Balistapus undulatusOrange striped triggerfish(Also: Red-lined triggerfish; Striped triggerfish; Undulate triggerfish; Vermiculated triggerfish)

Geographic Range

Balistapus undulates, the orange-lined triggerfish, can be found in the Red Sea and in the West Indo-Pacific (Smith and Heemstra, 1986). They reach down south to Natal in South Africa (Smith and Heemstra, 1986). (Smith and Heemstra, 1986)


Balistapus undulatus is found on coral reefs (Smith and Heemstra, 1986) in waters of the Indo-Pacific region (McClanahan, 2000). They can be seen using crevices in the reef as protection, lodging themselves with their first dorsal fin spine and pelvic bone (Randall et al., 1997). Adults tend to use rock, foliaceous and branching corals while juveniles used turf algae, sand, sponge, and soft corals more frequently (Bean et al., 2002). (Bean, et al., 2002; McClanahan, 2000; Randall, et al., 1997; Smith and Heemstra, 1986)

  • Aquatic Biomes
  • reef

Physical Description

Members of the family Balistidae have a first dorsal spine on the first dorsal fin that can be locked into place, a compressed body with high set eyes, and a small mouth placed on a long and tapering snout, chisel-like teeth (Randall et al., 1997). There are no pelvic fins, rather they have a spine-like knob at the end of a long and depressible pelvic bone (Randall et al., 1997). The second dorsal and anal fins are comprised of only soft rays (Randall et al., 1997). They possess rough skin that is made up of non-overlapping scales with an area of small tubercles in the center and have a gill opening that is a short slit above and in front of their pectoral fin base (Randall et al., 1997).

Balistapus undulatus has a terminal mouth, fully scaled cheeks, and enlarged bony plates behind its gill slit (Smith and Heemstra, 1986). There is no groove present in front of the eye (Masuda et al., 1984). The main color of the body is green to brown (Smith and Heemstra, 1986), and has diagonal curved orange lines as well as narrow stripes of orange and blue going from the mouth to below the pectoral fins (Randall et al., 1997). The caudal fin is orange-yellow in color, and there is a black area around on the caudal peduncle around the two rows of forward-curved spines (Randall et al., 1997).

The first dorsal fin is comprised of three spines; the second dorsal has about 26 soft rays, and the anal about 24 soft rays (Park, 1797). They can reach up to 30 centimeters in length (Smith and Heemstra, 1986). (Masuda, et al., 1984; Park, 1797; Randall, et al., 1997; Smith and Heemstra, 1986)


The eggs of Balistapus undulatus are laid in an adhesive mass (Lobel and Johannes, 1980). They hatch the night of the day they are laid, and embryos are active and free-swimming once they hatch (Lobel and Johannes, 1980).

Based on studies of various members of Balistidae, there is an age of maturity at about 2 years old (McClanahan and Humphries, 2012). (Lobel and Johannes, 1980; McClanahan and Humphries, 2012)


The spawning act has not been observed in Balistapus undulatus, but, during periods of spawning, aggregates were observed two to four meters from the sediment (Lobel and Johannes, 1980). Frequently during spawning times, two to four fish would be seen circling each other, occasionally with one nudging at the flank of another using its head (Lobel and Johannes, 1980). (Lobel and Johannes, 1980)

Balistapus undulatus nesting behavior was observed once by Lobel and Johannes (1980). The fish was seen turning onto one side, flexing its body, and flapping its dorsal and caudal fins. This resulted in a small hole in the sand in which to lay the eggs. Lobel and Johannes also observed guarding of the nests. One to two fish would protect the nest from any predators that would eat the eggs. (Lobel and Johannes, 1980)

The only parental investment observed was nest guarding (Lobel and Johannes, 1980). (Lobel and Johannes, 1980)


There have not been studies on the life span of Balistapus undulatus specifically. Studies of various members of the Balistidae family have shown a life span of about 10 years (McClanahan and Humphries, 2012). (McClanahan and Humphries, 2012)


Balistapus undulatus has been observed exhibiting solitary residing behavior, where they stay close to or in the vicinity of their home (Okuno, 1963). They are territorial of their nests, and when frightened will lodge themselves into crevices of the coral reefs using their dorsal spine and pelvic bone (Randall et al., 1997). (Okuno, 1963; Randall, et al., 1997)

Communication and Perception

No information is available for this species.

Food Habits

Balistids are mostly carnivorous (Randall et al., 1997). Balistapus undulatus has been shown to be a major predator of a sea urchin, particularly Echinometra mathaei (McClanahan, 2000). They eat a wide variety of animals from zooplankton to mollusks (Randall et al., 1997). (McClanahan, 2000; Randall, et al., 1997)


As Balistapus undulatus is a market fish, the main predation of this species occurs from humans (Matsuura, 2001). Natural predators include a couple of predatory fish species, Caranx melampygusi and Cephalopholis argus (Poelen et al., 2014). (Matsuura, 2001; Poelen, et al., 2014)

Ecosystem Roles

McClanahan and Shafir (1990) have shown that Balistapus undulatus is a key predator of a sea urchin species, Echinometra mathaei. The study showed that removal of Balistapus undulatus led to increases in the Echinometra mathaei population and resulted in negative effects on the coral reef. McClanahan and Shafir (1990) also observed a decline in the diversity of sea urchin species present. (McClanahan and Shafir, 1990)

Economic Importance for Humans: Positive

Many species of the family Balistidae are highly valued as food and frequently caught as bycatch in bottom trawls (Matsuura, 2001). They’re considered to be generally good as food (Randall et al., 1997). Multiple species of the Balistidae family are sought after for the aquarium trade as well (Prakask et al., 2017). (Matsuura, 2001; Prakash, et al., 2017; Randall, et al., 1997)

Economic Importance for Humans: Negative

There are no known negative impacts of this species on humans.

Conservation Status

The conservation status of Balistapus undulatus has not been evaluated (Prakask et al., 2017). (Prakash, et al., 2017)


Emily Nall (author), Louisiana State University, Prosanta Chakrabarty (editor), Louisiana State University, Tanya Dewey (editor), University of Michigan-Ann Arbor.


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.


an animal that mainly eats meat


uses smells or other chemicals to communicate


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


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


eats mollusks, members of Phylum Mollusca


having the capacity to move from one place to another.


specialized for swimming

pet trade

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


an animal that mainly eats plankton


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.


uses touch to communicate


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.


animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)


Bean, K., G. Jones, M. Caley. 2002. Relationships among distribution, abundance and microhabitat specialisation in a guild of coral reef triggerfish (family Balistidae). Marine Ecology Progress Series, 233: 263-272.

Lobel, P., R. Johannes. 1980. Nesting, eggs and larvae of triggerfishes (Balistidae). Environmental Biology of Fishes, 5(3): 251-252.

Masuda, H., K. Amaoka, C. Araga, T. Uyeno, T. Yoshino. 1984. The Fishes of the Japanese Archipelago. Tokyo University Press: Tokyo.

Matsuura, K. 2001. Balistidae. Tiggerfishes. Pp. 3911-3928 in K Carpenter, V Niem, eds. The Living Marine Resources of the Western Central Pacific, Vol. 6. Rome: FAO.

McClanahan, T. 2000. Recovery of a coral reef keystone predator, Balistapus undulatus, in East African marine parks. Biological Conservation, 94(2): 191-198.

McClanahan, T., A. Humphries. 2012. Differential and slow life-history response of fishes to coral reef closures. Marine Ecology Progress Series, 469: 121-131.

McClanahan, T., S. Shafir. 1990. Causes and consequences of sea urchin abundance and diversity in Kenyan coral reef lagoons. Oecologia, 83(3): 362-370.

Okuno, R. 1963. Observations and discussions on the social behaviors of marine fishes. Publications of the Seto Marine Biological Laboratory, 11(2): 281-336.

Park, M. 1797. IX. Descriptions of Eight New Fishes from Sumatra. Transactions of the Linnean Society of London, 3(1): 33-38.

Poelen, J., J. Simons, C. Mungall. 2014. Global biotic interactions: an open infrastructure to share and analyze species-interactions datasets. Ecological Informatics, 24: 148-159.

Prakash, S., T. Kumar, R. Raghavan, A. Rhyne, M. Tlusty, T. Subramoniam. 2017. Marine aquarium trade in India: Challenges and opportunities for conservation and policy. Marine Policy, 77: 120-129.

Randall, J., G. Allen, R. Steene. 1997. Fishes of the Great Barrier Reef and Coral Sea. Universy of Hawaii: University of Hawaii Press.

Smith, M., P. Heemstra. 1986. Smith's Sea Fishes. Johannesburg: Macmillan.