| Rabbitfish | |
|---|---|
 | |
| Marbled spinefoot (Siganus rivulatus) | |
 | |
| Foxface rabbitfish (S. vulpinus) | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Clade: | Eupercaria |
| Order: | Acanthuriformes |
| Family: | Siganidae |
| Genus: | Siganus Fabricius, 1775[1] |
| Type species | |
| Siganus rivulatus Fabricius, 1775[1] | |
| Species | |
About 29, seetext | |
| Synonyms[1][2] | |
Rabbitfishes orspinefoots,genusSiganus, areperciform fishes in thefamilySiganidae. It is the onlyextant genus in its family and has 29species. In some now obsolete classifications, the species having prominent face stripes—colloquially calledfoxfaces–are in the genusLo. Other species, such as themasked spinefoot (S. puellus), show a reduced form of the stripe pattern. Rabbitfishes are native to shallow waters in theIndo-Pacific, butS. luridus andS. rivulatus have become established in the easternMediterranean viaLessepsian migration. They are commercially importantfood fish, and can be used in the preparation of dishes such asbagoong.
The genusSiganus was described in 1775 by the DanishzoologistJohan Christian Fabricius withSiganus rivulatus, a species alsodescribed by Fabricius in 1775, designated as thetype species. The description was based on notes taken by the naturalistPeter Forsskål when he was on theDanish Arabia expedition (1761–67) and was published inCarsten Niebuhr'sDescriptiones animalium avium, amphibiorum, piscium, insectorum, vermium; quae in itinere orientali observavit Petrus Forskål. Post mortem auctoris edidit Carsten Niebuhr. Catalog of Fishes lists the authority as " Fabricius [J. C.] (ex Forsskål) in Niebuhr 1775" and states that the genus is valid as "Siganus Fabricius 1775".[1]
Carl Linnaeus originally described the genusTeuthis, with the type species beingTeuthis hepatus. One of the type specimens he used looks likeSiganus javus, although the other is definitely not a rabbitfish, and theInternational Commission on Zoological Nomenclature has been asked to suppress the nameTeuthis in favour ofSiganus to reflect the prevailing usage.
The nameSiganus is a latinisation of the local Arabic name for the marbled rabbitfish (S. rivulatus) in Yemen,Sidjan which can also be written asSigian, and means "rabbitfish".[3]
In 2007 Kurriwaet al., outlined a way to split the genus—if the scientific community so desires:[4]
Other lineages might exist and make obsolete the somewhat weak distinction between the second and third groups. Also, it is not known where thetype speciesS. rivulatus would fall, hence names for these threesubgenera orgenera are not established at present.
Hybridizaton has played a role in the evolution of the Siganidae, as evidenced by comparison ofmtDNAcytochromeb andnDNAinternal transcribed spacer 1sequence data. Evidence exists ofinterbreeding betweenS. guttatus andS. lineatus, as well as betweenS. doliatus andS. virgatus.[4]
Also, either females of the last common ancestor ofS. puellus and theS. punctatus interbred with females ancestral to the main non-foxface lineage, or males of the former hybridized with females of the last common ancestor ofS. punctatissimus and the foxfaces, while males of the latter mated with females of the original foxface species.[4]
An individual was found that looked like a slightly aberrant blue-spotted spinefoot (S. corallinus). On investigation, it turned out to be an offspring of a hybrid between a female of that species and a male masked spinefoot, which had successfullybackcrossed with the blue-spotted spinefoot.[4]
As noted above, several presumed species are suspected to actively interbreed even today; these might warrant merging as a single species. This applies to the white-spotted spinefoot (S. canaliculatus) and the mottled spinefoot (S. fuscescens), and to theblotched foxface (S. unimaculatus) and thefoxface rabbitfish (S. vulpinus). Alternatively they might be very recentlyevolved species that have not yet undergone completelineage sorting, but theirbiogeography suggests that each group is just colormorphs of a single species. On the other hand, themorphologically diverseblue-spotted spinefoot (S. corallinus) might represent more than one species; orange individuals are found at the north of its range, while yellow ones occur to the south, and these two may be completelyparapatric.[4]
.jpg)
There are currently 29 recognized species in this genus:[5]
Rabbitfishes have laterally compressed, oval bodies which may be deep, or slender. A few species have a tubular snout. The mouth is very small and is with non protractile jaws which have one row of compressed, closely set, incisor-like teeth in each jaw. The teeth overlap slightly and create a beak like structure. Thedorsal fin has 13 robust spines and 10 soft rays and the front spine is short, sharp and points forward, sometimes projecting from its "pocket" but it may be enfolded. Theanal fin has 7 robust spines and 9 soft rays. Thepelvic fins have 2 spines with 3 soft rays between them; this characteristic is unique to the Siganidae. There is a membrane which extends from the inner pelvic fin spine to the belly with the anus sitting between these membranes. The tiny scales arecycloid and may be absent from the head region. If present on the head they are restricted to a small area of the cheek under the eye.[6] The fin spines are equipped with well-developedvenom glands. The sting is very painful, but it is generally not considered medically significant in healthy adults.[7][8] They range in maximumtotal lengths of 20 cm (7.9 in) in the case of the blotched foxface (S. unimaculatus) to 53 cm (21 in) in the streaked spinefoot (S. javus).[9]
Rabbitfishes are found in theIndo-Pacific from theRed Sea and the coast of eastern Africa through the Pacific Ocean as far asPitcairn Island.[5] Two Red Sea speciesS. rivulatus andS. luridus have invaded the Mediterranean Sea through theSuez Canal, a process known asLessepsian migration.[10][11] These fishes are found in inshore tropical and subtropical waters where they occur in reefs, lagoons, mangroves and seagrass beds.[12]
All rabbitfish arediurnal; some live in schools, while others live more solitary lives among thecorals. Rabbitfish sleep in crevices in the reef matrix at night. While sleeping, the rabbitfishSiganus canaliculatus was observed being cleaned by the cleaner shrimpUrocaridella antonbruunii.[13] They areherbivorous, feeding onbenthicalgae in the wild. However,Siganus rivulatus was recently observed feeding on jellyfish (Scyphozoa) and comb jellies (Ctenophora) in theRed Sea.[14] AlsoSiganus fuscescens have been observed eatingprawns and other baits, suggesting that some species are opportunistic omnivorous feeders. The live passage of benthic organisms in the guts of invasive rabbitfish (ichthyochory) was shown to play a major role in thelong distance dispersal andbioinvasion offoraminifera.[15] Rabbitfish lay adhesive eggs and some species live as monogamous pairs.[6]
Rabbitfish have venomous spines in the dorsal and pelvic fins. In at least one species the venom has been found to be similar to that found instonefish.[16]
Rabbitfish can be important species for commercial fisheries, particularly the schooling species. The catch is largely sold fresh but juveniles may be dried or processed to make fish paste. Some species are used in aquaculture and some of the more colorful species are found in the aquarium trade.[6]Some species have been reported to behallucinogenic.[17][18][19]
Authority control databases: National |
|---|