The Powder blue tang or Acanthurus leucosternon is cataloged in the family Acanthuridae. This family is comprised of 80 species in 6 different genera. The family encompasses all surgeonfishes, tangs, and unicornfishes. Tangs are actually a category of surgeonfish. Surgeonfish receive their names from the curved pointed end at the top and bottom of their caudal fins. This curvature and pointed tip resembles a surgeon’s scalpel. The powder blue tang is native to the shallow water regions of both the Pacific and Indian Oceans.

This fish has the flat rounded body typical of tangs. Its light blue coloration is accented with black, white, and yellow.  It has a black face outlined in white and or light blue, white ventral and anal fins, and a yellow dorsal fin. Its caudal fin is predominantly white with a yellow triangular marking at the base, followed by a grayish blue or black vertical stripe. There is a second stripe towards the end of the tail fin.  This fish’s color palette does not fade as it matures as do most surgeonfish. They will reach an adult length of up to 9 inches. The powder blue tang is also marketed by the aquarium trade under the name powder blue surgeonfish.   

The powder blue has an aggressive temperament. They actually make good community fish provided they are housed with species of similar size and temperament. They will bully their smaller and more timid tank mates. These are active swimmers. Powder blues will work well in a marine reef tank if they are given plenty of room to maneuver. They will not nip at your coral or try to eat your ornamental crustaceans. However they may view any aquatic plant life as a tempting taste treat. Powders will also help you to keep the algae growth on your living rocks and reef formations in check. These fish are generally intolerant of their own species in the confined space of an aquarium. They will instinctively set out to establish territorial dominance. A male and a female may be kept together. A minimum tank size of 100 gallons is recommended if you plan on keeping this fish in a multi-species tank.

This species is rated at a moderate care level. Amateur aquarist should not attempt to raise one until they become more adept at the nuances of maintaining saltwater species. They require a higher level of oxygenation in their water than many other marine species. This can be achieved by the use of multiple power heads.

Tangs are highly susceptible to both ich and marine velvet. They frequently arrive at fish stores infected after having been subjected to the camped conditions of shipping containers. It is highly advisable that you isolate this fish in a quarantine tank for a minimum of 3 to 4 weeks before introducing it to the general population. Many larger exotic fish stores will quarantine your fish for you as part of the purchase agreement. If own a quarantine tank putting cleaner shrimp in with your new purchase is recommended. Skunk cleaner shrimp are well suited for helping to clean up your new arrival.

Powders are omnivorous. A well established collection of living rock is a must if they are not being added to a marine reef setup. In captivity they will frequently nibble at the protein based products intended for the aquarium’s other inhabitants. This is fine but make sure they receive plenty of plant matter in their diets to keep them healthy and active. Marine plant based food products are a good start. This should be supplemented with dried algae regularly.

Males and females have identical coloration. However the females of this species are considerably larger than the males. These fish are not known to breed in home aquariums.

A note of precaution to all first time tang owners: All tangs are surgeonfish. Surgeonfish derive their names from the scalpel-like projections at the base of their tails.  These self-defensive mechanisms are razor sharp and will easily slice through human flesh. All surgeonfish should be handled with extreme care!

Temperature	pH Level	Specific Gravity
72-78  °F	8.1-8.4	1.020-1.025