font settings

Font Size: Large | Normal | Small
Font Face: Verdana | Geneva | Georgia

Gasterosteiformes

(Order)

Overview

[ Back to top ]

Gasterosteiformes is an of ray-finned fishes that includes the sticklebacks and relatives.

In the Gasterosteiformes, the pelvic girdle is never attached to the cleithra directly, and the supramaxillary, orbitosphenoid, and basisphenoid bones are absent. The body is often partly or completely covered with dermal plates.

The name "Gasterosteiformes" means "bone-bellies". It is derived from Ancient Greek gaster (?ast??; "stomach", "abdomen") + ostoun (?st???; "bone"). The ending for fish orders "-formes" is derived from Latin and indicates "of similar form".

Systematics

Often Gasterosteiformes includes the sea horses, pipefishes and their relatives as suborder Syngnathoidei, with the sticklebacks and relatives in the suborder Gasterosteoidei[1]. In many more recent treatments the traditional placement[2] as different orders, with the former becoming Syngnathiformes, is used[3]. There is a growing body of evidence that this is correct; in fact, the two groups do not seem to be particularly close relatives among the Acanthopterygii.

As it seems, the loosely delimited Gasterosteiformes are paraphyletic with the Scorpaeniformes. The more typical members of that group (e.g. scorpionfishes) are apparently closer to the "true" Gasterosteiformes, whereas the keel-bodied flying gurnards (Dactylopteridae) seem actually to belong to the Syngnathiformes clade. It seems that the closest living relatives of the narrowly-delimited Gasterosteiformes are the gunnels (Pholidae) and eelpouts (Zoarcidae), traditionally placed in the massively paraphyletic "Perciformes". These two families, as well as the related Trichodontidae, would then appear to be derived offshoots of the scorpaeniform-gasterosteiform radiation which have apomorphically lost the bone "armour" found in their relatives[4].

Three families certainly belong to the Gasterosteiformes sensu stricto:

The armoured stickleback (Indostomidae) and the Pegasidae (dragonfishes and sea moths) are variously placed with the pipefish or the stickleback lineage. While the Pegasidae are almost certainly Syngnathiformes, the placement of the monotypic former family is essentially unresolved, as it has always been. At least provisionally it is better treated as an acathopterygian order of its own.[4]

Photos

[ Back to top ]

Taxonomy

[ Back to top ]

The Order Gasterosteiformes is further organized into finer groupings including:

Families

[ Back to top ]

Aulorhynchidae

[more]

Gasterosteidae

The Gasterosteidae are a of fish including the sticklebacks. FishBase currently recognises sixteen species in the family, grouped in five genera. However several of the species have a number of recognised subspecies, and the taxonomy of the family is thought to be in need of revision. Although some authorities give the common name of the family as "sticklebacks and tube-snouts", the tube-snouts are currently classified in the related family Aulorhynchidae. [more]

Hypoptychidae

[more]

Indostomidae

Indostomus is sole genus in the family of fishes Indostomidae and contains only three species. The indostomids are small, in the stickleback order Gasterosteiformes, and are closely related to seahorses and pipefishes. [more]

Macroramphosidae

[more]

Macrorhamphosidae

[more]

Pegasidae

The seamoths are a family, the Pegasidae, of fish found in coastal tropical waters. [more]

At least 15 species and subspecies belong to the Family Pegasidae.

More info about the Family Pegasidae may be found here.

References

[ Back to top ]

Footnotes

[ Back to top ]
  1. ^ E.g. ITIS (2004), Nelson (2006)
  2. ^ E.g. McAllister (1968)
  3. ^ E.g. FishBase (2005a,b)
  4. ^ a b Kawahara (2008)

Sources

[ Back to top ]
Last Revised: September 22, 2009
2009/09/22 07:53:19