Balistapus undulatus

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).

Habitat

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).

• Habitat Regions
• tropical tropical
• saltwater or marine saltwater or marine

• Aquatic Biomes
• reef 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).

• Other Physical Features
• ectothermic ectothermic
• bilateral symmetry bilateral symmetry

Development

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).

Reproduction

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).

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.

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

Lifespan/Longevity

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).

Behavior

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).

• Key Behaviors
• natatorial natatorial
• motile motile

Communication and Perception

No information is available for this species.

• Perception Channels
• tactile tactile
• chemical chemical

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).

• Primary Diet
• carnivore carnivore
  • molluscivore molluscivore
• planktivore planktivore

• Animal Foods
• mollusks
• zooplankton zooplankton

Predation

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).

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.

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).

• Positive Impacts
• pet trade pet trade
• food food

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).

Additional Links

Encyclopedia of Life

Contributors

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

References

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 The Living Marine Resources of the Western Central Pacific , Vol. 6. Rome: FAO.

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.

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

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.