News / Species Spotlight / Yellowfin Surgeonfish (Acanthurus xanthopterus) (07/25/18)

Yellowfin Surgeonfish (Acanthurus xanthopterus)

Species Spotlight - Yellowfin Surgeonfish (Acanthurus xanthopterus)
Among surgeonfishes, Acanthurus xanthopterus is a giant. The average size of this species is upwards of a foot and a half! The largest specimens easily exceed two feet!

To keep a single adult in an aquarium requires an enormous amount of space, somewhere on the order of 500-1000 gallons. But to keep this fish in a group, replicating its natural shoaling behavior, would require the sort of voluminous accomodations best left to public aquariums.

Aquarists tend to think of surgeonfishes as being universally herbivorous creatures, but, in fact, this group is far more diverse in its feeding ecology. There are those, like the Sohal Tang (Acanthurus sohal) or the Yellow Tang (Zebrasoma flavescens) which make their living grazing upon hairlike algae, but there are also zooplanktivores like Thompsons Tang (A. thompsoni), along with lesser known examples like the Blueline Surgeonfish (A. nubilus) and the Mata Surgeonfish (A. mata).

For A. xanthopterus, it belong to a diverse group which has taken to a primarily detritivores lifestyle, feeding upon the thin layer of organic waste, algae, and microinvertebrates that accumulates atop sand flats. Though it might sound a bit unsavory, it is actually a highly nutritious food source, far more densely packed with nutrients than what an algae-based diet affords. In captivity, these fishes will accept almost any offered foods, from shrimp and nori to flakes and pellets.

The Yellowfin Surgeonfish is distributed all across the Indo-Pacific, from the African coastline to Hawaii and east towards Mexico. The one place where you wont find it is in the Red Sea, where it is instead replaced by its sister species, the Black Surgeonfish (A. gahhm), which appears darker and with a short black mark behind the eye.

Acanthurus xanthopterus is sometimes mistaken for the aforementioned Mata Surgeonfish, as both are large brown species that have yellow fins. But mature specimens are easily told apart, as the former has a bump on its head and several stripes in the dorsal and anal fins, along with yellow (versus dark) pectoral fins. Another commonly confused relative is Dussumiers Surgeonfish, which is generally a more colorful species, having a beautiful blue and yellow caudal fin and prominent blue streaks across the face.