Neopterygii Explained

Neopterygii (from Greek νέος neos 'new' and πτέρυξ pteryx 'fin') is a subclass of ray-finned fish (Actinopterygii). Neopterygii includes the Holostei and the Teleostei, of which the latter comprise the vast majority of extant fishes, and over half of all living vertebrate species.[1] While living holosteans include only freshwater taxa, teleosts are diverse in both freshwater and marine environments. Many new species of teleosts are scientifically described each year.[1]

The potentially oldest known neopterygian is the putative "semionotiform" Acentrophorus varians from the Middle Permian of Russia;[2] [3] however, one study incorporating morphological data from fossils and molecular data from nuclear and mitochondrial DNA, places this divergence date at least 284 mya (million years ago), during the Artinskian stage of the Early Permian.[4] Another study suggests an even earlier split (360 myr ago, near the Devonian-Carboniferous boundary).[5]

Evolution and diversity

Living neopterygians are subdivided into two main groups (infraclasses): teleosts and holosteans.[6] Holosteans comprise two clades, the Ginglymodi and the Halecomorphi.[7] [1] [8] All of these groups have a long and extensive fossil record.[9] The evolutionary relationships between the different groups of Neopterygii is summarized in the cladogram below (divergence time for each clade in mya are based on[10]).

Neopterygians are a very speciose group. They make up over 50% of the total vertebrate diversity today, and their diversity grew since the Mesozoic era.[9] [11] However, the diversity of the various groups of neopterygians (or of fishes in general) is unevenly distributed, with teleosts making up the vast majority (96%) of living species.[1]

Early in their evolution, neopterygians 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.[1] While electroreception and the ampullae of Lorenzini are present in all other extant groups of fish (except for hagfish), neopterygians have lost this sense, even if it has later re-evolved within Gymnotiformes and catfishes, which possess non-homologous teleost ampullae.[12]

Only a few changes occurred during the evolution of neopterygians from the earlier actinopterygians. However, a very important step in the evolution of neopterygians is the acquisition of a better control of the movements of both dorsal and anal fins, resulting in an improvement in their swimming capabilities. They additionally acquired several modifications in the skull, which allowed the evolution of different feeding mechanisms and consequently the colonization of new ecological niches. All of these characters represented major improvements, resulting in Neopterygii becoming the dominant group of fishes (and, thus, taxonomically of vertebrates in general) today.[9]

The great diversity of extant teleosts has been linked to a whole genome duplication event during their evolution.[13]

Classification

Notes and References

  1. Book: Nelson, Joseph, S.. Fishes of the World. 2016. John Wiley & Sons, Inc. 978-1-118-34233-6 .
  2. Broughton . Richard E. . Betancur-R. . Ricardo . Li . Chenhong . Arratia . Gloria . Ortí . Guillermo . 2013-04-16 . Multi-locus phylogenetic analysis reveals the pattern and tempo of bony fish evolution . PLOS Currents . 5 . ecurrents.tol.2ca8041495ffafd0c92756e75247483e . 10.1371/currents.tol.2ca8041495ffafd0c92756e75247483e . 2024-02-27 . free . 2157-3999 . 3682800 . 23788273.
  3. Web site: PBDB . 2024-02-26 . paleobiodb.org.
  4. Hurley . Imogen A. . Mueller . Rachael Lockridge . Dunn . Katherine A. . 21 November 2006 . 10.1098/rspb.2006.3749 . A new time-scale for ray-finned fish evolution . 274 . 1609 . Proceedings of the Royal Society B. 489–498 . 17476768 . 1766393 .
  5. Thomas J. Near . etal . 2012 . Resolution of ray-finned fish phylogeny and timing of diversification . PNAS . 109 . 34 . 13698–13703 . 2012PNAS..10913698N . 10.1073/pnas.1206625109 . 3427055 . 22869754 . free.
  6. López-Arbarello . A . 2012 . Phylogenetic Interrelationships of Ginglymodian Fishes (Actinopterygii: Neopterygii) . PLOS ONE . 7 . 7. e39370 . 10.1371/journal.pone.0039370 . 22808031 . 3394768 . 2012PLoSO...739370L . free .
  7. Web site: Betancur-R . Phylogenetic Classification of Bony Fishes Version 4 . 2016.
  8. Web site: R. Froese and D. Pauly. FishBase . February 2006.
  9. Friedman . Matt . Sallan . Lauren Cole . Five hundred million years of extinczion and recovery: A Phanerozoic survey of large-scale diversity patterns in fishes . Palaeontology . June 2012 . 55 . 4 . 707–742 . 10.1111/j.1475-4983.2012.01165.x. 2012Palgy..55..707F . 59423401 . free .
  10. Resolution of ray-finned fish phylogeny and timing of diversification . Thomas J. Near . PNAS . 10.1073/pnas.1206625109 . 2012 . 109 . 34 . 13698–13703. etal . 22869754 . 3427055. 2012PNAS..10913698N . free .
  11. Romano . Carlo . Koot . Martha B. . Kogan . Ilja . Brayard . Arnaud . Minikh . Alla V. . Brinkmann . Winand . Bucher . Hugo . Kriwet . Jürgen . Permian-Triassic Osteichthyes (bony fishes): diversity dynamics and body size evolution . Biological Reviews . February 2016 . 91 . 1 . 106–147 . 10.1111/brv.12161 . 25431138 . 5332637 .
  12. https://books.google.com/books?id=d1-rak1asv0C&dq=Electroreception+Neopterygii&pg=PA229 Electroreception By Theodore Holmes Bullock
  13. Pasquier . Jeremy . Braasch . Ingo . Batzel . Peter . Cabau . Cedric . Montfort . Jérome . Nguyen . Thaovi . Jouanno . Elodie . Berthelot . Camille . Klopp . Christophe . Journot . Laurent . Postlethwai . John H. . Guigue . Yann . Bob . Julien . Evolution of gene expression after whole-genome duplication: new insights from the spotted gar genome . J Exp Zool (Mol Dev Evol) . 2017 . 328 . 7 . 709–721 . 10.1002/jez.b.22770. 28944589 . 5679426 . 2017JEZB..328..709P .
  14. Xu. Guang-Hui. 2021-01-09. A new stem-neopterygian fish from the Middle Triassic (Anisian) of Yunnan, China, with a reassessment of the relationships of early neopterygian clades. Zoological Journal of the Linnean Society. en. 191. 2. 375–394. 10.1093/zoolinnean/zlaa053. 0024-4082. free.
  15. In ITIS, Gobiesociformes is placed as the suborder Gobiesocoidei of the order Perciformes.
  16. In ITIS, Syngnathiformes is placed as the suborder Syngnathoidei of the order Gasterosteiformes.

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