Large-tooth flounders or sand flounders are a family, Paralichthyidae, of

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 estuary, estuaries. Taxonomy The name "flounder" is used for several only distantly related speci ...

s. The family contains 14

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

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, while the

Pleuronectidae Pleuronectidae, also known as righteye flounders, are a family of flounders. They are called "righteye flounders" because most species lie on the sea bottom on their left sides, with both eyes on their right sides. The Paralichthyidae are the o ...

usually (but not always) have their eyes on the right side of the head. Citharichthys macrops

They are found in

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

and

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

waters of the

Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

Indian Indian or Indians may refer to: Associated with India * of or related to India ** Indian people ** Indian diaspora ** Languages of India ** Indian English, a dialect of the English language ** Indian cuisine Associated with indigenous peoples o ...

and

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

s. Several species are important commercial and

game fish Game fish, sport fish or quarry refer to popular fish species pursued by recreational fishing, recreational fishers (typically angling, anglers), and can be freshwater fish, freshwater or saltwater fish. Game fish can be fish as food, eaten aft ...

es, notably the

California halibut The California halibut or California flounder (''Paralichthys californicus'') is a large-tooth flounder native to the waters of the Pacific Coast of North America from the Quillayute River in Washington (U.S. state), Washington to Magdalena Bay ...

, ''Paralichthys californicus'' and the

Pacific sanddab The Pacific sanddab (''Citharichthys sordidus''), also known as the soft flounder, mottle sanddab, or megrim, is a fish species in the order Pleuronectiformes, or flatfish. It is by far the most common sanddab, and it shares its habitat with the ...

, ''Citharichthys sordidus''. Phylogenetic analyses have long indicated the non-monophyly of this family e.g., and two lineages have been consistently apparent. Termed groups, the two groups were named after genera: a ''Cyclopsetta'' group and a ''Pseudorhombus'' group (see summary in ). A formal description of Cyclopsettidae in 2019 created this family consisting of four genera: ''Cyclopsetta'', ''Etropus'', ''Citharichthys'', and ''Syacium'' corresponding to the previously recognized ''Cyclopsetta'' group. Molecular phylogenetic evidence indicates that Paralichthyidae in this sense is sister to Pleuronectidae and Cyclopsettidae is sister to Bothidae e.g. The earliest known fossil remains of the Paralichthyidae are

Late Eocene The Priabonian is, in the International Commission on Stratigraphy, ICS's geologic timescale, the latest age (geology), age or the upper stage (stratigraphy), stage of the Eocene epoch (geology), Epoch or series (stratigraphy), Series. It spans ...

-aged fossil

otoliths An otolith (, ' ear + , ', a stone), also called otoconium, statolith, or statoconium, is a calcium carbonate structure in the saccule or utricle of the inner ear, specifically in the vestibular system of vertebrates. The saccule and utricle, i ...

assigned to ''

Citharichthys altissimus ''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 ...

'' from

Louisiana Louisiana ( ; ; ) is a state in the Deep South and South Central regions of the United States. It borders Texas to the west, Arkansas to the north, and Mississippi to the east. Of the 50 U.S. states, it ranks 31st in area and 25 ...

, USA. One extinct fossil genus is known in '' Evesthes'' from the

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, USA.

References

{{Authority control Marine fish families Carangiformes families