Pyroteuthis
Richard E. Young and Katharina M. Mangold (1922-2003)![taxon links](/Public/treeImages/Pyroteuthis.png?x=1619652307)
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close boxIntroduction
Members of Pyroteuthis are similar in appearance to those of Pterygioteuthis except that they are larger as adults and tend to have broader heads.
Brief diagnosis:
A pyroteuthid ...
- with one series of hooks on club manus.
- with more than 13 hooks on each arm.
Characteristics
- Arms
- Arm hooks in two series.
- More than 13 hooks/arm.
- Arms IV with >16 hooks.
- Right arm IV hectocotylized; toothed plate absent.
- Tentacles
- Tentacular club with one series of hooks and three series of suckers on manus.
- Tentacular club with one series of hooks and three series of suckers on manus.
- Photophores
- Oviducts.
- Both present; right may be reduced.
Comments
The major differences between the species lie in:
Discussion of Phylogenetic Relationships
P. addolux is more similar to P. serrata than to P. margaritifera in the arrangement of tentacular photophores and in the structure of the hectocotylus (Riddell, 1985).
Behavior
The quick, brilliant bioluminescent flashes observed in Pterygioteuthis spp. have not been seen in Pyroteuthis spp. This is not surprising since comparable photophores in Pyroteuthis are either absent (lidded ocular photophore) or less specialized (branchial photophores). However, we have seen P. addolux produce a peculiar, long-duration flash where all tentacular photophores, among others, glow for up to 4 or 5 seconds. We call this the Y-pattern display since the photophores are aligned in a pattern of this shape. All of the photophores involved have not been clearly identified but include four tentacular photophores and some ocular and visceral organs. To produce the Y-pattern, the tentacles are held straight and rigid at angles of approximately 45° to the body axis. This behavior is illicited when the squid is distrubed without direct physical contact. When physical contact is involved (i.e., squid touched or grabbed), the same photophores seem to be involved but the tentacles undulate instead of being held rigid.
Pyroteuthis addolux has been shown in the laboratory to counterilluminate (i.e., use bioluminescence to match the dim downwelling light and thereby eliminate the squid's silhouette) (Young and Roper, 1977). The photophores involved were, apparently, the ocular and anal organs.
Distribution
Species of Pyroteuthis are found throughout most of the tropical and temperate regions of the world's oceans but they are apparently absent from the Tropical Eastern Pacific (Nesis, 1982).
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This map shows the general localities (white circles) where Pyroteuthis has been captured. Areas where pyroteuthids, other than members of this genus, have been captured are represented by yellow crosses. (Records are listed here).
References
Nesis, K. N. 1982/87. Abridged key to the cephalopod mollusks of the world's ocean. 385+ii pp. Light and Food Industry Publishing House, Moscow. (In Russian.). Translated into English by B. S. Levitov, ed. by L. A. Burgess (1987), Cephalopods of the world. T. F. H. Publications, Neptune City, NJ, 351pp.
Riddell, D. J. 1985. Enoploteuthidae of the New Zealand Region. Fisheries Research Bulletin. New Zealand Ministry of Agriculture and Fisheries, No.27: 1-52.
Young, R. E. and C. F. E. Roper (1977). Intensity regulation of bioluminescence during countershading in living midwater animals. Fish. Bull., U.S., 75: 239-252.
Title Illustrations
![Click on an image to view larger version & data in a new window](/tree/img/magnify.gif)
Scientific Name | Pyroteuthis addolux |
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Location | Hawaiian waters |
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Copyright |
© 1996
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About This Page
University of Hawaii, Honolulu, HI, USA
Katharina M. Mangold (1922-2003)
Laboratoire Arago, Banyuls-Sur-Mer, France
Page copyright © 2019 and Katharina M. Mangold (1922-2003)
Page: Tree of Life
Pyroteuthis
Authored by
. Richard E. Young and Katharina M. Mangold (1922-2003).
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- Content changed 29 December 2009
Citing this page:
Young, Richard E. and Katharina M. Mangold (1922-2003). 2009. Pyroteuthis http://tolweb.org/Pyroteuthis/19748/2009.12.29 in The Tree of Life Web Project, http://tolweb.org/
. Version 29 December 2009 (under construction).