Biodiversity & Conservation

Sea bristletail - Petrobius maritimus

Petrobius maritimus

Image Harvey Tyler-Walters - Aggregation of Petrobius maritimus. Image width ca 5 cm.
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Distribution map

Petrobius maritimus recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

Why do the maps differ?

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Petrobius maritimus is not listed under any importance categories.

Taxonomy icon Taxonomy Taxon English term
Phylum Arthropoda Arthropods, joint-legged animals, e.g. insects, crustaceans & spiders
Class Insecta Insects
Authority (Leech, 1809)
Recent synonyms None
Map icon Recorded Distribution in Britain and Ireland Recorded around the coast of Britain but with an absence of records from north east Scotland and the south east of England. No records were found for Ireland. However, this species is likely to be under-recorded.
Habitat information icon Habitat information Found above high water, usually under stones and on screes or in chinks of rock and wood. Occurs inland in several places along the west coast of Britain.
Text page icon Description Petrobius maritimus are fast-running insects with elongate, tapered, grey mottled coloured bodies up to 1.5 cm long. They have three pairs of legs and a triple forked tail. Individuals have prominent eyes and a short pair of palps on the head set between a further pair of long, bristly antennae of 30 or more segments.
Identifying features
  • Elongate, tapered body, up to 1.5 cm.
  • Grey coloured body.
  • Triple forked tail.
  • Long, bristly antennae of 30 or more segments.
  • Prominent eyes.
Additional information icon Additional information Petrobius maritimus, may be confused with Petrobius brevistylis which occurs in the same habitat. The two species can be separated by the sub-coxae of the male. In Petrobius brevistylis the 8th abdominal segment is prolonged into rounded lobes, whereas lobes are absent in Petrobius maritimus.

This review can be cited as follows:

Susie Ballerstedt 2008. Petrobius maritimus. Sea bristletail. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 01/12/2015]. Available from: <>