Histioteuthis pacifica (Voss 1962)

Introduction

H. pacifica is one of the larger species of histioteuhids, reaching a ML in excess of 280 mm. It is known from a considerable number of squid, however, identification problems have caused confusion regarding which records are valid.

Characteristics

1. Photophores
   1. Photophores of Basal Row on head in simple, uniform row; sawtooth absent. 
      
   

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   Figure. Ventral view of the posterior region of head and anterior tip of funnel of H. pacifica, paratype, 33 mm ML, preserved. The row of prominent photophores is the Basal Row. Photograph by R. Young.

2. Club suckers
   1. Suckers of 2 ventral-marginal rows of manus with broad, asymmetrical outer rings (photograph and drawing below).
   2. Largest median suckers of manus with 28-32 pointed teeth around entire margin (photograph and  drawing below).
      

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      Figure. Left - Oral view of suckers from the third and fourth series from the ventral margin of the manus of the club of H. pacifica, holotype, preserved. Photograph by R. Young. Right - Oral view of largest club sucker (top) and ventral-marginal sucker below of H. pacifica. Drawings from Voss, 1969 (Figs. 17c,b).

   

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   Figure. Oral view of suckers belonging to the ventral two sucker series series of the club of H. pacifica, holotype, 74 mm ML, female. Photograph of preserved squid by R. Young.

   1. Central suckers enlarged 1.5 times over marginal suckers.
   

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   Figure. Oral view of tentacular club of H. pacifica, 74 mm ML, male, 25°S, 35°E. Drawing from Voss (1969).
   

Comments

Species of the celetaria-group are characterized by:

1. Head photophores:
   1. Type 1b pattern on head.
   2. Basal Row of head with 9 or 10 photophores.
   3. Right Basal Series of head absent.
   4. Arms IV with 3 longitudinal series on arm base (drawing below).
      
      

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   5. Most species with separate group of 4-8 compound photophores on ends of arms IV (drawing above) (Voss, et al., 1998). Apparently this feature is absent in H. inermis.
   6. Compound photophores of large, uniform size and evenly spaced on anterior 2/3 of ventral mantle.
2. Tubercles
   1. Absent.

The species differ in the following manner:

With the exception of the analysis of head photophores and the inclusion of H. inermis in this species group, most of the information presented here is from Voss (1969) and Voss, et al . (1998)

Nomenclature

Life History

Mature females are unknown. The largest immature female is 234 mm ML. Males mature between 60->280 mm ML. (Voss, et al., 1998)

Distribution

Geographical distribution

Type locality: off Dammi Island, Philippines. H. pacifica is widely distributed in the tropical and subtropical regions of the Pacific and Indian Oceans (Voss, et al. (1998). However, with the recognition of a separate form in Hawaiian waters, the Central and Eastern Pacific records are questionable.

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Figure. Distribution chart of H. pacifica. Chart modified from Voss, et al., 1998.

References

Voss, N. A. 1969. A monograph of the Cephalopoda of the North Atlantic: The family Histioteuthidae. Bull. Mar. Sci., 19: 713-867.

Voss, N.A., K. N. Nesis, P. G. Rodhouse. 1998. The cephalopod family Histioteuthidae (Oegopsida): Systematics, biology, and biogeography. Smithson. Contr. Zool., 586(2): 293-372.

Young, R. E. 1978. Vertical distribution and photosensitive vesicles of pelagic cephalopods from Hawaiian waters. Fish. Bull., 76: 583-615.