish readily eats, and tends to leave most other fish alone. On top of those good qualities it is also reef safe and affordable.