Biodiversity & Conservation

Common sea slater - Ligia oceanica

Ligia oceanica

Image Steve Trewhella - The sea slater, Ligia oceanica, on rock face. Image width ca 5 cm.
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Distribution map

Ligia oceanica 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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Ligia oceanica 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 Malacostraca Crabs, lobsters, sand hoppers and sea slaters
Authority (Linnaeus, 1767)
Recent synonyms None
Map icon Recorded Distribution in Britain and Ireland Ligia oceanica is abundant and widespread around the British coast, wherever rock substrata are present.
Habitat information icon Habitat information Abundant on rocky coasts within the terrestrial and littoral fringe, especially common in crevices, rock pools and under stones.
Text page icon Description Ligia oceanica is the largest of the oniscid isopods, up to 3 cm in length, and has large eyes similar to the compound eye of insects. It is oval shaped, dorso-ventrally flattened and the body is twice as long as broad. The antennae are approximately two thirds the length of the body. The head and first thoracic segment are fused into a cephalothorax, leaving seven externally visible thoracic segments. Ligia oceanica possess seven pairs of walking legs (pereopods) of similar appearance. Two large uropods project from the posterior margin of the telson, each with two long processes or rami. The colouration of Ligia oceanica varies in shade from grey to olive.
Identifying features
  • Body twice as long as broad.
  • Dorso-ventrally flattened body.
  • At least 10 segments on antennal flagellum.
  • Seven externally visible thoracic segments.
  • Large, up to 3 cm in length.
  • Large eyes
Additional information icon Additional information Ligia oceanica are omnivorous, their diet consisting of shore debris such as decaying seaweed and encrusting diatoms.

This review can be cited as follows:

Susie Ballerstedt 2005. Ligia oceanica. Common sea slater. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 19/05/2013]. Available from: <http://www.marlin.ac.uk/speciesinformation.php?speciesID=4745>