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Pyroteuthis addolux Young, 1972

Richard E. Young and Katharina M. Mangold (1922-2003)
Containing group: Pyroteuthis


This species is most easily separated from other members of the genus by the arrangement of photophores on the tentacles and the structure of the hectocotylus. It also appears to have shorter arms, relative to the mantle length, than in the other species.


  1. Tentacle-photophores 
    1. Four large, ellipsoidal photophores (three are double photophores).
      1. Most distal member near base of carpal cluster (i.e., distance between this photophore and distal, spherical photophore much less than distance between distal two ellipsoidal photophores).
    2. Two smaller, spherical photophores, one at base of tentacular stalk and one at base of club.
    3. Spherical to ovoid superficial photophore (smallest of all) near base of tentacle and whose presence is variable.
    4.  image info

      Figure. Diagramatic illustration of the tentacular photophores of P. addolux. Drawing by R. Young.

  2. Hectocotylus (right arm IV) with:
    1. 10 proximal hooks.
    2. Each proximal hook small with primary cusp bearing smooth inner edge and short secondary cusp.
    3. Flap short, almost semicircular.
    4. 6-7 hooks opposite flap.
    5. 6-15 suckers at tip.
      Figure. Oral view of the hectocotylus of P. addolux, holotype, 30 mm ML, from Young, 1972.


Compare the following structures with other species of Pyroteuthis:

Arm and tentacle armature is shown here. Characters of species value associated with these structures are not presently recognized except on the hectocotylus.

Life history

 image info

Figure. Ventral view of P. addolux, 2.9 mm ML. Drawing modified from Young, et al., 1992.

Paralarvae of this species are identified by:

  1. A series of chromatophores on the distal portion of each tentacle (see arrow in drawing). Unfortunately these are easily lost due to damage during capture.
  2. Small branchial photophores (smaller than the anal organs).
  3. Large ocular photophores.
  4. Few chromatophores on mantle.

Compare with paralarvae of Pterygioteuthis microlampas and Pterygioteuthis giardi.


Vertical distribution

Off Hawaii, P. addolux is generally found at 450-500 m deep during the day and 150-200 m at night (Young, 1978). It shows a clear pattern of vertical migration although a few large squid taken in three tows during the same cruise failed to migrate at night.

 image info

Figure. Vertical distribution of P. addolux from Hawaiian waters based on an opening-closing trawl. Yellow dots - Day captures. Blue dots - Night captures. Vertical lines indicate vertical-fishing range of the tow and the symbol represents the modal fishing depth of the trawl. In some cases, the vertical lines are covered by the symbols. Chart redrawn from Young, 1978.

Geographical distribution

P. addolux was first described from off southern California (Young, 1972). It is also known from Hawaiian waters. This map shows the general localities (white circles) where P. addolux has been captured. Areas where pyroteuthids, other than members of this species, have been captured are represented by yellow crosses. (records listed here).

 image info

Geographical variation

The second photophore from the base of the tentacle (photophore number 2) is less common in squid from Hawaiian waters than in squid from Californian waters. Otherwise, geographical variation in taxonomic characteristics is unknown.


Young, R. E. 1972. The Systematics and Areal Distribution of Pelagic Cephalopods from the Seas off Southern California. Smithsonian Contribution to Zoology, 97: 1-159.

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

Young, R. E., K. M. Mangold and M. Vecchione. 1992. The enoploteuthid group of families. P. 55-66. In: Sweeney, M. J., C. F. E. Roper, K. M. Mangold, M. R. Clarke and S. V. Boletzky (Eds.). "Larval" and juvenile cephalopods: A manual for their identification. Smithson. Contr. Zool. No. 513

Title Illustrations
Scientific Name Pyroteuthis addolux
Location off Hawaii
Copyright © 1996 R. E. Young
Scientific Name Pyroteuthis addolux
Location off California
Reference from Young, R. E. 1972. The Systematics and Areal Distribution of Pelagic Cephalopods from the Seas off Southern California. Smithsonian Contribution to Zoology, 97: 1-159.
Type holotype
About This Page

Richard E. Young

Dept of Oceanography
University of Hawaii
Honolulu, Hawaii 96822

Katharina M. Mangold (1922-2003)

Citing this page:

Young, Richard E. and Mangold (1922-2003), Katharina M. 1996. Pyroteuthis addolux Young, 1972. Version 01 January 1996 (under construction). http://tolweb.org/Pyroteuthis_addolux/19757/1996.01.01 in The Tree of Life Web Project, http://tolweb.org/

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Pyroteuthis addolux

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