Caprella mutica

Caprella mutica Schurin, 1935

Languages: English


General Description

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.

Author(s): Ashton, Gail
Rights holder(s): Ashton, Gail


Diagnostic Description

Length: 6-49mm. Head rounded. Most extreme body projections described here (fully developed adult male): Cephalon and pereonite 1 smooth (although with dense long setae, which also extend over gnathopod 2); pereonite 2 with 1-3 pairs dorsal spines and 2 pairs lateral spines (base of gnathopods 2 and posterior); pereonite 3 with 7 pairs dorsal spines and 3-7 spines near attachment of gills; pereonite 4 with 8 pairs dorsal spines and 3-7 spines near attachment of gills, 1 pair lateral spines at both anterior and posterior margin; pereonite 5 with 5 pairs dorsal spines, 1 pair antero-lateral spines; pereonites 6 and 7 with 2 pairs of spines dorsally (median and posterior). Antenna 1 longer than ½ body length. Antenna 2 less than ½ length of antenna 1; peduncle with two ventral rows of setae. Gnathopod 1 short, with setation on posterior margin; propodus with 2 grasping spines, grasping margin of dactylus and propodus serrate. Gnathopod 2 long, densely covered in setae; propodus palm with large projection proximo-medial and a distal triangular projection ; dactylus heavy and scimitar-shaped; basis having an antero-lateral projection distally. Gills oval to elliptical. Pereopods 5 - 7 propodus with 2 grasping spines. Females differ in presence of 1 pair spines on cephalon and posterior of pereonite 1 (not always present)

Author(s): Ashton, Gail
Rights holder(s): Ashton, Gail


Introduced throughout the northern hemisphere and to New Zealand in the southern hemisphere. Very abundant during summer months. Distinguished from C. acanthogaster: pereonite 2+3 covered in fine setae in mature male, gnathopod 2 poison spine less developed, gills are shorter.

Author(s): Ashton, Gail
Rights holder(s): Ashton, Gail


National Museum of Natural History, Washington DC: (NMNH); University of Alaska, Fairbanks

Author(s): Ashton, Gail
Rights holder(s): Ashton, Gail

Ecology and Distribution


Native to Sea of Japan (Russia and Japan); introduced widely in northern hemisphere and New Zealand in the southern hemisphere.

Author(s): Ashton, Gail
Rights holder(s): Ashton, Gail


In fouling communities on floats and pilings, on many substrates (hydroids, bryozoans, ascidians etc.)

Author(s): Ashton, Gail
Rights holder(s): Ashton, Gail


  • Caprella macho Platvoet et al., 1995 (synonym)
  • Caprella acanthogaster humboldtiensis Martin, 1977 (synonym)


Arimoto, I. (1976).  Taxonomic studies of caprellids (Crustacea, Amphipoda, Caprellidae) found in the Japanese adjacent waters.. Special publications from the Seto Marine Biological Laboratory Series III. 111. Osaka, Japan: Nippon Printing & Publishing Co., Ltd.
Ashelby, C. W. (2005).  The occurrence and distribution of non-native fauna in Harwich Harbour and the Stour and Orwell estuaries, including new records of Caprella mutica Schurin 1935 and Bugula stolonifera Ryland 1960.. Essex Naturalist. 22, 103-116.
Ashton, G. V. (2006).  Distribution and dispersal of the non-native caprellid amphipod, Caprella mutica Schurin 1935. PhD Thesis. Scottish Association for Marine Science, Oban.
Ashton, G. V., Willis K. J., Burrows M. T., & Cook E. J. (2007).  Environmental tolerance of Caprella mutica: Implications for its distribution as a marine non-native species. Marine Environmental Research. 64, 305-312.
Ashton, G. V., Willis K. J., Cook E. J., & Burrows M. T. (2007).  Distribution of the introduced amphipod, Caprella mutica Schurin on the west coast of Scotland and a review of its global distribution. Hydrobiologia. 590, 31-41.
Ashton, G., Stevens M. I., Hart M. C., Green D. H., Burrows M. T., Cook E. J., et al. (2008).  Mitochondrial DNA reveals multiple northern hemisphere introductions of Caprella mutica (Crustacea, Amphipoda). Molecular Ecology. 17, 1293-1303.
Buschbaum, C., & Gutow L. (2005).  Mass occurrence of an introduced crustacean (Caprella cf. mutica) in the south-eastern North Sea. Helgoland marine research. 59, 252-253.
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Marelli, D. C. (1981).  New records for Caprellidae in California, and notes on a morphological variant of Caprella verrucosa Boeck, 1871.. Proceeding of the Biological Society of Washington. 94, 654-662.
Michel, K., Nauwelaerts S., Boos K., & Stamhuis E. (2007).  Is the Japanese skeleton shrimp Caprella mutica a filter feeder? I. Head morphology and kinematics. Presentation.
Nauwelaerts, S., Michel K., Boos K., & Stamhuis E. (2007).  Is the Japanese skeleton shrimp Caprella mutica a filter feeder? II. Fluid Mechanics. Presentation.
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Platvoet, D., de Bruyne R. H., & Gmelig Meyling A. W. (1995).  Description of a new Caprella-species from the Netherlands: Caprella macho nov.spec. (Crustacea, Amphipoda, Caprellidae). Bulletin of the Zoological Museum, University of Amsterdam. 15, 1-4.
Sano, M., Omori M., & Taniguchi K. (2003).  Predator-prey systems of drifting seaweed communities off the Tohoku coast, northern Japan, as determined by feeding habit analysis of phytal animals. Fisheries Science. 69, 260-268. Abstract
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