Alluroteuthis antarcticus Odhner, 1923

Introduction

Diagnosis

A neoteuthid ...

• with greatly enlarged suckers in medial two sucker-series of distal-manus.
• with enlarged tooth on inner ring of proximal arm suckers, becoming a blunt hook in large individuals.

Characteristics

1. Arms
   1. In large individuals, suckers in middle of arms I-III with blunt hooks.
      
      
2. Tentacles
   1. Distal manus with suckers greatly enlarged in medial two series.
   2. Large distal-manal suckers with ca. 60 pointed teeth on inner rings.
   3. Length of proximal manus about equal to length of distal manus.
   4. Club proximal locking-apparatus along dorsal margin of proximal manus and oral midline of tentacle stalk.
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   Figure. Oral view of tentacular club of A. antarcticus. Drawing from Roper, et al., 1969.

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   Figure. Oral view of tentacular club of A. antarcticus, preserved. Photograph by R. Young.

3. Fins
   1. Length 35-40% of ML.

Comments

Life History

Unlike larger squids, in juvenile A. antarcticus, the tentacles are very small compared to the arms.

image info image info

Figure. Left - Oral view of brachial crown of A. antarcticus, type specimen, 14.5 mm ML. Drawing from Odhner (1923). Right - Side view of A. antarcticus, 18 mm ML, NMNH #727521, Antarctic ocean, preserved. The tentacles are indicated by white arrows in the illustration at right. Photograph by R. Young.

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Figure. Oral view of tentacle of a juvenile of A. antarcticus, type specimen, 14.5 mm ML. Drawing from Odhner (1923).

Odhner (1923) suggested that Parateuthis tunicata Thiele, 1920, described from a paralarva taken in Antarctic waters, might be the young of his Alluroteuthis antarcticus based on similarities of the radula. Roper, et al. (1969) indicated that new specimens in their possession suggested that Odhner was correct. However, their study was never completed and the synonomy of the two species remains uncertain. If the synonomy is proven correct, Parateuthis tunicata, the older species, will be the proper name.

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Figure. Dorsal, ventral and lateral views of Parateuthis tunicata, 8 mm ML. Drawings from Thiele (1920).

Distribution

The type locality is: 63°-64°S, 45°-51°W in Antarctic waters, 0-2800 m depth.

A distribution map of this species is maintained by the British Antarctic Survey.

References

Nesis, K. N. 1982/87. Abridged key to the cephalopod mollusks of the world's ocean. 385+ii pp. Light and Food Industry Publishing House, Moscow. (In Russian.). Translated into English by B. S. Levitov, ed. by L. A. Burgess (1987), Cephalopods of the world. T. F. H. Publications, Neptune City, NJ, 351pp.

Odhner, N.H. 1923. Die Cephalopoden. Zoological Results of the Swedish Antarctic Expedition 1901-03, 1(4):1-7.

Roper, C. F. E., R. E. Young and G. L. Voss (1969). An illustrated key to the families of the order Teuthoidea. Smiths. contr. zool., 13:1-32.

Thiele, J. 1921. Die Cephalopoden der deutschen Südpolar-Expedition 1901-1903. Deutsche Südpolar-Expedition 1901-1903, 16(Zoology 8):433-465. [Published 1920]