Under Construction

Gonatus Gray, 1849

Tsunemi Kubodera, F. G. Hochberg, Richard E. Young, and Michael Vecchione
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
This genus contains the following 12 species:
taxon links [up-->]Gonatus ursabrunae [up-->]Gonatus middendorffi [up-->]Gonatus antarcticus [up-->]Gonatus fabricii [up-->]Gonatus onyx [up-->]Gonatus berryi [up-->]Gonatus steenstrupi [up-->]Gonatus californiensis [up-->]Gonatus oregonensis [up-->]Gonatus madokai [up-->]Gonatus pyros [down<--]Gonatidae Interpreting the tree
close box

This tree diagram shows the relationships between several groups of organisms.

The root of the current tree connects the organisms featured in this tree to their containing group and the rest of the Tree of Life. The basal branching point in the tree represents the ancestor of the other groups in the tree. This ancestor diversified over time into several descendent subgroups, which are represented as internal nodes and terminal taxa to the right.

example of a tree diagram

You can click on the root to travel down the Tree of Life all the way to the root of all Life, and you can click on the names of descendent subgroups to travel up the Tree of Life all the way to individual species.

For more information on ToL tree formatting, please see Interpreting the Tree or Classification. To learn more about phylogenetic trees, please visit our Phylogenetic Biology pages.

close box
Containing group: Gonatidae

Introduction

Gonatus, the most speciose genus in the family, has its highest diversity in the high North Pacific. These squids reach a maximum length of 39 cm ML.

Brief diagnosis:

A gonatid ...

Characteristics

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

  2. Tentacles
    1. Tentacles present in subadults.
    2. Tentacular club with one or more hooks in median line; one greatly enlarged.
    3. Proximal locking-apparatus of club with suckers and knobs medial to 4-6 large ridges and grooves, and usually several smaller ones.
      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 tentacular club of G. californiensis, 315 mm GL, immature female, preserved. Photograph of preserved club by R. Young.

  3. Head
    1. Radula with 5 teeth in transverse row.

  4. Mantle
    1. Posterior tip of mantle muscle separable from fins (not confirmed in most species). The tip of the tail (see arrow below) in Gonatus spp. is loosely attached to the mantle. The photograph below shows the fins apparently separating from the mantle tip. Although not visible in the photograph, transparent integument does extend between the tip of the mantle and the fins. The tip of the fins can also curve ventrally beneath the mantle tip. Presumably this unusual flexibility of the tip of the muscular mantle and fins increases manuverability.
      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. Ventrolateral view of Gonatus sp. Insitu ROV photograph at 701 m depth. Photograph © 2011 MBARI.

  5. Fins
    1. Fins sagittate, drawn out posteriorly into a short tail.

  6. Photophores
    1. Ocular photophores present only in G. pyros.

Comments

Many of the species characteristics are found on the tentacles. The tentacles are complex and for descriptive purposes the club and stalk are divided into various zones, regions and series as follows:

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 club and distal stalk of G. californiensis showing the terminology (much of it color coded) used in describing the tentacle. Drawing modified from Young (1972).

The following table compares some characteristics of subadult species of Gonatus. The most useful character states are indicated in bold-red. The table doesn't separate all species.

Species / Character  Habitat  Ocular light organs  Proximal club hooks  Distal club hook  Medial suckers of tentacular stalk  Suckers on club  Club suckers of dorsal- and ventral marginal zones merge proximally. Arm II< III length  Club length 
G. antarcticus Antarctic waters  No  Yes Yes
 120-140 250-315   No 40-50% ML
16-17%  ML
G. berryi  North Pacific   No  Yes  Yes  0-2 159-181   No 60-70% GL  30-37% GL
G. californiensis  North Pacific
 No  Yes  Yes  40-80 215-270   No 46-53% GL  17-24% GL 
G. fabricii  North Atlantic   No  Yes  Yes  38-109 155-229  No 53-59% GL  12-20% GL 
G. madokai  North Pacific
 No  Yes  Yes  Many  ?  Yes 90% ML  20% ML 
G. middendorffi  North Pacific
 No  No  Yes  Few  ?  No 50% ML
10% ML 
G. onyx  North Pacific
 No  No  No  0-27  160-200   No 48-54% GL
20-25% GL 
G. oregonensis  North Pacific
 No  Yes  Yes  70 295-370   No 59-63% ML
21-30% ML 
G. pyros  North Pacific
 Yes  Yes  Yes  50-125 151-184   No 60-70% GL  20-25% GL 
G. steenstrupi  North Atlantic
 No  Yes  Yes  75-165 190-225   No 50-70% GL
20-36% GL 
G. ursabrunae North Pacific
 No  ?  ?  ?  ?  ? 42-56% ML  13-25% ML 

 *Known only from juveniles but with distinctive relative sucker sizes on arms and club dactylus.

Behavior

Some, at least, Gonatus spp. exhibit a "Parachutte posture" (see photographs below) similar to that seen is some other MBARI photographs of oceanic squids, which presumably reduces the sinking rate. In the upper left photograph, the squid is just entering into the posture. In the upper right photograph, the squid is in the posture and the squid is motionless with arms, tentacles and fins spread wide and the squid horizontally oriented. In the bottom photograph, the squid is just coming out of the posture. The squid held the posture for about 20 seconds. Presumably it would hold the it longer if not disturbed by the ROV.
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. Anterior and anterolateral views of Gonatus sp. (possibly G. onyx) in the parachute posture. The photographs were taken in situ from an MBARI ROV at a depth of 578 m (daytime) in Monterey Bay, © 2013 MBARI.

Gonatus spp. often swim with their tentacle clubs locked together. The clubs are often locked both at the base of the clubs (carpal locking apparatuses) and at the tips of the club (presumably the circle of suckers that form the terminal pad). At the carpal locking apparatus we assume that the suckers involved of one club grasp the corresponding knobs of the other club. The terminal pad, however, has suckers but no knobs. The following photographs suggest how the latter lock is formed.

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. Two views of the clubs of the same Gonatus sp. locked together. Left - The carpal areas are clearly solidly locked together (upper arrow) while at the club tips one terminal pad seems to attach to the outer surface of the other (bottom arrow). Right - The tips of the clubs seem to be slightly offset suggesting the inner surface of one tip overlaps the outer surface of the other. Photographs © 2013 MBARI.

Life History


Brooding of egg masses in G. onyx (Seibel et al., 2000) [suspected in G. fabricii (Bjorke et al., 1997), and documented in G. madokai (Bower et al., 2012)] occurs in deep water. Such brooding behavior, rare in oceanic squids, may prove to be characteristic of all members of the genus and perhaps the entire family. The long brooding period demanded by cold temperatures in deep water and its resulting slow population turnover rate, presumably is offset, in evolutionary time, by low egg mortality in the vast, dark, lowly populated bathypelagic environment (see Seibel, et al., 2000). For more information on brooding behavior, go to the G. onyx page.

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 Gonatus onyx brooding an egg mass at 2522 m depth off California in Monterey Canyon. ROV photograph from Seibel et al. (2005). © 2002 MBARI

References

Bower, J. R., K. Seki, T. Kubodera, J. Yamamoto and T. Nobetsu. 2012. Brooding in a gonatid squid off northern Japan. Biol. Bull. 223: 259-262.

Nesis, K. N. (1982). Abridged dey to the cephalopod mollusks of the world's ocean. 385+ii pp. Light and Food Industry Publishing House, Moscow. (In Russian.). Translated into English by B. S. Levitov, ed. by L. A. Burgess (1987), Cephalopods of the world. T. F. H. Publications, Neptune City, NJ, 351pp.

Okutani, T. and M. R. Clarke (1992). Family Gonatidae Hoyle, 1886. P. 139-156. In: Sweeney, M. J., C. F. E. Roper, K. M. Mangold, M. R. Clarke and S. V. Boletzky (eds.). "Larval" and juvenile cephalopods: a manual for their identification. Smiths. Contr. Zool., No. 513.

Seibel, B. A., F. G. Hochberg, and D. B. Carlini. 2000. Life history of Gonatus onyx (Cephalopoda: Teuthoidea): deep-sea spawning and post-spawning egg care. Marine Biology 137 (3): 519-526.

Seibel, B. A., B. H. Robison and S. H. D. Haddock. 2005. Post-spawning egg care by a squid. Nature 438: 929.

Title Illustrations
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
Scientific Name Gonatus sp.
Location Eastern North Pacific off Monterey, California at 36.7N, 122.05W
Comments In situ photograph of Gonatus sp. taken at a depth of 789 m.
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 Posteriolateral
Size Unknown
Copyright © 3013 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 Gonatus Gray, 1849. 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. 2013. Gonatus Gray, 1849. Version 08 January 2013 (under construction). http://tolweb.org/Gonatus/19767/2013.01.08 in The Tree of Life Web Project, http://tolweb.org/

edit this page
close box

This page is a Tree of Life Branch Page.

Each ToL branch page provides a synopsis of the characteristics of a group of organisms representing a branch of the Tree of Life. The major distinction between a branch and a leaf of the Tree of Life is that each branch can be further subdivided into descendent branches, that is, subgroups representing distinct genetic lineages.

For a more detailed explanation of the different ToL page types, have a look at the Structure of the Tree of Life page.

close box

Gonatus

Page Content

articles & notes

collections

people

Explore Other Groups

random page

  go to the Tree of Life home page
top