Description:
As with all Flabelliferan
isopods, the uropods
are lateral to the pleotelson
(photo), the uropodexopodites
do not arch over the pleotelson
(photo), pereopod
1 is not greatly enlarged and is not subchelate
(photo), and the
animal is less than 7
times as long as wide. Excirolana
kincaidi has 5 visible pleonites
plus the pleotelson.
Both the endopod
and the exopod
of the uropods
are well developed and lamellar.
The animal cannot roll into a ball and does not bore in wood.
None
of the pereopods
have large, hooklike dactyls
for attaching to fishes, though some do have small hooks (photo).
The posterior border of the telson
is fringed with long, plumose setae
(photo). The telson
is angular and comes to a fairly sharp point at the end (angle of point
about 120 degrees). The animal has a spatulaterostrum
(this and the long plumose setae
on the telson
distinguish genus Excirolana
from genus Cirolana).
The eyes are lateral on the head and the distance between them is
greater
than their diameter.
How to Distinguish from Similar Species: Excirolana vancouverensis has a rounded tip on its angular telson. Excirolana linguifrons has a broadly rounded or truncate tip to the telson and reaches only 4 mm in length. Geographical Range: British Columbia to Half Moon Bay, CA Depth Range: Intertidal Habitat: Sandy beaches. Biology/Natural History: These isopods alternately bury themselves in the sand and actively forage for dead animal matter. They seem to be especially active in the shallow swash of retreating waves on sandy beaches. Large numbers may quickly congregate around an animal carcass that washes in on a sandy beach while it is still in the water, and quickly strip the carcass of flesh. This is the most common Excirolana species along the Washington coast. Predators include sanderlings. Note: Very few crustaceans will actually bite you
but this nasty
little creature is definitely one of them. Barefoot waders in
an
area with Excirolana
will
find that the animals quickly swim toward and swarm over bare feet,
biting
them so hard that blood will be flowing within moments. Since
the
animals are so small the bites are tiny but painful like a pin prick,
and
the animals are often present in swarms of thousands. Rapidly
shuffling
the feet reduces but does not eliminate the number of bites.
References:Dichotomous Keys:Kozloff 1987, 1996 Smith and Carlton, 1975 General References:
Scientific Articles:
Web sites:
General Notes and
Observations: Locations,
abundances, unusual behaviors:
I have seen (and felt!) this species on sandy beaches of the
outer coast,
such as Kalaloch beaches, 2nd and 3rd beach, and Shi Shi beach.
This closeup ventral view of the head shows the hardened,
biting jaws
(mandibles) and the first several pereopods. The maxillae and
the
maxillipeds are light colored and lie between the mandibles and the
first
pereopods, which have small dark hooklike dactyls. The first
pereopod
is has a simple dactyl and is neither chelate nor subchelate.
Notice
that the eyes are lateral and can easily be seen from the ventral
side.
The spatulate rostrum can be seen protruding between the antennae.
Notice that both rami of the uropods have flattened plates. Some of the terminal setae from the uropods are projecting beyond the telson.
Authors and Editors of Page: Dave Cowles (2007): Created original page CSS coding for page developed by Jonathan Cowles (2007) |