Under Construction

Containing group: Pterygioteuthis

Introduction

Brief Diagnosis:

A Pterygioteuthis with... 

• hooks in 2 series on arms I-III.
• tentacular club suckers on manus of similar size in transverse rows.
• eyes each with 10 large and 5 minute photophores.
  

Characteristics

1. Arms - hooks are in 2 series on arms I-III.
   
   

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   Figure.  Oral view of arms I from a female P. hoylei. ©

   1. Arms I - distal suckers are globular.
      
      

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      Figure.  Close-up of distal suckers for P. hoylei. ©

   2. Arms IV - females without suckers or hooks, males with 2-3 hooks.
      
      

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      Figure.  Oral views of right arms IV from P. hoylei.  Top - female.  Bottom - male with 2 hooks and 1 small sucker.  ©

   3. Hectocotylus plate - contains 2 large teeth.
      
      

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      Figure.  Hectocotylus of P. hoylei. ©

2. Tentacular clubs - suckers (4 series) on manus of similar size in transverse rows.
   
   

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   Figure.  Oral view of the tentacular club from P. hoylei. ©

3. Buccal membrane - with ridges on inner surface.
   
   

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   Figure.  Oral view of the buccal membrane from P. hoylei. ©
4. Eye photophores - 10 large and 5 minute (see arrows below).
   
   

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   Figure.  Ventral view of the minute eye photophores (arrows) from the right eye of P. giardi. ©

Comparison table for P. giardi and P. hoylei

Character	P. giardi	P. hoylei
Arm I hooks	In 2 distinct sizes: regular and minute	Minute hooks absent
Male Arm III suckers	proximal suckers, distal hooks	hooks only*
Tentacular photophores	2	4
Tentacular stalk chromatophores	Stop midway up stalk (distal to 2nd photophore)	Continue along entire stalk in 1 row
Aboral tentacular club chromatophores	Absent	In 2 rows along edges of club
Funnel chromatophores	Few present anterior to funnel locking apparatus, generally absent from ventral funnel	Present anterior to locking apparatus, present on ventral funnel.

*Occasionally 1-2  tiny suckers also present.

Discussion of Phylogenetic Relationships

Pterygioteuthis hoylei was originally considered a subspecies of P. giardi: Hoyle (1904) was the first to note differences in 4 specimens of P. giardi collected from the eastern tropical Pacific, but he made no formal designation.  Pfeffer (1912) later erected the subspecies, Pterygioteuthis giardi hoylei based on the descriptions by Hoyle, but made no further examination of specimens himself. Further investigation (Lindgren, 2010) uncovered notable differences between the two subspecies (see table above), leading to the elevation of P. hoylei to specific status.

References

Lindgren, A.R. 2010. Systematics and distribution of the squid genus Pterygioteuthis (Cephalopoda: Oegopsida) in the eastern tropical Pacific Ocean

Nesis, K.N. 1973. Cephalopods of the eastern equatorial and south-eastern Pacific Ocean (in Russian). In: English translations of selected publications on Cephalopods by Kir Nesis. Vol. I (M.J. Sweeney, compiler), pp. 171-248. Smithsonian Institution Libraries, Aad Publications, Karachi.

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

Pfeffer, G. 1912. Die Cephalopoden der Plankton-Expedition. Ergebnisse der Plankton-Expedition der Humboldt-Stiftung. 2: 1-815.

Riddell, D.J. 1985. Enoploteuthidae of the New Zealand Region. Fish. Res. Bull., New Zealand. 27:1-52.

Young, R.E. 1972. The systematics and areal distribution of pelagic cephalopods from the seas off southern California. Smith. Contr. Zool. 97:1-59.