Magnapinna sp. C

Introduction

A magnapinnid, illustrated by Hardy (1956) from the South Atlantic and identified as Octopodoteuthopsis, is deposited in the Natural History Museum, London (BMNH). This squid was recognized as a magnapinnid by Vecchione and Young (2006). They list this species as Magnapinna sp. due to the slender tentacles which differed greatly from the previously only known species, M. pacifica.

Diagnosis

A Magnapinna ...

• with proximal-tentacles more slender than arms IV.
• with chromatophores.
• without glandular regions on proximal-tentacles.

Characteristics

1. Arms
   1. Proximal-arms approximately subequal in length (ca 40-45% of ML).
   2. Proximal-arms with gelatinous consistency and thick protective membranes.
   3. Arm tips stripped and damaged, distal-arms not recognizable.
   4. Proximal-arm suckers closely spaced, in 2 series.
   5. Proximal-arm suckers globular with smooth rings.
      
      
2. Tentacles
   1. Tentacles badly damaged, suckers absent.
   2. Tentacle diameter at base less than arm diameter.
   

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   Figure. Left - Ventral view of the base of the brachial crown of Magnapinna sp. C, showing relative size of arm and tentacle bases. Right - Lateral view of the head, arms and tentacles of Magnapinna sp. C showing funnel locking apparatus. Photographs by Wen-Sung Chung.

3. Funnel
   1. Funnel locking-apparatus oval, without tragus or antitragus.
      
      
4. Mantle
   1. Mantle length 79 mm.
      
      
5. Fins
   1. Fin length 59 mm (75% of ML); width 76 mm.
   2. Fins in terminal position.
   3. Fins attach to lateral sides of gladius.
      
      
6. Photophores
1. Photophores absent.
   
   
7. Viscera
1. Spermatophore glands present.


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Figure. Ventral view of the viscera of Magnapinna sp. C. Photograph by Wen-Sung Chung.

Comments

We examined the specimen in the year 2000 before we realized that it belongs to the Magnapinnidae. The brief description above is from some notes we made at the time. The arms and tentacles were badly damaged in capture. The squid is an immature male. The buccal mass is relatively large and the buccal membrane is very reduced. We are uncertain at present whether this represents a separate species or is conspecific with M. atlantica and/or M. talismani. This specimen needs to be re-examined. 

References

Vecchione, M. and R. E. Young. 2006. The squid family Magnapinnidae (Mollusca; Cephalopoda) in the North Atlantic with a description of Magnapinna atlantica, n. sp. Proc. Biol. Soc. Wash. 119 (3): 365-372.