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Planctoteuthis Pfeffer, 1912

Richard E. Young, Michael Vecchione, and Clyde F. E. Roper
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This genus contains five known species although P. exopthalmica, may be a junior synonym of P. levimana.
Containing group: Chiroteuthidae

Introduction

Species of Planctoteuthis are usually rather small and very fragile deep-sea squids that are often badly damaged during capture. As a result, few species have been described. Unlike other chiroteuthids, the subadult retains the peculiar doratopsid paralarval tentacular club. Roper and Young (1967) suggest that Planktoteuthis is a neotenic doratopsis.

Diagnosis

A chiroteuthid ...

Characteristics

  1. Arms
    1. Subequal in length in adults; arms IV much the longest in young.
    2. Arms IV with relatively few suckers in the proximal 1/3 of arm or less, remainder of arm without suckers. Suckers usually aligned in virtually single series.

      The reason for the peculiar structure of arms IV is unknown. The following images provides clues to this problem. These photographs show the bases of arms IV, presumably the sucker-bearing region, locked together. The tentacles (arrows in 1st and 3rd photos, in the 2nd photo, the tentacles have curlicue ends) emerge, adjacent to one another, from the joined arms IV . Apparently the proximal, sucker-bearing region of arms IV, and their lateral membranes, form a single tentacular sheath for holding both tentacles. The value of this arrangement and the function of the bare, distal arms IV is unknown. Also, the coiling of the tentacles suggests that they are not strongly retractile.

  2. 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. Planctoteuthis danae, Gulf of California, in situ ROV photographs. Left, middle - Slightly different anterodorsal views of the same squid, 1206 m depth. Right - Side view of a different, probably larger squid, ? depth. This species has 12-13 suckers on the proximal third of arms IV. All three photographs © 2013 MBARI.

  3. Tentacles
    1. Club small, compact.
    2. Club keel absent in some species.
    3. Club without carpal locking apparatus.
    4. Low protective membranes/ridges along both boarders of club.
    5. Not divided into proximal and distal regions by protective membranes.
      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 Planctoteuthis lippula, Hawaiian waters, 35 mm ML. Photograph by R. Young.

  4. Head
    1. Head with elongate neck and brachial pillar.
    2. Eyes commonly project ventrally from head.
      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. Lateral view of head of Planctoteuthis lippula, Hawaiian waters, 35 mm ML. Photograph by R. Young.

  5. Funnel
    1. Funnel valve absent.
    2. Funnel locking apparatus oval with posterior bump (antitragus) (see Comments).
      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 funnel locking-apparatus of P. danae, off California, 47 mm ML, showing posterior antitragus and no medial tragus. Drawing from Young (1972).

  6. Photophores
    1. Absent.

  7. Tail
    1. Tail present (usually lost during capture) with appendages. Appendages undescribed.

Comments

The exact form of the antitragus in the funnel locking-apparatus is often a species-specific feature. Unfortunately this structure is difficult to see and lighting and angle of view can often give different apparent results. The character must be used cautiously. Compare the locking apparatuses of the following species:

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

Figure. Funnel component of the funnel/mantle locking apparatus of various species of Planctoteuthis. A - P. danae. B - P. levimana, 60 mm ML. C - P. lippula, 55 mm ML. D - P. oligobessa. Photographs by R. Young.

The species are compared in the following table.

  Arm IV suckers, number Arm sucker dentition, arm I-III Antitragus Fin length Club shape Club keel Distribution
P. danae 12-13 7-9 distal truncated teeth Double. Lobes nearly equal 52% ML Symmetrical No Trop. Pacific
P. exopthalmica = P. levimana? 10 ? ? width=36% ML Symmetrical No S. Indian
P. levimana 6-8 Broad truncate teeth all around Double. Lobes unequal 40% ML Long, symmetrical No N. Atlantic, Trop. Pacific
P. lippula 25 >50 minute teeth, distal larger Single or slight double. Low, broad 40-45% ML Short, Asymmetrical Yes Atlantic, Trop. Pacific
P. oligobessa 2-4 25-35 blunt teeth, distal 2/3 Single. Slender 23-33% ML Symmetrical No Trop. Pacific

Nomenclature

The type species, Planctoteuthis danae, was originally placed in a new genus, Valbyteuthis, within a new family, Valbyteuthidae, by Joubin (1931). Roper and Young (1967) placed Valbyteuthis in the family Chiroteuthidae noting the similarity of Valbyteuthis paralarvae to those of Chiroteuthis. Young (1991) recognized that some paralarvae of Valbyteuthis had been previously descibed by Pfeffer (1912) as members of his new genus, Planctoteuthis, within the Chiroteuthidae. Valbyteuthis, therefore is a junior synonym of Planctoteuthis.

Life History

The doratopsis paralarva of Planctoteuthis can be recognized by:

  1. Strong ventral projection of eyes.
  2. Few suckers on arms, tentacles (young doratopsis).
  3. Relatively small, tapering tentacles (young doratopsis).
  4. Reduced vesicular region on mantle (young doratopsis).
Descriptions of paralarvae are found in pages on Planctoteuthis lippula and P. danae.

Distribution

Lower mesopelagic to bathypelagic depth distribution within tropical to temperate oceans of the world.

References

Joubin, L. 1931. Notes preliminaires sur les Cephalopodes des croiseires du "Dana" (1921-1922). Annales de l'Institut Oceanographique, 10: 169-211.

Pfeffer, G. 1912. Die Cephalopoden der Plankton-Expedition. Ergebniss der Plankton-Expedition der Humboldt-Stiftung. 2: 1-815.

Roper, C. F. E. and R. E. Young. 1967. A review of the Valbyteuthidae and an evaluation of its relationship with the Chiroteuthidae. Proc. U.S. Nat. Mus. 123: 1-9.

Young, R. E. 1972. The systematics and areal distribution of pelagic cephalopods from the seas off Southern California. Smithson. Contr. Zool., 97: 1-159.

Young, R. E. 1991. Chiroteuthid and related paralarvae from Hawaiian waters. Bull. Mar. Sci. 49: 162-185.

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 Planctoteuthis oligobessa
Location Northeast Pacific off Southern California at 32 52' N, 131 17' W
Comments 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
Behavior This was the first photograph showing the remarkable tail.
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Copyright © 2001 MBARI
About This Page


University of Hawaii, Honolulu, HI, USA


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


Smithsonian Institution, Washington, D. C., USA

Page: Tree of Life Planctoteuthis Pfeffer, 1912. Authored by Richard E. Young, Michael Vecchione, and Clyde F. E. Roper. 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., Michael Vecchione, and Clyde F. E. Roper. 2014. Planctoteuthis Pfeffer, 1912. Version 21 January 2014 (under construction). http://tolweb.org/Planctoteuthis/19464/2014.01.21 in The Tree of Life Web Project, http://tolweb.org/

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