Biodiversity & Conservation

Northern sea urchin - Strongylocentrotus droebachiensis

Strongylocentrotus droebachiensis

Image Sue Scott - Small group of individuals on rocky substratum Image width: c: 40 cm.
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Distribution map

Strongylocentrotus droebachiensis 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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Strongylocentrotus droebachiensis is not listed under any importance categories.

Taxonomy icon Taxonomy Taxon English term
Phylum Echinodermata Starfish, brittlestars, sea urchins & sea cucumbers
Class Echinoidea Sea urchins, heart urchins and sand dollars
Authority (O. F. Müller, 1776)
Recent synonyms None
Map icon Recorded Distribution in Britain and Ireland The species is recorded as occurring on north sea coasts from Shetland to the southern north sea. However, recent records from shallow inshore areas are for Shetland only.
Habitat information icon Habitat information Strongylocentrotus droebachiensis is found on the lower shore and infralittoral fringe down to 1200 m on rocky grounds browsing on algae. In the few locations, where it is found in Britain, it occurs in the lower infralittoral and upper circalittoral.
Text page icon Description Strongylocentrotus droebachiensis grows up to 8cm in diameter with a low flat profile. Skeletal plates are greenish-brown with numerous reddish, greenish, or even violet spines that are usually white tipped.
Identifying features
  • Anus situated outside apical system.
  • Jaws lack lateral teeth.
  • Shows full radial symmetry.
  • More than three pore plates per ambulacral plate.
  • Primary and secondary spines of similar length.
Additional information icon Additional information May retreat further north with rising water temperatures. Can occur in plagues or swarms which devastate kelp beds in Norway.

This review can be cited as follows:

Dean Russel 2001. Strongylocentrotus droebachiensis. Northern sea urchin. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 27/11/2015]. Available from: <>