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Gonatopsis Sasaki, 1920

Tsunemi Kubodera, F. G. Hochberg, Richard E. Young, and Michael Vecchione
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taxon links [up-->]Gonatopsis japonicus [up-->]Gonatopsis makko [up-->]Gonatopsis borealis [up-->]Gonatopsis octopedatus [down<--]Gonatidae Interpreting the tree
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Containing group: Gonatidae

Introduction

Diagnosis

A gonatid ...

Characteristics

  1. Arms
    1. Hooks in medial two armature series on arms I-III.

  2. Tentacles
    1. Tentacles absent beyond early juvenile stages.
      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. Oral view of the brachial crown of Gonatopsis borealis, 65 mm ML, off Aleutian Islands, preserved. White numerals identify the arms. Note that there is no trace of tentacles between arms III and IV. Photograph by R. Young.

  3. Head
    1. Radula with teeth in 5 or 7 series depending on species.

  4. Mantle
    1. Mantle tissue muscular or flabby depending on species.

  5. Fins
    1. Fins rhomboid or sagittate in shape depending on species.

  6. Photophores
    1. Photophores absent.

Comments

Gonatopsis is divided into two subgenera on the basis of the radular structure. G. (Gonatopsis) with a five-tooth radula and G. (Boreoteuthis) with a seven-tooth radula.

Species / Character  Habitat  Numerous sucker series at arm tips  Radular teeth  Arm length  Tail length 
G. borealis
 North Pacific   No  7 40-50% ML  No tail 
G. japonicus  Japanese waters   No  5 55% ML  long 
G. makko  Northern-, western North Pacific   No  5 65% ML  very short 
G. octopedatus  Western North Pacific, ? Gulf of California
  Yes  5 80-85% ML  No tail 
G. okutanii ? * Western North Pacific   No  5 ca. 100 % ML   ?
*Does not belong in Gonatopsis; tentacles apparently absent only in spent females. Correct genus uncertain.

Life History

Tentacles are present in paralarvae but are lost at different early stages depending on the species (Nesis, 1973).

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. Ventral view of a paralarva of G. borealis (bottom), 9 mm ML and an oral view of the paralarval tentacular club (top), 7 mm ML, off Southern California, U.S.A. Drawings from Young (1972).

References

Young, R.E. 1972. The Systematics and Areal Distribution of Pelagic Cephalopods from the Seas off Southern California. Smithsonian Contributions to Zoology, 97:159 pages.

Title Illustrations
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Scientific Name Gonatopsis borealis
Location Eastern North Pacific off Monterey, California at 37.7°N, 122.0°W
Comments In situ photograph of Gonatopsis borealis taken at a depth of 306 m (daytime).
Acknowledgements Image courtesy of the Monterey Bay Aquarium Research Institute (MBARI). You must obtain permission from MBARI to use this photo; please contact pressroom@mbari.org for further information.
Specimen Condition Live Specimen
Identified By R. E. Young
View Side
Size Unknown
Copyright © 2012 MBARI
About This Page


National Science Museum, Tokyo, Japan

F. G. Hochberg
Santa Barbara Museum of Natural History, Santa Barbara, California, USA


University of Hawaii, Honolulu, HI, USA


National Museum of Natural History, Washington, D. C. , USA

Page: Tree of Life Gonatopsis Sasaki, 1920. Authored by Tsunemi Kubodera, F. G. Hochberg, Richard E. Young, and Michael Vecchione. 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:

Kubodera, Tsunemi, F. G. Hochberg, Richard E. Young, and Michael Vecchione. 2014. Gonatopsis Sasaki, 1920. Version 06 December 2014 (under construction). http://tolweb.org/Gonatopsis/19764/2014.12.06 in The Tree of Life Web Project, http://tolweb.org/

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