Flatfish
Flatfish Temporal range:
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A camouflaged flatfish | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Clade: | Percomorpha |
Order: | Pleuronectiformes |
Type species | |
Families[2][3] | |
Suborder Psettodoidei
Suborder Pleuronectoidei
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A flatfish is a member of the
Many important
Taxonomy
Over 800 described species are placed into 16 families.
The
Hybrids
Distribution
Flatfishes are found in oceans worldwide, ranging from the
Characteristics
The most obvious characteristic of the flatfish is its asymmetry, 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 turbots include equal numbers of right- and left-sided individuals, and are generally less asymmetrical than the other families.[1] Other distinguishing features of the order are the presence of protrusible eyes, another adaptation to living on the seabed (benthos), and the extension of the dorsal fin onto the head.
The surface of the fish facing away from the sea floor is pigmented, often serving to
In general, flatfishes rely on their camouflage for avoiding predators, but some have
The flounders 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.[1]
Flatfishes range in size from Tarphops oligolepis, measuring about 4.5 cm (1.8 in) in length, and weighing 2 g (0.071 oz), to the Atlantic halibut, at 2.5 m (8.2 ft) and 316 kg (697 lb).[1]
This article is part of a series on |
Commercial fish |
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Large pelagic |
Forage |
Demersal |
Mixed |
Species and species groups
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, and do not dwell on the bottom, instead dispersing from their hatching grounds as plankton.[1]
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, was identified as an early relative of the flatfish and transitional fossil.[22] 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.[23] The researchers concluded, "the change happened gradually, in a way consistent with evolution via natural selection—not suddenly, as researchers once had little choice but to believe."[22]
Flatfishes have been cited as dramatic
...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 [flatfish] took 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.[24]
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The European plaice is the principal commercial flatfish in Europe.
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American soles are found in both freshwater and marine environments of the Americas.
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Halibut are the largest of the flatfishes, and provide lucrative fisheries.
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The turbot is a large, left-eyed flatfish found in sandy shallow coastal waters around Europe.
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Flatfish (left‐eyed flounder)
As food
Flatfish is considered a Whitefish[25] 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
See also
References
- ^ ISBN 0-12-547665-5.
- ^ ISBN 978-0-471-25031-9.
- ^ ISBN 978-1-118-34233-6. Archived from the originalon 2019-04-08. Retrieved 2018-05-24.
- ^ S2CID 202856805.
- )
- ^ ISBN 1-929054-03-3
- ^ a b 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.
- S2CID 46318428.
- ^ a b 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
- Food and Agriculture Organization of the United Nations: Platichthys flesus (Linnaeus, 1758).. Retrieved 18 May 2014
- S2CID 202856805.
- ^ Jamieson, A.J., and Yancey, P. H. (2012). On the Validity of the Trieste Flatfish: Dispelling the Myth. The Biological Bulletin 222(3): 171-175
- ^ Munroe, T.A.; and Hashimoto, J. (2008). A new Western Pacific Tonguefish (Pleuronectiformes: Cynoglossidae): The first Pleuronectiform discovered at active Hydrothermal Vents. Zootaxa 1839: 43–59.
- ^ Duplain, R.R.; Chapleau, F; and Munroe, T.A. (2012). A New Species of Trinectes (Pleuronectiformes: Achiridae) from the Upper Río San Juan and Río Condoto, Colombia. Copeia 2012 (3): 541-546.
- ^ Kottelat, M. (1998). Fishes of the Nam Theun and Xe Bangfai basins, Laos, with diagnoses of twenty-two new species (Teleostei: Cyprinidae, Balitoridae, Cobitidae, Coiidae and Odontobutidae). Ichthyol. Explor. Freshwat. 9(1):1-128.
- ^ Monks, N. (2007). Freshwater flatfish, order Pleuronectiformes. Archived 2014-08-15 at the Wayback Machine Retrieved 18 May 2014
- ISBN 978-1868253944
- ISBN 978-3925919541
- ^ Practical Fishkeeping (22 May 2012) Video: Tiny sole mimics a flatworm. Archived 2014-05-17 at the Wayback Machine Retrieved 17 May 2014.
- ^ Australian Museum (5 November 2010). This week in Fish: Flatworm mimic and shark teeth. Archived 2013-02-26 at the Wayback Machine Retrieved 17 May 2014.
- ^ Hanlon, R.T.; Warson, A.C.; and Barbosa, A. (2010). A "Mimic Octopus" in the Atlantic: Flatfish Mimicry and Camouflage by Macrotritopus defilippi. The Biological Bulletin 218(1): 15-24
- ^ a b "Odd Fish Find Contradicts Intelligent-Design Argument". National Geographic. July 9, 2008. Archived from the original on July 11, 2008. Retrieved 2008-07-17.
- (PDF) from the original on 2013-03-19.
- ISBN 0-14-014481-1.
- ^ "Flatfish BBC".
Further reading
- Sepkoski, Jack (2002). "A compendium of fossil marine animal genera". Bulletins of American Paleontology. 364: 560. Archived from the original on July 23, 2011. Retrieved 2011-05-17.
- Gibson, Robin N (Ed) (2008) Flatfishes: biology and exploitation. Wiley.
- Munroe, Thomas A (2005) "Distributions and biogeography." Flatfishes: Biology and Exploitation: 42–67.