News / Species Spotlight / The Blue Tang (2/11/2009)

The Blue Tang

The Blue Tang
by John Brandt
Scientific name: Paracanthurus hepatus
Common name: Blue Tang, Regal Tang, Hippo Tang, Palette Surgeonfish
Class: Actinopterygii
Order: Perciformes
Family: Acanthuridae
Genus: Paracanthurus
Species: hepatus

The Blue Tang has been a marine aquarium favorite for many years. Its popularity increased greatly with the release of the animated film, Finding Nemo. The boldly contrasting black "painter's palette" pattern is framed in an intense chromatic blue. The blue tang is an active fish and parades its flashy presence to the delight of any viewer. This species generally appears the same throughout its range, with the exception being individuals from East Africa which exhibit a yellow to orange coloration on the belly. The maximum size for the blue tang is about 12" (31 cm).

Natural Habitat and Ecology
The blue tang has a widespread occurrence throughout the Indo-Pacific extending into parts of the Indian Ocean. The typical habitat for this species is coastal coral reef with a preference for locations that receive continual influx of nutrient-rich upwelling currents. Unlike most members of its family, the blue tang is primarily a planktivore with some supplementary algae grazing. Localized aggregations of blue tangs situate themselves in close proximity to large growths of branching corals (primarily Pocillopora eydouxi) which provide protection from predators and other threats. Most commonly, the blue tang swims in the open water just above the reef and meanders back and forth while selecting passing plankton. The strategy to avoid approaching threats is to quickly retreat to the protection of the interwoven coral branches. A highly compressed body combined with precise swimming allows the blue tang to seek out and wedge itself within the most inaccessible recesses. Zooplankton is the preferred food and the blue tang is equipped to quickly move about the water column during active feeding.
Spawning occurs at dusk or evening with the production of small floating eggs. These eggs are pelagic drifters which hatch into the planktonic community as developing larvae. Eventually, some will drift near coastal areas where the larvae will successfully develop into juveniles.
The blue tang has always been a high demand species. For decades, the Philippines was the primary supplier. The cumulative detrimental combination of overcollecting and habitat destruction has now made the blue tang very rare in many regions of the Philippines. Reports of irresponsible collecting include using cyanide to capture the fishes from their protective coral refuge and the removal or destruction of the coral heads where the fish seeks shelter between the branches.

Aquarium Care
The blue tang is a generally hardy and easy to maintain species. Most individuals maintain a somewhat shy personality that may or may not subside over time. It's common for this fish to retreat to some hidden crevice when nervous or threatened. It's best not to make sudden movements near the aquarium if you want to make them feel at ease. It is recommended to keep no more than one specimen per 50 gallons. For larger aquariums where it is desirable to have multiple specimens, it is best to introduce more than one at the same time.
Captive blue tangs will readily feed on a variety of offered foods. Emphasis should be placed on using natural foods that are zooplanktonic such as mysis shrimp, copepods, Nutramar Ova (prawn eggs), and enriched brine shrimp. For aquariums that lack available turf algae, regularly offer dehydrated algae such as Nutramar Ogo. Established individuals will eagerly feed from all locations in an aquarium including taking food from the bottom. Blue tangs should be fed 2-3 times per day.
Aquarists should pay extra care when handling or being in close physical proximity to a blue tang. This species has an array of sharp spines including venomous spikes on either side of the tail. A jab from one of those can result in intense pain.
Common ailments include an initial vulnerability to ectoparasites with increasing resistance over time. As with all fishes, new specimens should be quarantined and can be medicated there if necessary. Head and lateral line erosion is fairly common and may be prevented by maintaining high water quality and feeding a variety of vitamin-enriched foods.
Special note to retailers: Blue tangs can be terribly difficult to catch from display aquariums. Plan ahead by decorating their aquariums with structures that do not allow the fish to wedge themselves tightly. Always use two nets to capture blue tangs. Fish that are not overly stressed during capture are more able to easily accept the transport and acclimation to a new home.
The blue tang is a spectacular and rewarding aquarium species. With normal care, aquarists can expect many years of enjoyment.