Holostei

Holostei

taxobox
name = Holostei
fossil_range = Mesozoic–Recent



image_width = 250px
image_caption = Spotted gar, "Lepisosteus oculatus"



image2_width = 250px
image2_caption = Bowfin, "Amia calva"
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
infraclassis = Holostei
subdivision_ranks = Orders
subdivision =
Amiiformes
Lepisosteiformes

Holostei are bony fish that show primitive characteristics. There are eight species divided among two orders, the Amiiformes represented by a single living species, the bowfin ("Amia calva"), and the Lepisosteiformes, the gars. There are more species to be found in the fossil record.

Holostei share with other primitive fishes a mixture of characteristics of teleosts and sharks. In comparison with the other group of primitive fishes, the chondrosteans, the Holostei are closer to the teleosts and further from sharks: the spiracle found in sharks and chondrosteans is reduced to a remnant structure; the skeleton is ossified (a thin layer of bone covers a mostly cartiliginous 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 considered more primitive than the bowfin.cite web | url =http://www.liv.ac.uk/~rickl/Fisheries_Web/ichthyology/holostei.htm| title=Holostei| author=Rick Leah |publisher=University of Liverpool (http://www.liv.ac.uk)|]

The Holostei is often regared as paraphyletic; as a result this infraclass is often not used, the two orders contained in it being often treated simply as members of the sub-class Neopterygii without any taxonomic association.ITIS | ID = 161089 | taxon = Holostei | year = 2006 | date = 30 June] However, recent work mitochondrial analysis of DNA seems to support its recognition, so the question is not yet resolved. Nearly all living bony fishes are teleosts.

The name derives from the Greek, "holos" meaning whole and "osso" (osteo) meaning bone: a reference to their bony skeletons.

References

External links

* [http://www.liv.ac.uk/~rickl/Fisheries_Web/ichthyology/holostei.htm liv.ac.uk/.../holostei]


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Look at other dictionaries:

  • Holostei — Ho*los te*i, n. pl. [NL., fr. Gr. o los whole + ? a bone.] (Zo[ o]l.) An extensive division of ganoids, including the gar pike, bowfin, etc.; the bony ganoids. See Illustration in Appendix. [1913 Webster] …   The Collaborative International Dictionary of English

  • Holostei — ⇒ Actinopterygii …   Deutsch wörterbuch der biologie

  • Holostei — Für die Einteilung der existieren nebeneinander mehrere Vorschläge. Das hier behandelte entspricht nicht der gegenwärtig in der deutschsprachigen Wikipedia verwendeten Systematik. Die Knochenganoiden (Holostei) sind eine heute nicht mehr… …   Deutsch Wikipedia

  • Holostei —   Holostei Lepisosteus oculatus …   Wikipedia Español

  • holostei — ēˌī noun plural Usage: capitalized Etymology: New Latin, from hol + ostei (from Greek osteon bone) more at osseous in many classifications : an order of ganoid fishes having a well developed bony skeleton and approaching teleosts in struct …   Useful english dictionary

  • Holostei — Holọste|i   [zu griechisch ostéon »Knochen«], die Knochenganoiden …   Universal-Lexikon

  • holostei — ho·los·tei …   English syllables

  • Костные ганоиды — (Holostei)         надотряд рыб из группы лучепёрых. Занимают промежуточное положение между хрящевыми ганоидами (См. Хрящевые ганоиды) и костистыми рыбами (См. Костистые рыбы). Череп, челюстной аппарат и жаберный построены по типу костистых, но… …   Большая советская энциклопедия

  • holostean — ▪ fish Introduction       any member of a group of primitive bony fishes (bony fish) that make up one of the three major subdivisions of the superclass Actinopterygii (ray finned fishes). Holosteans are represented today by the bowfins (bowfin)… …   Universalium

  • Лучепёрые рыбы — Рыба белка (Sargocentron spiniferum) …   Википедия

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