Powder blue tang

Geographic Origin and Biotope: Widespread along the entire Indian Ocean (from the African coast to Indonesia). Prefers the outer slopes of coral reefs (reef flats) rich in constant wave motion and surface algal cover deriving from high solar penetration.

Taxonomy and Morphology: Very famous as the Powder Blue Tang, leading exponent of the Acanthuridae family. Flat discoidal structure. Also equipped with fearsome retractable and venomous razors on the caudal peduncle. It can touch 23 cm (9 inches) in the aquarium.

Social Behavior: Proud, restless and dominant. Swims with nervous elegance. Similar to the Achilles, it violently claims immense territorial perimeters to the detriment of any other algae-fed animal. In nature it occasionally aggregates in immense and frantic "grazing gangs".

Coloration and Sexual Dimorphism: Iconic and flashy color: the livery shows off a vibrant matte powder blue. The head and throat are deep black, separated by a distinct ice-white maxillary collar. The dorsal is entirely painted sparkling lemon yellow, highlighting the contrast. Sexually isomorphic.

Aquarium Setup: Requires exceptional dimensions: never go below aquariums of 150 cm (5 feet) on the long side (at least 400-500 liters). Prefers very strong directional pumps to swim against the current and large free swimming areas framed by coral live rocks for constant benthic predatory activity.

Diet and Feeding: Pure herbivore. Although it voraciously tastes frozen brine shrimp and krill, the basic diet to prevent chronic diseases must consist of pressed macro-marine algae (Nori, spirulina). It is advisable to administer the vegetable food divided into several micro-portions throughout the day.

Water Quality: Does not forgive management lightness. Requires perfect (SG 1.022-1.025) and oligotrophic marine water. The pH must border on 8.2/8.4 via a solid dKH. In addition to excellent filtration, oxygenation must be kept at spasmodic levels via the rippled water surface.

Compatibility and Tankmates: Perfect reef safe. An inflexible master: the subsequent insertion of Zebrasoma or other Acanthurus will often turn into a real carnage, as the Powder Blue will stress to death or stab the potential food rival on sight. Peaceful with corals and invertebrates.

Aquarium Reproduction: Absolutely absent in the home hobby sector registers, similar to other pelagic surgeonfish whose larval phase is excessively technical to conduct and sustain outside specialized laboratories (such as recent Asian/American achievements on Paracanthurus hepatus).

Risks and Diseases: Boasts a dramatically weak systemic resistance towards ectoparasites (Oodinium and Cryptocaryon), which it magnetically attracts at any immune lowering caused by sudden changes or overcrowding. Stress is lethal. Be extremely careful of painful accidental stabbings during captures with the net.