Holostei is a group of ray-finnedbony fish. It is divided into two major clades, the Halecomorphi, represented by a single living species, the bowfin (Amia calva), as well as the Ginglymodi, the sole living representatives being the gars (Lepisosteidae), represented by seven living species in two genera (Atractosteus, Lepisosteus).[1] The earliest members of the clade appeared during the Early Triassic, over 250 million years ago.[2]
Holostei was thought to be regarded as paraphyletic. However, a recent study provided evidence that the Holostei are the closest living relates of the Teleostei, both within the Neopterygii. This was found from the morphology of the Holostei, for example presence of a paired vomer.[3] Holosteans are closer to teleosts than are the chondrosteans, the other group intermediate between teleosts and cartilaginous fish, which are regarded as (at the nearest[a]) a sister group to the Neopterigii.
The spiracles of holosteans are reduced to vestigial remnants and the bones are lightly ossified. The thick ganoid scales of the gars are more primitive than those of the bowfin.
Holosteans share with other non-teleost ray-finned fish a mixture of characteristics of teleosts and sharks. In comparison with the other group of non-teleost ray-finned fish, the chondrosteans, the holosteans are closer to the teleosts and further from sharks: the pair of spiracles found in sharks and chondrosteans is reduced in holosteans to a remnant structure: in gars, the spiracles do not even open to the outside;[4] the skeleton is lightly ossified: a thin layer of bone covers a mostly cartilaginous skeleton in the bowfins. In gars, the tail is still heterocercal but less so than in the chondrosteans. Bowfins have many-rayed dorsal fins and can breathe air like the bichirs.
The gars have thick ganoid scales typical of sturgeons whereas the bowfin has thin bony scales like the teleosts. The gars are therefore in this regard considered more primitive than the bowfin.[5]
The name Holostei derives from the Greek words holos, meaning whole, and osteon, meaning bone: a reference to their bony skeletons.
The Holostei hypothesis is better supported[7][8][9][10] than the Halecostomi hypothesis, rendering the latter paraphyletic. It proposes Halecomorphi as the sister group of Ginglymodi, the group which includes living gars (Lepisosteiformes) and their fossil relatives.[11][12][1] Ginglymodi and Halecomorphi form the clade Holostei, which is the sister group to Teleostei.
Ginglymodi comprises three orders: Lepisosteiformes, Semionotiformes and Kyphosichthyiformes. Lepisosteiformes includes 1 family, 2 genera, and 7 species that are commonly referred to as gars. Semionotiformes and Kyphosichthyiformes are extinct orders.
Halecomorphi contains the orders Parasemionotiformes, Panxianichthyiformes, Ionoscopiformes, and Amiiformes. In addition to many extinctspecies, Amiiformes includes only 1 extant species that is commonly referred to as the bowfin. Parasemionotiformes, Panxianichthyiformes, and Ionoscopiformes have no living members.
Gars and bowfins are found in North America and in freshwater ecosystems. The differences in each can be spotted very easily from just looking at the fishes. The gars have elongated jaws with fanlike teeth, only 3 branchiostegal rays, and a small dorsal fin. Meanwhile the bowfins have a terminal mouth, 10-13 flattened branchiostegal rays, and a long dorsal fin.
The cladogram shows the relationships of holosteans to other living groups of bony fish, the great majority of which are teleosts,[14] and to the terrestrial vertebrates (tetrapods) that evolved from a related group of lobe-finned fish.[15][16] Approximate dates are from Near et al. (2012).[14]
^Depending who you ask, the Chondrostei may be paraphyletic, or the Polypteridae may be considered not part of them.
^Thus the former "Chondrostei" is not a clade, but is broken up. See Actinopteri for a possible reclassification.
References
^ abLópez-Arbarello, Adriana; Sferco, Emilia (March 2018). "Neopterygian phylogeny: the merger assay". Royal Society Open Science. 5 (3): 172337. Bibcode:2018RSOS....572337L. doi:10.1098/rsos.172337. PMC5882744. PMID 29657820.
^Romano, Carlo (2021). "A Hiatus Obscures the Early Evolution of Modern Lineages of Bony Fishes". Frontiers in Earth Science. 8: 672. doi:10.3389/feart.2020.618853. ISSN 2296-6463.
^Hastings, Walker Jr., Galland (2014). FISHES, A GUIDE TO THEIR DIVERSITY. Oakland, California: University of California Press. pp. 60–62.{{cite book}}: CS1 maint: multiple names: authors list (link)
^Patterson C. Interrelationships of holosteans. In: Greenwood P H, Miles R S, Patterson C, eds. Interrelationships of Fishes. Zool J Linn Soc, 1973, 53(Suppl): 233–305
^Betancur-R (2016). "Phylogenetic Classification of Bony Fishes Version 4".
^Nelson, Joseph, S. (2016). Fishes of the World. John Wiley & Sons, Inc. ISBN978-1-118-34233-6.
^R. Froese and D. Pauly, ed. (February 2006). "FishBase".
^Olsen P. E. (1984). "The skull and pectoral girdle of the parasemionotid fish Watsonulus eugnathoides from the Early Triassic Sakemena Group of Madagascar with comments on the relationships of the holostean fishes". J Vertebr Paleontol. 4 (3): 481–499. doi:10.1080/02724634.1984.10012024.
^Grande, Lance; Bemis, William E. (1998). "A Comprehensive Phylogenetic Study of Amiid Fishes (Amiidae) Based on Comparative Skeletal Anatomy. an Empirical Search for Interconnected Patterns of Natural History". Journal of Vertebrate Paleontology. 18 (sup001): 1–696. doi:10.1080/02724634.1998.10011114.
^Brito, Paulo M.; Alvarado-Ortega, Jesus (2013). "Cipactlichthys scutatus, gen. nov., sp. nov. a New Halecomorph (Neopterygii, Holostei) from the Lower Cretaceous Tlayua Formation of Mexico". PLOS ONE. 8 (9): e73551. Bibcode:2013PLoSO...873551B. doi:10.1371/journal.pone.0073551. PMC3762789. PMID 24023885.
^ abThomas 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. PMC3427055. PMID 22869754.
^Betancur-R, Ricardo; et al. (2013). . PLOS Currents Tree of Life. 5 (Edition 1). doi:10.1371/currents.tol.53ba26640df0ccaee75bb165c8c26288. hdl:2027.42/150563. PMC3644299. PMID 23653398. Archived from the original on 2013-10-13.
^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.
External links
January 31, 2023
holostei, group, finned, bony, fish, divided, into, major, clades, halecomorphi, represented, single, living, species, bowfin, amia, calva, well, ginglymodi, sole, living, representatives, being, gars, lepisosteidae, represented, seven, living, species, genera. Holostei is a group of ray finned bony fish It is divided into two major clades the Halecomorphi represented by a single living species the bowfin Amia calva as well as the Ginglymodi the sole living representatives being the gars Lepisosteidae represented by seven living species in two genera Atractosteus Lepisosteus 1 The earliest members of the clade appeared during the Early Triassic over 250 million years ago 2 HolosteiTemporal range Early Triassic Recent PreꞒ Ꞓ O S D C P T J K Pg NSpotted gar Lepisosteus oculatusBowfin Amia calvaScientific classificationKingdom AnimaliaPhylum ChordataClass ActinopterygiiSubclass NeopterygiiInfraclass HolosteiMuller 1846Clades with orders Halecomorphi Amiiformes Ionoscopiformes Parasemionotiformes Panxianichthyiformes Ginglymodi Kyphosichthyiformes Lepisosteiformes SemionotiformesFish portalHolostei was thought to be regarded as paraphyletic However a recent study provided evidence that the Holostei are the closest living relates of the Teleostei both within the Neopterygii This was found from the morphology of the Holostei for example presence of a paired vomer 3 Holosteans are closer to teleosts than are the chondrosteans the other group intermediate between teleosts and cartilaginous fish which are regarded as at the nearest a a sister group to the Neopterigii The spiracles of holosteans are reduced to vestigial remnants and the bones are lightly ossified The thick ganoid scales of the gars are more primitive than those of the bowfin Contents 1 Characteristics 2 Systematics of Neopterygii 2 1 Halecostomi hypothesis 2 2 Holostei hypothesis 3 Phylogeny of bony fishes 4 Notes 5 References 6 External linksCharacteristics EditHolosteans share with other non teleost ray finned fish a mixture of characteristics of teleosts and sharks In comparison with the other group of non teleost ray finned fish the chondrosteans the holosteans are closer to the teleosts and further from sharks the pair of spiracles found in sharks and chondrosteans is reduced in holosteans to a remnant structure in gars the spiracles do not even open to the outside 4 the skeleton is lightly ossified a thin layer of bone covers a mostly cartilaginous skeleton in the bowfins In gars the tail is still heterocercal but less so than in the chondrosteans Bowfins have many rayed dorsal fins and can breathe air like the bichirs The gars have thick ganoid scales typical of sturgeons whereas the bowfin has thin bony scales like the teleosts The gars are therefore in this regard considered more primitive than the bowfin 5 The name Holostei derives from the Greek words holos meaning whole and osteon meaning bone a reference to their bony skeletons Systematics of Neopterygii EditThe evolutionary relationships of gars bowfin and teleosts were a matter of debate There are two competing hypotheses on the systematics of neopterygians Halecostomi hypothesis Edit The Halecostomi hypothesis proposes Halecomorphi bowfin and its fossil relatives as the sister group of Teleostei the major group of living neopterygians rendering the Holostei paraphyletic 6 Neopterygii Ginglymodi Halecostomi Halecomorphi Teleostei Holostei hypothesis Edit The Holostei hypothesis is better supported 7 8 9 10 than the Halecostomi hypothesis rendering the latter paraphyletic It proposes Halecomorphi as the sister group of Ginglymodi the group which includes living gars Lepisosteiformes and their fossil relatives 11 12 1 Ginglymodi and Halecomorphi form the clade Holostei which is the sister group to Teleostei Neopterygii Holostei Ginglymodi Halecomorphi Teleostei Ginglymodi comprises three orders Lepisosteiformes Semionotiformes and Kyphosichthyiformes Lepisosteiformes includes 1 family 2 genera and 7 species that are commonly referred to as gars Semionotiformes and Kyphosichthyiformes are extinct orders Halecomorphi contains the orders Parasemionotiformes Panxianichthyiformes Ionoscopiformes and Amiiformes In addition to many extinct species Amiiformes includes only 1 extant species that is commonly referred to as the bowfin Parasemionotiformes Panxianichthyiformes and Ionoscopiformes have no living members Gars and bowfins are found in North America and in freshwater ecosystems The differences in each can be spotted very easily from just looking at the fishes The gars have elongated jaws with fanlike teeth only 3 branchiostegal rays and a small dorsal fin Meanwhile the bowfins have a terminal mouth 10 13 flattened branchiostegal rays and a long dorsal fin Phylogeny of bony fishes Edit Cipactlichthys scutatus holotype fossil from the Lower Cretaceous Tlayua Formation of Mexico 13 The cladogram shows the relationships of holosteans to other living groups of bony fish the great majority of which are teleosts 14 and to the terrestrial vertebrates tetrapods that evolved from a related group of lobe finned fish 15 16 Approximate dates are from Near et al 2012 14 Osteichthyes Actinopterygii 400 mya part of Chondrostei b Polypteridae bichirs part of Chondrostei Acipenseriformes sturgeons paddlefish Neopterygii 360 mya Holostei bowfins gars 275 mya Teleostei 310 mya Sarcopterygii Actinistia Coelacanths Dipnoi Lungfish Tetrapods Amphibians Amniota Mammals Sauropsids reptiles birds Notes Edit Depending who you ask the Chondrostei may be paraphyletic or the Polypteridae may be considered not part of them Thus the former Chondrostei is not a clade but is broken up See Actinopteri for a possible reclassification References Edit a b Lopez Arbarello Adriana Sferco Emilia March 2018 Neopterygian phylogeny the merger assay Royal Society Open Science 5 3 172337 Bibcode 2018RSOS 572337L doi 10 1098 rsos 172337 PMC 5882744 PMID 29657820 Romano Carlo 2021 A Hiatus Obscures the Early Evolution of Modern Lineages of Bony Fishes Frontiers in Earth Science 8 672 doi 10 3389 feart 2020 618853 ISSN 2296 6463 Hastings Walker Jr Galland 2014 FISHES A GUIDE TO THEIR DIVERSITY Oakland California University of California Press pp 60 62 a href Template Cite book html title Template Cite book cite book a CS1 maint multiple names authors list link Ontario Game and fish commission Rick Leah Holostei University of Liverpool http www liv ac uk Patterson C Interrelationships of holosteans In Greenwood P H Miles R S Patterson C eds Interrelationships of Fishes Zool J Linn Soc 1973 53 Suppl 233 305 Betancur R 2016 Phylogenetic Classification of Bony Fishes Version 4 Nelson Joseph S 2016 Fishes of the World John Wiley amp Sons Inc ISBN 978 1 118 34233 6 Actinopterygii Integrated Taxonomic Information System Retrieved 3 April 2006 R Froese and D Pauly ed February 2006 FishBase Olsen P E 1984 The skull and pectoral girdle of the parasemionotid fish Watsonulus eugnathoides from the Early Triassic Sakemena Group of Madagascar with comments on the relationships of the holostean fishes J Vertebr Paleontol 4 3 481 499 doi 10 1080 02724634 1984 10012024 Grande Lance Bemis William E 1998 A Comprehensive Phylogenetic Study of Amiid Fishes Amiidae Based on Comparative Skeletal Anatomy an Empirical Search for Interconnected Patterns of Natural History Journal of Vertebrate Paleontology 18 sup001 1 696 doi 10 1080 02724634 1998 10011114 Brito Paulo M Alvarado Ortega Jesus 2013 Cipactlichthys scutatus gen nov sp nov a New Halecomorph Neopterygii Holostei from the Lower Cretaceous Tlayua Formation of Mexico PLOS ONE 8 9 e73551 Bibcode 2013PLoSO 873551B doi 10 1371 journal pone 0073551 PMC 3762789 PMID 24023885 a b 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 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 hdl 2027 42 150563 PMC 3644299 PMID 23653398 Archived from the original on 2013 10 13 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 External links EditHolostei on The University of Liverpool website Retrieved from https en wikipedia org w index php title Holostei amp oldid 1127563203, wikipedia, wiki, book, books, library,
