Pistol shrimp (Alpheus glaber)

Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help



A small shrimp usually up to 43 mm in length (max. length 65 mm). Its colour is dorsally red, with white lateral borders to the carapace and appendages. The narrow rostrum is straight and unarmed, being distinctively pointed and short at the top. There are two antennae, one being a third of the length of the other. The anterior projections of the carapace actually cover the eyes in the dorsal view. The chelae are noticeable dissimilar in size with a normal join of the dactyl. The third thoracic appendage is slightly longer than scaphocerite (outer/exopod branch in antenna). And the tail fan/telson has two pairs of lateral spines.

Recorded distribution in Britain and Ireland

Occurs off the SW and W coasts of England, and off the east, south and west coasts of Ireland. Also recorded off the west coast of the Isle of Man, with numerous records in the Celtic Sea, and a recent record (05/04) off Sellafield in the east Irish Sea.

Global distribution



Found at a depth range of 30-100 m, and are either partly or completely buried in sand, silt or mud.

Depth range


Identifying features

  • Max length 65 mm; usually 43 mm.
  • Dorsally red in colour.
  • White lateral borders of carapace and appendages.
  • Narrow rostrum, short and pointed at top.
  • Dissimialer size and shape of chelae.

Additional information

The shrimp produces the snapping sound by an extremely rapid closure of its large snapper claw. The loud snap has been attributed to the mechanical contact made when the dactyl and the probus edges hit each other as the claw closes. The snapping plays an important role in intraspecific communication. In addition, it is used to defend a shelter or territory and to stun and even kill prey (for example see Versluis et al., 2000).

Listed by

- none -


  1. Bruce, J.R., Colman, J.S. & Jones, N.S., 1963. Marine fauna of the Isle of Man. Liverpool: Liverpool University Press.

  2. Hayward, P., Nelson-Smith, T. & Shields, C. 1996. Collins pocket guide. Sea shore of Britain and northern Europe. London: HarperCollins.

  3. Howson, C.M. & Picton, B.E., 1997. The species directory of the marine fauna and flora of the British Isles and surrounding seas. Belfast: Ulster Museum. [Ulster Museum publication, no. 276.]

  4. Smaldon, G., Holthuis, L.B. & Fransen, C.H.J.M., 1993. Coastal Shrimps and Prawns (Revised edn). Shrewsbury: Field Studies Council.

  5. Versluis, M., Schmitz, B., von der Heydt, A. & Lohse, D., 2000. How snapping shrimp snap: through cavitating bubbles. Science, 289, 2114-2117.


  1. NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.

  2. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2024-06-25


This review can be cited as:

Rowley, S.J. 2008. Alpheus glaber Pistol shrimp. In Tyler-Walters H. and Hiscock K. Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 25-06-2024]. Available from: https://marlin.ac.uk/species/detail/2068

Last Updated: 17/04/2008