Description:
As with other members
of Family Crangonidae, this species has a subchelate
pereopod
1 (photo) and the carpus
of pereopod
2 is not subdivided into several units. Crangon
alba has a very short rostrum
(photo). The dactyl
of leg 5 (the last walking leg) is not broad and flattened. The eyestalks are not
parallel
nor shielded by a hood made of spines (photo).
Its carapace
is smooth. It has a single median
dorsal spine shortly behind the rostrum (photo)
but no submedian spines. Abdominal segment 5 has no spines on
the
upper posterolateral margins (photo).
Abdominal segment 6 has no prominent longitudinal ridges on the dorsal
surface (photo) and also has no median
groove on the ventral surface (photo).
How to Distinguish from Similar Species: Crangon franciscorum has a spine on the upper posterolateral margin of abdominal segment 5. C. handi, C. alaskensis, and C. nigricauda have a median ventral groove on abdominal segment 6. Geographical Range: East Pacific Depth Range: Habitat: Biology/Natural
History: Crangon
shrimp are common on sandy bottoms, where their camouflage helps them
blend
in well. If disturbed they will often swim down to the sand,
rest
their ventral surface on it, and quickly burrow out of sight (using their legs, but probably
also using their pleopods--see the photo
below and this movie).
References:Dichotomous Keys:Kozloff 1987, 1996 General References:
Scientific Articles:
Web sites: General Notes and
Observations: Locations,
abundances, unusual behaviors:
In this
underside (ventral) view of the
head the subchelate
first pereopods
can be clearly seen.
In this dorsal view of the head the small rostrum and the single median spine behind it can be seen. The arrangement of the eyestalks can also be clearly seen. The
upper posterolateral margin
of abdominal segment 5 has no spines, as seen in this dorsal
view.
Anterior is to the right, and segment 6 is to the left.
Abdominal
segment 6 has a dorsal
median
groove (sulcus)
but no median
ridge. Anterior is to the right and the tailfan is to the
left.
The
ventral sides of abdominal
segments 5 (right) and 6 (left) are both smooth and clear, with no median
groove (sulcus).
The feathery exopods
of the pleopods
are typically held out to the side. They are used for
swimming and
likely also for burrowing.
This individual
was
carrying a large batch of white
eggs.
Authors and Editors of Page: Dave Cowles (2008): Created original page CSS coding for page developed by Jonathan Cowles (2007) |