Abralia astrolineata Berry 1914

Introduction

A. astrolineata is a large sized species for this genus attaining 100mm DML, and known only from a very limited area along the slope of the Kermadec Islands and coast of Queensland, eastern Australia and just north of Samoa (Nesis,1982/87; pers. observation).

Brief diagnosis:

An Abralia (Astrabralia) with ...

• distinct longitudinal stripes of photophores on mantle and head.

Characteristics

1. Tentacle clubs
   1. About four hooks on ventral side.
   2. Two rows of large suckers on dorsal side of manus.
   

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   Figure. Oral view of the tentacular club of A. astrolineata. Drawing from Riddell (1985).
   

2. Hectocotylus
   1. Right ventral arm of male hectocotylized.
   2. Hectocotylus with two subequal sized off-set flaps with flap of ventral margin more proximal than that of dorsal margin.
   

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   Figure. Oral view of the hectocotylus of A. astrolineata. Drawing from Tsuchiya (2000). Note the relativelly large, photophores at the arm tip.
   

3. Eye Photophores
   1. Five large silvery organs of subequal size.
      
      
4. Integumental Photophores
   1. Ventral mantle with distinctly four, distinct longitudinal stripes of photophores with broad spaces between stripes.
   2. Ventral head with three distinct, longitudinal stripes of photophores.
      
      

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      Figure. Ventral view of A. astrolineata, female, 47 mm ML, showing integumental photophores. Insert shows closer view of large ellipsoidal photophores (arrows) near arm tip. Photograph by R. Young.
      

5. Terminal Arm Photophores
   1. Arm IV with 3-4, large, ellipsoidal photophores near tip.
   2. Terminal suckers absent on oral side arms opposite photophores in both sexes (as in Abraliopsis).
      
      
6. Caudal Photophores
   1. At mantle apex, a pair of ellipsoidal photophores buried in tissue.

Comments

The three photophores at the tips of arms IV, a feature which is shared with A. astrosticta, is similar to the arrangement in genus Abraliopsis except that they are  smaller. These terminal organs are pigmented in young A. astrolineata (as in species of Abraliopsis) but not in A. astrosticta .

Distribution

Vertical distribution

A. astrolineata seems to be a component of mesopelagic boundary community in the subtropical South Pacific.

Geographical distribution

This species was first described from the Kermadec Islands. Nesis (1982/87) also recorded this species from off Queensland, eastern Australia.

References

Berry, S.S. 1914. Notes on a Collection of Cephalopods from the Kermadec Islands. Transactions and Proceedings of the New Zealand Institute, 46(24):134-149.

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.

Riddell, D.J. 1985. The Enoploteuthidae (Cephalopoda: Oegopsida) of the New Zealand Region. Fisheries Research Bulletin (N.Z. Ministry of Agriculture & Fisheries), 27:1-52.

Tsuchiya, K. 2000. Illustrated book of the Enoploteuthidae. In: Okutani T., ed. True face of Watasenia scintillans. Tokai University Press, Tokyo, p 196–269. (in Japanese)