Under Construction

Onykia sp. A

Richard E. Young
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Containing group: Onykia

Introduction

Wakabayashi et al. (2007) found a paralarval Onykia near Hawaii (28°30'N 155°W at a surface temperature of 23.3°C) that could not be assigned to any know species of the genus from the North Pacific based on molecular analysis of the COI gene. Therefore, we suspect that Onykia sp. A, found commonly in waters around the main Hawaiian Islands but known primarily from paralarvae, is a new species. A nearly mature female taken from the stomach of a sword fish with a small size further supports this possibility.

Brief diagnosis:

An Onykia with ...

Characteristics

The following information is from the nearly mature female (272 mm ML, see title photograph) taken, partly digested, from the stomach of a swordfish.
  1. Arms
    1. Arm tips very attenuate.
  2. Tentacles
    1. Right club with about 25-26 hooks, left club with about 22 hooks.
  3. Head
    1. Beaks: Descriptions can be found here: Lower beak; upper beak.
    2. Funnel groove with inverse Y-shaped ridge.
  4. Mantle
    1. Mantle appears to have been covered with round/irregular warts.
  5. Fins
    1. Fins sagittate; extend to posterior tip of tail.
  6. Viscera
    1. Gladius rostrum of 272 mm ML female: 45 mm long, measured from ventral edge of conus.
    2. Irregular shape in cross-section.
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      Click on an image to view larger version & data in a new window

      Figure. Onykia sp. A, distal part of rostrum. Left - Side view. Right - Cross section. Photographs by R. Young.

    3. Nidamental and oviducal glands well developed.

  7. Measurements:
    Female
    mm
    Mantle length
    272 
    Head width
    34 
    Funnel lock, lenght
    25
    Mantle lock, length
    45
    Arm I, length
    152
    Arm II, length
    170
    Arm III, length
    178
    Arm IV, length
    188
    Tentacle length
    400
    Club length
    68
    Fin length*
    145 
    Fin width
    150
    *Measured to tip of tail.

Comments

Onykia sp. A is similar to the the warm water O. robsoni/O.carriboea but cannot be clearly separated from them at present.

Life History

The paralarvae of Onykia sp. A  (Figs. A-C below) are easily distinguished from other squid paralarvae in Hawaiian waters: They are broad and have a characteristic line of large dorsal mantle chromatophores whose widths generally increase posteriorly. Small paralarvae often are observed in preserved samples with the head mostly withdrawn into the mantle cavity as shown in Fig. A.
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Figure. Ventral and dorsal views of paralarvae and an early juvenile of Onykia sp. A - 1.7 mm ML paralarva. B - 2.7 mm ML paralarva. C - 3.4 mm ML paralarva. D - 5.6 mm ML juvenile. A-C show paralarvae with contracted anterior mantle margins which are commonly observed in preserved paralarvae. These growth stages were taken from plankton tows in Hawaiian waters.  The scale bar is 1 mm. Drawings by R. Young.

Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window

Figure. Side view of a juvenile (about 1 cm ML) of Onykia sp. A in a shipboard aquarium. Photograph by R. Young.

Distribution

Onykia sp. A is known only from the tropical/subtropical central North Pacific.

References

Wakabayashi, T., T. Kubodera, M. Sakai, T. Ichii, and S. Chow. 2007. Molecular evidence for synonymy of the genera Moroteuthis and Onykia and identification of their paralarvae from northern Hawaiian waters. Journal of the Marine Biological Association of the UK, 87: 959-965.

Title Illustrations
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Scientific Name Onykia sp. A
Comments Squid taken from the stomach of a swordfish
Sex Female
Life Cycle Stage Nearly mature
View Side
Size 272 mm ML
Collector Anela Choy
Image Use creative commons This media file is licensed under the Creative Commons Attribution License - Version 3.0.
Copyright ©
About This Page


University of Hawaii, Honolulu, HI, USA

Correspondence regarding this page should be directed to Richard E. Young at

Page: Tree of Life Onykia sp. A. Authored by Richard E. Young. The TEXT of this page is licensed under the Creative Commons Attribution-NonCommercial License - Version 3.0. Note that images and other media featured on this page are each governed by their own license, and they may or may not be available for reuse. Click on an image or a media link to access the media data window, which provides the relevant licensing information. For the general terms and conditions of ToL material reuse and redistribution, please see the Tree of Life Copyright Policies.

Citing this page:

Young, Richard E. 2011. Onykia sp. A. Version 08 March 2011 (under construction). http://tolweb.org/Onykia_sp._A/137607/2011.03.08 in The Tree of Life Web Project, http://tolweb.org/

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