A sea spider (Endeis spinosa)

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



Endeis spinosa has a small body up to 3 mm in length and legs 15 mm long. The proboscis is swollen at the tip, oval in cross-section, and is usually held at a 45 degree angle below the long axis of the body. The body is covered with a number of irregularly arranged spines, which are larger in males than females. The mouth section is circled by concentric rows of irregularly arranged spines. Endeis spinosa have neither chelifores nor palps, and the auxilary claws are notably shorter than the main claws. The eyes are a pale brown, slightly paler than in other pycnogonids. Only the males in this species have 7 segmented ovigerous legs.

Recorded distribution in Britain and Ireland

Endeis spinosa are relatively uncommon, but can be found all around the coast of the British Isles. Confusion with the species Endeis laevis may to some degree account for the lack of records of this species.

Global distribution



Endeis spinosa inhabitat the littoral zone and the shallow sublittoral up to depths of 12 m.

Depth range


Identifying features

  • Proboscis is swollen at the tip and oval in cross-section.
  • Numerous spines surround the mouth.
  • Auxilary claw less than half the length of the main claw.
  • Chelifores and palps are absent.

Additional information

Although the food preferences have not been fully determined, it is thought that they feed on the detritus that gathers on the branches of various hydroids (King, 1974).

Listed by

- none -


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

  2. Hayward, P.J. & Ryland, J.S. 1994. The marine fauna of the British Isles and north-west Europe. Volume 1. Introduction and Protozoans to Arthropods. Oxford: Clarendon Press.

  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. JNCC (Joint Nature Conservation Committee), 1999. Marine Environment Resource Mapping And Information Database (MERMAID): Marine Nature Conservation Review Survey Database. [on-line] http://www.jncc.gov.uk/mermaid

  5. King, P.E., 1974. British Sea Spiders. Arthropoda: Pycnogonida. London: Academic Press. [Synopses of the British Fauna (New Series) No. 5.]

  6. MarLIN (Marine Life Information Network), 2005. SEArchable BEnthic Data (SEABED) Map [on-line]. Data Access Sub-programme, Marine Life Information Network for Britian and Ireland http://www.marlin.ac.uk,


  1. Centre for Environmental Data and Recording, 2018. Ulster Museum Marine Surveys of Northern Ireland Coastal Waters. Occurrence dataset https://www.nmni.com/CEDaR/CEDaR-Centre-for-Environmental-Data-and-Recording.aspx accessed via NBNAtlas.org on 2018-09-25.

  2. Fenwick, 2018. Aphotomarine. Occurrence dataset http://www.aphotomarine.com/index.html Accessed via NBNAtlas.org on 2018-10-01

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

  4. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2024-06-16


This review can be cited as:

Heard, J.R. 2005. Endeis spinosa A sea spider. 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 16-06-2024]. Available from: https://www.marlin.ac.uk/species/detail/2109

Last Updated: 14/02/2005