Gonatidae

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Gonatidae
Temporal range: Pliocene - recent[1]
Berryteuthis magister
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Oegopsida
Family: Gonatidae
Hoyle, 1886[2]
Type genus
Gonatus
Gray, 1849
Genera

Berryteuthis
Gonatopsis
Gonatus

The Gonatidae, also known as armhook squid, are a

allozymes and mitochondrial DNA have indicated that this species nests within the genus Gonatus,[3] although other authorities treat it as a synonym of Gonatopsis okutanii.[4]

Description

Oral view of Berryteuthis magister, showing the arrangement of suckers

Morphologically, armhook squid are fairly uniform: all species are characterised by the suckers of their

magister armhook squid (Berryteuthis magister), only the females possess hooks. Species of the genus Gonatus
differ from the rest of the family (and from most squid) by their lack of tentacles as adults.

Only one species, the fiery armhook squid (Gonatus pyros), possesses photophores; these are located on the ventral periphery of the eyes.

Gonatids typically have muscular, cylindrical bodies with very soft, reddish to purplish-brown skin. The arms are thick and capable; the fins vary in shape and size, from sagittate and about 50% of the mantle length, to reniform and about 30% of the mantle length. Of moderate size, these squid range in size from 11 to 40 cm—most species are 25 cm or less. Females are somewhat larger than males.

Life history

Gonatus onyx on the Davidson Seamount at a depth of 1,328 m
Gonatus fabricii, the boreoatlantic armhook squid

These squid are pelagic, associated with the continental shelf and may roam as deep as 4,500 m or more, depending on the species. Their habits are poorly studied, but the squid are thought to undertake diel migration; by day, the squid remain in the blackness of the depths in midwater. By night, they ascend to the upper layers of the water column to feed by starlight. One species, however, Gonatopsis octopedatus, has curiously recurved arms, suggesting a benthic existence.

Little is known about the reproductive cycle of armhook squid. Most squid species whose reproduction has been observed have been seen to deposit eggs on the sea floor, then leave the eggs to hatch on their own. Five female Gonatus onyx squids have been observed in Monterey Canyon dragging a membrane sack containing 2,000 to 3,000 developing eggs.[5] It is uncertain if this behavior extends to other members of the family Gonatidae or if it is particular to this species.

Prey items include both

Cannibalism is also known to occur among the Gonatidae.[6]

southern fur seals, as well as several species of albatross and penguin, feed upon Gonatus antarcticus
.

Species

The species listed above with an asterisk (*) is questionable and needs further study to determine if it is a valid species or a synonym.

References

  1. ^ "Statoliths of Cenozoic teuthoid cephalopods from North America | The Palaeontological Association". www.palass.org. Retrieved 2023-10-09.
  2. ^ Julian Finn (2016). "Gonatidae Hoyle, 1886". World Register of Marine Species. Flanders Marine Institute. Retrieved 4 March 2018.
  3. ISBN 978-92-5-106720-8
    .
  4. ^ Kubodera, Tsunemi; F. G. Hochberg; Richard E. Young & Michael Vecchione (2014). "Eogonatus Nesis, 1972". Tree of Life Web Project. Retrieved 4 March 2018.
  5. PMID 16355206
    .
  6. doi:10.1016/j.dsr.2016.08.001
    . Retrieved 2021-03-02.

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Gonatidae&oldid=1188069382"