Abraliopsis sp. E

Introduction

Abraliopsis sp. E is known from a single small (21 mm ML), but mature, male taken in the Central Equatorial Pacific at 7°15'N, 149°54'W.

Brief diagnosis:

An Abraliopsis (Micrabralia) ...

• without long, bare, distal region on the non-hectocotylized (left)arm IV.
• without blue photophores between Medial and Lateral Head Series. 
• with photophores in distinct series on mantle.
  

Characteristics

1. Arms
   1. All arms lack tubercules; left ventral arm without special modifications.
   2. Arms I-III with well developed trabeculate protective membranes, with slender trabeculae, only on ventral margins. 
      
   3. Very low protective membranes on arms IV (excluding hectocotylization) with short trabeculae projecting freely from membranes especially on both margins of left arm IV.
      
   4. Arms I-III with 18-20 hooks and two series of small suckers at extreme distal end of arms. Left arm IV with 24 hooks and no suckers.
   5. Hooks of arms IV smaller than those of other arms.
      
   6. Hectocotylus (right arm IV) with long, wide ventral flap, and shorter, wide offset dorsal flap. Low membrane extends from distal end of ventral flap to base of arm tip bearing large, black photophores.
      
   7. Hectocotylus with 18 hooks; distal-most hook at proximal end of dorsal flap; suckers absent. Left arm IV with 24 hooks; distal-most hook very near terminal large photophores.
      
   

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   Figure. Arms III and IV of Abraliopsis sp. E, mature male, 21 mm ML, central Equatorial Pacific. Left - Oral views of left arms III and IV. Middle - Dorso-oral view of right arm IV (hectocotylus). Right - Ventral view of the distal portion of right arm IV. Note the large trabecula at the proximal end of the ventral flap. Photographs by R. Young.

2. Tentacles
   1. Largest hooks of ventral series of manus about 2.5 times height of dorsal counterparts.
      
   2. Manus with 6 or 7 hooks.
      
   3. Narrow, short keel restricted to dactylus; narrow carpal flap.
   

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   Figure.Tentacular clubs of Abraliopsis sp. E. Left - Oral view of right club showing the carpal flap and keel. Right - Dorsal (left) and Ventral (right) views of left club showing the relative sizes of the hooks. Photographs by R. Young.
   

3. head
   
   1. Occipital crest with occipital folds 3 and 4 joined posteriorly by distinct crescent-shaped ridge.
      
      
4. Fins
   
   1. Fins large, nearly 70 % of ML.



5. Photophores
   1. Ocular photophores: 5 photophores with end members about 2X larger than adjacent photophores.
   2. Integumental photophores: 3 series on ventral head, 6 on ventral mantle.
      
      

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      Figure. Ventral view of the mantle and funnel of Abraliopsis sp. E. Left - Photograph of the preserved squid. Middle - Outline drawing from photograph with all integumental photophores represented by colored dots.  Red dots - Complex photophores. Blue dots - Non-complex photophores. Images by R. Young.

      More information on integumental photophores can be found here.
      

6. Viscera
   1. Mantle cavity
      
      

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      Figure. Ventral view of the mantle cavity of Abraliopsis sp. E, showing the penis and Needham's sac full of spermatophores. Photograph by R. Young.

   2. Spermatophore
      
      

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      Figure. View of the spermatophore (6 mm long) of Abraliopsis sp. E with enlarged insert of oral end, mature male, 21 mm ML, central tropical  Pacific. Photograph by R. Young.

7. Measurements (mm) and counts.
   

   	R/L
   Sex	Male, mature
   Mantle length	21
   Head width index	42.9
   Fin Length index	68
   Fin width index	100
   Arm Length index (R/L): I	58.6/60.5
   II	66.7/69.5
   III	66.7/67.6
   IV	83.3/81
   No. arm hooks (R/L): I	19/19
   II	-/20
   III	19/18
   IV	18/24
   Club length index (R/L)	24.8/26.7
   Club hooks (D/V)(R:L)	3/3; 3/3
   Carpal suckers (R/L)	5/5

Comments.

Superficially Abraliopsis sp. E looks like a member of the subgenus Pfefferiteuthis; however it lacks the highly modified arms IV of that group.  It is easily separated from other members subgenus Micrabralia by the characters listed in the "Brief diagnosis" above.

See Abraliopsis (Micrabralia) page for comparisons among all species of the subgenus.