Disclaimer:

The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

---

Common name: Red-toothed Triggerfish

Synonyms and Other Names: Xenodon niger Rüppell, 1836; Balistes erythrodon Günther, 1870

Taxonomy: available through www.itis.gov

Identification: Randall (2005) described the red-toothed triggerfish as having a moderately and deeply compressed blue to purplish-blue body with the eyes high on the head. There is a deep groove in front of the eye. Two dark blue lines run from the front of the eye to the upturned mouth. In adults, the teeth are red and chisel-like with two of the upper teeth visible even when the mouth is closed. Triggerfish have a first dorsal fin with a spike-like spine that can be locked into place by the smaller second and third dorsal spines, all of which fit into a groove when not upright. The caudal fin is lunate with long lobes. The second dorsal fin, anal fin, and caudal fin margins are lined in electric blue. The skin is rough to the touch with non-overlapping scales.

Size: Up to 40 cm total length (Randall 2005)

Native Range: Red-toothed triggerfish is a marine species native to the Indo-Pacific region from the Red Sea to the Society Islands, southern Japan to the Great Barrier Reef, and throughout Micronesia (Myers 1999).

Interactive maps: Point Distribution Maps

Ecology: The red-toothed triggerfish is usually seen over outer reef slopes, often in large groups (Randall 2005), in 3 to 55 m of water (Lieske and Myers 2004). If approached or alarmed, it hides in a hole in the reef and erects its dorsal spine to lock itself into position (Randall 2005). The species feeds primarily on zooplankton (Randall 2005), but also on other benthic animals such as crustaceans, sea urchins, corals, and mollusks (Lieske and Myers 2004).

This species of triggerfish exhibits biparental care. The eggs are tended by the female, but the nest is guarded by both parents (Kawase 2002). Spawning occurs in the early morning with the adhesive eggs being laid on the sandy bottom near the reef (Kawase 2002). The eggs hatch that evening (Kawase 2002). Many species in this family (Balistidae) aggressively defend their nest (Randall et al. 1997).

Means of Introduction: Probable aquarium release.

Status: Eradicated. The individual seen at Blue Heron Bridge in May 2021 was live-captured by a team of divers from Phillip and Patricia Frost Museum of Science and put on display (Frost Science 2021).

Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.

References: (click for full references)

Kawase, H. 2002. Simplicity and diversity in the reproductive ecology of triggerfish (Balistidae) and filefish (Monacanthidae). Fisheries Science 68:119-122.

Lieske, E. and R.F. Myers. 2004. Coral Reef Guide: Red Sea to Gulf of Aden, South Oman. Harper Collins, London, UK.

Myers, R.F. 1999. Micronesian reef fishes: A guide for divers and aquarists. Coral Graphics, Guam, USA.

Phillip and Patricia Frost Museum of Science (Frost Science).  2021.  Marine exotic species removal.   https://www.frostscience.org/marine-exotic-species-removal/.  Accessed 12 May 2021.

Randall, J.E. 2005. Reef and Shore Fishes of the South Pacific: New Caledonia to Tahiti and the Pitcairn Islands. University of Hawaii Press, Honolulu, Hawaii, USA.

Randall, J.E., G.R. Allen, and R.C. Steene. 1997. Fishes of the Great Barrier Reef and Coral Sea. University of Hawaii Press, Honolulu, Hawaii, USA.

Other Resources:

Author: Brown, M.E., and Schofield, P.J.

Peer Review Date: 5/14/2021

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.