Caprella
angusta Mayer, 1903
Common name(s): Skeleton shrimp
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Synonyms:
Smith
and Carlton (1975) state that Caprella
uniforma is probably a junior synonym. ITIS
does not list C.
angusta
at all but does list C.
augusta
with no range information. |
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Phylum Arthropoda
Subphylum Crustacea
Class Malacostraca
Subclass Peracarida
Order Amphipoda
Suborder Caprellidea
Infraorder Caprellida
Family Caprellidae
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Caprella
angusta from eelgrass
in Padilla Bay. Total length about 4 cm. One of the
ventral
flaplike gills is visible posterior to the large grasping gnathopods
2, right at the end of the eelgrass. |
(Photo by: Dave Cowles,
July 2008) |
Description:
This freeliving
caprellid amphipod has gills on only pereonites
3 and 4 (not on pereonite
2). It has no pereopods
on pereonites
3 and 4. Gnathopod
2 (the large set) has a propodus
which is less than 2/3 as wide as it is long (photo),
and the propodus
of pereopods
5-7(the back legs, with which it grasps the substrate) (photo)
has only one grasping spine or tooth (Smith and Carlton 1975 says there
are two or more). There is no spine on the ventral body
surface between
gnathopods
2 (photo), but there is
a large, dorsal, anteriorly
directed triangular spine on the back of the head (photo).
It has few or no tubercles
on the dorsal surface of the pereonites,
and none on pereonite
1. Gnathopod
2 of the male is attached at the anterior end of pereonite
2.
How to Distinguish from
Similar Species: Tritella
pilimana has a vestigial pereopod
on pereonites
3 and 4, while Caprella angusta does not.
Several other members
of genus Caprella either do not have the large
triangular spine
on the dorsal side of the head, or also have large dorsal tubercles
on their pereonites
and gnathopod
2 is attached near the middle of pereonite
2.
Geographical Range:
Depth Range:
Habitat:
Biology/Natural History:
Caprellid
amphipods such as this species are roving predators. We often
find
them climbing on eelgrass or hydroids searching for prey.
With their
large claws (gnathopods)
and bizarre shape they would truly be monsters if they were our size!
References:
Dichotomous Keys:
Kozloff
1987, 1996
Smith
and Carlton (1975) (as C. uniforma)
General References:
Scientific Articles:
Web sites:
General Notes and
Observations: Locations,
abundances, unusual behaviors:
This closeup shows pereonites
5-7 with their appendages, pereopods
5-7. Pereopods
5-7 arise from the posterior end of their segment (pereonite)
and are used for gripping the substrate such as this eelgrass
blade.
The left pereopod
7 is missing.
The propodus
of gnathopod
2 is less than 2/3 as wide as it is long. Note also the gill
on the
segment behind.
This ventral view shows there is no spine between the large gnathopods
2 and shows the location of the gills.
This view of the head (animal is looking to the left) shows the very
large second antennae to the left, then the head with sessile
eyes and prominent, forward-directed head spine. Below the
head can
be seen the first gnathopods
which are on the anterior end of the first thoracic segment (pereonite),
which extends out of view to the right.
Authors and Editors of Page:
Dave Cowles (2008): Created original page
CSS coding for page developed by Jonathan Cowles (2007)
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