When mating, males change colors and exhibit a shimmering movement to attract females. In defense or aggression, yellow tangs extend their fins to full length, greatly increasing their size. They also expose their scalpel-like scales on their fins as a warning sign. They use these not only to defend themselves from predators, but also to scare away competitors for food or territory.
Communication Channels: visual ; tactile
Perception Channels: visual ; tactile ; chemical
Predators of Zebrasoma scopas include larger fish and predatory invertebrates such as crabs and octopi. Yellow tangs rely on camouflage and their scalpel-like fins to protect themselves. To humans, these fish appear bright yellow, but, to other fish, yellow tangs blend in very well with coral reef backgrounds. According to Marshall et al. (2003) wavelength differences between yellow and average reef color become negligible at the depths where yellow tangs are found. In addition to camouflage, Zebrasoma scopas use their scalpel-like fins for defense.
Known Predators:
Anti-predator Adaptations: cryptic
Yellow tangs have a clear larval stage before developing into juveniles. Juveniles and adults have a narrow, oval body. They have an average length-weight ratio between 2.93 and 3.16. They have a long snout for eating algae, a large dorsal fin with four to five spines, and an anal fin with three spines. Like other surgeonfish and tangs (Acanthuridae), yellow tangs have a white, scalpel-like spine on both sides of the tail that can be used for defense or aggression. Yellow tangs are named for their bright yellow coloring; the only area that is not yellow is the white spine. At night, this bright yellow color changes to a darker, grayer yellow with a white lateral line.
Range length: 20 (high) cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes alike
Not much is known about the lifespan of yellow tangs. However, some sources have found them living up to about 30 years on the reef and 10 years in captivity.
Range lifespan
Status: wild: 30 (high) years.
Range lifespan
Status: captivity: 10 (high) years.
Yellow tangs are reef-associated fish. Their preferred water temperature is around 21 degrees Celsius. They inhabit coral reefs in subtropical waters, but generally do not live in tropical seas. Yellow tangs mainly live in the sub-surge zone of a coral reef, this is the area with the least wave action. Zebrasoma scopas live at depths of 2 to 46 meters. The clear larva of yellow tangs develop into marine plankton, in this stage they are carried close to reefs where they settle in coral crevices.
Range depth: 2 to 46 m.
Habitat Regions: tropical ; saltwater or marine
Aquatic Biomes: reef
Yellow tangs, Zebrasoma scopas, are reef fish found in the waters west of Hawaii and east of Japan in the Pacific Ocean. They mainly live off the coast of Hawaii, but are also found in the more western ranges of their habitat, including the islands Ryukyu, Mariana, Marshall, Marcus, and Wake. They prefer subtropical waters.
Biogeographic Regions: pacific ocean (Native )
Yellow tangs have a long, down-turned mouth with small teeth that are specialized for grazing on algae. Because they are mainly herbivores, they spend a large amount of their time grazing either alone or in groups. A large portion of their diet consists of uncalcified and filamentous algae that grows on coral reefs. In addition to smaller types of algae, yellow tangs feed on macroalgae, such as seaweed. Yellow tangs will also eat some types of zooplankton.
Animal Foods: zooplankton
Plant Foods: algae; macroalgae
Primary Diet: herbivore (Algivore)
Yellow tangs, along with other algae feeders, are crucial parts of coral reef ecosystems. They feed on algae and seaweed that grow on the reefs, preventing them from overgrowing and killing corals. Yellow tangs are also a food source for larger fish and invertebrates.
Mutualist Species:
Yellow tangs are important for tourism and the aquarium trade. Their bright yellow color is well recognized by scuba divers and other tourists on Hawaiian reefs. They are also a valuable resource in aquarium trade; they are the number one collected fish for export out of Hawaii. Their coloring, hardiness, and low cost all attribute to their popularity in marine aquariums, making them one of the ten most popular fish.
Positive Impacts: pet trade ; ecotourism
Yellow tangs, along with other surgeonfish (Acanthuridae), are not generally dangerous. When they are young, they possess venom glands. As they age into juveniles and adults, they lose these glands. If yellow tangs are provoked, they can inflict deep injuries with the sharp blades on their tails.
Negative Impacts: injures humans (bites or stings, venomous )
Yellow tangs begin their lives as fertilized eggs floating in open water. After hatching, the clear, pelagic larvae develop in the plankton. They enter the acronurus larva stage where they develop an oval body, dorsal and ventral fins, and spines. After about ten weeks, they enter a planktonic stage. Here, waves carry them to a coral reef where they take refuge and continue to develop and grow.
Development - Life Cycle: metamorphosis
Zebrasoma scopas is not a threatened or endangered species.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Zebrasoma scopas can spawn in groups or in pairs. When in groups, females release eggs and males release sperm into open water where fertilization occurs. When in pairs, the male courts a female by changing colors and exhibiting a shimmering movement. The two fish then swim upward and simultaneously release their eggs or sperm into the water. Males may spawn with multiple females in one session, while females typically spawn only once a month.
Mating System: polygynandrous (promiscuous)
Yellow tangs reproduce externally. Their spawning peaks from March to September, but some fish spawn at all times throughout the year. An average female can release about 40,000 eggs.
Breeding interval: Females spawn about once a month
Breeding season: Breeding occurs year-round, but more often from March to September
Range number of offspring: 40,000 (high) .
Key Reproductive Features: iteroparous ; seasonal breeding ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); broadcast (group) spawning; oviparous
There is no parental investment in yellow tangs beyond the fertilization of eggs.
Parental Investment: no parental involvement; pre-fertilization (Provisioning, Protecting: Female)
The yellow tang (Zebrasoma flavescens) is a saltwater fish species of the family Acanthuridae. It is one of the most popular marine aquarium fish. It is bright yellow in color, and it lives in reefs. The yellow tang spawn around a full moon. The yellow tang eats algae. The yellow tang has a white barb, located just before the tail fin, to protect itself.[3]
The yellow tang was first 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 other fish in the genus. Its species name is the Latin adjective flavescens which refers to the tang's yellow color.[4]
Yellow tangs are in the surgeonfish family.
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.[5]
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 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.[6] 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.[3]
The yellow tang is a marine fish that lives in reefs. The yellow tang is found by itself or in very small groups/schools. The yellow tang is mainly herbivorous and eats filamentous algae.[3]
Spawning happens throughout the year, and it peaks once. Spawning normally happens around the time the moon is full, so this suggests there is some sort of lunar periodicity going on. Spawning happens in pairs or groups, and fertilization is external. Eggs are left in open water and yellow tang are substratum egg scatterers. Yellow tang do not guard their eggs, and once the eggs hatch the juveniles receive no parental care.[3]
In the wild, yellow tangs 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 scepticism 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 tangs provide cleaner services to marine turtles, by removing algal growth from their shells.
It is commonly found in shallow reefs, from 2–46 metres (6.6–150.9 ft) deep, in the Pacific Ocean (Ryukyu, Mariana, Marshall, Marcus, Wake, and Hawaiian islands),[3] west of Hawaii and east of Japan. There have also been reports that they have been found off the coast of Florida in the Western Central Atlantic.[7] A single specimen was filmed in the Mediterranean Sea in spanish waters in 2008, a likely aquarium release.[8]
Their habitat is tropical with a temperature range of 24–28 °C (75–82 °F).[3] Hawaii was the most common place for aquarium harvesting, prior to the export ban, where up to 70% of the yellow tangs for the aquarium industry were sourced from.[9] Over 70% of the yellow tang's natural range is protected from collection and fishing.[10] The yellow tang is listed as "Least Concern" by the International Union for Conservation of Nature (IUCN).[11]
The yellow tang has many natural predators, including larger fish, sharks, crabs, and octopuses.[12][13] Another threat is habitat destruction that is caused by humans. Examples of habitat destruction caused by humans are pollution that started on land and flows into the water, physical damage and destruction from harmful fishing practices, as well as overfishing, coral harvesting,[14] and snorkeling, which can potentially cause reef damage.[10]
Conservation status is labelled as least concern, but there are many ways yellow tang are being protected. The most prominent is that yellow tangs are being bred in captivity for aquarium use now more than they were, so collecting yellow tang from the ocean has decreased sharply. This allows wild yellow tang to be able to thrive without too many being taken, so the species is more likely to survive.[15]
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.[2] They investigated the yellow tang, because larva of this species stay in the general area of the reef in which they first settle.[16] The tropical yellow tang is heavily fished by the aquarium trade. By the late 1990s, their stocks were collapsing. Nine MPAs were established off the coast of Hawaii to protect them. Larval drift has helped them establish themselves in different locations, and the fishery is recovering.[16] "We've clearly shown that fish larvae that were spawned inside marine reserves can drift with currents and replenish fished areas long distances away," said coauthor Mark Hixon.[16]
The yellow tang is very commonly kept as a saltwater aquarium fish. In 2015, researchers successfully bred them in captivity.[17] Captive-bred yellow tangs are now routinely available for purchase at fish stores and online vendors. They can grow up to 8 inches (20 cm) in the wild, but are introduced to aquariums in the 2-to-4-inch (5.1 to 10.2 cm) range. Some specimens as large as 6 inches (15 cm) are occasionally available. Life expectancy in the wild can exceed 30 years.[18]
Prior to January 2021 the Yellow Tangs were commonly selling for around $65 to $70 in the USA. However, after a collection ban in Hawaii, the prices have more than quadrupled to over $400.[19][20]
{{cite web}}: CS1 maint: url-status (link) Yellow tangs in their natural habitat in Kona, Hawaii The larvae of the yellow tang can drift more than 100 miles and reseed in a distant location. In a zoo aquarium The yellow tang (Zebrasoma flavescens) is a saltwater fish species of the family Acanthuridae. It is one of the most popular marine aquarium fish. It is bright yellow in color, and it lives in reefs. The yellow tang spawn around a full moon. The yellow tang eats algae. The yellow tang has a white barb, located just before the tail fin, to protect itself.
