Abraliopsis falco Young 1972

Introduction

A. falco is a rather large member of the subgenus Pfefferiteuthis, reaching a length of at least 46 mm ML. It is very similar to Abraliopsis sp. A and Abraliopsis sp. P from the tropical Pacific and A. atlantica from the Atlantic Ocean.

Brief diagnosis:

An Abraliopsis (Pfefferiteuthis) ...

• without keel or carpal flap on tentacular club.
• with small size difference (about 2x) between largest ventral club hook and its dorsal counterpart. 
• with central bare strip of Median Mantle Sector that can be difficult to detect.
  

Characteristics

1. Arms
   1. Arms IV relatively long; ALI-ALIV = 55-79; formula - 4=2>3>1.
   2. Arms of males longer and hooks smaller than in females.
      
   3. Arms I-III with 16-23 hooks (females), and 24-34 (males).
   4. First basal hook, arms III, ventral series much larger than second basal hook of same series and about equal or larger in size to counterpart in dorsal series. Basal hooks 2-4 of arms III, dorsal series much larger than counterparts of ventral series.
   5. Arms IV with 21-26 hooks (females) and 39-45 (males, left) or 26-32 (males, right = hectocotylus). 
   6. Hectocotylus with two subequal-sized offset flaps.
   7. Proximal modified portion of hectocotylus with armature.
   8. Protective membrane and its spatulate trabeculae well developed on left arm IV, web-like; with minute conical papillae on trabeculae.
   9. Arms IV of males with hooks of varying sizes depending on margin and position along arm.
      
   10. Largest suckers of distal arm with 10-12 rounded to truncate teeth on distal margin of inner ring.
   11. Males with proximal hook of ventral margin greatly enlarged over succeeding hook of series (see arrow in image below).
       
       

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       Figure. Oral views of arms of A. falco. Left - Mature male, about 40 mm ML, off Southern California. Drawing from Young (1972). Middle, Right - Paratype, 30 mm ML, off Baja California. Photographs by R. Young.
       

2. Tentacle clubs
   1. Large ventral hooks of manus about 2x height of dorsal counterparts; ventral series with 3-4 hooks, dorsal series with 2-4 hooks.
      
   2. Carpal flap absent; keel absent.
      
      

      Click on an image to view larger version & data in a new window

      
      

      Figure. Tentacular club of Oral view of A. falco. Left - 40 mm ML, off Southern California. Drawing modified from Young (1972). Right - Ventral (left), oral (middle) and aboral (right) views, paratype, male, 39 mm ML, off Baja California. Photographs by R. Young.
      

3. Photophores
   1. Ocular photophores: 5 photophores, terminal members "considerably" larger than middle 3. 
   2. Integumental photophores: 3 series on ventral head, 6 on ventral mantle.
      

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      Figure. Ventral views of the integumental photophores of A. falco, holotype, mature male, 37 mm ML, off Baja California. Left - Photograph of the preserved squid. Right - Outline drawing from previous photograph with all integumental photophores represented by colored dots. Red dots - Comples photophores. Blue dots - Non-complex photophores. Images by R. Young.
      

      Detailed information on the integumental photophores can be found here.
      

4. Viscera
   1. Spermatangia receptacles: A large female (see photograph below) had spermatangia in the stellate pocket (pocket between stellate ganglia) but none in the dorsal-collar pocket which lacked pigmentation but showed many folds.
      
      

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      Figure. Dorsolateral view of an anterior region of the mantle cavity of A. falco, paratype, female, 41 mm ML, off Baja California, showing actual and potential pockets for storage of spermatangia. Photograph by R. Young.

5. Table of measurements and counts
   
   

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   Figure. Table from Young, 1972 (title modified).

Comments

Comparisons of all species in the subgenus can be found on the Abraliopsis (Pfefferiteuthis) page.

Distribution

Geographical Distribution

Type locality: Eastern North Pacific at 28°54'N, 118°08'W. The type series (9 squid) all came within a degree (latitude and longitude) of this locality. Considering the similarity with other species of the subgenus now known to exist, other literature records must be suspect for the present.

References

Okutani, T. 1974. Epipelagic decapod cephalopods collected by midwater tows during the EASTROPAC Expedition, 1967-1968 (systematic part). Bull. Tokai Reg. Fish. Res. Lab., 80:29-118.

Young, R.E. 1972. The systematics and areal distribution of pelagic cephalopods from the sea off southern California. Smiths. Contr. Zool., 97:1-159.