The group is divided into two mainclades, theray-finned fish (Actinopterygii, which makes up the vast majority of extant fish) and thelobe-finned fish (Sarcopterygii, which gave rise to all land vertebrates). The oldest knownfossils of bony fish are about 425 million years old from the lateSilurian,[1] which are alsotransitional fossils showing atooth pattern that is in between thetooth rows ofsharks and true bony fishes.[4] Despite the name, these earlybasal bony fish had not yet evolvedossification and their skeletons were still mostly cartilaginous, and the main distinguishing feature that set them apart from other fish clades were the development offoregut pouches that eventually evolved into theswim bladders andlungs, respectively.
Osteichthyes is broadly equivalent toEuteleostomi. Inpaleontology the terms are synonymous. Inichthyology the difference is that Euteleostomi presents acladistic view which includes the terrestrial tetrapods that evolved from lobe-finned fish. Until recently, the view of most ichthyologists has been that Osteichthyes wereparaphyletic and include only fishes.[5] However, since 2013 widely cited ichthyology papers have been published with phylogenetic trees that treat the Osteichthyes as a clade including tetrapods.[6][7][8][5]
Bony fish are characterized by a relatively stable pattern ofcranial bones, rooted, medial insertion ofmandibular muscle in the lower jaw. The head andpectoral girdles are covered with large dermal bones. The eyeball is supported by asclerotic ring of four small bones, but this characteristic has been lost or modified in many modern species. The labyrinth in theinner ear contains largeotoliths. The braincase, or neurocranium, is frequently divided intoanterior andposterior sections divided by afissure.
Bony fish do not haveplacoid scales like cartilaginous fish, but instead have scales that lie underneath the epidermis and do not penetrate it. The three categories of scales in Osteichthyes are cosmoid scales, ganoid scales, and teleost scales. Teleost scales are then divided into two subgroups which are cycloid scales and ctenoid scales. All of these scales have a base of bone that they all originate from; the main difference is that teleost scales have only one layer of bone. Ganoid scales have lamellar bone, and vascular bone that lies on top of the lamellar bone, then enamel that lies on top of both layers of bone. Cosmoid scales have the same two layers of bone that ganoid scales have except that they have dentin in between the enamel and vascular bone.
...it is increasingly widely accepted that tetrapods, including ourselves, are simply modified bony fishes, and so we are comfortable with using the taxon Osteichthyes as a clade, which now includes all tetrapods...
Traditionally, Osteichthyes was considered aclass, recognised on the presence of aswim bladder, only three pairs ofgill arches hidden behind a bonyoperculum, and a predominantly bony skeleton.[12] Under this classification system, Osteichthyes was consideredparaphyletic with regard toland vertebrates, as the common ancestor of all osteichthyans includestetrapods amongst its descendants. While the largest subclass, Actinopterygii (ray-finned fish), is monophyletic, with the inclusion of the smaller subclass Sarcopterygii, Osteichthyes was regarded as paraphyletic.
This has given way to the currentcladistic classification which splits the Osteichthyes into several clades. Under this scheme Osteichthyes is monophyletic, as it includes the tetrapods making it a synonym of the cladeEuteleostomi. Most bony fish belong to the ray-finned fish (Actinopterygii).
Inichthyology the difference between Euteleostomi and Osteichthyes is that the former presents acladistic view, i.e. that the terrestrialtetrapods evolved from lobe-finned fish (Sarcopterygii). Until recently, the view of most ichthyologists has been that Osteichthyes wereparaphyletic and include only bony fishes.[13] However, since 2013 widely cited ichthyology papers have been published withphylogenetic trees that treat the Osteichthyes as a clade including tetrapods, making the terms Euteleostomi and Osteichthyes synonymous.[13][14][15][16]
Actinopterygii, members of which are known asray-finned fishes, is aclass of the bony fishes. The ray-finned fishes are so called because they possesslepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines ("rays"), as opposed to the fleshy, lobed fins that characterize the cladeSarcopterygii which also possess lepidotrichia. 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). In terms of numbers, actinopterygians are the dominant class ofvertebrates, comprising nearly 99% of the over 30,000 species of fish (Davis, Brian 2010). They are ubiquitous throughoutfreshwater andmarine environments from the deep sea to the highest mountain streams. Extant species can range in size fromPaedocypris, at 8 mm (0.3 in), to the massivegiant sunfish, at 2,700 kg (6,000 lb), and the long-bodiedgiant oarfish, at up to 8 m (26 ft) (or possibly 11 m (36 ft)).
Sarcopterygii(fleshy fin), members of which are known aslobe-finned fish, is an unrankedclade of the bony fishes. Traditionally, it is aclass or subclass that excludesTetrapoda, a group of typically terrestrial vertebrates that descends from lobe-finned fish. However, under moderncladistic classification schemes, Sarcopterygii is aclade that includes the tetrapods. The living sarcopterygians are thecoelacanths,lungfish, and tetrapods. Early lobe-finned fishes had fleshy, lobed, paired fins, joined to the body by a single bone.[17] Their fins differ from those of all other fish in that each is borne on a fleshy, lobelike, scaly stalk extending from the body. Pectoral and pelvic fins have articulations resembling those of tetrapod limbs. These fins evolved into legs of the first tetrapod land vertebrates,amphibians. They also possess twodorsal fins with separate bases, as opposed to the single dorsal fin ofactinopterygians (ray-finned fish). The braincase of sarcoptergygians primitively has a hinge line, but this is lost in tetrapods and lungfish. Many early lobe-finned fishes have a symmetrical tail. All lobe-finned fishes possess teeth covered with trueenamel.
All bony fish possessgills. For the majority this is their sole or main means of respiration.Lungfish and other osteichthyan species are capable of respiration through lungs or vascularized swim bladders. Other species can respire through their skin, intestines, and/or stomach.[22]
Some bony fish arehermaphrodites, and a number of species exhibitparthenogenesis. Fertilization is usually external, but can be internal. Development is usuallyoviparous (egg-laying) but can beovoviviparous, orviviparous. Although there is usually no parental care after birth, before birth parents may scatter, hide, guard or brood eggs, withsea horses being notable in that the males undergo a form of "pregnancy", brooding eggs deposited in a ventral pouch by a female.
Thegiant sunfish is the heaviest bony fish in the world.
Thegiant sunfish is the heaviest bony fish in the world. In late 2021, Portuguese fishermen found a dead sunfish near the coast ofFaial Island,Azores. At 2,744 kilograms (6,049 lb) in weight, 3.6 metres (12 ft) in height, and 3.5 metres (11 ft) in length, it was the biggestgiant sunfish ever captured.[28]
^Betancur-R, R., Wiley, E.O., Arratia, G., Acero, A., Bailly, N., Miya, M., Lecointre, G. and Orti, G. (2017) "Phylogenetic classification of bony fishes".BMC evolutionary biology,17(1): 162.doi:10.1186/s12862-017-0958-3.
^Hughes, L.C., Ortí, G., Huang, Y., Sun, Y., Baldwin, C.C., Thompson, A.W., Arcila, D., Betancur-R, R., Li, C., Becker, L. and Bellora, N. (2018) "Comprehensive phylogeny of ray-finned fishes (Actinopterygii) based on transcriptomic and genomic data".Proceedings of the National Academy of Sciences,115(24): 6249–6254.doi:10.1073/pnas.1719358115.
^Betancur-R, R., Wiley, E.O., Arratia, G., Acero, A., Bailly, N., Miya, M., Lecointre, G. and Orti, G. (2017) "Phylogenetic classification of bony fishes".BMC evolutionary biology,17(1): 162.doi:10.1186/s12862-017-0958-3.
^Hughes, L.C., Ortí, G., Huang, Y., Sun, Y., Baldwin, C.C., Thompson, A.W., Arcila, D., Betancur-R, R., Li, C., Becker, L. and Bellora, N. (2018) "Comprehensive phylogeny of ray-finned fishes (Actinopterygii) based on transcriptomic and genomic data".Proceedings of the National Academy of Sciences,115(24): 6249–6254.doi:10.1073/pnas.1719358115.
^Clack, J. A. (2002)Gaining Ground. Indiana University
^"Warm Blood Makes Opah an Agile Predator". Fisheries Resources Division of the Southwest Fisheries Science Center of theNational Oceanic and Atmospheric Administration. May 12, 2015. Retrieved May 15, 2015. "New research by NOAA Fisheries has revealed the opah, or moonfish, as the first fully warm-blooded fish that circulates heated blood throughout its body..."
^Romer, Alfred Sherwood; Parsons, Thomas S. (1977).The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. pp. 396–399.ISBN978-0-03-910284-5.
.jpg)
.jpg)
.jpg)
_(white_background).jpg)
.jpg)
.jpg)
.jpg)
.png)
