Acanthurus lineatusSpoted box crab(Also: Striped surgeon)

Geographic Range

Acanthurus lineatus, more commonly known as the lined surgeonfish, lives between 30 degrees north and 40 degrees south latitude. It can be found in or around most coral reefs throughout the Indo-Pacific region, and from southern Japan southward to southern Australia. Lined surgeonfish are prevalent in the Great Barrier Reef, the Indian Ocean, and in reefs around the American Samoa. This species also lives in large populations along the coasts of eastern Africa and Madagascar, the southeastern coast of India, the coasts of the Philippines and Indonesia, and the northeast and northwest coasts of Australia. Historically, there have been just two sightings of this fish around the Hawaiian Islands. (Choat, et al., 2012; Craig, 1996; Randall, 1980; Randall, 2001; Randall, 2010)


Lined surgeonfish inhabit 26°C to 30°C coastal waters and tropical seas where coral reefs are found. They live mainly along the coast in waters with depths of 1 to 3 meters, but have been found to live as deep as 10 meters. Juvenile lined surgeonfish tend to live in shallow water in the pelagic zone, as they mature they migrate to deeper water around reefs. The lined surgeonfish lives in shallower water compared to other surgeonfish. (Craig, 1996; Randall, 2001; Sale, 1991)

  • Range depth
    1 to 10 m
    3.28 to 32.81 ft

Physical Description

Lined surgeonfish have distinct markings. These fish are bright yellow and have blue stripes lined by black stripes running lengthwise across their bodies. The stripes curve around their facial features.

Lined surgeonfish range in size from 2.7 to 3.2 centimeters as juveniles. As adults, they range from 18.3 to 38 centimeters and weigh an average of 285 grams. They have dorsal fins consisting of 9 spines and 27 to 29 soft rays, and anal fins consisting of 3 spines and 25 to 28 soft rays. Both of these sets of fins are yellow with blue stripes. These fish have 16 transparent yellow pectoral fins, and 14 to 16 gill-rakers. Lined surgeonfish also have yellow-black pelvic fins, black caudal fins, and a violet-silver underside. The caudal spine of this species is highly venomous. Male and female lined surgeonfish do not have any different physical attributions.

Lined surgeonfish have closely-placed, rounded teeth with denticulate edges (tooth-like projections), that allow for easy grazing of algae. This species also has a thick-walled stomach that acts as a gizzard when sand is ingested and helps grind its food for better digestion.

The colors of lined surgeonfish change in certain situations. When they get excited or aggressive their colors intensify and their caudal fins turn from black to white. At night, the fish become lighter in color in order to be more visible in the water column. (Green, et al., 2009; Nursall, 1974; Randall, 2001; Randall, et al., 1996; Robertson, et al., 1979; Winterbottom, 1971)

  • Sexual Dimorphism
  • sexes alike
  • Average mass
    285 g
    10.04 oz
  • Range length
    18.3 to 38 cm
    7.20 to 14.96 in


When a lined surgeonfish egg is laid, it is less than 1 millimeter in diameter. The egg contains a drop of oil so it can float. Upon development of the yolk the egg begins to sink. Approximately 27 hours after spawning the egg hatches and after 42 hours the lined surgeonfish has a sense of awareness of its surroundings. At 4 days old, the larva is 2.7 to 3.2 centimeters and has a moving jaw and swimbladder. The larval stage lasts for 39.5 days in the pelagic zone of the ocean, until they metamorphose to adulthood and move to coral reefs. Lined surgeonfish have indeterminate growth but experience rapid growth for the first 3 to 4 years of their life, reaching close to maximum adult size within the first 10% of their lifespan. (Choat, et al., 2012; Mutz, 2006; Randall, 2001)


Lined surgeonfish spawn in large groups of 50 to 200 fish. They are polygynandrous, meaning the males and females have multiple mates. Usually the female releases her eggs and multiple males fertilize them with their milt (seminal fluid). (Barlow, 1981; Craig, 1998; Robertson, et al., 1979)

Male and female lined surgeonfish are gonochoric and iteroparous. The fish reach sexual maturity around 4 years old or when they are about 160 millimeters long. While spawning occurs year-round, it is concentrated from October through February. Spawning times vary upon location, but lined surgeonfish mainly spawn in early morning hours and around the time of a full moon. In Palau and Guam, this species has been observed spawning early in the morning. In the Great Barrier Reef, spawning takes place in the afternoon. Because spawning requires leaving their territory, it is thought that the time of day for spawning is a strategy to minimize food loss in their territories from competitors. This species forms a spawning aggregation and form non-permanent pairs to mate. Lined surgeonfish spawn on the outer reef channel in waters 3 to 5 meters deep. The eggs are less than 1 millimeter in diameter when spawned and independent immediately after spawning. (Choat, et al., 2012; Craig, et al., 1997; Craig, 1998; Robertson, et al., 1979)

  • Breeding interval
    Lined surgeonfish breed throughout the year.
  • Breeding season
  • Average time to hatching
    27 hours
  • Average time to independence
    0 minutes
  • Average age at sexual or reproductive maturity (female)
    4 years
  • Average age at sexual or reproductive maturity (male)
    4 years

Lined surgeonfish do not provide any parental care post-egg laying. Once spawned, the juveniles fend for themselves until adulthood. (Thresher, 1984)

  • Parental Investment
  • no parental involvement


Lined surgeonfish have a lifespan of 30 to 45 years. The members of this species that live near the Great Barrier Reef live to an average age of 32 years. The lined surgeonfish that live in American Samoa have an average lifespan of 11 years. Their average lifespan in captivity is unknown. (Choat, et al., 2012; Green, et al., 2009; Randall, 2001)

  • Range lifespan
    Status: wild
    45 (high) years
  • Typical lifespan
    Status: wild
    11 to 32 years


Lined surgeonfish live solitary, sedentary lives. They establish their territories individually around coral reefs, although they spend nights in deep-water fissures. This species have site fidelity and have a 99.9% return rate to their territories. The lined surgeonfish also leave its territory to spawn. Lined surgeonfish spend about 80% of their day eating and have been spotted taking food from neighboring territories.

Lined surgeonfish are very territorial and defend the algae found in their territory from other grazing fish. This species become very aggressive to the fish that enter their territory and have been observed circling, parallel swimming, chasing, and changing their body colors to warn the intruders. The lined surgeonfish become more aggressive to others during high tide. With low tide, these fish are forced to move into deeper waters. Lined surgeonfish are also affected by high water turbulence. It causes them to feed less, leave their territory, and become less aggressive. They live along the edges of coral reefs and on flat algal mats near reefs. (Barlow, 1974; Craig, et al., 1997; Craig, 1996; Hutchings, et al., 2008; Nursall, 1974; Ogden and Lobel, 1978; Robertson, et al., 1979; Thibaut, et al., 2012)

  • Range territory size
    4 to 12.5 m^2

Home Range

Lined surgeonfish have territories that range in size from 4 to 12.5 square meters. (Robertson, et al., 1979)

Communication and Perception

All fish, including lined surgeonfish, have a lateral line system. This system allows organisms to detect movement and vibrations in the water surrounding them. Lateral lines provide lined surgeonfish with a sense of space so that they have awareness of what is near them. Epithelial cells detect the vibrations and send electrical impulses to alert the organism.

Lined surgeonfish live in schools and are very territorial to other species of fish. They change color to show that they are agitated or excited; their colors become brighter and their caudal fins change from black to white.

Little else is known about the communication and perception of the lined surgeonfish. (Coombs, et al., 1989; Nursall, 1974; Robertson, et al., 1979)

  • Communication Channels
  • visual

Food Habits

Lined surgeonfish are herbivores, more specifically, algivores. They graze on the salts and filaments of rhodophytes (red algae), chlorophytes (green algae), and turf algae on rocks and corals. Because of their diet, this species has high levels of short-chained fatty acids and low levels of protein amino acids, meaning they do not rely heavily on fermentation to gain energy. Lined surgeonfish feed in shallow water during the daytime. (Craig, 1996; Crossman, et al., 2005; Green and Bellwood, 2009; Robertson, et al., 1979; Sale, 2006)

  • Animal Foods
  • aquatic crustaceans
  • Plant Foods
  • algae


Humans Homo sapiens are predators to the lined surgeonfish by way of intentional fishing efforts. Groupers and other predaceous fish are the only reported natural predators of this species. (Choat, et al., 2012; Craig, et al., 1997; Craig, 1996; Randall, 2001)

  • Known Predators

Ecosystem Roles

Lined surgeonfish, like other herbivorous fish, are beneficial to the growth of benthic plants. This species is also known to help the growth of red algae.

Lined surgeonfish found in the Philippines can be a host to the trematode Megasolena acanthuri, a parasite found in their intestines. (Hutchings, et al., 2008; Machida and Uchida, 1991; Ogden and Lobel, 1978)

Commensal/Parasitic Species
  • Trematode (Megasolena acanthuri)

Economic Importance for Humans: Positive

Lined surgeonfish are popular catches in the spearfishing trade and used as a food source in American Samoa. In French Polynesia, lined surgeonfish are ornamental and part of the marine aquarium trade. (Choat, et al., 2012; Craig, et al., 1997)

Economic Importance for Humans: Negative

Lined surgeonfish have venom in their caudal spines that cause painful wounds to humans. It is unknown if the venom affects other species. (Randall, 2001)

  • Negative Impacts
  • injures humans

Conservation Status

Lined surgeonfish are listed as a species of "least concern" on the IUCN Red List. This species is not listed by the United States Endangered Species Act, on the CITES Appendices, or on the State of Michigan List. By Executive Order, in 2001, night spearfishing and SCUBA fishing were banned in America Samoa to help prevent overfishing. To help sustain this species, Australia has put a catch limit into effect. Only five lined surgeonfish that are longer than 25 centimeters can be kept per day. (Choat, et al., 2012)


Madison Krablin (author), Radford University, Karen Powers (editor), Radford University, April Tingle (editor), Radford University, Emily Clark (editor), Radford University, Cari Mcgregor (editor), Radford University, Jacob Vaught (editor), Radford University, Genevieve Barnett (editor), Colorado State University.



Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

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living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

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bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate


the nearshore aquatic habitats near a coast, or shoreline.


animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

external fertilization

fertilization takes place outside the female's body


union of egg and spermatozoan


A substance that provides both nutrients and energy to a living thing.


An animal that eats mainly plants or parts of plants.

indeterminate growth

Animals with indeterminate growth continue to grow throughout their lives.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).


A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.


having the capacity to move from one place to another.


specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

oceanic islands

islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.


found in the oriental region of the world. In other words, India and southeast Asia.

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reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pet trade

the business of buying and selling animals for people to keep in their homes as pets.


the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.


structure produced by the calcium carbonate skeletons of coral polyps (Class Anthozoa). Coral reefs are found in warm, shallow oceans with low nutrient availability. They form the basis for rich communities of other invertebrates, plants, fish, and protists. The polyps live only on the reef surface. Because they depend on symbiotic photosynthetic algae, zooxanthellae, they cannot live where light does not penetrate.

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.


remains in the same area


reproduction that includes combining the genetic contribution of two individuals, a male and a female


lives alone


uses touch to communicate


defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement


an animal which has an organ capable of injecting a poisonous substance into a wound (for example, scorpions, jellyfish, and rattlesnakes).


movements of a hard surface that are produced by animals as signals to others


uses sight to communicate

year-round breeding

breeding takes place throughout the year


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Mutz, S. 2006. Comparative growth dynamics of Acanthurid fishes. Queensland, Australia: James Cook University.

Nursall, J. 1974. Some territorial behavioral attributes of the surgeonfish Acanthurus lineatus at Heron Island, Queensland. Copeia, 1974/4: 950-959.

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Randall, J. 2001. Surgeonfishes of Hawai'i and the World. Honolulu, Hawai'i: Mutual Publishing and Bishop Museum Press.

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Robertson, D., N. Polunin, K. Leighton. 1979. The behavioral ecology of the three Indian Ocean surgeonfishes (Acanthurus lineatus, A. leucosternon and Zebrasoma scopas): Their feeding strategies, and social and mating systems. Environmental Biology of Fishes, 4/2: 125-170.

Sale, P. 2006. Coral Reef Fishes: Dynamics and Diversity in a Complex Ecosystem. San Diego, California: Elsevier.

Sale, P. 1991. The Ecology of Fishes on Coral Reefs. San Diego, California: Academic Press.

Thibaut, L., S. Connolly, H. Sweatman. 2012. Diversity and stability of herbivorous fishes on coral reefs. Ecology, 93/4: 891-901.

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Winterbottom, R. 1971. Movement of the caudal spine of some surgeonfishes (Acanthuridae, Perciformes). Copeia, 1971/3: 562-566.