Abraliopsis morisii (V?rany, 1839)

Introduction

A. morisii is distributed widely in the tropical to warm temperate waters of the Atlantic Ocean. This species has a scattered arrangement of photophores on the ventral mantle and head, and carpal flaps and distinct aboral keels on the clubs. This is the only known species in the Atlantic in the Abraliopsis (Abraliopsis) subgenus (i.e., A. morisii, A. hoylei, A. tui and A. pacificus) that shares these characters.

Characteristics

1. Tentacle clubs
   1. Two rows of different-sized hooks on manus.
   2. Carpal flap and aboral keel distinct.
      

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      Figure. Oral view of the tentacular club of A. morisii. Top - Drawing from Tsuchiya (2000). Bottom - Photograph by R. Young.

2. Arms
   1. Arms IV relatively long; ALI IV = ca.70.
   2. Arms with 14 - 22 hooks and suckers.
      
      
3. Hectocotylus
   1. Hectocotylus with two different-sized flaps: long narrow proximal flap on the ventral margin and a short distal flap on the dorsal margin.
   2. Modified portion with armature.
      

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      Figure. Oral-dorsal view of the hectocotylus of A. morisii, North Atlantic Ocean. Drawing from Tsuchiya (2000).

4. Integumental Photophores
   1. Ventral mantle and head with scattered arrangement of integumental organs.
      
      

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      Figure. Ventral view of the head, funnel and anterior mantle of A. morisii showing the arrangement of photophores. Photograph by R. Young.

Comments

This group with a scattered integumental photophore pattern, has few taxonomic characters but each species occupies a different watermass. They are identified by some morphometric or meristic characters such as fin length index, arm length index, hook and sucker count, etc.

Nomenclature

This species was formerly called A. pfefferi Joubin, 1896. Bello (2005) after re-examining the original description of A. morisii, determined that discarding this name, which has precedence, due to problems with the original description, was a mistake and that the original discription was sufficient to identify the species. Unfortunately the type specimen appears to be lost. A. pfefferi, therefore, is a junior synonym of A. morisii.

Life history

Age and maturation

Based on statolith analyses, males mostly matured at 120-130 days and females at 150-160 days; minimum age at maturity is 105 days in males, 127 days in females (Arkhipkin, 1996).

Distribution

Geographical Distribution

Type locality: North Atlantic Ocean at 39°N, 20°W. This species is distributed in the tropical to warm temperate Atlantic Ocean, the Gulf of Mexico, and Mediterranean Sea (Nesis, 1982/87).

References

Bello, G. 2005. Abraliopsis morisii vs. Abraliopsis pfefferi (Cephalopoda: Enoploteuthidae): which is the right name? Journal of Conchology, 38 (5):561-565.

Arkhipkin, A.I. 1996. Age and growth of the squid Abraliopsis pfefferi (Oegopsida: Enoploteuthidae) from the central-east Atlantic based on the statolith microstructure. Scientia Marina 60:325-330.

Nesis, K. N. 1982. 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.