Yellow tang

Yellow tang
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Perciformes
Suborder:	Acanthuroidei
Family:	Acanthuridae
Genus:	Zebrasoma
Species:	Z. flavescens
Binomial name
Zebrasoma flavescens (E. T. Bennett, 1828)
Synonyms
Zebrasoma rhombeum Bishop

The yellow tang (Zebrasoma flavescens) is a saltwater fish species of the family Acanthuridae. It is one of the most popular aquarium fish.

Taxonomy

The yellow tang was first described by English naturalist Edward Turner Bennett as Acanthurus flavescens in 1828 from a collection in the Hawaiian Islands. Its species name is the Latin adjective flavescens "yellow".

Yellow tang are in the surgeonfish family.

Description

Adult fish can grow to 20 centimetres (7.9 in) in length, and 1–2 centimetres (0.39–0.79 in) in thickness. Adult males tend to be larger than females. Yellow tang 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 resume their bright yellow color during daylight.

Food

In the wild, yellow tang feed on benthic turf algae and other marine plant material. In captivity they are commonly fed meat/fish based aquarium food, but the long term health effects of this diet are questionable. However, most experts in the marine aquarium industry express little skepticism that such a well rounded and balanced diet including plant and animal material would be in any way detrimental to mostly herbivorous fishes like tangs, since they still need on occasion, complex amino acids and nutrients that only ocean animals can provide. In the wild, yellow tang provide cleaner services to marine turtles, by removing algal growth from their shells.

Distribution and habitat

File:Coral reefs at kona.jpg

Yellow tangs in their natural habitat in Kona, Hawaii

It is commonly found in shallow reefs, from 2–46 metres (6.6–150.9 ft) deep, in the Pacific and Indian Oceans, west of Hawaii and east of Japan. Hawaii is the most common place for aquarium harvesting, where up to 70% of the yellow tangs for the aquarium industry are sourced from.

The yellow tang has been recorded in waters around Florida, where it is not native.

In the aquarium

File:Zebrasoma flavescens - uShaka Sea World.webm

In a zoo aquarium

The yellow tang is very commonly kept as a saltwater aquarium fish. They can grow up to 8 inches (20 cm) in the wild, but are introduced to aquariums in the 2" to 4" range. Some specimens as large as 6" are occasionally available. Life expectancy in the wild can exceed 30 years. Captive lifespan is typically at least 2–5 years to as long as 20 years in a very large aquarium, with 5–10 years in the average aquarium being typical. "Some, not most, are however likely 'killed off' in the first month of care (from hobbyist mistakes, inappropriate tankmates, starvation...)".

Often ranked as a good beginner fish in the marine aquarium industry, the more prudent approach is for them to be kept by a marine aquarist who has at least two years' experience of successfully keeping a marine/reef type biotope. They require an aquarium of 55-gallon show tank size (48"L × 21"H × 13"W) at the absolute minimum, whereas a single smaller specimen 2"–3" may be kept provided it is done by an experienced marine aquarist who can provide the fish with highly stable water chemistry parameters, very low to undetectable nitrate levels and a highly nutritious, balanced diet of seaweed and high protein frozen or live, meaty foods. A 75-gallon tank or larger is better for a single specimen, while an aquarium of 100 gallons or 60" or more in length is ideal.

Like all tangs, they are quite susceptible to cryptocaryon irritans, or "marine ich" (a parasite resembling "freshwater ich") and other common saltwater diseases. However, "marine ich" is usually quite avoidable in a marine tank as long as it is not introduced from incoming specimens and provided rapid, sudden temperature drops caused by heater breakdown are avoided or quickly corrected. There is also no evidence to suggest that tangs and other surgeon fishes in general are any more susceptible to marine ich than any other smooth-skinned, scaleless marine fishes. They are also susceptible to poisoning by high levels of nitrate, so care should be taken to keep measurable levels less than 30 parts per million (PPM) in whatever type marine ecosystem the tang is housed in.

They are semi-aggressive, though normally successfully cohabit with other semi-aggressive fish close to their own size. They are successfully kept in a multitude of privately owned aquariums that keep them peacefully and successfully with smaller fish such as chromis, damsels, and smaller clownfish. Tangs can thrive with others in pairs or in a group in large tanks (150+ gallons). If kept in groups of two or more specimens, at least a 72" length aquarium is strongly recommended. Other suitable tankmates include fish such as cardinalfish, large clownfish, lionfish, eels. They are reef-safe, and can be kept with any invertebrates in a reef aquarium.

The yellow tang is a peaceful ocean inhabitant that is an important part of the reef ecosystem. Collection of yellow tangs in Hawaii is regulated by the state and is conducted by licensed collectors.

References

• Froese, Rainer and Pauly, Daniel, eds. (2005). "Zebrasoma flavescens" in FishBase. November 2005 version.

External links

• Yellow Tang (Zebrasoma flavescens)
• AquariumDomain Complete Resource for the Marine Aquarium Hobbyist.
• Hawaii Efforts to Protect Yellow Tangs