Cirroctopus glacialis Description Continued

1. Arms and web
   1. Arm formula: I>II>III>IV.
   2. Web formula: A>B>C>D>E; sector E about half sector A.
   3. longest arm with 74 suckers.
   4. Cirri short (max. 5.5 mm in 78 mm ML male).
   

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   Figure. Oral view of an arm segment of C. glacialis showing deeply embedded suckers. Photograph by R. Young.

2. Eyes
   1. Eyes large with a distinct dorsal tilt.
      
      
3. Funnel
   1. Funnel organ with broad V-shaped pad.
   

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   Figure. Funnel organ of C. glacialis. Drawing from Robson, 1930.

4. Fins
   1. Fins massive; length equal to ML; width nearly 3/4  of fin length.
      
      
5. Mantle cavity
   1. Mantle septum very thick, long; fused with posterior mantle wall.
   2. Gills half-orange shape.
   3. Gills with 6 primary lamellae (inner-most reduced in size).
      
      
6. Optic lobe and nerves
   1. Optic lobe kidney shaped.
   2. Position of optic nerves unknown.
      
      
7. Digestive tract
   1. Radula absent.
   2. Anterior salivary glands very small; posterior glands absent.
   3. Esophagus without distinct crop.
   4. Caecum much larger than stomach.
   5. Intestine not straight.
   

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   Figure. Two views of the digestive tract of C. glacialis. Left - Drawing from Robson (1930). Right - Drawing from Vecchione and Young (1997).

8. Beaks
   1. Beaks not described.
      
      
9. Male reproductive system
   1. See: "Reproductive systems - cirrates" in glossary.
      
      
10. Female reproductive system
    1. Female reproductive system with large oviducal gland approaching ovary in size. Largest mature eggs from distal oviduct 14x22 mm.
       
       
11. Pigmentation
    1. Numerous areolae present in small animals; two pair present in adults.
    2. Holotype: Head, arms and dorsal surface of mantle bluish purple. Fins and undersurface of body more reddish.
    3. Distinctive color pattern on oral surface of arms and web (see C. glacialis species page).
       
       
12. Measurements and counts.

    Mantle Length	78
    Eyes to web edge, sector A	140
    Head width	80
    Mantle width	58
    Fin length	75
    fin width	54
    Arm I, length	200
    Arm II, length	195
    Arm III, length	185
    Arm IV, length	175
    Web sector A, depth	148
    Web sector B, depth	136
    Web sector C, depth	116
    Web sector D, depth	92
    Web sector E, depth	66
    Arm I, sucker counts	-/72
    Arm II, sucker counts	72-69
    Arm III, sucker counts	69/69
    Arm IV, sucker counts	70/67

    Measurements are in mm and are of the holotype. Sucker counts are from O'Shea (1999). Other counts are from Robson (1930).

Comments

The above description is taken mostly from Robson (1930), Vecchione and Young (1997) and Vecchione, et al. (1998).

References

Robson, G. C. (1930). Cephalopoda, I. Octopoda. Discovery Report, 2:371-401.

Vecchione, M. and R. E. Young. 1997 Aspects of the functional morphology of cirrate octopods: locomotion and feeding. Vie Milieu 47(2):101-110.

Vecchione, M., U. Piatkowski and A. L. Allcock. 1998. Biology of the cirrate octopod Grimpoteuthis glacialis (Cephalopoda; Opisthoteuthidae) in the South Shetland Islands, Antarctica. S. Afr. J. Mar. Sci. 20: 421-428.