A flatfish is a member of the

ray-finned Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

demersal fish Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 They o ...

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

Pleuronectiformes, also called the Heterosomata, sometimes classified as a suborder of

Perciformes Perciformes (), also called the Percomorpha or Acanthopteri, is an order or superorder of ray-finned fish. If considered a single order, they are the most numerous order of vertebrates, containing about 41% of all bony fish. Perciformes means ...

. In many species, both eyes lie on one side of the head, one or the other migrating through or around the head during development. Some species face their left sides upward, some face their right sides upward, and others face either side upward. Many important

food fish Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is inges ...

are in this order, including the

flounder Flounders are a group of flatfish species. They are demersal fish, found at the bottom of oceans around the world; some species will also enter estuaries. Taxonomy The name "flounder" is used for several only distantly related species, tho ...

s, soles,

turbot The turbot (''Scophthalmus maximus'') is a relatively large species of flatfish in the family Scophthalmidae. It is a demersal fish native to marine or brackish waters of the Northeast Atlantic, Baltic Sea and the Mediterranean Sea. It is an ...

plaice Plaice is a common name for a group of flatfish that comprises four species: the European, American, Alaskan and scale-eye plaice. Commercially, the most important plaice is the European. The principal commercial flatfish in Europe, it is ...

, and

halibut Halibut is the common name for three flatfish in the genera '' Hippoglossus'' and '' Reinhardtius'' from the family of right-eye flounders and, in some regions, and less commonly, other species of large flatfish. The word is derived from ''h ...

. Some flatfish can

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...

themselves on the ocean floor.

Taxonomy

Over 800 described species are placed into 16 families. Broadly, the flatfishes are divided into two suborders, Psettodoidei and Pleuronectoidei, with > 99% of the species diversity found within the Pleuronectoidei. The largest families are

Soleidae The true soles are a family, Soleidae, of flatfishes. It includes saltwater and brackish water species in the East Atlantic, Indian Ocean, and West and Central Pacific Ocean. Freshwater species are found in Africa, southern Asia, New Guinea, a ...

, Bothidae and Cynoglossidae with more than 150 species each. There also exist two monotypic families (

Paralichthodidae The peppered flounder (''Paralichthodes algoensis'') is a flatfish of the family Paralichthodidae and the only species of the genus ''Paralichthodes''. It is a demersal fish that lives on sandy and muddy bottoms in subtropical waters, at depths ...

and Oncopteridae). Some families are the results of relatively recent splits. For example, the

Achiridae The American soles are a family (Achiridae) of flatfish occurring in both freshwater and marine environments of the Americas. The family includes about 35 species in seven genera. These are closely related to the soles (Soleidae), and have bee ...

were classified as a subfamily of Soleidae in the past, and the Samaridae were considered a subfamily of the Pleuronectidae.Randall, J. E. (2007). ''Reef and Shore Fishes of the Hawaiian Islands.'' Cooper, J.A.; and Chapleau, F. (1998). ''Monophyly and intrarelationships of the family Pleuronectidae (Pleuronectiformes), with a revised classification.'' Fish. Bull. 96 (4): 686–726. The families

, Poecilopsettidae, and Rhombosoleidae were also traditionally treated as subfamilies of Pleuronectidae, but are now recognised as families in their own right. The

Paralichthyidae Large-tooth flounders or sand flounders are a family, Paralichthyidae, of flounders. The family contains 14 genera with a total of about 110 species. They lie on the sea bed on their right side; both eyes are always on the left side of the head, ...

has long been indicated to be paraphyletic, with the formal description of Cyclopsettidae in 2019 resulting in the split of this family as well. The

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

of some groups is in need of a review, as the last monograph covering the entire order was

John Roxborough Norman John Roxborough Norman (1898, Wandsworth, London – 26 May 1944, Berkhamsted, Hertfordshire) was an English ichthyologist. He started as a clerk in a bank. His lifetime affliction with rheumatic fever began during his military service during the ...

's ''Monograph of the Flatfishes'' published in 1934. In particular, ''

Tephrinectes sinensis ''Tephrinectes sinensis'', the Chinese brill, is a species of flatfish in the large-tooth flounder family, Paralichthyidae. It is the only member of its genus ''Tephrinectes''. Like the rest of the large-tooth flounders, it has both eyes on the ...

'' may represent a family-level lineage and requires further evaluation e.g. New species are described with some regularity and

undescribed species In taxonomy, an undescribed taxon is a taxon (for example, a species) that has been discovered, but not yet formally described and named. The various Nomenclature Codes specify the requirements for a new taxon to be validly described and name ...

likely remain.

Hybrids

Hybrids are well known in flatfishes. The Pleuronectidae, of marine fishes, have the largest number of reported hybrids.Garrett, D.L.; Pietsch, T.W.; Utter, F.M.; and Hauser, L. (2007). ''The Hybrid Sole Inopsetta ischyra (Teleostei: Pleuronectiformes: Pleuronectidae): Hybrid or Biological Species?'' American Fisheries Society 136: 460–468 Two of the most famous

intergeneric hybrid In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Hybrids are not always intermediates between their parents (such as in ...

s are between the European plaice (''Pleuronectes platessa'') and

European flounder The European flounder (''Platichthys flesus'') is a flatfish of European coastal waters from the White Sea in the north to the Mediterranean and the Black Sea in the south. It has been introduced into the United States and Canada accidentally th ...

(''Platichthys flesus'') in the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and fr ...

, and between the English sole (''Parophrys vetulus'') and

starry flounder The starry flounder (''Platichthys stellatus''), also known as the grindstone, emery wheel and long-nosed flounder, is a common flatfish found around the margins of the North Pacific. The distinctive features of the starry flounder include the c ...

(''Platichthys stellatus'') in

Puget Sound Puget Sound ( ) is a sound of the Pacific Northwest, an inlet of the Pacific Ocean, and part of the Salish Sea. It is located along the northwestern coast of the U.S. state of Washington. It is a complex estuarine system of interconnected m ...

. The offspring of the latter species pair is popularly known as the hybrid sole and was initially believed to be a valid species in its own right.

Distribution

Flatfishes are found in oceans worldwide, ranging from the

Arctic The Arctic ( or ) is a polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada ( Yukon, Northwest Territories, Nunavut), Danish Realm ( Greenland), Finland, Iceland ...

, through the tropics, to

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest co ...

. Species diversity is centered in the Indo-West Pacific and declines following both latitudinal and longitudinal gradients away from the Indo-West Pacific. Most species are found in depths between 0 and , but a few have been recorded from depths in excess of . None have been confirmed from the

abyssal The abyssal zone or abyssopelagic zone is a layer of the pelagic zone of the ocean. "Abyss" derives from the Greek word , meaning bottomless. At depths of , this zone remains in perpetual darkness. It covers 83% of the total area of the ocean an ...

hadal zone The hadal zone, also known as the hadopelagic zone, is the deepest region of the ocean, lying within oceanic trenches. The hadal zone ranges from around below sea level, and exists in long, narrow, topographic V-shaped depressions. The cum ...

s. An observation of a flatfish from the

Bathyscaphe Trieste ''Trieste'' is a Swiss-designed, Italian-built deep-diving research bathyscaphe which reached a record depth of about in the Challenger Deep of the Mariana Trench near Guam in the Pacific. On 23 January 1960, Jacques Piccard (son of the boa ...

at the bottom of the

Mariana Trench The Mariana Trench is an oceanic trench located in the western Pacific Ocean, about east of the Mariana Islands; it is the deepest oceanic trench on Earth. It is crescent-shaped and measures about in length and in width. The maximum know ...

at a depth of almost has been questioned by fish experts, and recent authorities do not recognize it as valid. Among the deepwater species, ''

Symphurus thermophilus ''Symphurus thermophilus'' is a species of tonguefish notable for being the only flatfish known to be an obligate inhabitant of hydrothermal vents. It is known from several widely dispersed locations in the western Pacific Ocean and occurs in ...

'' lives congregating around "ponds" of

sulphur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...

at hydrothermal vents on the seafloor. No other flatfish is known from hydrothermal vents. Many species will enter

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

or fresh water, and a smaller number of soles (families

and

) and tonguefish ( Cynoglossidae) are entirely restricted to fresh water.

Characteristics

The most obvious characteristic of the flatfish is its

asymmetry Asymmetry is the absence of, or a violation of, symmetry (the property of an object being invariant to a transformation, such as reflection). Symmetry is an important property of both physical and abstract systems and it may be displayed in pre ...

, with both eyes lying on the same side of the head in the adult fish. In some families, the eyes are usually on the right side of the body (dextral or right-eyed flatfish), and in others, they are usually on the left (sinistral or left-eyed flatfish). The primitive

spiny turbot The spiny turbots are a family, Psettodidae, of relatively large, primitive flatfish found in the tropical waters of the east Atlantic and Indo-Pacific. The family contains just three species, all in the same genus, ''Psettodes''. The common nam ...

s include equal numbers of right- and left-sided individuals, and are generally less asymmetrical than the other families. Other distinguishing features of the order are the presence of protrusible eyes, another adaptation to living on the

seabed The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'. The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...

(

benthos Benthos (), also known as benthon, is the community of organisms that live on, in, or near the bottom of a sea, river, lake, or stream, also known as the benthic zone.camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...

the fish, but sometimes with striking coloured patterns. Some flatfishes are also able to change their pigmentation to match the background, in a manner similar to some

cephalopods A cephalopod is any member of the molluscan Taxonomic rank, class Cephalopoda (Greek language, Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral symm ...

. The side of the body without the eyes, facing the seabed, is usually colourless or very pale. In general, flatfishes rely on their camouflage for avoiding predators, but some have

aposematic Aposematism is the advertising by an animal to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defences which make the prey difficult to kill and eat, such as toxicity, venom, foul taste o ...

traits such as conspicuous eyespots (e.g., ''

Microchirus ocellatus ''Microchirus'' is a genus of soles native to the Eastern Atlantic Ocean and Mediterranean Sea. Species There are currently seven recognized species in this genus: * ''Microchirus azevia'' ( Brito Capello, 1867) (Bastard sole) * ''Microchirus b ...

'') and several small tropical species (at least '' Aseraggodes'', ''

Pardachirus ''Pardachirus'' is a genus of soles mainly native to coastal water in the Indo-Pacific. A single species, ''P. poropterus'' is restricted to estuaries and lower sections of freshwater streams. At least some species in the genus are toxic.Randall ...

'' and '' Zebrias'') are poisonous. Juveniles of '' Soleichthys maculosus''

mimic MIMIC, known in capitalized form only, is a former simulation computer language developed 1964 by H. E. Petersen, F. J. Sansom and L. M. Warshawsky of Systems Engineering Group within the Air Force Materiel Command at the Wright-Patterson AFB in ...

toxic flatworms of the genus ''

Pseudobiceros ''Pseudobiceros'' is a genus of flatworms. Like all flatworms, Pseudobiceros are hermaphrodites. This particular genus engages in penis fencing. When the "winner" touches its penis to the "skin" of the other, insemination occurs, and the "loser" ...

'' in both colours and swimming mode. Conversely, a few

octopus An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefis ...

species have been reported to mimic flatfishes in colours, shape and swimming mode. The

s and spiny turbots eat smaller fish, and have well-developed teeth. They sometimes seek prey in the midwater, away from the bottom, and show fewer extreme adaptations than other families. The soles, by contrast, are almost exclusively bottom-dwellers, and feed on invertebrates. They show a more extreme asymmetry, and may lack teeth on one side of the jaw. Flatfishes range in size from ''

Tarphops oligolepis ''Tarphops'' is a genus of large-tooth flounders native to the northwest Pacific Ocean. Species The currently recognized species in this genus are: * '' Tarphops elegans'' Amaoka, 1969 * '' Tarphops oligolepis'' (Bleeker Bleeker is a Dutch occu ...

'', measuring about in length, and weighing , to the

Atlantic halibut The Atlantic halibut (''Hippoglossus hippoglossus'') is a flatfish of the family Pleuronectidae. They are demersal fish living on or near sand, gravel or clay bottoms at depths of between . The halibut is among the largest teleost (bony) fish in ...

, at and .

Species and species groups

* Brill * Dab *

Sanddab ''Citharichthys'' is a genus of flatfish in the large-tooth flounder family, Paralichthyidae. They have both eyes on the left sides of their heads. They are native to the oceans around the Americas, with a single species, ''C. stampflii'' off the ...

Flounder Flounders are a group of flatfish species. They are demersal fish, found at the bottom of oceans around the world; some species will also enter estuaries. Taxonomy The name "flounder" is used for several only distantly related species, tho ...

Halibut Halibut is the common name for three flatfish in the genera '' Hippoglossus'' and '' Reinhardtius'' from the family of right-eye flounders and, in some regions, and less commonly, other species of large flatfish. The word is derived from ''h ...

Megrim The megrim, megrim sole, whiff, or Cornish sole (''Lepidorhombus whiffiagonis'') is a species of left-eyed flatfish in the family Scophthalmidae. It is found in the northeast Atlantic and Mediterranean Sea between below sea level. It is caught ...

Plaice Plaice is a common name for a group of flatfish that comprises four species: the European, American, Alaskan and scale-eye plaice. Commercially, the most important plaice is the European. The principal commercial flatfish in Europe, it is ...

* Sole *

Tonguefish Tonguefishes are flatfish in the family Cynoglossidae. They are distinguished by the presence of a long hook on the snout overhanging the mouth, and the absence of pectoral fins. Their eyes are both on the left side of their bodies, which also ...

Turbot The turbot (''Scophthalmus maximus'') is a relatively large species of flatfish in the family Scophthalmidae. It is a demersal fish native to marine or brackish waters of the Northeast Atlantic, Baltic Sea and the Mediterranean Sea. It is an ...

Reproduction

Flatfishes lay eggs that hatch into larvae resembling typical, symmetrical, fish. These are initially elongated, but quickly develop into a more rounded form. The larvae typically have protective spines on the head, over the gills, and in the pelvic and pectoral fins. They also possess a

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ that contributes to the ability of many bony fish (but not cartilaginous fish) to control their buoyancy, and thus to stay at their current water depth w ...

, and do not dwell on the bottom, instead dispersing from their hatching grounds as

plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a cr ...

. The length of the planktonic stage varies between different types of flatfishes, but eventually they begin to metamorphose into the adult form. One of the eyes migrates across the top of the head and onto the other side of the body, leaving the fish blind on one side. The larva also loses its swim bladder and spines, and sinks to the bottom, laying its blind side on the underlying surface.

Evolution

In 2008, a 50-million-year-old fossil, ''

Amphistium ''Amphistium paradoxum'' (from el, ἀμφί , 'on both sides', el, ιστίον 'sail', and el, παράδοξος 'extraordinary'), the only species classified under the genus ''Amphistium'', is a fossil fish which has been identified as a ...

'', was identified as an early relative of the flatfish and

transitional fossil A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group. This is especially important where the descendant group is sharply differentiated by gross a ...

. In a typical modern flatfish, the head is asymmetric, with both eyes on one side of the head. In ''Amphistium'', the transition from the typical symmetric head of a vertebrate is incomplete, with one eye placed near the top of the head. The researchers concluded, "the change happened gradually, in a way consistent with evolution via

natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Cha ...

—not suddenly, as researchers once had little choice but to believe." Flatfishes have been cited as dramatic examples of evolutionary adaptation.

Richard Dawkins Richard Dawkins (born 26 March 1941) is a British evolutionary biologist and author. He is an emeritus fellow of New College, Oxford and was Professor for Public Understanding of Science in the University of Oxford from 1995 to 2008. An at ...

, in ''

The Blind Watchmaker ''The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe without Design'' is a 1986 book by Richard Dawkins, in which the author presents an explanation of, and argument for, the theory of evolution by means of natural selecti ...

'', explains the flatfishes' evolutionary history thus:

…bony fish as a rule have a marked tendency to be flattened in a vertical direction…. It was natural, therefore, that when the ancestors of latfishtook to the sea bottom, they should have lain on one ''side''…. But this raised the problem that one eye was always looking down into the sand and was effectively useless. In evolution this problem was solved by the lower eye ‘moving’ round to the upper side.

File:Pleuronectes platessa.jpg, The European plaice is the principal commercial flatfish in Europe. File:Lined sole.jpg, American soles are found in both freshwater and marine environments of the Americas. File:Alaska 2007 071.jpg,

are the largest of the flatfishes, and provide lucrative fisheries. File:Psetta maxima Luc Viatour.jpg, The

is a large, left-eyed flatfish found in sandy shallow coastal waters around Europe. File:Flatfish-lefteyed-flounder.jpg, Flatfish (left‐eyed flounder)

As food

Flatfish is considered a Whitefish because of the high concentration of oils within its liver. Its lean flesh makes for a unique flavor that differs from species to species. Methods of cooking include grilling, pan-frying, baking and deep-frying.

Timeline of genera

ImageSize = width:600px height:auto barincrement:15px PlotArea = left:10px bottom:50px top:10px right:10px Period = from:-65.5 till:15 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:5 start:-65.5 ScaleMinor = unit:year increment:1 start:-65.5 TimeAxis = orientation:hor AlignBars = justify Colors = #legends id:CAR value:claret id:ANK value:rgb(0.4,0.3,0.196) id:HER value:teal id:HAD value:green id:OMN value:blue id:white value:black id:white value:white id:cenozoic value:rgb(0.54,0.54,0.258) id:paleogene value:rgb(0.99,0.6,0.32) id:paleocene value:rgb(0.99,0.65,0.37) id:eocene value:rgb(0.99,0.71,0.42) id:oligocene value:rgb(0.99,0.75,0.48) id:neogene value:rgb(0.999999,0.9,0.1) id:miocene value:rgb(0.999999,0.999999,0) id:pliocene value:rgb(0.97,0.98,0.68) id:quaternary value:rgb(0.98,0.98,0.5) id:pleistocene value:rgb(0.999999,0.95,0.68) id:holocene value:rgb(0.999,0.95,0.88) BarData= bar:eratop bar:space bar:periodtop bar:space bar:NAM1 bar:NAM2 bar:NAM3 bar:NAM4 bar:NAM5 bar:NAM6 bar:NAM7 bar:NAM8 bar:NAM9 bar:NAM10 bar:NAM11 bar:NAM12 bar:NAM13 bar:NAM14 bar:NAM15 bar:NAM16 bar:NAM17 bar:NAM18 bar:NAM19 bar:NAM20 bar:NAM21 bar:NAM22 bar:NAM23 bar:NAM24 bar:NAM25 bar:NAM26 bar:NAM27 bar:NAM28 bar:NAM29 bar:NAM30 bar:NAM31 bar:NAM32 bar:NAM33 bar:NAM34 bar:NAM35 bar:NAM36 bar:NAM37 bar:NAM38 bar:space bar:period bar:space bar:era PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 shift:(7,-4) bar:periodtop from: -65.5 till: -55.8 color:paleocene text:

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

from: -55.8 till: -33.9 color:eocene text:

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

from: -33.9 till: -23.03 color:oligocene text:

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but ...

from: -23.03 till: -5.332 color:miocene text:

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...

from: -5.332 till: -2.588 color:pliocene text: Plio. from: -2.588 till: -0.0117 color:pleistocene text: Pleist. from: -0.0117 till: 0 color:holocene text: H. bar:eratop from: -65.5 till: -23.03 color:paleogene text:

Paleogene The Paleogene ( ; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago (Mya) to the beginning of ...

from: -23.03 till: -2.588 color:neogene text:

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago (Mya) to the beginning of the present Quaternary Period Mya. ...

from: -2.588 till: 0 color:quaternary text: Q. PlotData= align:left fontsize:M mark:(line,white) width:5 anchor:till align:left color:eocene bar:NAM1 from:-55.8 till:-33.9 text:

color:eocene bar:NAM2 from:-55.8 till:-33.9 text:

Eobothus ''Eobothus'' ('Dawn flounder') is an extinct genus of flatfish from the Eocene epoch of China, India and Europe. ''Eobothus'' is significant as one of the earliest genera of flatfish, one of the last major fish groups to evolve. It closely resem ...

color:eocene bar:NAM3 from:-55.8 till:-33.9 text:

Eobuglossus ''Eobuglossus'' is an extinct genus of prehistoric bony fish that lived from the early to middle Eocene. See also * Prehistoric fish * List of prehistoric bony fish A ''list'' is any set of items in a row. List or lists may also refer to: ...

color:eocene bar:NAM4 from:-55.8 till:-33.9 text: Imhoffius color:eocene bar:NAM5 from:-55.8 till:-33.9 text:

Joleaudichthys ''Joleaudichthys'' is an extinct genus of prehistoric flatfish that lived from the early to middle Eocene of Egypt. See also * Prehistoric fish * List of prehistoric bony fish A ''list'' is any set of items in a row. List or lists may also re ...

color:eocene bar:NAM6 from:-55.8 till:-33.9 text:

Turahbuglossus ''Turahbuglossus'' is an extinct genus of prehistoric bony fish that lived from the early to middle Eocene. See also * Prehistoric fish * List of prehistoric bony fish A ''list'' is any set of items in a row. List or lists may also refer to ...

color:eocene bar:NAM7 from:-55.8 till:0 text:

Scophthalmus ''Scophthalmus'' is a genus of turbots, relatively large flatfish native to the northeast Atlantic Ocean, Baltic Sea, Mediterranean Sea and Black Sea. Species There are currently four recognized species in this genus: *''Scophthalmus aqu ...

color:eocene bar:NAM8 from:-55.8 till:0 text:

Citharus ''Citharus linguatula'', the spotted flounder or Atlantic spotted flounder, is a species of fish in the Citharidae, a family of flounders. It is native to the eastern Atlantic Ocean (off northwest Africa) and the Mediterranean Sea, where it is fo ...

color:eocene bar:NAM9 from:-55.8 till:0 text: Psettodes color:eocene bar:NAM10 from:-37.2 till:0 text:

Arnoglossus The scaldfishes comprise a genus, ''Arnoglossus'', of lefteye flounders. They are found in the Pacific, Indian and Atlantic Oceans, including the Mediterranean and Black Sea. They are entirely absent from most of the Americas; the only exceptions ...

color:oligocene bar:NAM11 from:-33.9 till:0 text: Bothus color:oligocene bar:NAM12 from:-33.9 till:0 text: Monolene color:oligocene bar:NAM13 from:-33.9 till:0 text:

Solea Solea may refer to: * Solea, a simple sandal with a thong between the toes and a hobnailed sole from Roman times * Soleá, a form of Flamenco music * ''Solea'' (novel) by Jean-Claude Izzo * Soléa, a public transit system in the French city of Mul ...

color:oligocene bar:NAM14 from:-28.4 till:0 text: Buglossidium color:oligocene bar:NAM15 from:-28.4 till:0 text:

Hippoglossoides ''Hippoglossoides'' is a genus of righteye flounders native to the North Pacific and North Atlantic oceans. Species There are currently four recognized species in this genus: * '' Hippoglossoides dubius'' Schmidt, 1904 (Flathead flounder) * ...

color:oligocene bar:NAM16 from:-28.4 till:0 text:

Lepidorhombus ''Lepidorhombus'' is a genus of turbots native to the northeastern Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth#Surface, Earth's surface a ...

color:miocene bar:NAM17 from:-23.03 till:0 text: Dicologoglossa color:miocene bar:NAM18 from:-23.03 till:0 text:

Paraplagusia ''Paraplagusia'' is a genus of tonguefish. It is indigenous to the Indo-Pacific region, where commonly found in shallow waters on a muddy or sandy bottom. The largest species reaches in length. Species The currently recognized species in this ...

color:miocene bar:NAM19 from:-23.03 till:0 text:

Platichthys ''Platichthys'' is a genus of flatfish native to the North Pacific and North Atlantic oceans. Despite being in the family Pleuronectidae Pleuronectidae, also known as righteye flounders, are a family of flounders. They are called "righteye ...

color:miocene bar:NAM20 from:-15.97 till:0 text: Achiurus color:miocene bar:NAM21 from:-15.97 till:0 text:

Microchirus ''Microchirus'' is a genus of soles native to the Eastern Atlantic Ocean and Mediterranean Sea. Species There are currently seven recognized species in this genus: * '' Microchirus azevia'' ( Brito Capello, 1867) (Bastard sole) * '' Microchirus ...

color:miocene bar:NAM22 from:-15.97 till:0 text:

Microstomus ''Microstomus'' is a genus of righteye flounders native to the North Pacific and Northeast Atlantic oceans. Etymology The word ''Microstomus'' is derived from the Greek ''μικρὸς'' (''mikros''), meaning "small", and ''στόμα'' (''s ...

color:miocene bar:NAM23 from:-11.608 till:-5.332 text:

Evesthes ''Evesthes'' is an extinct genus of prehistoric bony fish that lived during the Upper Miocene subepoch. See also * Prehistoric fish * List of prehistoric bony fish A ''list'' is any set of items in a row. List or lists may also refer to: ...

color:miocene bar:NAM24 from:-11.608 till:0 text: Citharichthys color:miocene bar:NAM25 from:-11.608 till:0 text:

Monochirus ''Monochirus'' is a genus of small soles. It contains two species; one from the northeast Atlantic and Mediterranean, and the second from the South China Sea. Species There are currently two recognized species in this genus: * '' Monochirus hisp ...

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Paralichthys ''Paralichthys'' is a genus of large-tooth flounders. Most species are native to the coastal waters of the Americas, but ''P. olivaceus'' is from northeast Asia. The largest species reaches about in length. Species There are currently almost 20 ...

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Pleuronichthys ''Pleuronichthys'' is a genus of fish in the family Pleuronectidae found in the Pacific Ocean. Species There are currently 7 recognized species in this genus: * '' Pleuronichthys coenosus'' Girard, 1854 (C-O sole) * '' Pleuronichthys cornutus'' ...

color:pliocene bar:NAM28 from:-5.332 till:0 text: Atheresthes color:pliocene bar:NAM29 from:-5.332 till:0 text:

Clidoderma ''Clidoderma'' is a genus of righteye flounders containing one extant species and two described fossil species from Japan. Fossil species Two fossil species are known from the Miocene of Japan. '' C. chitaensis'' Ohe & Kawase 1995 is known fr ...

color:pliocene bar:NAM30 from:-5.332 till:0 text: Glyptocephalus color:pliocene bar:NAM31 from:-5.332 till:0 text:

Limanda ''Limanda'' is a genus of righteye flounders native to the northern Atlantic and Pacific oceans. A 2018 cladistic morphological and genetic analysis found that the genus is not monophyletic, and has proposed ''L. ferruginea'', ''L. proboscidea'' ...

color:pliocene bar:NAM32 from:-5.332 till:0 text: Lyopsetta color:pliocene bar:NAM33 from:-5.332 till:0 text:

Pegusa ''Pegusa'' is a genus of soles native to the Eastern Atlantic Ocean, Mediterranean Sea, and Black Sea. Species The currently recognized species in this genus are: * ''Pegusa cadenati'' Chabanaud, 1954 (Cadenat's sole) * ''Pegusa impar'' ( ...

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Chibapsetta ''Chibapsetta dolichurostyli'' is an extinct species of prehistoric right-eye flounder that lived during the Pleistocene epoch in what is now Japan. See also * Prehistoric fish * List of prehistoric bony fish A ''list'' is any set of items ...

color:pleistocene bar:NAM35 from:-2.588 till:0 text: Eopsetta color:pleistocene bar:NAM36 from:-2.588 till:0 text:

Isopsetta The butter sole (''Isopsetta isolepis'') is an edible flatfish of the family Pleuronectidae. It is a demersal fish that lives on soft, silty bottoms in temperate waters at depths between . Its native habitat is the northeastern Pacific, from the ...

color:pleistocene bar:NAM37 from:-2.588 till:0 text: Parophrys color:pleistocene bar:NAM38 from:-2.588 till:0 text:

Symphurus ''Symphurus'' is a genus of fish in the family Cynoglossidae found in the Atlantic, Indian and Pacific Ocean. Most species mainly occur in relatively shallow water, including estuaries. Some species are also found in deeper water, includ ...

PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 bar:period from: -65.5 till: -55.8 color:paleocene text:

from: -55.8 till: -33.9 color:eocene text:

from: -33.9 till: -23.03 color:oligocene text:

from: -23.03 till: -5.332 color:miocene text:

from: -5.332 till: -2.588 color:pliocene text: Plio. from: -2.588 till: -0.0117 color:pleistocene text: Pleist. from: -0.0117 till: 0 color:holocene text: H. bar:era from: -65.5 till: -23.03 color:paleogene text:

from: -23.03 till: -2.588 color:neogene text:

from: -2.588 till: 0 color:quaternary text: Q.

References

Further references

* * Gibson, Robin N (Ed) (2008) Flatfishes: biology and exploitation. Wiley. * Munroe, Thomas A (2005) "Distributions and biogeography." Flatfishes: Biology and Exploitation: 42-67.

External links

Information on Canadian fisheries of plaice
{{Authority control Commercial fish Articles which contain graphical timelines Extant Paleocene first appearances Asymmetry