Doctorfish tang

Taxonomy

The doctorfish tang was first formally described as Chaetodon chirurgus in 1787 by the German physician and naturalist Marcus Elieser Bloch with its type locality given as Martinique. The genus Acanthurus is one of two genera in the tribe Acanthurini which is one of three tribes in the subfamily Acanthurinae which is one of two subfamilies in the family Acanthuridae.

Etymology

The doctorfish tang has the specific name chirurgus, meaning "surgeon", an allusion to the sharp scalpel-like spines on caudal peduncle, these also gave rise to the common names surgeonfish and doctorfish.

Description

The doctorfish tang reaches a maximum size of 39 cm and 5.1 kg.

There is a black morph, as well, but it is neither a subspecies nor a regional mutation. It has only been documented a limited number of times.

Range and habitat

This species is typically found among rocky outcrops and coral reefs. Its distribution includes the Atlantic from Massachusetts to Brazil, and the tropical west coast of Africa,

Behavior

Acanthurus chirurgus spends its daylight hours grazing on algae and organic detritus. Its teeth are specially shaped for scraping algae and plant matter from rocks. Because it swallows its food whole, it has a gizzard-like organ in the intestine filled with particles of sand which help to grind food before it starts the digestive process.

Spawning occurs during evening hours in a group event. Each egg is less than a millimeter in diameter and contains a small amount of oil for flotation. The translucent, plankton-like larvae hatch within 24 hours of fertilization. They are laterally compressed and diamond-shaped with large eyes and pectoral fins. Many body parts, such as scales and the dorsal and anal fins, do not develop until the larvae have reached 2–6 mm in length. The "scalpel" does not appear until they are about 13 mm long. As the "scalpel" grows, the anal and dorsal spines shrink. Once the fish reaches around 25 mm in length, it moves to the bottom where it continues to grow, eventually reaching sexual maturity in roughly nine months.

References

References

1. Rocha, L.A.. (2012). "''Acanthurus chirurgus''".
2. {{FishBase. Acanthurus. chirurgus. (2023)
3. {{Cof genus
4. (2016). "Fishes of the World". Wiley.
5. (12 January 2021). "Order ACANTHURIFORMES (part 2): Families EPHIPPIDAE, LEIOGNATHIDAE, SCATOPHAGIDAE, ANTIGONIIDAE, SIGANIDAE, CAPROIDAE, LUVARIDAE, ZANCLIDAE and ACANTHURIDAE". Christopher Scharpf and Kenneth J. Lazara.
6. "Acanthurus chirurgus". Florida Museum.