Length: 2.5-9.5 mm. Head with a small anteriorly pointing spine; pereonite 2 with antero-lateral anteriorly pointing projections; other body tuberculations minute or absent. Antenna 1 equals approximately ½ body length. Antenna 2 shorter than antenna 1 peduncle articles 1 an 2. Gnathopod 2 basis attached anteriorly on pereonite 2; propodus nearly rectangular; palm with proximal grasping spine, median poison spine separated from distal portion by a deep cleft; proximal margin finely denticulate, distal margin coarsely denticulate; palm and distal portion bear long hairs. Pereopods 3 and 4 small, with ring of setae at distal end of first segment. Pereopods 5 - 7 six-segmented; propodus with concave palmar surface, with proximal series of knobs bearing grasping spines. Female with small median knob on head; gnathopod 2 without cleft or large poison spine and with short hairs.
California-Alaska (Pacific coast of North America). Probably endemic to the Pacific.
Caprellid, “Ghost” or “Skeleton” shrimps, so called for their skeletal appearance. Amphipod crustaceans, easily distinguished by the elongate stick-like body form and reduction of the abdominal appendages. Head is generally fused with pereonite 1. Pereopods on first 2 segments (pereonites) are most flexible and called gnathopods; gnathopods 2 being the largest, used in defense, feeding and substrate attachment. In many species pereopods 3 and 4 may also be reduced or absent. Gills on pereonites 3 + 4, rarely on pereonite 2. Pereopods 5 - 7 much smaller than 1 + 2, used for clinging to the substratum. In females, brood plates (öostegites) develop on pereonites 3 + 4. Much remains to be learnt about their biology, ecology and in many cases changing distributions.
Open rocky shore on pilings of marine wharfs, on many substrates (algae, bryozoans, hydroids, eelgrass, compound ascidians, tentacles of sabellid worm), also deeper water
