Length: 5-22mm. Head and body smooth dorsally except pereonite 5 may have paired spines; laterally large anteriorly pointing spines at the bases of gnathopod 2, antero-lateral spines on pereonites 3 and 4; pereonite 5 distinctly sculptured anteriorly, giving the appearance of large lateral spines. Distinct lateral spine between insertions of gnathopod 2. Antenna 1 as long as cephalon plus pereonite 2; antenna 2 shorter than the two basal articles of antenna 1. Gnathopod 1 with barely serrate grasping margin to propodus and dactylus. Gnathopod 2 attached posterior to median of pereonite 2; basis with antero-lateral ridge ending in a spine-like process; propodus with proximal grasping spine, distal ‘tooth’, groove and triangular projection. Gills large, oval. Pereopods 5 - 7 increasing in length; propodus with proximal grasping spines, palm slightly concave and bearing a few spines. Female differs in antenna 2 equal in length to peduncle of antenna 1; gnathopod 2 attached anteriorly on pereonite 2 and having a longer basis.
World-wide (may be species complex)
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.
Most common in intertidal + shallow waters on seaweeds, hydroids, gorgonians, bryozoans, and ascidians, artificial structures: wharf pilings, aquaculture structures and marina floats. Found down to 3000 m (Schellenberg 1926).
Variations described within range, but thus far no taxonomic decision has been reached on these. Parts of distribution likely due to ship associated introductions
National Museum of Natural History, Washington DC: (NMNH) 113619* (C. aequilibra); (NMNH) 39409; Near Port Royal , South Carolina; (NMNH) 258977
