A flatfish is a member of the ray-finned demersal fish order Pleuronectiformes, also called the Heterosomata, sometimes classified as a suborder of Perciformes. 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.
The Percidae are a family of ray-finned fish, part of the order Perciformes, which are found in fresh and brackish waters of the Northern Hemisphere. The majority are Nearctic, but there are also Palearctic species. The family contains more than 200 species in 11 genera. The perches and their relatives are in this family; well-known species include the walleye, sauger, ruffe, and three species of perch. However, small fish known as darters are also a part of this family.
The mackerel, tuna, and bonito family, Scombridae, includes many of the most important and familiar food fishes. The family consists of 51 species in 15 genera and two subfamilies. All species are in the subfamily Scombrinae, except the butterfly kingfish, which is the sole member of subfamily Gasterochismatinae.
Characidae, the characids or characins is a family of freshwater subtropical and tropical fish, belonging to the order Characiformes. The name "characins" is the historical one, but scientists today tend to prefer "characids" to reflect their status as a by and large monophyletic group at family rank. To arrive there, this family has undergone much systematic and taxonomic change. Among those fishes that remain in the Characidae for the time being are the tetras, comprising the very similar genera Hemigrammus and Hyphessobrycon, as well as a few related forms such as the cave and neon tetras. Fish of this family are important as food and also include popular aquarium fish species.
Batrachoididae is the only family in the ray-finned fish order Batrachoidiformes. Members of this family are usually called toadfish or frogfish: both the English common name and scientific name refer to their toad-like appearance.
Loricariidae is the largest family of catfish, with 92 genera and just over 680 species. Loricariids originate from freshwater habitats of Costa Rica, Panama, and tropical and subtropical South America. These fish are noted for the bony plates covering their bodies and their suckermouths. Several genera are sold as "plecos", notably the suckermouth catfish, Hypostomus plecostomus, and are popular as aquarium fish.
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 West African coast. Most are found in relatively shallow depths, but the genus also includes species found in deep water and species that enter fresh water.
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 opposite, with their eyes on the left side. A small number of species in Pleuronectidae can also have their eyes on the left side, notably the members of the genus Platichthys.
The Girellinae are a subfamily of fish in the sea chub family. They may be referred to as nibblers.
The viviparous brotulas form a family, the Bythitidae, of ophidiiform fishes. They are known as viviparous brotulas as they generally bear live young, although there are indications that some species do not. They are generally infrequently seen, somewhat tadpole-like in overall shape and mostly about 5–10 cm (2–4 in) in length, but some species grow far larger and may surpass 60 cm (2 ft).
The yellowtail flounder, also known as the rusty dab, is a species of flatfish in the family Pleuronectidae. Reaching 56 cm (22 in) in length, it has reddish brown upperparts, pale underparts and yellow fins. Both its eyes are on the right (upper) side of its body. Found in the western North Atlantic, it has been fished commercially by North American fisheries for food. A victim of overfishing, the yellowtail flounder is categorized as "Vulnerable" by the International Union for Conservation of Nature.
Lutjanidae, or snappers are a family of perciform fish, mainly marine, but with some members inhabiting estuaries, feeding in fresh water. The family includes about 113 species. Some are important food fish. One of the best known is the red snapper.
Pleuronectinae is a subfamily of fish in the family Pleuronectidae, comprising 27 genera and 62 extant species. Members of the subfamily are demersal carnivores that live in arctic and northern seas.
Rhombosoleidae is a family of flatfish in the order Pleuronectiformes, comprising nine genera and 19 species; all members of this family are right eye flounders with asymmetrical pelvic fins. Species are typically demersal, living on bottoms in temperate marine waters on the continental shelf, although some species of Rhombosolea enter fresh water in New Zealand. Most are restricted to waters around Australia and New Zealand, though the Remo flounder, Oncopterus darwinii, occurs in the southwestern Atlantic and the Indonesian ocellated flounder, Psammodiscus ocellatus, occurs in Indonesia.
Gyrodactylidae is a family of flatworms in the order Gyrodactylidea.
The Scombrinae are a subfamily of ray-finned bony fishes in the family Scombridae. Of the 51 species in the Scombridae, 50 are in Scombrinae – with the sole exception being the butterfly kingfish, which is placed in the monospecific subfamily Gasterochismatinae.
Brachypleura novaezeelandiae, the yellow-dabbled flounder or yellow citharid, is a species of citharid flounder native to the western and central Indo-Pacific. It occurs at depths from 18 to 92 m and is of minor importance to commercial fisheries. This species grows to a length of 14 cm (5.5 in). This species is the only known member of the genus Brachypleura.
Citharoides is a genus of citharid flounders native to the Indian and West Pacific Oceans.
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 and the Mediterranean Sea, where it is found to a depth of 300 m (980 ft). This species grows to a total length of 30 cm (12 in). It is of minor importance to local commercial fisheries. This species is the only known member of its monotypic genus.
