Perciformes

Perciformes (), also called the Acanthopteri, is an order or superorder of ray-finned fish in the clade Percomorpha. ''Perciformes'' means " perch-like". Among the well-known members of this group are perches and darters ( Percidae), and also sea basses and groupers (Serranidae). This order contains many familiar freshwater temperate and tropical marine fish groups, but also extremophiles that have successfully colonized both the North and South Poles, as well as the deepest depths of the ocean.

Taxonomy

Formerly, this group was thought to be even more diverse than it is thought to be now, containing about 41% of all bony fish (about 10,000 species) and about 160 families, which is the most of any order within the vertebrates. However, many of these other families have since been reclassified within their own orders within the clade Percomorpha, significantly reducing the size of the group. In contrast to this splitting, other groups formerly considered distinct, such as the Scorpaeniformes, are now classified in the Perciformes.

Evolution

The earliest fossil perciform is the extinct stem group-perciform '' Paleoserranus'' (originally considered an early serranid) from the Early Paleocene of Mexico, but potential records of "percoids" are known from the Maastrichtian, including '' Eoserranus'' and '' Prolates'', although their exact taxonomic identity remains uncertain. The earliest crown-group perciform fossils are known from the Early Eocene, including the scorpaenoid '' Eosynanceja'' and platycephalid otoliths from New Zealand.

Classification

Classification of this group has long been controversial, with various families being placed in and out of Perciformes depending on the study. Only in recent decades, with the advent of molecular phylogenetics, has the classification of the family been largely resolved. Based on these studies, many suborders formerly placed within the Perciformes are better placed elsewhere in the Percomorpha, but former members of the Scorpaeniformes, Gasterosteiformes, and some members of the Trachiniformes (including the type genus) are now considered true perciforms.

Present classification

The following classification is based on '' Eschmeyer's Catalog of Fishes'':

* Order Perciformes
** Genus †'' Paleoserranus'' Cantalice, Alvarado-Ortega & Alaniz-Galvan, 2018
** Suborder Percoidei
*** Family Serranidae Swainson, 1839 (sea basses)
*** Family Anthiadidae Poey, 1861 (fairy basslets or streamer basses)
*** Family Epinephelidae Bleeker, 1874 (groupers)
*** Family Liopropomatidae Poey, 1867 (painted basslets)
*** Family Grammistidae Bleeker, 1857 (soapfishes)
*** Family Percidae Rafinesque, 1815 ( perches and darters)
*** Family Niphonidae Jordan, 1923 (Ara groupers)
*** Family Trachinidae Rafinesque, 1815 (weeverfishes)
*** Family Bembropidae Regan, 1913 (flatheads or duckbill flatheads)
** Suborder Notothenioidei
*** Family Percophidae Swainson, 1839 (Brazilian flatheads)
*** Family Bovichtidae Gill, 1862 (thornfishes)
*** Family Pseudaphritidae McCulloch, 1929 (congollis)
*** Family Eleginopidae Gill, 1893 (Patagonian blennies)
*** Family Nototheniidae Günther, 1861 (cod icefishes)
*** Family Harpagiferidae Gill, 1861 (plunderfishes)
*** Family Bathydraconidae Regan, 1913 (Antarctic dragonfishes)
*** Family Channichthyidae Gill, 1861 (crocodile icefishes)
** Suborder Scorpaenoidei
*** Family Platycephalidae Swainson, 1839 (flatheads)
*** Family Hoplichthyidae Kaup, 1873 (spiny flatheads)
*** Family Triglidae Rafinesque, 1815 (searobins)
*** Family Bembridae Kaup, 1873 (deepwater flatheads)
*** Family Synanceiidae Swainson, 1839 (stonefishes)
*** Family Neosebastidae Matsubara, 1943 (gurnard scorpionfishes)
*** Family Plectrogeniidae Fowler, 1938 (stinger flatheads)
*** Family Scorpaenidae Risso, 1827 (scorpionfishes)
*** Family Congiopodidae Gill, 1889 (racehorses or pigfishes)
*** Family Zanclorhynchidae Andriashev, 1993 (horsefishes)
*** Family Normanichthyidae Clark, 1937 (barehead scorpionfishes )
** Suborder Cottoidei
*** Family Anoplopomatidae Jordan & Gilbert ,1883 (sablefishes)
*** Family Zaniolepididae Jordan & Gilbert, 1883 (combfishes)
*** Family Hexagrammidae Jordan, 1888 (greenlings)
*** Family Rhamphocottidae Jordan & Gilbert, 1883 (horsehead sculpins)
*** Family Jordaniidae Jordan & Evermann, 1898 (longfin sculpins)
*** Family Cottidae Bonaparte, 1831 (sculpins)
*** Family Psychrolutidae Günther, 1861 (marine sculpins)
*** Family Agonidae Swainson, 1839 (poachers)
*** Family Trichodontidae Bleeker, 1859 (sandfishes)
*** Family Cyclopteridae Bonaparte, 1831 (lumpfishes)
*** Family Liparidae Gill, 1861 (snailfishes)
** Suborder Gasterosteoidei
*** Family Hypoptychidae Steindachner, 1880 (sand-eels)
*** Family Gasterosteidae Bonaparte, 1831 (sticklebacks)
*** Family Aulorhynchidae Gill, 1861 (tubesnouts)
** Suborder Zoarcoidei
*** Family Zoarcidae Swainson, 1839 (eelpouts)
*** Family Anarhichadidae Bonaparte, 1835 (wolffishes)
*** Family Neozoarcidae Jordan & Snyder, 1902 (largemouth kissing eelpouts)
*** Family Eulophiidae Smith, 1902 (spinous eelpouts)
*** Family Stichaeidae Gill, 1864 (pricklebacks)
*** Family Lumpenidae Jordan & Evermann, 1898 (eel pricklebacks)
*** Family Opisthocentridae Jordan & Evermann, 1898 (rearspined fin pricklebacks)
*** Family Pholidae Gill, 1893 (gunnels)
*** Family Ptilichthyidae Jordan & Gilbert, 1883 (quillfishes)
*** Family Zaproridae Jordan, 1896 (prowfishes)
*** Family Cryptacanthodidae Gill, 1861 (wrymouths)
*** Family Cebidichthyidae Gill, 1862 (monkeyface pricklebacks)
*** Family Scytalinidae Jordan & Starks, 1895 (graveldivers)
*** Family Bathymasteridae Jordan & Gilbert, 1883 (ronquils)

Past classifications

As traditionally defined before the introduction of cladistics, the Perciformes are almost certainly paraphyletic. Other orders that should possibly be included as suborders are the Scorpaeniformes, Tetraodontiformes, and Pleuronectiformes.
Of the presently recognized suborders, several may be paraphyletic, as well. These are grouped by suborder/superfamily, generally following the text '' Fishes of the World''.

Characteristics

The dorsal and anal fins are divided into anterior spiny and posterior soft-rayed portions, which may be partially or completely separated. The pelvic fins usually have one spine and up to five soft rays, positioned unusually far forward under the chin or under the belly. Scales are usually ctenoid (rough to the touch), although sometimes they are cycloid (smooth to the touch) or otherwise modified.

References

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Ray-finned fish orders
Taxa named by Pieter Bleeker
Extant Danian first appearances