Onykia knipovitchi (Filippova, 1972)

Introduction

O. knipovitchi reaches a size of at least 450 mm ML (Kubodera, et al., 1998) and is found in circumpolar Antarctic waters.

Diagnosis

An Onykia ...

• with smooth skin (no warts, ridges or welts). 

Characteristics

1. Tentacles
   1. Club with 10-15 (Kubodera et al., 1998) or 13 (Filippova1972) pairs of slender hooks.
   2. Long, slender hooks of ventral series have asymmetrical bases (see drawing below).
      

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      Figure. Oral view of tentacular club and large club hook of O. knipovitchi. Drawings from Filippova, 1972.

      

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      Figure. Oral view of tentacular club of O. knipovitchi, 295 mm ML, female. Photograph by R. Young.

      Scanning electron micrographs of the club hooks can be found here.

2. Mantle
   1. Skin smooth (i,e, no welts or ridges)(photograph of anterolateral mantle skin at right).
      

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      Figure. Portion of skin on anterodorsal mantle of O. knipovitchi, 295 mm ML, female. Photograph by R. Young.

3. Fins
   1. Rhomboidal shape, not drawn out into a tail.
   2. Length 50-60% of ML.
   3. Width ca. 70% of ML.
      

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      Figure. Ventral view of fin of O. knipovitchi with indication of rostrum length, 295 mm ML, female. Photograph by R. Young.

4. Gladius
   1. Rostrum short, 1/12th of GL (measured from ventral edge of conus); triangular in cross-section (dorsal surface flat, ventral surface pointed).
   2. Keel thickened posteriorly.
      

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      Figure. Ventral view of gladius O. knipovitchi with cross-sections. Drawings from Filippova, 1972.

Comments

Except where noted, this description is taken from Filippova (1972). The slender, asymmetrical hooks, smooth skin, homodont radula (see mext page) and the rhomboidal fins characterize this species.

Additional features of the description are found here.

Distribution

The type locality is near South Georgia Island. This species is found only in Antarctic waters. A map of its distribution can be found here.

References

Filippova, J. A. 1972. New data on the squids (Cephalopoda: Oegopsida) from the Scotia Sea (Antarctic). Malacologia, 11: 391-406.

Kubodera, T., U. Piatkowski, T. Okutani and M.R. Clarke. 1998. Taxonomy and Zoogeography of the Family Onychoteuthidae (Cephalopoda: Oegopsida). Smithsonian Contributions to Zoology, No. 586: 277-291.