thumb|With fins fully extended
thumb|right|Yellow tangs in their natural habitat in [[Kona District, Hawaii|Kona, Hawaii|alt=Photo of two fish with rock in background]]
thumb|In a zoo aquarium
The yellow tang (Zebrasoma flavescens), also known as the lemon sailfin, yellow sailfin tang or somber surgeonfish, is a species of marine ray-finned fish belonging to the family Acanthuridae which includes the surgeonfishes, unicornfishes and tangs. Bright yellow in color, it is one of the most popular marine aquarium fish, though in its natural state, it lives in reefs. The yellow tang spawns around a full moon, eats algae, and has a white barb, located just before the tail fin, to protect itself.
Taxonomy and etymology
The yellow tang was first formally described by English naturalist Edward Turner Bennett as Acanthurus flavescens in 1828 from a collection in the Hawaiian Islands. Zebrasoma refers to the body and the zebra-like stripes or bars on the body of the type species the genus, the sailfin tang (Z. velifer). Its species name is the Latin adjective , which refers to the tang's yellow color.
Within the genus Zebrasoma the yellow tang forms a species pair with the scopas tang (Z. scopas). The genera Zebrasoma is one of two genera that make up the tribe Zebrasomini within the subfamily Acanthurinae of the family Acanthuridae.
Evolution and genetics
Based on the gene Cytochrome C-oxidase 1 (CO1), a group of researchers was able to reconstruct the phylogenetic tree of the genus Zebrasoma with mitochondrial barcoding sequences.
Description and biology
Adult fish can grow to in length, and in thickness. Adult males tend to be larger than females. Yellow tangs are bright yellow in color. At night, the yellow coloring fades slightly, and a prominent brownish patch develops in the middle with a horizontal white band. They rapidly regain their bright yellow color during daylight. They can be aggressive, are prone to marine ich, and may damage coral within a reef tank. Male and female yellow tang look very similar. When mating, however, males change color and have a "shimmering" behavior which makes them identifiable. The yellow tang has 5 dorsal spines along with 23–26 dorsal soft rays. The yellow tang also has 3 anal spines as well as 19–22 anal soft rays. There is a white spine on its caudal peduncle that it can use for defense. Its snout is moderately protruding. Its mouth is small with spatulate teeth that are place classed relatively close together inside of the yellow tang's mouth. In juveniles, there are 12 upper and 14 lower teeth. In adults, there are 18 upper and 22 lower teeth. A single specimen was filmed in the Mediterranean Sea in Spanish waters in 2008, a likely aquarium release. As of July of 2024, yellow tangs have been spotted several times on the shallow reefs of Mexico's Riviera Maya.
Their habitat is tropical with a temperature range of . Over 70% of the yellow tang's natural range is protected from collection and fishing. The yellow tang is listed as "Least Concern" by the International Union for Conservation of Nature (IUCN).
Predators and other threats
The yellow tang has many natural predators, including larger fish, sharks, crabs, and octopuses. Another threat is habitat destruction that is caused by humans. Examples of habitat destruction caused by humans are pollution that starts on land and flows into the water, physical damage and destruction from harmful fishing practices, as well as overfishing, coral harvesting, and snorkeling, which can potentially cause reef damage.
In 2010, one study found that fish larvae can drift on ocean currents and reseed fish stocks at a distant location. This finding demonstrated that fish populations can be connected to distant locations through the process of larval drift. They investigated the yellow tang, because larva of this species stay in the general area of the reef in which they first settle.
In the aquarium
The yellow tang is very commonly kept as a saltwater aquarium fish. In 2015, researchers successfully bred them in captivity. Captive-bred yellow tangs are now routinely available for purchase at fish stores and online vendors. They can grow up to in the wild, but are introduced to aquariums in the range. Some specimens as large as are occasionally available. Life expectancy in the wild can exceed 30 years.
Prior to January 2021, yellow tangs were commonly selling for around $65 to $70 in the US. However, after a collection ban in Hawaii, the prices have more than quadrupled to over $400.