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Opisthoteuthis borealis: Description continued

Martin Collins, Roger Villanueva, and Richard E. Young
  1. Arms and web
    1. Arms subequal with length about 4 times ML; no consistent arm formula.
    2. About 80 suckers in single series on each arm; suckers embedded in semi-gelatinous tissue of arms.
    3. Web extends about 2/3 of arm length. Web formula: A=B>C=D>E.

  2. Head
    1. Eyes 50% of ML.
    2. Optic lobes large, kidney shaped, with 3 bundles of nerves running to each eye.
    3. White body large, dark brown/purple in color.
      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. Optic tract of O. borealis. Drawing from Collins (2006).

    4. Beak with  typical Opisthoteuthis form.
    5. Radula absent.
      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. Beaks of O. borealis. Left - Upper beak. Right - Lower beak. Drawing from Collins (2006).

  3. Funnel
    1. Funnel flaccid and moderately long (64% of ML) and darkly pigmented.

  4. Mantle
    1. Mantle short, about 20% of total length.
    2. Mantle opening closely surrounds funnel.

  5. Fins
    1. Fins moderate in size, positioned posterolaterally.
    2. Anterior and posterior fin margins thin and without proximal, anterior lobe.
    3. Each fin with internal cartilage extending from shell sac.

  6. Pigmentation
    1. Skin surface smooth, reddish-brown color in preservation; Oral surface of web deeply pigmented.
    2.  Areolar spots not apparent on skin.

  7. Shell
    1. Shell U-shaped with short, flaring lateral wings.
    2. Basal portion of shell with concave outer surface and convex inner surface.
    3. Lateral wings of shell with in-rolled margins, taper to acute points.
    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. Three views of the shell of O. borealis. Drawing from Collins (2006).

  8. Viscera
    1. Gills small, compact, spherical with 7-8 lamellae.
    2. Branchial heart rounded, half size of gill.
    3. Medial pallial adductor muscle thin, narrow.
    4. Digestive system
      1. Oesophagus, stomach and caecum with dark purple pigmentation.
      2. Digestive ducts unite prior to entering caecum.
      3. Intestine shorter than oesophagus, with S-shape.
      4. Anal flaps,ink sac absent and posterior salivary glands absent.

  9. Reproductive system
    1. Male
      1. Large testis with short vas deferens; large convoluted seminal vesicle complex; three accessory glands with gland 2 largest; terminal organ short.
      2. Spermatophores oval in shape.
        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 male genital apparatus of O. borealis. Drawing from Collins (2006).

    2. Female
      1. Ovary with thin-walled proximal oviduct, oviducal glands and short distal oviduct.
        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. The female genital apparatus of O. borealis. The proximal oviduct and Ovary are filled with ova. Drawing from Collins (2006).

  10. Measurements and counts
      ZMUC CEPH-3
    Holotype
    ZMUC CEPH-4
    Paratype
    ZMUC CEPH-4
    Paratype
    ZMUC CEPH-5
    Paratype
    ZMUC CEPH-6
    Paratype
    ZMUC CEPH-5
    Paratype
    Sex  M
    M
    F
    M
    F
    F
    Dorsal mantle length
    60  55  65  75  68  ~70 
    Head width  88  105  --    102 
    Fin span  --  130  --  150  120  135 
    Fin length  32  32    48  40  37 
    Fin width  16  16    32  22  20 
    Eye diameter  25  31    42  42  35 
    Funnel length  38  39  30  58  52  37 
    Gill lamellae
    8/8    7/7  7/8  8/8 
    Web Formula  A=B>C=D>E    A=B>C=D>E
    Ovarial egg length  --  --  12  --
    12  11 
    Length, Arm I  260  280  190 
              Arm II
    230  280  205 
              Arm III
    250  240  255  185 
              Arm IV 
    245  235  230 
    Width, Arm I  23  31  22 
    Max. sucker diameter, proximal field  5.8 6.3  4.5  7.2  4.2 
    Max sucker diameter, distal field  4.8 6.0  --  7.0  -- 
    Proximal sucker field, location  4-9 5-9  --  5-10  -- 
    Distal sucker field, location  22-23 24-34  --  24-35  -- 
    Maximum cirrus length  5.0  6.0  6.8  6.0 
    Sucker count  * ~81  ~80 
    *The count or measurement could not be obtained due to damage.
    Measurements in mm.

Comments

The above description is from Collins (2006). 

References

Collins, M.A. 2006. Opisthoteuthis borealis: A new species of cirrate octopod from Greenland waters. Journal of the Marine Biological Association of the United Kingdom 85: 1475-1479.

About This Page

Martin Collins
Aberdeen University, Aberdeen, UK


Instituto de Ciencias del Mar (CSIC), Barcelona, Spain


University of Hawaii, Honolulu, HI, USA

Page: Tree of Life Opisthoteuthis borealis: Description continued Authored by Martin Collins, Roger Villanueva, and 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.

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