Systellaspis cristata (Faxon, 1893)
Common name(s): Krygier's spinytail
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Synonyms:Acanthephyra
cristata |
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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.
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
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