Pagurus hirsutiusculus

Taxobox
name = Hairy hermit crab


image_width = 250px
image_caption = "Pagurus hirsutiusculus"
regnum = Animalia
phylum = Arthropoda
subphylum = Crustacea
classis = Malacostraca
subclassis = Eumalacostraca
ordo = Decapoda
subordo = Pleocyemata
infraordo = Anomura
familia = Paguridae
genus = "Pagurus"
species = "P. hirsutiusculus"
binomial = "Pagurus hirsutiusculus"
binomial_authority = Dana, 1852

"Pagurus hirsutiusculus" is commonly called the hairy hermit crab.

Description

Adults range in color from olive green to brown to black. Distinguishing characteristics of this hermit crab are white and often also blue bands on the walking legs at the joint of the propodus and the dactyl. The antennae are grayish-brown with distinct white bands. This hermit crab is also easily identified by the remarkable amount of hair covering its body.

ize

The carapace of an adult "P. hirsutiusculus" may measure up to 19 mm in length.

Range and Habitat

"P. hirsutiusculus" is found from the Pribilof Islands, Alaska to southern California. They can be found from the middle intertidal zone to water depths of up to 110 meters. They are commonly found in tide pools with sand or rock, and under rocks, logs, and seaweed.

Diet

"P. hirsutiusculus" mainly feeds on detritus, but is an opportunistic feeder and also feeds on seaweeds.

Natural History

The right chela of "P. hirsutiusculus" is significantly larger than the left and is used primarily for defense. The smaller left chela is used for fine motor work such as eating and selecting gastropod shells. The setae on the minor chela are sensetive to calcium, and help the hermit to judge whether the gastropod shell will be adequate to suit its needs. As is common with hermit crabs, "P. hirsutiusculus" carries an abandoned gastropod shell to protect itself. Unlike many hermit crabs which seem to prefer shells into which they can completely withdraw, "P. hirsutiusculus" often chooses small gastropod shells that can be easily abandoned when it encounters a potential predator, using speed as its primary defense against predation. The primary predators of "P. hirsutiusculus" are sculpins.

Life History

The color pattern and hairiness of "P. hirsutiusculus" varies with age. A "P. hirsutiusculus" can be identified as female by the small pleopod appendages on the left side of her abdomen. She attaches her eggs to these pleopods after mating and may carry up to 5 broods through spring and summer.

References

*Duane, S. J. (1999). "The Beachcomber's Guide to Seashore Life in the Pacific Northwest". (pp. 117). Maderia Park, B. C. Harbour Publishing.
*Jensen, G. C. (1995). "Pacific Coast Crabs and Shrimps". (pp. 66). Montgomery, CA. Sea Challengers.
*Kozloff, E. N. (1993). "Seashore Life of the Northern Pacific Coast, an Illustrated Guide to Northern California, Oregon, Washington, and British Columbia". (pp. 132). Seattle, WA. University of Washington Press.
*Lamb, A. and Hanby, B. P. (2005). "Marine Life of the Pacific Northwest: A Photographic Encyclopedia of Invertebrates, Seaweeds, and Selected Fishes". (pp. 314). Maderia Park, B. C. Harbour Publishing.
*Mesce, K. A. (1993). Morphological and Physiological Identification of Chelar Sensory Structures in the Hermit Crab "Pagurus hirsutiusculus" (Decapoda). "Journal of Crustacean Biology, 13", 95-110.

External links

* [http://www2.evergreen.edu/wikis/ize/index.php?title=Invertebrate_Zoology_and_Evolution&redirect=no Link to Invertebrate Species Pages]