There are over 600 wrasse species in 81 genera, which are divided into 9 subgroups or tribes. They are typically small, most of them less than 20 centimeters (7.9 in) long, although the largest, the humphead wrasse, can measure up to 2.5 meters (8.2 feet). [Source: Wikipedia]
According to Animal Diversity Web: Wrasses display myriad colors and shapes. Razorfishes are elongate and laterally compressed, while members of Cheilinus, Choerodon, and many of Bodianus are large and stocky. However, most are elongate and tapered at both ends, often referred to as “cigar-shaped.” Cigar-shaped fishes are found in the genera Thalassoma, Halichoeres, and Labroides
Since male, female, and juvenile wrasses come in radically different colors and shapes and are conspicuous in shallow waters around the world, investigators initially named far too many distinct wrasse species. The number of species has been steadily declining but wrasses are still the third largest family of perciform fishes and the second largest family of marine fishes. Although many subfamilies and tribes are recognized, only one is monophyletic: tribe Cheilinini with 21 species. /=\
Websites and Resources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Fishbase fishbase.se ; Encyclopedia of Life eol.org ; Smithsonian Oceans Portal ocean.si.edu/ocean-life-ecosystems ; Woods Hole Oceanographic Institute whoi.edu ; Cousteau Society cousteau.org ; Monterey Bay Aquarium montereybayaquarium.org ; MarineBio marinebio.org/oceans/creatures
small cleaner wrasse cleaning a large Humphead wrasse
Cleaners wrasses are small slim fish, about 7.5 centimeters (three inches) long, with blue and white stripes that play an important role in the reef community by feeding on parasites that feed on other fish. They also eat dead skin and mucus. The wrasses set up cleaning stations at well defined areas. Fish signal they are ready to be cleaned by assuming a relaxed pose with their fins erect. The fish line up for their turn. One scientist observed 300 fish get cleaned by a single wrasse at a single station in a six hour period.
The wrasses clean squirrelfish, sea bass, butterflyfish, moray eels, parrot fish, scorpionfish, jacks, grouper and other predators much larger than themselves. The wrasses even clean divers feet and climb into the gills and mouths of sharks and clean their teeth. The grooming of algae and other marine growths by wrasses is believed to help manta rays fend off life-threatening infections.
Cleaners wrasses swim in the mouths and clean many creatures that could easily consume them as a meal. Barracuda have been observed swallowing wrasses after having their mouths cleaned. Studies have shown that the wrasses seem to distinguish hungry hosts from non-hungry ones by oscillating around the host to size it up. When a wrasse faces a hungry coral trout in an aquarium in an experiment at the University of Queensland the cleaner wrasse oscillate to the side and did not go near the trout’s mouth. Around a well-fed trout the wrasse oscillated less often.
According to Animal Diversity Web: The ecological role of cleaner wrasses of the Indo-Pacific region provides a good example of the complexity of seemingly mutualistic relationships between fishes. Typically, cleaner fishes are elaborately colored and perform displays over a patch of reef while larger fish approach and assume a relaxed posture. Cleaner fishes are commonly thought to benefit the host by removing dead or damaged tissue and ectoparasites. Accordingly, investigators reported higher recovery rates for wounded fish in the presence of cleaners. However, in experiments where all cleaners were removed from an environment there was no incidence of fishes leaving the area or becoming particularly unhealthy. Further, when levels of parasitic infections are high the host benefits from cleaning but when infection levels are low, which they usually are, some cleaners feed on healthy tissue, such as scales, pieces of fin, mucous, or in some cases the eggs of other reef fishes. Despite these parasitic qualities of the relationship, fishes being cleaned have a positive response to the tactile stimulation from cleaners, suggesting that some cleaners are mildly beneficial while others have taken advantage of the cleaning arrangement.
Wrasse Cleaning Stations
Some fish pull up to sections of reef inhabited with cleaning wrasses like cars pulling up to a car wash. The fish wait and line and when it is their turn the wrasse picks off parasites, fungus and pests. The wrasses also provide free medical service, munching on tasty parasites which congregate around a given fish's open wounds. Wrasse cleaning station are often manned by a group of female wrasses and one male. When the male dies one of the females turns into a male.
Describing a cleaner wrasse at work on a grouper, David Attenborough wrote: The wrasse "dances in front of the new arrival with a bobbing motion. The grouper now hangs in the water, holding open its gill covers and mouth, often with its body tipped more vertically than horizontally, sometimes head-up. sometimes head-down, in a posture that signals its willingness to have its toilet attended to...The little wrasse swims in and fusses all over its client, trimming off pieces of dead skin, snipping away infestations of fungus, boldly venturing right into the huge jaws and coming out through the gaping gill covers."
Describing a Pacific cleaner wrasse in action, Douglass Faulkner, "Boldly he swims up to one of them and pops his head into its mouth. The squirrel fish appears to be swallowing him whole. But the four-inch daredevil backs out unscathed. Approaching each squirrelfish in turn, he nibbles at the flanks of one, at the gill covers of another. When the visitors swim away, the slim blue-and-black fish remains by his post on the coral reef."
In a phenomena only discovered in 1988, normally-open-ocean manta rays were observed coming to special "cleaning stations," specific rocks or areas along channels off the island of Yap in Micronesia, where wrasses removed parasites from their bodies while the manta rays fluttered in place in the current. The grooming of algae and other marine growths by wrasses is believed to help manta rays fend off life-threatening infections. Describing the wrasses at work, David Doubilet wrote in National Geographic, "Suddenly wrasses about three inches long dart from the coral below and head for the manta. The creature then opens its enormous mouth, and a wrasse enters the white cave, picking between the gill arches that support the gills.”
The slingjaw wrasse (Epibulus insidiator) is a species of wrasse native to the tropical waters of the Indo-Pacific where it lives around coral reefs. The most notable feature of this fish is that its mouth has a highly protrusible jaws which unfold into a tube that more than half its body length. Peter Wainwright of the University of California, Davis recorded an amazing video of the wrasse feeding in slow motion. [Source: Wikipedia; Peter Chung, Business Insider Jul 13, 2016]
Male slingjaw wrasses are greyish-brown with orange on the back, a yellowish transverse bar on the flank and a pale grey head which is marked with a thin black stripe running through the eye. The females can be either bright yellow or dark brown while the juveniles are brown with thin white bars on their flanks and white lines radiating out from their eyes.The dorsal fin has 9–10 spines and 9–11 soft rays while the anal fin has 3 spines and 8–9 soft rays. The largest individuals reach a length of 54 centimetres (21 inches).
The sling-jaw wrasse can protrude its jaws out further than any other fish. The species can extend its jaws up to 65 percent the length of its head. The rapid speed and length to which the jaw protrudes allows it to capture small fish and crustaceans. The genus this species belongs to possess one unique ligament (vomero-interopercular) and two enlarged ligaments (interoperculo-mandibular and premaxilla-maxilla), which along with a few changes to the form of cranial bones, allow it to achieve extreme jaw protrusion.
The slingjaw wrasse is found in a wide area of the Indo-Pacific region from the eastern coast of Africa, Madagascar and the Red Sea through the Indian Ocean coasts and islands into the Pacific as far east as Johnston Atoll. It reaches north to Japan and south to New Caledonia. It is found along the northern coasts of Australia to reefs in the Coral Sea off Queensland
Harlequin tuskfish (Scientific name: Choerodon fasciatus) is a kind of wrasse. It is found throughout the Indo-Pacific region, with specimens collected in Australia, the Philippines, Indonesia, South Japan, New Hebrides and Taiwan. In Australia they are found in the Great Barrier Reef from Queensland to New South Wales.[Source: Cassandra Coco, Animal Diversity Web (ADW) /=]
Harlequin tuskfish are typically found at depths of five to 35 meters (16 to 115 feet) in lagoons that are located on the outer edges of reef areas in waters with temperature of around 25-28 degrees Celsius (77 to 82 degrees F). Adults will usually live together in small loose groups in caves or by reef slopes. Juveniles tend to be isolated, living by reef walls that drop off to channels.
Harlequin tuskfish feed on aquatic worms, crustaceans, echinoderms, and mollusks. Among its anti-predator adaptations and being brightly colored which is a warning to potential predators that its flesh could taste bad, be poisonous, or inedible When threatened its teeth from blue to pink. Humans utilize the fish for the pet and aquarium trade. The fish is not endangered. Harlequin tuskfish was not found on the International Union for Conservation of Nature (IUCN) Red List or Convention on International Trade in Endangered Species (CITES) list.
Harlequin tuskfish can reach lengths of 30 centimeters (12 inches). According to Animal Diversity Web: The head and body of adults has blue lined orange-red stripes. The caudal fins are yellow. As the fish ages the back half of the body darkens to a dark blue-purple color. Juveniles have ocelli, eye-like spots, on the anal and dorsal fins. These spots go away with age. The body of a juvenile also has brown banding.. A mouth full of big blue teeth is a very distinctive feature of this species.
Harlequin tuskfish hatch as females. As they become adults, loose social groups form. Within each social group, the most dominant female undergoes physiological changes to become a male. Each group consists of one male and multiple females. When the males dies or leaves the second most dominant female becomes the male. Like other wrasses, the mating group of Harlequin tuskfish consists of one male with multiple females. The general reproductive behavior of this species is not known. /=\
The clown wrasse (Scientific name: Coris aygula) is a species of wrasse native to the Indian Ocean and the western Pacific Ocean. Also known as the clown coris, redthroated rainbowfish, false clownwrasse, red-blotched rainbowfish or twinspot wrasse, it is brightly colored, which may offer camoflauge among the bright colors of coral reefs, its natural habitat.[Source: Joshua Lehto-Jacobs, Animal Diversity Web (ADW) /=]
The clown wrasse is found primarily in rocky reef and coral areas at depths of two to 30 meters (6.56 to 98.43 feet) in waters between 24 and 28 degrees Celsius (75 and 82.5 degrees F) near Eastern Africa and Southern Asia, and are most heavily concentrated near Comores, Madagascar, Cargados Carajos/St. Brandon’s Shoals, Aldabra, Sychelles, Maldives, the Chagos Archipelago to the Ducie Islands. They have also been observed as far north and east as the, Ryukyu, Bonin and Ogawawara Islands in southern Japan, and as far south the Lord Howe and Rapa Islands. /=\
Clown wrasse eat shelled mollusks, hermit crabs, other crabs, and sea urchins. They in turn are eaten by sharks, groupers, snappers, jacks and pompanos and barracudas and thus helps to sustain the large reef predators. Clown wrasse also help to control the populations of the small reef invertebrates that they eat. Clown wrasse are also a valuable and popular aquarium species. Some people eat them for food and fish for tThey are also considered to be a game fish. /=\
Clown Wrasse Characteristics and Behavior
Clown wrasse reach lengths of 120 centimeters (47 inches) and are polymorphic (“many forms”, species in which individuals can be divided into easily recognized groups, based on structure, color, or other similar characteristics). Large males change color and form as they develop. Juveniles start out white with orange or red spots on the back and a large black spot on each dorsal fin. They eventually become a dark-green color, with less variation in color on their body. The first dorsal spine becomes elongated and a hump forms on the forehead. [Source: Joshua Lehto-Jacobs, Animal Diversity Web (ADW) /=]
Clown wrasse have 9 dorsal spines, between 12 and 13 dorsal soft rays, three anal spines, 14 pectoral rays, and 12 anal soft rays. According to Animal Diversity Web: The first two spines lie closer together than others. They also have between 59 and 67 lateral line scales. Males and females are slightly different. Males develop a hump on the forehead. The caudal fin of the famale is slightly more rounded than that of the male. Also, males have very long pelvic fins. Females have a white-colored streak in front of the anal fin. They also have light yellow or green coloring on the body with small, maroon spots and scales with dark edges, while males are blue-green in color. Onmales there are often broad, pale, green bars along the middle of the body. Juveniles have an extremely different appearance than adults. They are white and have black spots on each dorsal fin. They also have two circular orange/red spots on their back. /=\
Clown wrasse adults are solitary except when spawning. They spend much time searching for prey by over turning rocks. They communicate with vision and sense using touch and chemicals usually detected with smell. Clown wrasse uses body coloration to signal either members of their own species or other species. This would not be possible without the extreme clarity of reef water. This subject is somewhat controversial, but the colors may be a warning signal or camouflauge against the reef. /=\
Clown Wrasse Sexuality and Reproduction
Clown wrasse are sequential hermaphrodites in which individuals change their sex at some point in their lives and typically produces eggs and sperm at different stages their lives. They generally have female organs and eggs before male organs and sperm). Reproduction is external, meaning the male’s sperm fertilizes the female’s egg outside her body. Young are hatched from eggs. That are produced in large masses. Members of the wrasse family engage in seasonal breeding and spawn along the outer edge of a reef patch. In more extensive reef complexes, fish will spawn along the outer slope. There is no parental involvement in the raising of offspring. [Source: Joshua Lehto-Jacobs, Animal Diversity Web (ADW) /=]
According to Animal Diversity Web: When spawning, wrasses gather in loose aggregations where one dominant male oversees many females within a general territory. If the dominant male dies then usually the largest female will transform into the resident male. /=\
The differences between the primary males (born male) and secondary males (born female) are evident in the structure of the gonads, which are located in the upper sides of the abdominal cavity between the viscera and the coelomic wall. In primary males, the gonads are elongate, white, and solid with a small, tubular sperm duct extending posteriorly. This sperm duct extends to the urogenital opening. In secondary males, the gonads are hollow, short, thick, and yellowish because the gonads began as ovaries and later developed into testes. The secondary male testes have a large central space referred to as the lumen. The lumen has a ring of lobe-like projections around it. These are the ovarian lamellae. In females, when the eggs are ripe, they burst free from the lamellae and enter the lumen. They are then expelled through the urogenital opening. /=\
The exquisite wrasse (Scientific name: Cirrhilabrus exquisitus) is a species of the wrasse found in the Indo-West Pacific region, sold as aquarium fish and sought after by scientists study because of its ability to change sex mid-life. It moves in schools where there are only one or two dominant males. If these males are removed, the largest female quickly changes sex and becomes the dominant male. In order to change sex, the female cuts down its supply of estrogen. This process insures that offspring will always be produced.
The exqusite wrasse is normally found on reef slopes and lagoon habitats that are around ten meters (33 feet) deep in the Pacific Ocean and Indian Ocean as far east as the Tuamotu Islands of east Africa, as far north as Japan and as far south and east as the Great Barrier Reef of Australia. They prefer areas that are prone to strong currents.[Source: Erin Wayman, Animal Diversity Web (ADW) /=]
The exquisite wrasse is a rare fish to see and may be threatened by damage to their reef environments. The fish has an unpleasant taste and is generally not fished for food by humans. The exquisite wrasse mates year round. Males court females by following them and flashing the brilliant colors located on the sides of their body. Males release sperm into the water and females filters it through their gills to becomes impregnated. The eggs hatch and the wrasse emerge as colorless larvae with a spot on the end of their nose. For food, they often clean the bacteria off other fishes gills until they are big enough to find food in other places.
Exquisite Wrasse Characterics and Behavior
Exquisite wrasse on average weigh around two kilograms (4.4 pounds). They feed on molluscs, zooplankton, rotifers and copepods. For small organisms they filter them from the water. The fish has a unique, sharp, tooth-like appendage in its mouth that that it uses to break open the shells of molluscs. [Source: Erin Wayman, Animal Diversity Web (ADW) /=]
Color varies due to geographic differences, is common between the Pacific and Indian Ocean forms. According to Animal Diversity Web: Males and females do not have the same coloring, although females attain the ability to change sex during their lifetime. When the female changes sex, her coloring and markings change into that of the male. The females are usually olive or reddish-brown in color with dark and light stripes that run along the sides of the body. A blue stripe is present on the posterior side of the female's body and dark spots are located on the underside of the fins. The males are more colorful and have bright red areas on the dorsal and pectoral fins. The younger forms do not differ greatly from the adults, but are distinguishable from the adults because they have a white spot on their nose. /=\
The exquisite wrasse is normally found in small or fairly large schools and senses using touch and chemicals usually detected with smell. During courtship, the male Wrasse displays his purple markings. These markings serve as a multi-functional characteristic. While the male is courting any number of females, he can display these colors to other males to warn them not to take these females away from him. In order to protect itself from predators during the night while it sleeps, the wrasse uses its carnivorous front teeth to burrow into the sand, creating a little hollow in the sea floor. This protects it from predators who do not look on the ocean floor for their food.
Image Sources: Wikimedia Commons; YouTube, Animal Diversity Web, NOAA, group pictures from researchgate, EvoDevo and Oceans, Reefs and Aquariums (ORA)
Text Sources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Wikipedia, National Geographic, Live Science, BBC, Smithsonian, New York Times, Washington Post, Los Angeles Times, The New Yorker, Reuters, Associated Press, Lonely Planet Guides and various books and other publications.
Last Updated March 2023