Onykia ingens (Smith 1881)

Introduction

O. ingens reaches a length of at least 500 mm ML (Kubodera, et al., 1998) and is found in circumpolar but sub-Antarctic waters.

Diagnosis

An Onykia ...

• with rhomboidal fins (ie fins not drawn-out posteriorly).
• with warts on the skin.
• with rostrum of gladius having a triangular cross-section.
  

Characteristics

1. Tentacles
   1. Club with usually 14 pairs of hooks (range - 13-16 hooks, dorsal series, 13-15, ventral series).
      

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      Figure. Oral view of tentacular club of O. ingens. Drawing from Pfeffer, 1912.

2. Mantle
   1. Ventral mantle with soft, irregular warts.
      

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      Figure. A piece of ventral mantle skin of O. ingens. Drawing from Pfeffer, 1912.

3. Fins
   1. Rhomboidal shape, not drawn out into a tail.
   2. Length 50-60% of ML.
   3. Width 60-70% of ML.
   
   
4. Gladius
   1. Maximum width of vanes ca. 11% of gladius length (to tip of conus).
   2. Rostrum 11-12% of the ML, triangular in cross-section.
      

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      Figure. Ventral view of gladius of O. ingens with cross-sections. Drawing from Pfeffer, 1912.

comments

Additional features of the description can be found here.

Life History

The tentacular club of a young O. ingens, 77mm ML has a few marginal suckers still remaining on the proximal dorsal margin and on the distal ventral margin.

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Figure. Oral view of tentacular club of O. ingens, 77 mm ML. Drawing from Tsuchiya and Okutani, 1981, p. 145, Fig. 35.

Dubinina (1980) described a juvenile squid from the Southwest Atlantic as Onykia robsoni (drawing to the right) but according to C. Nigmatullin (personal communication) it probably is a young O. ingens. The scale bar is 1 mm.

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Figure. Ventral and dorsal views, probably, of O. ingens, 13 mm ML. Drawing from Dubinina (1980).

Distribution

Other Names for Onykia ingens (Smith 1881)

• Moroteuthis ingens

References

Clarke, M. R. 1980. Cephalopoda in the diet of sperm whales of the Southern Hemisphere and their bearing on sperm whale biology. Discovery Reports, 37: 1-324.

Dubinina, T. S. 1980. On a finding of a larvae Moroteuthis robsoni (Oegopsida, Onychoteuthidae) in South-west Atlantic.

T. Kubodera, 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.

Tsuchiya, K., and T. Okutani. 1991. Growth Stages of Moroteuthis robusta (Verrill, 1881) with the Re-evaluation of the Genus. Bulletin of Marine Science, 49(1/2):137-147.