Acanthephyra curtirostris Wood-Mason, 1891

Common name(s): Peaked shrimp

Phylum Arthropoda
 Subphylum Crustacea
  Class Malacostraca
   Subclass Eumalacostraca
    Superorder Eucarida
     Order Decapoda
      Suborder Pleocyemata
       Infraorder Caridea (true shrimp)
        Family Oplophoridae
Acanthephyra curtirostris, caught at about 500 m depth off Point Conception, CA
(Photo by: Dave Cowles, May 1996)
Description:  This is a true shrimp from the family Oplophoridae, which lives in deep midwater offshore.  True (Caridean) shrimp have the second abdominal epimera overlapping that of segment 1 and 2.  Family Oplophoridae is almost entirely midwater, has exopodites on its pereopods, and pereopods 1 and 2 are longer and more stout than the others.  Acanthephyra curtirostris is an all-red shrimp which has a median dorsal ridge on abdominal segment 6 but not on segment 1.  It has a blunt rostrum as in the photo above.  The second somite of the abdomen is dorsally carinate.  The dorsal carina on the carapace does not extend back onto the posterior third of the carapace.  The branchiostegal spine is supported by a carina which extends to the posterior half of the branchial region.  The rostrum is triangular and drawn out into a sharp point.  The telson has 7 to 15 dorsolateral spines.  Up to about 79 mm total length.

How to Distinguish from Similar Species: This species looks rather similar to the rare  A. brevirostris and A. chacei, and to A. smithi, which grows larger, is found farther south, and has a more acute rostrum.  Few other species have the distinctively shaped rostrum.

Geographical Range: Worldwide at lower latitudes; to 51 degrees north in the Eastern Pacific.

Depth Range: Deep midwater, 200 - 2200 m

Habitat: Midwater

Biology/Natural History: This bathypelagic midwater shrimp is an active, steady swimming predator but does not vertically migrate.  A cosmopolitan species at tropical and subtropical latitudes, there is substantial genetic distance between populations separated by large geographical distances (such as between California and Hawaii, John F. Scarbrough dissertation, Loma Linda Universtiy 2004).  It is less common this far north than it is in tropical and subtropical waters.

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Dichotomous Keys:
  Kozloff 1987, 1996
  Wicksten, 2009

General References:
Butler, TH (1980). Shrimps of the Pacific Coast of Canada. The Canadian Bulletin of Fisheries and Aquatic Sciences 202: 1–280

Chase, Fenner A., 1986.  The Caridian Shrimps (Crustacea: Decapoda) of the Albatross Philippine Expedition, 1907-1910, Part 4:  Families Oplophoridae and Nematocarcinidae.  Smithsonian Contributions to Zoology Number 432.  Paperback, 82 pp.

Hendrickx, Michel E. and Flor Delia Estrada navarrete, 1996.  Los Camarones Pelagicos (Crustacea: Dendrobranchiata y Caridea) del Pacifico Mexicano.  Comision Nacional para el Conocimiento y Use de la Biodiversidad.  Paperback, Spanish 157 pp.  ISBN 968-29-8882-9

Scientific Articles:
Cowles, D.L, J.J.,Childress, and M.E.Wells (1991). Metabolic rates of midwater crustaceans as a function of depth occurance off the Hawaiian Islands: Food availibility as a selective factor? Marine Biology 110: 75–83

Krygier, E.E and W.G. Pearcy (1981) Vertical Distribution and biology of pelagic decapod crustaceans off Oregon. Journal of Crustacean Biology 1: 70–95

Wasmer, Robert A., 1967.  Bathypelagic shrimps (Penaeidea and Caridea) from the eastern North Pacific.  Master's thesis, Walla Walla College, College Place, WA.   86 pp.

General Notes and Observations:  Locations, abundances, unusual behaviors:

Another photo of this species.  Dave Cowles, 1995.  Caught off southern CA.

Click Here for a mpg video of this shrimp and a description, taken by me on shipboard in 1996 off Point Conception, CA (9 megabytes)

This species is widespread.  Below is a photo of the same species caught off Oahu, Hawaii.
Acanthephyra curtirostris from midwater off Oahu, Hawaii.  Photo by Dave Cowles, July 1987

Authors and Editors of Page:
Dave Cowles (2005):  Created original page