Description: This skeleton shrimp (Caprellid) has two forward-projecting spines on the back of its head. The articles of the peduncle of antenna 1 are much longer than wide, and the flagellum of the first antenna is shorter than the peduncle (see photo above). On males, the peduncle of antenna 1 is stout and setose (photo) and the flagellum has less than 20 articles. Its mandible has a molar process but does not have a palp. The merus of gnathopod 2 has a sharp, spiny anteroventral projection or a stout, spinelike seta. The propodus of gnathopod 2 is less than 2/3 as wide as long, and the second gnathopods do not have a ventral spine on the pereonite surface between them. Pereonites 1 and 2 of males are more than twice as long as wide. It has gills only on pereonites 3 and 4. Pereonites 3 and 4 also have several pairs of spines and have oostegites on mature females, but not even rudimentary legs on either sex. Pereopods 5-7 (the legs near the back) have a single grasping spine or tooth on their propodus. Females have a rough texture, with spines on all segments. Has pink spots and bands.
How to Distinguish from Similar Species: This is an unusually large skeleton shrimp species. Metacaprella anomala has the flagellum of antenna 1 longer than the peduncle and pereonites 1 and 2 of males are not more than twice as long as wide.
Geographical Range: All along the N American Pacific coast
Depth Range: Intertidal and subtidal
Habitat: Many different substrates and fouling communities (first described from a fouling community on a ship in Port Townsend). Often in Abietenaria hydroid colonies.
especially well-camouflaged on Plumularia
lagenifera hydroids. The setae on the antennae
are apparently used to scrape algae off the body. Filter
and detritus eaters scrape their body clean, such as this
Carnivorous predator and scavenger species allow algae to grow on them,
presumably to increase their camouflage.
Kozloff, 1987, 1996 (as Metacaprella kennerlyi)
Caine, E.A., 1980. Ecology of two littoral species of caprellids (Crustacea) from Washington, USA. Marine Biology 56: pp 327-335
Jensen, M.P., 1969. The ecology and taxonomy of the Caprellidae (Order: Amphipoda; Suborder: Caprellidea) of the Coos Bay, Oregon, area. Ph.D. dissertation, Department of Entomology, University of Minnesota
Martin, D.M., 1977. A survey of the family
Amphipoda) from selected sites along the northern California
Bulletin of the Southern California Academy of Sciences 76: pp 146-167
General Notes and Observations: Locations, abundances, unusual behaviors:
Authors and Editors of
Salish Sea Invertebrates web site provided courtesy of Walla