Pleuronectiformes(Greek pleua (similar)+ Greek nektos (to swim) + Greek forma (shape))
Taxononmy: Superclass Gnathostomata (jawed fishes)
Class Osteichthyes, subclass Actinopterygii (ray-finned fishes)
Super Order Acanthopterygii
Families: Psettodidae-psettodids(3 sp.), Citharidae-citharids (5 sp.), Scophthalmidae-turbots
(18 sp.), Bothidae- lefteye flounders(116 sp.), Pleuronectidae-righteye flounders(93 sp.), Soleidae-soles(89
sp.) Achiridae-American soles(28 sp.), Achiropsettidae-Southern flounders(4 sp.), Cynoglossidaetonguefishes(110 sp.), Paralichthyidae-large-tooth flounders(86 sp.), Samaridae-crested flounders(20sp.)
Description: Adults not bilaterally symmetrical, one eye migrating to the other side of the cranium, body
highly compressed and somewhat rounded on the eyed side and flat on the blind side; asymmetry may also
occur in dentition, squamation and paired fins; Scales are cycloid, ctenoid or tuberculate; dorsal and anal
fins are usually long, usually 6 or 7 branchiostegal rays, rarely eight; small body cavity; adults rarely have
swim bladder; upper side pigmented, lower usually white, several species can modify the pigmentation
pattern of their eye side to mimic the environment(Nelson, 1994); young flatfishes are bilaterally
symmetrical and swim upright; range in size from about 4.5 centimeters to 2.5 meters
Habitat
Marine, fresh, brackish, benthic fishes
Distribution
Tropical and subtropical seas to temperate seas; West Africa, indo-west Pacific, Mediterranean, Indian
Ocean, Arctic ocean
Ecology and life history
Benthic and carnivorous (Nelson,1994); usually cover their body with a fine layer of sand and stay
immobile for varying period of time; primitive flatfishes are fish eaters, large nearly symmetrical mouths
with well-developed dentition, these fishes will often forage in mid-waters and migrate between feeding,
wintering, or spawning grounds. (Paxton et al., 1998); probably share a unique and common ancestor with
a still unidentified group of symmetrical fishes (Paxton et al., 1998); oldest fossils from the Paleocene
epoch(65 -57 mya)
Additional details
Several species such as halibut, flounder, and plaice support important fisheries in the Arctic, Atlantic and
Pacific oceans; both eyes on left side- sinistral, both eyes on right side- dextral
Recent research
A study was done to determine the role that flatfish play in the organization and structure of the eastern
Bering Sea ecosystem. Though no flatfish species were found to have a particularly profound effect on the
overall ecosystem several were found to be keystone predators when in combination with birds and
mammals.
References used
Paxton, J. R. and W. N. Eshmeyer. 1998. Encyclopedia of fishes 2nd ed. Academic Press.
Nelson, J. S. 1994. Fishes of the World. 3rd. ed. Wiley and Sons, New York.
Fishbase.org
Chang Ik Zhang, et al. “The role of flatfishes in the organization and structure of the Eastern Bering Sea
Ecosystem.” Fisheries Science. 76.3 (2010): 411-434. Wildlife & Ecology Studies Worldwide. Web. 12
Mar. 2013.