Members of the Acanthuridae family are the surgeonfish and the unicornfish. Both have gruesome spines and agonizingly sharp bony blades at the sides. These ‘scalpel-like weapons’ can cause injuries with surgical accuracy. On top of that these blades can fold into a groove and used both offensively and defensively.

In essence, the diurnal members of this family are herbivorous. Some however are planktivorous. Please always bear in mind the spines are potentially dangerous to humans. The Acanthuridae prefer areas with bright reefs and where algae grow in abundance. Some unicorn species develop a horn-like  ‘protuberance’ on their forehead, hence resembling unicorns, the legendary mythical creatures.

Family Members

Blue-spine Unicornfish

Size up to 70 cm (2,3 ft). Depth up to 80m (262 ft)

The bluespine unicornfish is  a slightly weird species in more than one aspect. It loves  currents but also feels comfortable in shallower waters near drop-offs. The bluespine unicornfish carries a prominent frontal ‘horn’ on its head, conjuring up visions of the aforementioned antique creatures. The vivid olivaceous green to greyish tone changes to blue at the spines. It is diurnal and has herbivorous tendencies, venturing in smaller schools near the fringing Red Sea reefs.

Orange-spine Unicornfish

Size up to 45 cm (1,47ft). Depth up to 90m (295 ft)

The orange-spine unicornfish in the Red Sea mingles in pairs or in schools on shallow inner and outer reef crests and seaward coral reef slopes. The body is darkish grey to black, but distinctively yellow at the margins. They have a black ‘Zorro’ band with a yellow border, covering their eyes and their mouth. Please beware of the bright orange razor-sharp spines on each side of the tail. They feed on plankton and also like brown algae.

Sleek Unicornfish

Size up to 75 cm (2,46 ft). Depth up to 137m ( 450 ft)

The sleek unicornfish distinguishes itself from other species with a wonderful olive green color, tending to greyish. The ones exceeding 25 cm are equipped with a blackish tongue. The diurnal sleek unicornfish has pelagic tendencies but also feels comfortable in the proximity of outer reefs. They circulate in fairly large schools, feeding on zooplankton and algae.

Other Family Members

Long-Nose Unicornfish

Short-Nose Unicornfish

Spotted Unicornfish