Actinopterygii

Actinopterygii (/ˌæktɪˌnɒptəˈrɪdʒiaɪ/), or the ray-finned fishes, constitute a class or subclass of the bony fishes.[1]

The ray-finned fishes are so called because their fins are webs of skin supported by bony or horny spines ("rays"), as opposed to the fleshy, lobed fins that characterize the class Sarcopterygii (lobe-finned fish). These actinopterygian fin rays attach directly to the proximal or basal skeletal elements, the radials, which represent the link or connection between these fins and the internal skeleton (e.g., pelvic and pectoral girdles).

Numerically, actinopterygians are the dominant class of vertebrates, comprising nearly 99% of the over 30,000 species of fish.[2] They are ubiquitous throughout freshwater and marine environments from the deep sea to the highest mountain streams. Extant species can range in size from Paedocypris, at 8 mm (0.3 in), to the massive ocean sunfish, at 2,300 kg (5,070 lb), and the long-bodied oarfish, at 11 m (36 ft).

Ray-finned fish
Temporal range: Late Silurian - recent
Georgia Aquarium - Giant Grouper
Different species of Actinopterygii
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Superclass: Osteichthyes
Class: Actinopterygii
Klein, 1885
Subclasses

Characteristics

Anatomia dei pesci
Anatomy of a typical ray-finned fish (cichlid)
A – dorsal fin: B – fin rays: C – lateral line: D – kidney: E – swim bladder: F – Weberian apparatus: G – inner ear: H – brain: I – nostrils: L – eye: M – gills: N – heart O – stomach: P – gall bladder: Q – spleen: R – internal sex organs (ovaries or testes): S – ventral fins: T – spine: U – anal fin: V – tail (caudal fin). Possible other parts not shown: barbels, adipose fin, external genitalia (gonopodium)

Ray-finned fishes occur in many variant forms. The main features of a typical ray-finned fish are shown in the adjacent diagram.

Bluefin-big

Tuna are streamlined for straight line speed with a deeply forked tail

Xiphias gladius1

The swordfish is even faster and more streamlined than the tuna

Salmo salar GLERL 1

Salmon generate enough thrust with their powerful tail fin to jump obstacles during river migrations

Atlantic cod

Cod have three dorsal and two anal fins, which give them great maneuverability

Ancylopsetta dilecta 2

Flatfish have developed partially symmetric dorsal and pelvic fins

Anoplogaster cornuta 2

Fangtooth are indifferent swimmer who try to ambush their prey

Melanocetus johnsonii

The first spine of the dorsal fin of anglerfish is modified like a fishing rod with a lure

Conger conger Gervais

European conger are ray-finned fish

So are seahorses

Lion Fish

The venomous red lionfish

TigerfishHydrocynusVittatus2

African tigerfish (Hydrocynus vittatus)

Reproduction

Gasterosteus aculeatus 1879
Three-spined stickleback males (red belly) build nests and compete to attract females to lay eggs in them. Males then defend and fan the eggs. Painting by Alexander Francis Lydon, 1879

In nearly all ray-finned fish, the sexes are separate, and in most species the females spawn eggs that are fertilized externally, typically with the male inseminating the eggs after they are laid. Development then proceeds with a free-swimming larval stage.[3] However other patterns of ontogeny exist, with one of the commonest being sequential hermaphroditism. In most cases this involves protogyny, fish starting life as females and converting to males at some stage, triggered by some internal or external factor. Protandry, where a fish converts from male to female, is much less common than protogyny.[4] Most families use external rather than internal fertilization.[5] Of the oviparous teleosts, most (79%) do not provide parental care.[6] Viviparity, ovoviviparity, or some form of parental care for eggs, whether by the male, the female, or both parents is seen in a significant fraction (21%) of the 422 teleost families; no care is likely the ancestral condition.[6] Viviparity is relatively rare and is found in about 6% of teleost species; male care is far more common than female care.[6][7] Male territoriality "preadapts" a species for evolving male parental care.[8][9]

There are a few examples of fish that self-fertilise. The mangrove rivulus is an amphibious, simultaneous hermaphrodite, producing both eggs and spawn and having internal fertilisation. This mode of reproduction may be related to the fish's habit of spending long periods out of water in the mangrove forests it inhabits. Males are occasionally produced at temperatures below 19 °C (66 °F) and can fertilise eggs that are then spawned by the female. This maintains genetic variability in a species that is otherwise highly inbred.[10]

Fossil record

Evolution of ray-finned fish

The earliest known fossil actinopterygiian is Andreolepis hedei, dating back 420 million years (Late Silurian). Remains have been found in Russia, Sweden, and Estonia.[11]

Classification

Actinopterygians are divided into the subclasses Chondrostei and Neopterygii. The Neopterygii, in turn, are divided into the infraclasses Holostei and Teleostei. During the Mesozoic and Cenozoic the teleosts in particular diversified widely, and as a result, 96% of all known fish species are teleosts. The cladogram shows the major groups of actinopterygians and their relationship to the terrestrial vertebrates (tetrapods) that evolved from a related group of fish.[12][13][14] Approximate dates are from Near et al., 2012.[12]

Osteichthyes
Sarcopterygii

Coelacanths, Lungfish Coelacanth flipped

Tetrapods

Amphibians Deutschlands Amphibien und Reptilien (Salamandra salamdra)

Amniota

Mammals Phylogenetic tree of marsupials derived from retroposon data (Paucituberculata)

Sauropsids (reptiles, birds) Zoology of Egypt (1898) (Varanus griseus)

Actinopterygii
Cladistia

Polypteriformes (bichirs, reedfishes) Cuvier-105-Polyptère

Actinopteri
Chondrostei

Acipenseriformes (sturgeons, paddlefishes) Atlantic sturgeon flipped

Neopterygii
Holostei

Lepisosteiformes (gars) Longnose gar flipped

Amiiformes (bowfins) Amia calva 1908 flipped

275 mya

Teleostei Cyprinus carpio3

310 mya
360 mya
400 mya

The polypterids (bichirs and ropefish) are the sister lineage of all other actinopterygians, The Acipenseriformes (sturgeons and paddlefishes) are the sister lineage of Neopterygii, and Holostei (bowfin and gars) are the sister lineage of teleosts. The Elopomorpha (eels and tarpons) appears to be the most basic teleosts.[12]

Chondrostei Atlantic sturgeon flipped
Atlantic sturgeon
Chondrostei (cartilage bone) are primarily cartilaginous fish showing some ossification. There are 52 species divided among two orders, the Acipenseriformes (sturgeons and paddlefishes) and the Polypteriformes (reedfishes and bichirs). It is thought that the chondrosteans evolved from bony fish but lost the bony hardening of their cartilaginous skeletons, resulting in a lightening of the frame. Elderly chondrosteans show beginnings of ossification of the skeleton, suggesting that this process is delayed rather than lost in these fish.[15] This group has at times been classified with the sharks: the similarities are obvious, as not only do the chondrosteans mostly lack bone, but the structure of the jaw is more akin to that of sharks than other bony fish, and both lack scales (excluding the Polypteriforms). Additional shared features include spiracles and, in sturgeons, a heterocercal tail (the vertebrae extend into the larger lobe of the caudal fin). However the fossil record suggests that these fish have more in common with the Teleostei than their external appearance might suggest.[15] Chondrostei is paraphyletic meaning that this subclass does not contain all the descendants of their common ancestor; reclassification of the Chondrostei is therefore not out of the question.
Neopterygii Salmo salar flipped
Atlantic salmon
Neopterygii (new fins) appeared somewhere in the Late Permian, before the time of the dinosaurs. There are only few changes during their evolution from the earlier actinopterygians. They are a very successful group of fishes, because they can move more rapidly than their ancestors. Their scales and skeletons began to lighten during their evolution, and their jaws became more powerful and efficient. While electroreception and the ampullae of Lorenzini is present in all other groups of fish, with the exception of hagfish, Neopterygii has lost this sense, though it later re-evolved within Gymnotiformes and catfishes, who possess nonhomologous teleost ampullae.[16]
Lophius piscatorius MHNT
Skeleton of the angler fish, Lophius piscatorius. The first spine of the dorsal fin of the anglerfish is modified so it functions like a fishing rod with a lure
Lingcodskeleton1600ppx
Skeleton of another ray-finned fish, the lingcod
Hypsospondylus
Hypsospondylus fossil

The listing below follows Phylogenetic Classification of Bony Fishes[13][17] with notes when this differs from Nelson,[18] ITIS[19] and FishBase[20] and extinct groups from Van der Laan 2016.[21]

Blue catfish skeleton
Blue catfish (Ictalurus furcatus) skeleon on display at the Museum of Osteology.
Naturalis Biodiversity Center - RMNH.ART.157 - Ateleopus japonicus Bleeker - Kawahara Keiga - 1823 - 1829 - Siebold Collection - pencil drawing - water colour.jpeg

Ateleopus japonicus (Ateleopodiformes)

Pomocanthus imperator facing right

Pomacanthus imperator (Spariformes)

Fish4396 - Flickr - NOAA Photo Library

Polymixia lowei (Polymixiiformes)

Scopelogadus mizolepis mizolepis

Scopelogadus mizolepis (Stephanoberyciformes)

See also

  • Portal-puzzle.svg Actinopterygii portal

References

  1. ^ Kardong, Kenneth (2015). Vertebrates: Comparative Anatomy, Function, Evolution. New York: McGraw-Hill Education. pp. 99–100. ISBN 978-0-07-802302-6.
  2. ^ (Davis, Brian 2010).
  3. ^ Dorit, R.L.; Walker, W.F.; Barnes, R.D. (1991). Zoology. Saunders College Publishing. p. 819. ISBN 978-0-03-030504-7.
  4. ^ Avise, J.C.; Mank, J.E. (2009). "Evolutionary perspectives on hermaphroditism in fishes". Sexual Development. 3 (2–3): 152–163. doi:10.1159/000223079. PMID 19684459.
  5. ^ Pitcher, T (1993). The Behavior of Teleost Fishes. London: Chapman & Hall.
  6. ^ a b c Reynolds, John; Nicholas B. Goodwin; Robert P. Freckleton (19 March 2002). "Evolutionary Transitions in Parental Care and Live Bearing in Vertebrates". Philosophical Transactions of the Royal Society B: Biological Sciences. 357 (1419): 269–281. doi:10.1098/rstb.2001.0930. PMC 1692951. PMID 11958696.
  7. ^ Clutton-Brock, T. H. (1991). The Evolution of Parental Care. Princeton, NJ: Princeton UP.
  8. ^ Werren, John; Mart R. Gross; Richard Shine (1980). "Paternity and the evolution of male parentage". Journal of Theoretical Biology. 82 (4): 619–631. doi:10.1016/0022-5193(80)90182-4. Retrieved 15 September 2013.
  9. ^ Baylis, Jeffrey (1981). "The Evolution of Parental Care in Fishes, with reference to Darwin's rule of male sexual selection". Environmental Biology of Fishes. 6 (2): 223–251. doi:10.1007/BF00002788.
  10. ^ Wootton, Robert J.; Smith, Carl (2014). Reproductive Biology of Teleost Fishes. Wiley. ISBN 978-1-118-89139-1.
  11. ^ "Fossilworks: Andreolepis".
  12. ^ a b c Thomas J. Near; et al. (2012). "Resolution of ray-finned fish phylogeny and timing of diversification". PNAS. 109 (34): 13698–13703. Bibcode:2012PNAS..10913698N. doi:10.1073/pnas.1206625109. PMC 3427055. PMID 22869754.
  13. ^ a b Betancur-R, Ricardo; et al. (2013). "The Tree of Life and a New Classification of Bony Fishes". PLOS Currents Tree of Life. 5 (Edition 1). doi:10.1371/currents.tol.53ba26640df0ccaee75bb165c8c26288. PMC 3644299. PMID 23653398. Archived from the original on 13 October 2013.
  14. ^ Laurin, M.; Reisz, R.R. (1995). "A reevaluation of early amniote phylogeny". Zoological Journal of the Linnean Society. 113 (2): 165–223. doi:10.1111/j.1096-3642.1995.tb00932.x.
  15. ^ a b "Chondrosteans: Sturgeon Relatives". paleos.com. Archived from the original on 25 December 2010.
  16. ^ Theodore Holmes Bullock; Carl D. Hopkins; Arthur N. Popper (2005). Electroreception. Springer Science+Business Media, Incorporated. p. 229. ISBN 978-0-387-28275-6.
  17. ^ Betancur-Rodriguez; et al. (2017). "Phylogenetic Classification of Bony Fishes Version 4". BMC Evolutionary Biology. 17 (1): 162. doi:10.1186/s12862-017-0958-3. PMC 5501477. PMID 28683774.
  18. ^ Nelson, Joseph, S. (2016). Fishes of the World. John Wiley & Sons, Inc. ISBN 978-1-118-34233-6.
  19. ^ "Actinopterygii". Integrated Taxonomic Information System. Retrieved 3 April 2006.
  20. ^ R. Froese and D. Pauly, editors (February 2006). "FishBase".CS1 maint: Extra text: authors list (link)
  21. ^ Van der Laan, Richard (2016). Family-group names of fossil fishes. doi:10.13140/RG.2.1.2130.1361.
  22. ^ In Nelson, Polypteriformes is placed in its own subclass Cladistia.
  23. ^ In Nelson and ITIS, Syngnathiformes is placed as the suborder Syngnathoidei of the order Gasterosteiformes.

External links

Acanthopterygii

Acanthopterygii (meaning "spiny finned one") is a superorder of bony fishes in the class Actinopterygii. Members of this superorder are sometimes called ray-finned fishes for the characteristic sharp, bony rays in their fins; however this name is often given to the class Actinopterygii as a whole.

Caesioperca

Caesioperca is a genus of ray-finned fish in the sub-family Anthiadinae in the sea bass family Serranidae. It contains just two species, found in the ocean off Southern Australia and New Zealand.

Caprodon

Caprodon is a small genus of fish belonging to the subfamily Anthiadinae. It contains three species.

Cichliformes

Cichliformes is an order of fishes, previously classifies under the order Perciformes but now many authorities consider it to be an order within the subseries Ovalentaria.

Euteleostomi

Euteleostomi is a successful clade that includes more than 90% of the living species of vertebrates. Euteleostomes are also known as "bony vertebrates". Both its major subgroups are successful today: Actinopterygii includes the majority of extant fish species, and Sarcopterygii includes the tetrapods.

"Osteichthyes" in the paleontological sense (i.e., "bony vertebrates"), is synonymous with Euteleostomi. However, in ichthyology and Linnaean taxonomy Osteichthyes, literally "bony fish," refers to the paraphyletic group that differs by excluding tetrapods. The name Euteleostomi, coined as a monophyletic alternative that unambiguously includes the living tetrapods, is more widely used in bioinformatics and related fields. The term Euteleostomi comes from Eu-teleostomi, where "Eu-" comes from the Greek εὖ meaning well or good, so the clade can be defined as the living teleostomes.

Euteleostomes originally all had endochondral bone, fins with lepidotrichs (fin rays), jaws lined by maxillary, premaxillary, and dentary bones composed of dermal bone, and lungs. Many of these characters have since been lost by descendant groups, however, such as lepidotrichs lost in tetrapods, and bone lost among the chondrostean fishes. Lungs have been retained in dipnoi (lungfish), and many tetrapods (birds, mammals, reptiles, and some amphibians). In many ray-finned fishes lungs have evolved into swim bladders for regulating buoyancy, while in others they continue to be used as respiratory gas bladders.

Flying fish

The Exocoetidae are a family of marine fish in the order Beloniformes class Actinopterygii, known colloquially as flying fish. About 64 species are grouped in seven to nine genera. While they cannot fly in the same way as a bird does, flying fish can make powerful, self-propelled leaps out of water where their long wing-like fins enable gliding for considerable distances above the water's surface. This uncommon ability is a natural defense mechanism to evade predators. The Exocet missile is named after them, as variants are launched from underwater, and take a low trajectory, skimming the surface, before striking their prey.

The oldest known fossil of a flying or gliding fish, Potanichthys xingyiensis, dates back to the Middle Triassic, 235–242 million years ago. However, this fossil is not related to modern flying fish, which evolved independently about 66 million years ago.

Kurtiformes

The Kurtiformes consist of two extant families of ray-finned fish, the Indo-Pacific Kurtidae, the nursery fish, with two species and the much more diverse and widespread Apogonidae, the cardinalfishes, the order is part of the Percomorpha clade and is regarded by many authorities as a sister taxon to the Gobiiformes.

Lepidoperca

Lepidoperca is a small genus of fish belonging to the Anthiadinae subfamily. It includes ten species.

List of Lessepsian migrant species

Lessepsian migrants, named after Ferdinand de Lesseps, the French engineer in charge of the Suez Canal's construction, are marine species that are native to the waters on one side of the Suez Canal, and which have been introduced by passage through the canal to the waters on its other side, giving rise to new colonies there and often becoming invasive.

Most Lessepsian migrations are of Red Sea species invading the Mediterranean Sea; few occur in the opposite direction.

List of chordate orders

This page contains a list of all of the classes and orders that are located in the Phylum Chordata.

Mullet (fish)

The mullets or grey mullets are a family (Mugilidae) of ray-finned fish found worldwide in coastal temperate and tropical waters, and some species in fresh water. Mullets have served as an important source of food in Mediterranean Europe since Roman times. The family includes about 78 species in 20 genera.Mullets are distinguished by the presence of two separate dorsal fins, small triangular mouths, and the absence of a lateral line organ. They feed on detritus, and most species have unusually muscular stomachs and a complex pharynx to help in digestion.

Neopterygii

Neopterygii are a group of fish. Neopterygii means "new fins" (from Greek νέος neos, new, and πτέρυξ pteryx, fin). Only a few changes occurred during their evolution from the earlier actinopterygians. They appeared sometime in the Late Permian, before the time of the dinosaurs. The Neopterygii were a very successful group of fish, because they could move more rapidly than their ancestors. Their scales and skeletons began to lighten during their evolution, and their jaws became more powerful and efficient. While electroreception and the ampullae of Lorenzini are present in all other groups of fish, with the exception of hagfish (although hagfish are not Actinopterygii, they are Agnathans), Neopterygii have lost this sense, even if it has later been re-evolved within Gymnotiformes and catfishes, which possess nonhomologous teleost ampullae.

Osteichthyes

Osteichthyes (), popularly referred to as the bony fish, is a diverse taxonomic group of fish that have skeletons primarily composed of bone tissue, as opposed to cartilage. The vast majority of fish are members of Osteichthyes, which is an extremely diverse and abundant group consisting of 45 orders, and over 435 families and 28,000 species. It is the largest class of vertebrates in existence today.

The group Osteichthyes is divided into the ray-finned fish (Actinopterygii) and lobe-finned fish (Sarcopterygii). The oldest known fossils of bony fish are about 420 million years old, which are also transitional fossils, showing a tooth pattern that is in between the tooth rows of sharks and bony fishes.Osteichthyes can be compared to Euteleostomi. In paleontology, the terms are synonymous. In ichthyology, the difference is that Euteleostomi presents a cladistic view which includes the terrestrial tetrapods that evolved from lobe-finned fish, whereas prior to 2014 the view of most ichthyologists was that Osteichthyes includes only fishes, and were therefore paraphyletic. However, in 2014, an ichthyology paper was published with phylogenetic trees that treat the Osteichthyes as a clade including tetrapods.

Palaeonisciformes

The Palaeonisciformes are an extinct order of early ray-finned fishes (Actinopterygii) which began in the Late Silurian and ended in the Late Cretaceous. The name of the order is derived from the Greek words paleo (ancient) and ὀνίσκος (oniskos or woodlouse), probably pertaining to the organization of the fishes' scales, similar to the exoskeletal plating of woodlice.

Paracanthopterygii

Paracanthopterygii is a superorder of fishes. Members of this group are called paracanthopterygians.

It includes five orders:

†Sphenocephaliformes

Percopsiformes (trout-perches & allies)

Zeiformes (dories)

Stylephoriformes (Tube-eyes)

Gadiformes (cods & allies)

Percomorpha

The Percomorpha is a large clade of bony fish that includes the tuna, seahorses, gobies, cichlids, flatfish, wrasse, perches, anglerfish, and pufferfish.

Teleostomi

Teleostomi is an obsolete clade of jawed vertebrates that supposedly includes the tetrapods, bony fish, and the wholly extinct acanthodian fish. Key characters of this group include an operculum and a single pair of respiratory openings, features which were lost or modified in some later representatives. The teleostomes include all jawed vertebrates except the chondrichthyans and the extinct class Placodermi.

Recent studies indicate that Osteichthyes evolved from placoderms like Entelognathus, while acanthodians are more closely related to modern chondrichthyes. Teleostomi, therefore, is not a valid, natural clade, but a polyphyletic group of species.The clade Teleostomi should not be confused with the similar-sounding fish clade Teleostei.

Zaniolepis

Zaniolepis is a genus of scorpaeniform fish native to the eastern Pacific Ocean. Z. frenata is known to have been a source of food to the Native American inhabitants of San Nicolas Island off the coast of southern California, United States during the Middle Holocene.

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