Under Construction

Planctoteuthis oligobessa Young 1972

Richard E. Young and Clyde F. E. Roper
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
The holotype is deposited in the Santa Barbara Museum of Natural History, Santa Barbara, California.
Containing group: Planctoteuthis

Introduction

Planctoteuthis oligobessa is a small species (maximum size = 76 mm ML). It can be separated from subadults of other members of the genus by the small fins and few suckers on arms IV. Little is known of its biology.

Brief diagnosis:

A Planctoteuthis with ...

Characteristics

  1. Arms
    1. 2-4 suckers on each arm IV.
    2. Arm lengths: Arms I: 32-39% of ML (subadults); arms I: 24-25% of ML (adults); arms III: 47-61% of ML (subadults). arms IV: 121-135% of ML (subadults); arms II-IV 29-39% of ML (adults).
    3. Large arm suckers with 25-35 small, narrow, blunt teeth on distal 3/4 of ring.
      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 large arm suckers of P. oligobessa, 27 mm ML. A-D - Suckers from arm I-IV respectively.

  2. Tentacles
    1. Clubs bilaterally symmetrical in shape.
    2. Club length 12-18% of ML.
    3. Suckers without teeth on inner ring.
    4. Clubs without keels.
      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 views of club sucker and club, 27 mm ML. Drawings from Young (1972).

  3. Head
    1. Beaks: Descriptions can be found here: Lower beak; upper beak.

  4. Funnel
    1. Locking apparatus with slender antitragus consisting of a single lobe.
      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. Funnel locking apparatuses of P. oligobessa. Left - 27 mm ML. Drawing from Young (1972). Right - Subadult, off Southern California.

  5. Fins
    1. Length 23-33% of ML.
  6. Measurements
      Paratype Paratype Holotype
    Sex -- -- Female
    Mantle length 34 34 76
    Mantle width 11 11 28
    Fin length 7 8 14
    Fin width 12 -- --
    Length, arm I 12 11 19
    Length, arm II 15 15 27
    Length, arm III 18 16 29
    Length, arm IV 46 41 30
    Club length* 6 4 --
    Arm IV sucker count (left / right) 3 / -- 3 / 2 2 / 3
    *Without carpus

Comments


Individuals of Planctoteuthis taken in trawls invariably show a broken gladius at the posterior end of the fin. The existence of a long and decorative tail was not known until ROV photographs captured insitu images. These images were taken by the Monterey Bay Aquarium Research Institute. The ventrally bulging eyes identify it as Planctoteuthis and the locality off California strongly suggests that it is P. oligobessa. The function of the tail is unknown although Vecchione et al. (1992) noted that the tail of Chiroteuthis (see Chiroteuthidae page) causes the young squid to resemble certain siphonophores suggesting protective mimicry.

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

Figures. Lateral views, insitu with natural orientation, apparently of P. oligobessa, taken by a remotely operated vehicle (ROV) off California. Left image © MBARI 2001. Right image © MBARI 2011.

Nomenclature

This species was originally described as Valbyteuthis oligobessa. Valbyteuthis is now placed in the synonomy of Planctoteuthis (Young, 1991).

Life history

Paralarval stages for P. oligobessa are unknown.

The holotype is a gravid, mated female with mature ovarian eggs of 1.5 mm in diameter. Spermatangia were found within the ovary. Fertilization, apparently, is internal.

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. These two images of, presumably, P. oligobessa are apparently much older than those shown previously judging by the heavy pigmentation. Both images could be of adult squid, especially the bottom one with the damaged tail. Both images: © 2011 MBARI.

Distribution

Vertical distribution

The vertical distribution of P. oligobessa off southern California extends from 700 - 1200m (the maximum depth of the trawling program). The highest capture rate occurred in the 1100-1200 m zone and this species was one of the deepest living cephalopods taken in this program (Roper and Young, 1975). There is no difference between daytime and nighttime distributions.

Geographical distribution

P. oligobessa has been described only from the waters off southern California and northern Baja California; Nesis (1982/87) indicates that the distribution extends to Indonesian waters.

References

7276

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, Planctoteuthis oligobessa (2)
Location Pacific Ocean off California
Comments note the long arms IV and the strong ventral protrusion of the eyes from the head (1)
Reference Young, R. E. 1972. The systematics and areal distribution of pelagic cephalopods from the seas off southern California. Smithson. Contr. Zool., No. 97: 159pp
Creator C. McSweeny
Specimen Condition Dead Specimen
Sex f (2)
Life Cycle Stage subadult, mature (2)
View Ventral
Size 23 mm ML, 76 mm ML (2)
Type holotype (2)
Image Use creative commons This media file is licensed under the Creative Commons Attribution-NonCommercial License - Version 3.0.
Copyright ©
About This Page


University of Hawaii, Honolulu, HI, USA


Smithsonian Institution, Washington, D. C., USA

Page: Tree of Life Planctoteuthis oligobessa Young 1972. Authored by Richard E. Young 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. and Clyde F. E. Roper. 2014. Planctoteuthis oligobessa Young 1972. Version 21 January 2014 (under construction). http://tolweb.org/Planctoteuthis_oligobessa/19496/2014.01.21 in The Tree of Life Web Project, http://tolweb.org/

edit this page
close box

This page is a Tree of Life Leaf Page.

Each ToL leaf page provides a synopsis of the characteristics of a group of organisms representing a leaf at the tip of the Tree of Life. The major distinction between a leaf and a branch of the Tree of Life is that a leaf cannot generally be further subdivided into 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

Planctoteuthis oligobessa

Page Content

articles & notes

collections

people

Explore Other Groups

random page

  go to the Tree of Life home page
top