Onykia robsoni
Michael Vecchione, Richard E. Young, and Kotaro Tsuchiya
Introduction
Adults of O. robsoni reach a length of 470 mm ML. This species apparently has the broadest distribution of any member of the genus.
Diagnosis
An Onykia ...
- with sagittate fins (fins drawn-out posteriorly).
- with warts rather than ridges on skin.
Characteristics
- Tentacles
- Club with 13-16 pairs of hooks.
Scanning electron micrographs of the hooks can be found here.
- Club with 13-16 pairs of hooks.
- Mantle
- Covered with fleshy, irregular warts. Click on an image to view larger version & data in a new window
Figure. Dorsal view of mantle warts of O. robsoni, holotype. Photograph from Adam, 1962.
- Covered with fleshy, irregular warts.
- Fins
- Sagittate shape.
- Length 53-62% of ML at 156-370 mm ML.
- Width 51-70% of ML at 156-370 mm ML.
- Gladius
- Rostrum ventral length 23-36% of GL; triangular in cross-section.
Comments
The above data is from Kubodera et al., 1998. This species is very similar to O. robusta in the shape of the fins but is separated by the structure of the skin (i.e., warts vs ridges), and the fewer pairs of club hooks (13-16 vs 16-18).
Nomenclature
Onykia aequatorialis (Thiele, 1920) was described from the equatorial Atlantic at 18°07'W. Kubodera, et al., 1998, examined a spent female of O. robsoni from Bermuda that was very similar to O. aequatorialis which caused them to question the validity of the latter. Since the holotype has been lost and there are no distinguishing features in the type description, they designated O. aequatorialis a nomen dubium.
Distribution
The type locality is off Angola at 16° 36'S, 11°20'E. This species occurs north of the southern subtropical convergence, off southwestern Australia, New Zealand and southern Africa and it is indistinguishable from specimens taken from the Gulf of Mexico and off Bermuda in the North Atlantic (Kubodera, et al., 1998). It is also reported off the southwestern coast of South America.
References
Adam, W. 1962. Cephalopodes de l’Archipel du Cap-Vert, de l’Angola et du Mozambique. Memorias da Junta de Investigacoes do Ultramar, series 2, 33: 9-64.
T. Kubodera, U. Piatkowski, T. Okutani and M.R. Clarke. 1998. Taxonomy and Zoogeography of the Family Onychoteuthidae (Cephalopoda: Oegopsida). Smithsonian Contributions to Zoology, No. 586: 277-291.
Title Illustrations
| Scientific Name | Onykia robsoni |
|---|---|
| Reference | Adam, W. 1962. Cephalopodes de l?Archipel du Cap-Vert, de l?Angola et du Mozambique. Memorias da Junta de Investigacoes do Ultramar, series 2, 33: 9-64. |
| View | Dorsal |
| Type | Holotype |
| Scientific Name | Onykia robsoni |
|---|---|
| Reference | Kubodera, T., U. Piatkowski, T. Okutani and M.R. Clarke. 1998. Taxonomy and Zoogeography of the Family Onychoteuthidae (Cephalopoda: Oegopsida). Smithsonian Contributions to Zoology, No. 586: 277-291. |
| View | Dorsal |
About This Page
National Museum of Natural History, Washington, D. C. , USA
Richard E. Young
University of Hawaii, Honolulu, HI, USA
Tokyo University of Fisheries, Tokyo, Japan
Page copyright © 2003 , Richard E. Young, and
Page: Tree of Life
Onykia robsoni .
Authored by
Michael Vecchione, Richard E. Young, and Kotaro Tsuchiya.
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- First online 23 June 2003
Citing this page:
Vecchione, Michael, Richard E. Young, and Kotaro Tsuchiya. 2003. Onykia robsoni . Version 23 June 2003 (under construction). http://tolweb.org/Onykia_robsoni/19975/2003.06.23 in The Tree of Life Web Project, http://tolweb.org/
