Tang fish

Naso brevirostris, also known as the short-nosed unicornfish, spotted unicornfish, brown unicornfish, lined unicornfish, longnose surgeonfish, palefin unicornfish, paletail unicornfish, shorthorned unicornfish or shortsnouted unicornfish, is a species of marine ray-finned fish belonging to the family Acanthuridae, the surgeonfishes, unicornfishes and tangs. It occurs in the Indian Ocean and western Pacific Ocean. Taxonomy Naso brevirostris was first formally described as Naseus brevirostris in 1829 by the French zoologist Georges Cuvier with its type locality not given but considered to be Indonesia.[3] It is classified within the nominate subgenus of the genus Naso.[4] The genus Naso is the only genus in the subfamily Nasinae in the family Acanthuridae. Etymology Naso brevirostris has a specific name which means "short nose".  Description Naso brevirostris has 6 spines and between 27 and 29 soft rays supporting the dorsal fin while the anal fin is supported by 2 spines and 27 to 29 soft rays. The depth of the body fits into its standard length between roughly 2 and 2.7 times. The snout is very short in length and is very steep, almost vertical. Subadults and adults have long, tapering bony protuberances in front of their eyes which may extend past one's mouth by as much as the length of the head, first appearing as a bump in individuals of around 10 cm (3.9 in) total length. A pair of bony plates with a poorly developed keels are on each side of the caudal peduncle and the caudal fin varies from truncate to slightly rounded. The overall colour is light blueish-grey to olive-brown, although there is a colour phase where the front quarter of the body is pale with a clear demarcation from the remainder of the body. The middle of the flanks are marked with thin, vertical dark grey lines that break up into small spots on the lower body. The head is marked with small dark spots or by a lattice of lines. The protuberance is marked with diagonal black lines, the membrane of the operculum is white, the lips have pale blue edges and the caudal fin is largely whitish.This species has a maximum published total length of 60 cm (24 in). Distribution and habitat Naso brevirostris is widespread throughout the Indian and Pacific Oceans, from the Red Sea south along the eastern coast of Africa as far as Durban in South Africa and eastward across the Indian Ocean into the Western Pacific Ocean, extending east to the Pitcairn Islands and the Hawaiian Islands, north to southern Japan and south to Australia.[1] In Australia the distribution goes from Ningaloo Reef around the northern tropical coasts to the northern Great Barrier Reef and the Coral Sea as far south as Moreton Bay in Queensland, as well as in the region of Lord Howe Island in the Tasman Sea.In the eastern Pacific it is found around the Galápagos Islands.These fish live in lagoon and seaward reefs down to depths of 46 m (151 ft) Naso brevirostris forms spawning aggregations, pairing to spawn and the males have larger keels on the caudal peduncle than the females. The eggs hatch into pelagic larvae which may remain in the water column for up to 90 days and the adults attain sexual maturity at around 25 cm (9.8 in).Adults feed mainly on gelatinous zooplankton, while juveniles mainly feed on benthic algae. The switch from grazing to preying on gelatinous zooplankton coincides with the development of the bony protuberance.  

Read more less

Acanthurus leucosternon, commonly known as the blue surgeonfish, powder blue tang or powder-blue surgeonfish, is a species of marine ray-finned fish belonging to the family Acanthuridae, the surgeonfishes, unicornfishes and tangs. This species is found in the Indian Ocean. Taxonomy Acanthurus leucosternon was first formally described in 1833 by the English naturalist Edward Turner Bennett with its type locality given as Sri Lanka. 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 Acanthurus leucosternon has the specific name leucosternon. This combines the Greek words leukos, meaning "white", and sternon, meaning "breast"; this refers to the white chest shown by this species. Description The fish can reach an average size of 23 cm (9 in) in length. The body has an oval shape and is compressed laterally. Like other surgeonfishes, Acanthurus leucosternon swims with its pectoral fins. The caudal fin has a crescent shape. The fish has a "surgeon's scalpel," an erected part of the spine located at the base of the tail. The mouth is small and pointed in a beak-like manner with tiny and sharp teeth for reaching narrow spaces of food. Its sides are blue; its dorsal fin and the base of caudal fin are yellow; the head is black; the mouth, the throat area, the anal and pelvic fins are white. The pectoral fins are transparent with yellow reflections. The intensity of its blue color shows off if the fish is healthy or not.[citation needed] The fish does not undergo color changes as it matures; as some tangs, surgeonfish and unicornfish do. Distribution and habitat Acanthurus leucosternon is found in tropical waters from the Indian Ocean. The species inhabits shallow and clear coastal waters always associated with a reef. It prefers flat top reefs and areas along seaward slopes. Behaviour The powder blue tang, like most fish in the family Acanthuridae, is herbivorous, eating mostly benthic algae.Acanthurus leucosternon has a diurnal activity. It is solitary, territorial and aggressive with other surgeonfish. In cases where food is plentiful, it may feed in shoals, but in cases of scarcity, it may compete individually for food. It may use its surgeon's scalpel as a defensive weapon.

Read more less

Naso vlamingii, the bignose unicornfish, scibbled unicornfish, Vlaming's unicornfish, and zebra unicornfish, is a species of marine ray-finned fish belonging to the family Acanthuridae, the surgeonfishes, unicornfishes and tangs. This species is found in the Indo-Pacific. Taxonomy Naso vlamingii was first formally described as Naseus vlamingii in 1835 by the French zoologist Achille Valenciennes with its type locality given as Molucca Island in Indonesia.[3] This species is classified within the nominate subgenus of the genus Naso.[4] The genus Naso is the only genus in the subfamily Nasinae in the family Acanthuridae. Etymology Naso vlamingii has the specific name which honours the Dutch explorer Admiral Cornelis de Vlamingh who collected specimens and drew illustrations of fishes for the Muséum national d’Histoire naturelle and Valenciennes based his description on one of Vlamingh's illustrations.[4] Description Naso vlamingii has 6 spines and 26 or 27 soft rays all of similar height supporting the tall dorsal fin and 2 spines and between 27 and 29 soft rays supporting the anal fin. It has a relatively deep body with standard lengths ranging from 2.2, in subadults, to 2.6, in adults, times the body's depth. There is an obvious bulbous protuberance growing from the head above the snout. There are two bony plates on each side of the caudal peduncle and these have keels with anterior pointing spines. The adults develop long filaments from the tips of the caudal fin lobes. The overall colour of the adults is greyish-brown or reddish brown, and they have the ability to change colour quickly, with small dark blue spots on the head and upper flanks. These spots join up to form stripes on the lower flanks. There is a wide blue band running from the eye to the front of the bulbous protuberance. The lips are blue and there is an irregular blue blotch to the rear of the base of the pectoral fin. The caudal fin is blue at its base, grey in the middle with an ill-defined yellow marginand blue outer edges of the lobes and this extends onto the filaments. The intensity of the colour of the blue markings can be increased to a brilliant blue when the fish is displaying in courtship or to communicate with cleaner fish at cleaning stations.This species has a maximum published length of 60 cm (24 in). Distribution and habitat Naso vlamingii has a wide Indo-Pacific range which extends from the eastern coast of Africa between Kenya and South Africa, through the Indian Ocean islands, but it is absent the continental southern Asian waters, through the Andaman Sea, Indonesia and into the Pacific. In the Pacific it extends north to southern Japan, east to the Galápagos Islands and south to New Caledonia and Australia.[1] In Australia the species is found at a number of offshore islands and reefs, as well as from the northern Great Barrier Reef south to waters off Sydney in New South Wales and in the waters around Lord Howe Island in the Tasman Sea. The bignose unicornfish is found in deep lagoons and seaward reefs, frequently aggregating in schools that feed on zooplankton around the higher areas of deep slopes and drop-offs. Biology Naso vlamingii can live up to 40 years in captivity.[8] Their eggs are fertilized externally after being released in batches by the female. Spawning typically occurs in aggregations, where many individuals come together to release their eggs and sperm simultaneously. They change their feeding pattern throughout their lives. Juveniles are herbivores; feeding mainly with algae, semi-adults are omnivores and adults are primarily carnivores; hunting for zooplankton. 

Read more less

Naso lituratus, the clown unicornfish, orangespined unicornfish, black-finned unicornfish, Pacific orangespined unicornfish, blackfinned unicornfish or stripefaced unicornfish, is a species of marine ray-finned fish belonging to the family Acanthuridae, the surgeonfishes, unicornfishes and tangs. This fish is found in the eastern Indian Ocean and western Pacific Ocean. Unique to members of Acanthuridae, including Naso lituratus, are the Epulopiscium bacteria. These bacteria influence the digestion of Naso lituratus, helping them process the algae in their diet.[3][4][5] Naso lituratus can be found in the Indian Ocean and the Pacific Ocean. This species can be easily recognised by two bright orange forward-hooked spines on the caudal peduncle (the tail base), its orange lips and black face mask. The body is brownish grey with yellow nape and there is a broad black band on the dorsal fin. It reaches about 45 cm (18 in) in length. It can be found on coral reefs, often in pairs. Taxonomy Naso lituratus was first formally described in 1801 as Acanthurus lituratus by the German naturalist Johann Reinhold Forster without stating a type locality, although this is considered to be Tahiti in the Society Islands of French Polynesia.[7] This species is classified within the nominate subgenus of the genus Naso.[8] The genus Naso is the only genus in the subfamily Nasinae in the family Acanthuridae. Description and biology The features of Naso lituratus include orange lips, a caudal peduncle with a brash-hooked spine, and a black face mask. The descriptions of these features include one dorsal fin on top of head and is encircled by a broad black band around 45 centimeters long. They barely grow in size. Long anal fin with II spines and 28–30 soft rays, and a continuous, unnotched dorsal fin with VI spines and 27–30 soft rays. Contains 8 to 9 gill rakers on the lower leg whereas the upper limb has 4. There are 6 spines in total, each with 26–29 soft rays. Adipose fins do not exist. There is one anal fin, two spines overall, and between 27 and 30 soft rays on it. The pectoral and pelvic fins are two of its paired fins. The pectoral fin contains 17–18 soft rays and 0 spines. The pelvic fin has a single spine and three soft rays. In adult males, the lobe's apex produces a lengthy filament. Caudal fin is lunate or crescent-shaped. Two sharp blades that point forward are on the caudal peduncle. In Juveniles, their blades are not fully grown, as they have a stifling gray-brown tint with black, yellow, and white patterns. No forehead "horns" or front protuberance that can be seen in certain other Acanthuridae species. Distribution and habitat Naso lituratus live in the East Indian and Pacific Ocean, with their habitat is living in the coral reefs that lay around in those specified oceans. The reproduction of this species are that the sexes are separate among the Acanthuridae and have distinct differences in size. Spawning occurs year round in Guam. They need high oxygen levels, strong water currents, same companions and need to feed on wild algae. Their self defense tactic is that they will extend their strong tail spines to strike any approaching predators. Naso lituratus has various human use including as a food source and as a commodity in the pet and aquarium trade.

Read more less

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 flavescens, 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).[5] 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 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.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. The yellow tang is a marine fish that lives in reefs and is typically found by itself or in small groups/schools. It is mainly herbivorous and eats filamentous algae. Reproduction Spawning happens throughout the year, and it peaks once, normally occurring around the time the moon is full, so this suggests there is some sort of lunar periodicity to the spawning behavior. 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. Food 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. Distribution and habitat 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.[9] A single specimen was filmed in the Mediterranean Sea in spanish waters in 2008, a likely aquarium release.[10] 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 24–28 °C (75–82 °F). 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. 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 started 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. Conservation status 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. 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. 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. "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. 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 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.  

Read more less

Zebrasoma desjardinii, the Red Sea sailfin tang, Desjardin's sailfin tang, Indian sailfin tang or Indian sailfin surgeonfish, is a species of marine ray-finned fish belonging to the family Acanthuridae, the surgeonfishes, unicornfishes and tangs. This fish is found in the Indian Ocean. Taxonomy Zebrasoma desjardinii was first formally described in 1836 as Acanthurus desjardinii by the English zoologist Edward Turner Bennett with its type locality given as Mauritius. In the past, this taxon was treated as conspecific or synonymous with Zebrasoma velifer.The genera Zebrasoma and Paracanthurus make up the tribe Zebrasomini within the subfamily Acanthurinae in the family Acanthuridae, according to the 5th edition of Fishes of the World. Etymology The specific name of Zebrasoma desjardinii honours the French zoologist Julien Desjardins; he lived for a number of years in Mauritius and donated a collection of fishes to the British Museum of Natural History, including the type of this species. Description Zebrasoma desjardinii has a tall dorsal fin that has 4 spines and between 27 and 31 soft rays (the longest of which is around half of the standard length), while these figures for the anal fin are 2 and between 22 and 24 respectively. It has a deep body, with the standard length being 1.8 to 2 times its depth; the maximum published total length of this species is 40 cm (16 in). The mouth protrudes with a concave profile on the snout. The spine in the caudal peduncle has a narrow posterior connection to the body, and the caudal fin is truncate. The body is grey, with around 8 dark grey vertical bars; each bar houses 2 to 3 orange or yellow vertical lines, which break up into spots towards the lower body and on the anal fin. There are 2 dark brown bars on the head, with the first one passing through the eye. There is a dense pattern of small, light yellow spots on the head and body, and a similar pattern of spots arranged in bands can be on the dorsal fin. The caudal fin is marked with pale blue spots. The juveniles have slender grey and yellow bars on the body and 2 black bars on the head. Distribution and habitat Zebrasoma desjardinii is found in the Indian Ocean. It can be found off the eastern coast of Africa (as south as Sodwana Bay, South Africa), as well as in the Middle East, including off the coasts of Israel, Saudi Arabia and Yemen. It is also found across the islands of the Indian Ocean (such as Sri Lanka, islands in the Andaman Sea, Sumatra, Java, the Cocos (Keeling) Islands and Christmas Island). In 1999, a pair of this species was recorded in the Atlantic Ocean, off Florida, but this was probably due to aquarium release. Zebrasoma desjardinii is found at depths between 1 and 30 m (3 ft 3 in and 98 ft 5 in) in lagoon and seaward reefs, although the juveniles are more typically found in sheltered areas within reefs. Behaviour Zebrasoma desjardinii adults usually can be found in pairs, while juveniles are solitary.They feed primarily on filamentous algae, macroalgae and plankton, but individuals in the Red Sea have been regularly observed feeding on moon jellies (Scyphozoa) and comb jellies (Ctenophora) as well.[10] This species may form aggregations while feeding on algae; if they do so within the territory of the predatory slingjaw wrasse, the wrasse may darken its colour so as to match the colour of the tangs. The wrasse then joins in the aggregation and mimics their algae-feeding actions while hunting prey. Zebrasoma desjardinii is a pair spawner; while this is a typical trait of other fish in its genus, group spawning is more common at the family level.

Read more less

Paracanthurus hepatus is a species of Indo-Pacific surgeonfish. A popular fish in marine aquaria, it is the only member of the genus Paracanthurus. A number of common names are attributed to the species, including regal tang, palette surgeonfish, blue tang , royal blue tang, hippo tang, blue hippo tang, flagtail surgeonfish, Pacific regal blue tang, and blue surgeonfish, hepatus tang, Indo-Pacific blue tang, regal blue surgeonfish, wedge-tailed tang, wedgetail blue tang. Description Paracanthurus hepatus has a royal blue body, yellow tail, and black "palette" design. Its length at first sexual maturity is 149.2 mm. Adults typically weigh around 600 g (21 oz) and males are generally larger than females.The back has a broad black area that encloses at the tip of the pectoral, creating a blue oval on each side of the fish that extends in the direction of the eye. The tail has a bright yellow triangle with its apex anterior to the caudal spine and its base at the posterior end of the caudal fin. Black surrounds the triangle on the upper and lower lobes of the caudal fin, in the same hue as the back area. Paracanthurus has small small scales, each with short ctenii on the upper surface. Scales on the caudal spine possess ctenii approximately three times as long as scales on the rest of the body. Scales anteriorly placed on the head between the eye and the upper jaw are larger with tuberculated, bony plates. This fish has a compressed, elliptical body shape, and a terminal snout. It has nine dorsal spines, 26–28 dorsal soft rays, three anal spines, and 24–26 anal soft yellow rays, and 16 principal caudal rays with slightly projecting upper and lower lobes. Its pelvic fin is made up of one spine and three rays; this characteristic is considered a synapomorphy of the Naso and Paracanthurus genus. The caudal peduncle has a spine located in a shallow groove, which is also a characteristic of its sister taxa Zebrasoma. It has 22 vertebrae. Paracanthurus has teeth that are small, close-set, denticulated, and described as incisor-like. Jaw morphology includes an ectopterygoid that links the palatine to the quadrate near the articular condyle. A crest is present on the anterodorsal surface of the hyomandibular. The opercle is less developed, with a distinctly convex profile. Some slight variation in appearance is present within Paracanthurus. The lower body is yellow in west-central Indian Ocean individuals, and bluish in Pacific individuals . Additionally, the blue color on the trunk of Paracanthurus loses pigmentation in response to changes in light and/or melatonin levels, making its appearance slightly lighter in color at night. Distribution The regal blue tang can be found throughout the Indo-Pacific. It is seen in the reefs of the Philippines, Indonesia, Japan, the Great Barrier Reef of Australia, New Caledonia, Samoa, East Africa, and Sri Lanka. A single specimen was photographed in 2015 in the Mediterranean Sea off Israel. Vagrants were found two separate occasions in Hawaii, and are assumed to be aquarium releases. Paracanthurus is an extant resident in the following territories: American Samoa; Australia; British Indian Ocean Territory; Brunei Darussalam; Christmas Island; Cocos (Keeling) Islands; Comoros; Cook Islands; Disputed Territory (Paracel Is., Spratly Is.); Fiji; French Southern Territories (Mozambique Channel Is.); Guam; India (Nicobar Is., Andaman Is.); Indonesia; Japan; Kenya; Kiribati (Kiribati Line Is., Phoenix Is., Gilbert Is.); Madagascar; Malaysia; Maldives; Marshall Islands; Mauritius; Mayotte; Micronesia, Federated States of ; Myanmar; Nauru; New Caledonia; Niue; Northern Mariana Islands; Palau; Papua New Guinea; Philippines; Réunion; Samoa; Seychelles; Singapore; Solomon Islands; Somalia; South Africa; Sri Lanka; Taiwan, Province of China; Tanzania, United Republic of; Thailand; Timor-Leste; Tokelau; Tonga; Tuvalu; United States (Hawaiian Is.); United States Minor Outlying Islands (US Line Is., Howland-Baker Is.); Vanuatu; Viet Nam; Wallis and Futuna. Ecolog Paracanthurus is a diurnal marine species that occupies marine neritic habitats along coastlines. It is found in clear water on exposed outer reef areas or in channels with a moderate or strong current. It primarily utilizes coral reef habitats, but is also known to utilize seagrass beds, mangroves, algal beds, and rocky reefs [1]. It has an upper and lower depth limit of 2 meters and 40 meters, respectively .They live in pairs or small groups of 8 to 14 individuals. They can also be found near cauliflower corals on the seaweed side of coral reefs. Juveniles can be found in schools using Acropora for shelter. Numbers of males and females tend to maintain a 1:1 ratio. The fish is important for coral health as it eats algae that may otherwise choke it by overgrowth. Diet As a juvenile, its diet consists primarily of plankton. Adults are omnivorous and feed on zooplankton, but will also graze on filamentous algae.[16] Life cycle Spawning takes place year round, with a peak between April and September. Spawning occurs during late afternoon and evening hours around outer reef slopes. This event is indicated by a change in color from a uniform dark blue to a pale blue. Males aggressively court female members of the school, leading to a quick upward spawning rush toward the surface of the water during which eggs and sperm are released. The eggs are small, approximately 0.8 millimetres (1⁄32 in) in diameter. The eggs are pelagic, each containing a single droplet of oil for flotation. The fertilized eggs hatch in twenty-four hours, revealing small, translucent larvae with silvery abdomens and rudimentary caudal spines. Once opaque, the black "palette" pattern on juveniles do not fully connect until mature. These fish reach sexual maturity at 9–12 months of age, and at approximately 149.22 mm in size.[6] Fecundity has a tendency to positively correlate with weight. Fishes in the family Acanthuridae, including Paracanthurus, produce altricial larvae that receive no v. parental care. After hatching, these larvae rely on yolk reserves in order to survive their first two to three days of life. Importance to humans The regal blue tang is of minor commercial fisheries importance; however, it is a bait fish. The flesh has a strong odor and is not highly prized. This fish may cause ciguatera poisoning if consumed by humans. However, regal blue tangs are collected commercially for the aquarium trade. Handling the tang risks the chances of being badly cut by the caudal spine. These spines, one on each of the two sides of the caudal peduncle, the area where the tail joins the rest of the body, are extended when the fish is stressed. The quick, thrashing sideways motion of the tail can produce deep wounds that result in swelling and discoloration, posing a risk of infection. It is believed that some species of Acanthurus have venom glands while others do not. The spines are used only as a method of protection against aggressors. The regal blue tang is one of the most common and most popular marine aquarium fish all over the world, holding its place as the 8th most traded species worldwide. In 1997–2002, 74,557 individuals were traded in official tracked sales and in 2011 approximately 95,000 Paracanthurus were imported for use as a marine ornamental fish. When harvesting Paracanthurus in the wild, juveniles are specifically targeted since they are easiest to collect due to their tendency to travel in schools. Paracanthurus for human use are harvested in the wild rather than raised in aquaculture. Conservationists encourage efforts to switch to aquaculture in order to better preserve wild populations.

Read more less