Triggerfishes are about 40 species of often brightly colored
fishFish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
es of the
familyIn biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Balistidae. Often marked by lines and spots, they inhabit tropical and subtropical oceans throughout the world, with the greatest
species richnessSpecies richness is the number of different species in a given area. It is represented in equation form as S.Species richness is the fundamental unit in which to assess the homogeneity of an environment. Typically, species richness is used in conservation studies to determine the sensitivity of...
in the
Indo-PacificThe Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia...
. Most are found in relatively shallow, coastal habitats, especially at
coral reefCoral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
s, but a few, such as the aptly named oceanic triggerfish (
Canthidermis maculata), are pelagic. While several species from this family are popular in the marine
aquariumAn aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
trade, they are often notoriously ill-tempered.
Anatomy and appearance
The largest member of the family, the
stone triggerfishThe stone triggerfish is the largest species of triggerfish. It is found at reefs and over sandy bottoms in the east Pacific, ranging from Baja California to Chile. It can reach in length, but is more common at about half that size....
(
Pseudobalistes naufragium) reaches 1 metres (3.3 ft), but most species have a maximum length between 20 and 50 cm (7.9 and 19.7 in).
Triggerfish have an oval shaped, highly compressed body. The head is large, terminating in a small but strong- jawed mouth with teeth adapted for crushing shells. The eyes are small, set far back from the mouth, at the top of the head. The anterior
dorsal finA dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
is reduced to a set of three spines. The first spine is stout and by far the longest. All three are normally retracted into a groove. The ventral and the posterior dorsal fins are capable of undulating from side to side to provide slow speed movement. The sickle shaped caudal fin is used only to escape predators.
The two pelvic fins are overlaid by skin for most of their length and fused to form a single
spineA spine is a hard, thorny or needle-like structure which occurs on various animals. Animals such as porcupines and sea urchins grow spines as a self-defense mechanism. Spines are often formed of keratin...
, terminated by very short rays, their only external evidence. Gill plates
operculumThe operculum of a bony fish is the hard bony flap covering and protecting the gills. In most fish, the rear edge of the operculum roughly marks the division between the head and the body....
too, although present are not visible, overlaid by the tough skin, covered with rough, rhomboid
scalesIn most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...
, that forms a stout armor on their body. The only gill opening is a vertical slit, directly above the pectoral fins. This peculiar covering of the gill plates is shared with other members of the Tetradontae order. Each jaw contains a row of four teeth on either side, while the upper jaw contains an additional set of six plate-like pharingeal teeth.
As a protection against
predatorsIn ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
, triggerfish can erect the first two dorsal spines: The first, (anterior) spine is locked in place by erection of the short second spine, and can be unlocked only by depressing the second, “trigger” spine, hence the family name “triggerfish”.
With the exception of a few species from the genus
Xanthichthys, the genders of all species in this family are similar in appearance.
Behavior
The rather bizarre anatomy of the triggerfishes reflects their typical diet of slow-moving, bottom dwelling crustaceans, mollusks, sea urchins and other
echinodermEchinoderms are a phylum of marine animals. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone....
s, generally creatures with protective shells and spines. Many will also take small fishes and some, notably the members of the genus
MelichthysMelichthys is a genus in the triggerfish family .- Species :*Melichthys indicus : Indian triggerfish*Melichthys niger : Black triggerfish*Melichthys vidua : Pinktail triggerfish...
, feed on
algaeAlgae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
. A few, for example the
redtoothed triggerfishThe redtoothed triggerfish or Niger trigger, Odonus niger, is a triggerfish of the tropical Indo-Pacific area, the sole member of its genus.-Characteristics:...
(
Odonus niger), mainly feed on
planktonPlankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
. They are known to exhibit a level of
intelligenceIntelligence has been defined in different ways, including the abilities for abstract thought, understanding, communication, reasoning, learning, planning, emotional intelligence and problem solving....
that is unusual among fishes, and have the ability to learn from previous experiences.
Some triggerfish species can be quite aggressive when guarding their eggs. Both the
picassoThe lagoon triggerfish, also known as the blackbar triggerfish, the Picassofish, and the Jamal, is a triggerfish, up to 30 cm in length, found on reefs in the Indo-Pacific region....
(
Rhinecanthus aculeatus) and
titan triggerfishThe titan triggerfish, giant triggerfish or moustache triggerfish is a large species of triggerfish found in lagoons and at reefs in most of the Indo-Pacific, though it is absent from Hawaii...
(
Balistoides viridescens) viciously defend their nests against intruders, including scuba divers and snorkelers. Their territory extends in a cone from the nest toward the surface, so swimming upwards can put a diver further into the fishes' territory; a horizontal swim away from the nest site is best when confronted by an angry triggerfish. Unlike the relatively small picasso triggerfish, the titan triggerfish poses a serious threat to inattentive divers due to its large size and powerful teeth.
Triggerfish are notorious bait stealers; rather than swallowing a bait whole, they nibble off small bites of it, making a small, stout hook essential to success in hooking them. Accordingly, the best baits are tough strips of fish skin, squid mantle etc.
Life history
Triggerfish lay their demersal eggs in a small hole dug in the sea bottom. Off Florida, juveniles of some species of triggerfishes are found in floating
sargassumSargassum is a genus of brown macroalga in the order Fucales. Numerous species are distributed throughout the temperate and tropical oceans of the world, where they generally inhabit shallow water and coral reefs. However, the genus may be best known for its planktonic species...
, where they feed on the small shrimp, crabs and molluscs found there.
Edibility
Some species of triggerfish, such as the titan triggerfish, may be
ciguatoxicCiguatera is a foodborne illness caused by eating certain reef fishes whose flesh is contaminated with toxins originally produced by dinoflagellates such as Gambierdiscus toxicus which lives in tropical and subtropical waters. These dinoflagellates adhere to coral, algae and seaweed, where they are...
and should be avoided. Others, such as the
gray triggerfishThe grey triggerfish , a.k.a. , is a triggerfish of the western Atlantic, found from Nova Scotia to Argentina.It is also reported from the Mediterranean sea and off Angola on the west coast of Africa...
(
Balistes capriscus), are excellent table-fare.
Genera and species
- Abalistes
Abalistes is a small triggerfish genus. It has three species which are all found in the Indo-Pacific and eastern Atlantic.-Species:*Abalistes filamentosus Matsuura & Yoshino, 2004...
BlochMarcus Elieser Bloch was a German medical doctor and naturalist. He is generally considered one of the most important ichthyologists of the 18th century.- Life :...
& SchneiderJohann Gottlob Theaenus Schneider was a German classicist and naturalist.-Biography:Schneider was born at Collm in Saxony...
, 1801
- Abalistes filamentosus Matsuura & Yoshino, 2004
- Abalistes stellaris (Bloch
Marcus Elieser Bloch was a German medical doctor and naturalist. He is generally considered one of the most important ichthyologists of the 18th century.- Life :...
& SchneiderJohann Gottlob Theaenus Schneider was a German classicist and naturalist.-Biography:Schneider was born at Collm in Saxony...
, 1801) (Starry triggerfish)
- Abalistes stellatus
Abalistes stellatus is a member of the triggerfish family that occurs along the coasts of the Indian Ocean, the Red Sea, the Persian Gulf, and along the western edge of the Pacific Ocean....
(Anonymous - referred to Lacépède, 1798)
- Balistapus Tilesius, 1820
- Balistapus undulatus (Park
Mungo Park was a Scottish explorer of the African continent. He was credited as being the first Westerner to encounter the Niger River.-Early life:...
, 1797) (Orange-lined triggerfish)
- Balistes
Balistes is a genus of triggerfish. Species include:* B. capriscus * B phaleratus* B ellioti* B polylepis * B punctatus...
LinnaeusCarl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
, 1758
- Balistes capriscus J. F. Gmelin
Johann Friedrich Gmelin was a German naturalist, botanist, entomologist, herpetologist and malacologist.- Education :Johann Friedrich Gmelin was born as the eldest son of Philipp Friedrich Gmelin in 1748 in Tübingen...
, 1789 (Grey triggerfish)
- Balistes ellioti Day
Francis Day CIE was Inspector-General of Fisheries in India and Burma and an ichthyologist.He was born on 2 March 1829 Maresfield, Sussex, UK third son of William and Ann Day. He became the medical officer in the Madras Presidency, East India Company services in 1852.Francis Day was created a...
, 1889
- Balistes polylepis Steindachner
Franz Steindachner was an Austrian zoologist.- Work and career :Being interested in natural history, Steindachner took up the study of fossil fishes on the recommendation of his friend Eduard Suess...
, 1876 (Finescale triggerfish)
- Balistes punctatus
The bluespotted triggerfish, Balistes punctatus is a species of triggerfish from the Eastern Atlantic. It occasionally makes its way into the aquarium trade. It grows to a size of ....
J. F. GmelinJohann Friedrich Gmelin was a German naturalist, botanist, entomologist, herpetologist and malacologist.- Education :Johann Friedrich Gmelin was born as the eldest son of Philipp Friedrich Gmelin in 1748 in Tübingen...
, 1789 (Bluespotted triggerfish)
- Balistes rotundatus Marion de Procé, 1822
- Balistes vetula
Balistes vetula, also known as the queen triggerfish, is a reef dwelling fish of the Atlantic Ocean. It is occasionally caught as a gamefish, and sometimes kept in marine aquaria.-Appearance:...
LinnaeusCarl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
, 1758 (Queen triggerfish)
- Balistes willughbeii Lay
George Tradescant Lay was a British naturalist, missionary and diplomat.Lay was a naturalist on the English sailing ship HMS Blossom under the command of Captain Frederick William Beechey from 1825 to 1828, where he collected specimens in the Pacific including California, Alaska, Kamchatka, China,...
& BennettEdward Turner Bennett was an English zoologist and writer. He was the elder brother of the botanist John Joseph Bennett. Bennett was born at Hackney and practiced as a surgeon, but his chief pursuit was always zoology...
, 1839
- Balistoides Fraser-Brunner, 1935
- Balistoides conspicillum (Bloch
Marcus Elieser Bloch was a German medical doctor and naturalist. He is generally considered one of the most important ichthyologists of the 18th century.- Life :...
& SchneiderJohann Gottlob Theaenus Schneider was a German classicist and naturalist.-Biography:Schneider was born at Collm in Saxony...
, 1801) (Clown triggerfish)
- Balistoides viridescens (Bloch
Marcus Elieser Bloch was a German medical doctor and naturalist. He is generally considered one of the most important ichthyologists of the 18th century.- Life :...
& SchneiderJohann Gottlob Theaenus Schneider was a German classicist and naturalist.-Biography:Schneider was born at Collm in Saxony...
, 1801) (Titan triggerfish)
- Canthidermis
Canthidermis is a genus of triggerfish of the family Balistidae.- Description :These dark-colored triggerfishes are found in all the world's oceans in tropical and subtropical areas. They are absent in the Mediterranean...
Swainson, 1839
- Canthidermis macrolepis (Boulenger
George Albert Boulenger FRS was a Belgian-British zoologist who identified over 2000 new animal species, chiefly fish, reptiles and amphibians.-Life:...
, 1888) (Large-scale triggerfish)
- Canthidermis maculata (Bloch
Marcus Elieser Bloch was a German medical doctor and naturalist. He is generally considered one of the most important ichthyologists of the 18th century.- Life :...
, 1786) (Ocean triggerfish)
- Canthidermis sufflamen (Mitchill, 1815)
- Melichthys
Melichthys is a genus in the triggerfish family .- Species :*Melichthys indicus : Indian triggerfish*Melichthys niger : Black triggerfish*Melichthys vidua : Pinktail triggerfish...
Swainson, 1839
- Melichthys indicus Randall & Klausewitz, 1973 (Indian triggerfish)
- Melichthys niger (Bloch
Marcus Elieser Bloch was a German medical doctor and naturalist. He is generally considered one of the most important ichthyologists of the 18th century.- Life :...
, 1786) (Black triggerfish)
- Melichthys vidua (J. Richardson
Sir John Richardson was a Scottish naval surgeon, naturalist and arctic explorer.Richardson was born at Dumfries. He studied medicine at Edinburgh University, and became a surgeon in the navy in 1807. He traveled with John Franklin in search of the Northwest Passage on the Coppermine Expedition of...
, 1845) (Pinktail triggerfish)
- Odonus Gistel
Johannes von Nepomuk Franz Xaver Gistel Johannes von Nepomuk Franz Xaver Gistel Johannes von Nepomuk Franz Xaver Gistel (1809 - 1873 (or 1874) was a German naturalist.He was the author of works on entomology such as Die jetzt lebenden Entomologen, Kerffreunde und kerfsammler Europa’s und der...
, 1848
- Odonus niger (Rüppell
Wilhelm Peter Eduard Simon Rüppell was a German naturalist and explorer. Rüppell is occasionally transliterated to "Rueppell" for the English alphabet....
, 1836) (Redtooth Trigger)
- Pseudobalistes Bleeker
Pieter Bleeker was a Dutch medical doctor and ichthyologist, famous for his work on the fishes of East Asia – Atlas Ichthyologique des Orientales Neerlandaises – which was published 1862–1877....
, 1865
- Pseudobalistes flavomarginatus (Rüppell
Wilhelm Peter Eduard Simon Rüppell was a German naturalist and explorer. Rüppell is occasionally transliterated to "Rueppell" for the English alphabet....
, 1829) (Yellowmargin triggerfish)
- Pseudobalistes fuscus (Bloch
Marcus Elieser Bloch was a German medical doctor and naturalist. He is generally considered one of the most important ichthyologists of the 18th century.- Life :...
& SchneiderJohann Gottlob Theaenus Schneider was a German classicist and naturalist.-Biography:Schneider was born at Collm in Saxony...
, 1801) (yellow-spotted triggerfish)
- Pseudobalistes naufragium (Jordan
David Starr Jordan, Ph.D., LL.D. was a leading eugenicist, ichthyologist, educator and peace activist. He was president of Indiana University and Stanford University.-Early life and education:...
& StarksEdwin Chapin Starks was an ichthyologist most associated with Stanford University. He was known as an authority on the osteology of fish. He also did studies of fish of the Puget Sound. Additionally his wife and daughter were both involved in either science or natural history....
, 1895) (Stone triggerfish)
- Rhinecanthus
Rhinecanthus is a triggerfish genus from the Indo-Pacific. They are found at reefs, and all except R. abyssus are restricted to relatively shallow depths. They are among the smallest members of the family, with no species surpassing in length. They are primarily brownish, greyish and white, and...
Swainson, 1839
- Rhinecanthus abyssus Matsuura & Shiobara, 1989
- Rhinecanthus aculeatus (Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
, 1758) (White-banded triggerfish)
- Rhinecanthus assasi (Forsskål
Peter Forsskål, sometimes spelled Pehr Forsskål, Peter Forskaol, Petrus Forskål or Pehr Forsskåhl, was a Swedish explorer, orientalist, naturalist and an apostle of Carl Linnaeus.-Early life:...
, 1775) (Picasso triggerfish)
- Rhinecanthus cinereus (Bonnaterre
Abbé Pierre Joseph Bonnaterre was a French naturalist who contributed sections on cetaceans, mammals, birds, reptiles, amphibians, and insects to the Tableau encyclopédique et méthodique...
, 1788)
- Rhinecanthus lunula Randall & Steene, 1983 (Halfmoon picassofish)
- Rhinecanthus rectangulus (Bloch
Marcus Elieser Bloch was a German medical doctor and naturalist. He is generally considered one of the most important ichthyologists of the 18th century.- Life :...
& SchneiderJohann Gottlob Theaenus Schneider was a German classicist and naturalist.-Biography:Schneider was born at Collm in Saxony...
, 1801) (Wedge-tail triggerfish)
- Rhinecanthus verrucosus
Rhinecanthus verrucosus is a Triggerfish from the Indo-West Pacific. It occasionally makes its way into the aquarium trade. It grows to a size of 23 cm in length....
(LinnaeusCarl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
, 1758) (Blackbelly triggerfish)
- Sufflamen Jordan
David Starr Jordan, Ph.D., LL.D. was a leading eugenicist, ichthyologist, educator and peace activist. He was president of Indiana University and Stanford University.-Early life and education:...
, 1916
- Sufflamen albicaudatum
Sufflamen albicaudatum is a Triggerfish from the Western Indian Ocean. It occasionally makes its way into the aquarium trade. It grows to a size of 22 cm in length....
(RüppellWilhelm Peter Eduard Simon Rüppell was a German naturalist and explorer. Rüppell is occasionally transliterated to "Rueppell" for the English alphabet....
, 1829) (Bluethroat triggerfish)
- Sufflamen bursa
Sufflamen bursa is a Triggerfish from the Indo-Pacific. It occasionally makes its way into the aquarium trade. It grows to a size of 25 cm in length. "Scythe" markings on the lei triggerfish contain pigments which may change hue from light yellow to dark brown depending on mood of the fish....
(BlochMarcus Elieser Bloch was a German medical doctor and naturalist. He is generally considered one of the most important ichthyologists of the 18th century.- Life :...
& SchneiderJohann Gottlob Theaenus Schneider was a German classicist and naturalist.-Biography:Schneider was born at Collm in Saxony...
, 1801) (Boomerang triggerfish)
- Sufflamen chrysopterum
The Halfmoon triggerfish, Sufflamen chrysopterum, is a triggerfish of the tropical Indo-West Pacific area.The Halfmoon triggerfish lives around seaward reefs and shallow lagoons...
(BlochMarcus Elieser Bloch was a German medical doctor and naturalist. He is generally considered one of the most important ichthyologists of the 18th century.- Life :...
& SchneiderJohann Gottlob Theaenus Schneider was a German classicist and naturalist.-Biography:Schneider was born at Collm in Saxony...
, 1801) (Halfmoon triggerfish)
- Sufflamen fraenatum (Latreille
Pierre André Latreille was a French zoologist, specialising in arthropods. Having trained as a Roman Catholic priest before the French Revolution, Latreille was imprisoned, and only regained his freedom after recognising a rare species he found in the prison, Necrobia ruficollis...
, 1804) (Masked triggerfish)
- Sufflamen verres
The orangeside triggerfish is a species of fish in the Balistidae family....
(GilbertCharles Henry Gilbert was a pioneer ichthyologist and fishery biologist of particular significance to natural history of the western United States. He collected and studied fishes from Central America north to Alaska and described many new species...
& StarksEdwin Chapin Starks was an ichthyologist most associated with Stanford University. He was known as an authority on the osteology of fish. He also did studies of fish of the Puget Sound. Additionally his wife and daughter were both involved in either science or natural history....
, 1904) (Orangeside triggerfish)
- Xanthichthys Kaup
Johann Jakob Kaup was a German naturalist.-Biography:He was born at Darmstadt. After studying at Göttingen and Heidelberg he spent two years at Leiden, where his attention was specially devoted to the amphibians and fishes. He then returned to Darmstadt as an assistant in the grand ducal museum,...
in RichardsonSir John Richardson was a Scottish naval surgeon, naturalist and arctic explorer.Richardson was born at Dumfries. He studied medicine at Edinburgh University, and became a surgeon in the navy in 1807. He traveled with John Franklin in search of the Northwest Passage on the Coppermine Expedition of...
, 1856
- Xanthichthys auromarginatus (Bennett
Edward Turner Bennett was an English zoologist and writer. He was the elder brother of the botanist John Joseph Bennett. Bennett was born at Hackney and practiced as a surgeon, but his chief pursuit was always zoology...
, 1832) (Gilded triggerfish)
- Xanthichthys caeruleolineatus
Xanthichthys caeruleolineatus is a Triggerfish from the Indo-West Pacific. It occasionally makes its way into the aquarium trade. It grows to a size of 35 cm in length....
Randall, Matsuura & Zama, 1978 (Outrigger triggerfish)
- Xanthichthys lima (Bennett
Edward Turner Bennett was an English zoologist and writer. He was the elder brother of the botanist John Joseph Bennett. Bennett was born at Hackney and practiced as a surgeon, but his chief pursuit was always zoology...
, 1832)
- Xanthichthys lineopunctatus (Hollard, 1854) (Striped triggerfish)
- Xanthichthys mento
Xanthichthys mento is a Triggerfish from the Western Pacific. It occasionally makes its way into the aquarium trade. It grows to a size of 29 cm in length. When properly grilled it makes for a delicious topping on almost any sandwich....
(JordanDavid Starr Jordan, Ph.D., LL.D. was a leading eugenicist, ichthyologist, educator and peace activist. He was president of Indiana University and Stanford University.-Early life and education:...
& GilbertCharles Henry Gilbert was a pioneer ichthyologist and fishery biologist of particular significance to natural history of the western United States. He collected and studied fishes from Central America north to Alaska and described many new species...
, 1882) (Redtail triggerfish)
- Xanthichthys ringens (Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
, 1758) (Sargassum triggerfish)
- Xenobalistes Matsuura, 1981
- Xenobalistes tumidipectoris Matsuura, 1981