Systellaspis cristata (Faxon, 1893)

Common name(s): Krygier's spinytail
Synonyms:Acanthephyra cristata
Phylum Arthropoda
 Subphylum Crustacea
  Class Malacostraca
   Subclass Eumalacostraca
    Superorder Eucarida
     Order Decapoda
      Suborder Pleocyemata
       Infraorder Caridea (true shrimp)
        Family Oplophoridae
Systellaspis cristata, caught off Point Conception, CA at 600-750 m depth.
(Photo by: Dave Cowles, Sept 1995)
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.  Systellaspis have a well-developed rostrum and no dorsal ridge (carina) on the sixth abdominal segment (photo).  There is no dorsal carina or posteromesial tooth on the second abdominal segment (photo), but there is at least a small posteromesial tooth on the fifth abdominal segment. The sixth abdominal segment is much longer than the 5th segment (at least nearly twice as long).  The telson ends in a spiny endpiece which has a pair of longer spines on the sides of its base (photo).  Their eyes are well pigmented, eggs are large and few (less than 50). S. cristata has a long rostrum which is more than half as long as the rest of the carapace and extends to at least the distal fourth of the antennal scale (photo).  The dorsal carina on the carapace runs back nearly to the posterior carapace margin, and a sinuous lateral carina runs along the side of the carapace from near the eye almost to the posterior carapace margin (photo).  Another carina runs along the ventral margin of the carapace (photo).  The third abdominal segment also has a dorsal spine on the posterior edge (posteromesial spine), as seen above (photo).  The telson has 2 or more rows of at least small spines on each side (photo).  Total length to 81 mm for males and 169 mm for females.

How to Distinguish from Similar Species: S. braueri has a shorter, triangular rostrum (no more than half as long as the carapace) with the distal third free of spines. S. debilis, which lives further south, does have a long rostrum but does not have the sinuous lateral or ventral carina on the carapace.  Its 6th abdominal segment is also only about 1 2/3 as long as the 5th and it has dorsolateral rows of not more than 10 spines on the telson.

Geographical Range:  Vancouver Island to Gulf of Panama, Bay of Biscay to Angola in the Atlantic Ocean, Indian Ocean.  Type specimen was captured near Panama.

Depth Range:  600-2500 m

Habitat:  Bathypelagic

Biology/Natural History:  This bathypelagic species is not very common.  Only 2 individuals have been recorded captured off British Columbia (Butler, 1980).  Atlantic individuals carry large reddish-orange eggs.


 
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References:

Dichotomous Keys:
  Chace, 1986
  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
   Chace, Fenner A., 1986.  The caridean shrimps (Crustacea: Decapoda) of the Albatross Philippine expedition, 1907-1910, Part 4: Families Oplophoridae and Nematocarcinidae.  Smithsonian Contributions to Zoology 432

Scientific Articles:
 

Web sites:


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

The photographs below are of an individual we captured at 800 m depth Northwest of Oahu, Hawaii on New Horizon cruise NH96-2 trawl 87.  Photographs of a formalin-preserved specimen taken by Dave Cowles, January 2013.  Note that when preserved the animals lose almost all their dark red pigment.



Whole individual.  Carapace length 1.9 cm.  Notice how the 6th abdominal segment is twice as long or more than the 5th abdominal segment, and that it does not have a dorsal carina.  Also note that abdominal segments 3, 4, and 5 have a posteromesial spine.



Lateral view of abdominal segments 2-3.  Segment 2 has no dorsal carina nor posteromesial spine, while segment 3 has both a carina and a spine.



Dorsal (slight angle) view of the uropods and telson.  The spiny endpiece on the telson has been slightly damaged but the long lateral spines at the base can still be seen.  A few of the dorsolateral spines along the telson can also be seen along the top margin.



This side view of the head shows the long, toothed rostrum which extends out to near the end of the antennal scales (which are deflected downward out of view in this photo)



The three characteristic carinae which run nearly to the posterior end of the carapace can be seen in this side view.  Dorsally there is a carina which runs from the rostrum (left) to near the posterior end of the carapace on the right.  A small, sinuous carina runs from near the eye along the mid-side of the carapace.  In this photo a number of bubbles are adhered to it.  A sharp carina lines the ventral margin of the carapace.  In this preserved specimen the ventral carina has retained much of its red color while the rest of the carapace has faded to yellow.
 
 
 
 


Authors and Editors of Page:
Dave Cowles (2006):  Created original page.  Edited by Dave Cowles 2013