A sea spider (Achelia echinata)
|Researched by||Saskiya Richards||Refereed by||This information is not refereed|
|Other common names||-||Synonyms||-|
Recorded distribution in Britain and IrelandAchelia echinata is the most common British species of Achelia and is widely distributed on the coasts of Britain and Ireland.
Global distributionAchelia echinata is distributed throughout the North East Atlantic and the Mediterranean.
HabitatAchelia echinata inhabits rocky shores from the mid-water zone to depths of 24 m. It is common in rock pools and crevices and amongst various types of algae, bryozoans, sponges and hydroids.
Depth range0-160 m
- Small, flat, oval-shaped body up to 0.2 cm in length.
- Body divided into four segments that are defined by sutures on the dorsal surface, between the first three segments.
- Body surface covered with bi-branched spines.
- Proboscis tapered and same length as body.
- Chelifores half the length of the body.
- Legs three times the length of the body bearing one pair of spines on lateral process and two pairs on first segment.
- Males have a protrusion on second segment of third and fourth pairs of legs.
Additional informationAchelia echinata are a slow-moving species. They are carnivorous, suctorial grazers preying on bryozoans, sea anemones, hydroids such as Dynaema pumila and algae such as Griffithsia and Ulva. This species has been known to feed on Flustra foliacea by lying in wait until the bryozoan opens its operculum then putting its proboscis inside the zooid. Reproduction is via external fertilization and the release of protonymphan larvae.
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Arnaud, F. & Bamber, R.N., 1987. The biology of Pycnogonida. Advances in Marine Biology, 24, 1-96.
Bamber, R.N. & Davis, M.H., 1982. Feeding of Achelia echinata Hodge (Pycnogonida) on marine algae. Journal of Experimental Marine Biology and Ecology, 60, 181-187.
Bruce, J.R., Colman, J.S. & Jones, N.S., 1963. Marine fauna of the Isle of Man. Liverpool: Liverpool University Press.
Crothers, J.H. (ed.), 1966. Dale Fort Marine Fauna. London: Field Studies Council.
Foster-Smith, J. (ed.), 2000. The marine fauna and flora of the Cullercoats District. Marine species records for the North East Coast of England. Sunderland: Penshaw Press, for the Dove Marine Laboratory, University of Newcastle upon Tyne.
Hayward, P., Nelson-Smith, T. & Shields, C. 1996. Collins pocket guide. Sea shore of Britain and northern Europe. London: HarperCollins.
Hayward, P.J. & Ryland, J.S. (ed.) 1995b. Handbook of the marine fauna of North-West Europe. Oxford: Oxford University Press.
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.]
King, P.E. & Case, R.M., 1986. Sea Spiders (Pycnogonids) in and around Milford Haven (South West Wales). Field Studies, 6, 517-529.
King, P.E., 1974. British Sea Spiders. Arthropoda: Pycnogonida. London: Academic Press. [Synopses of the British Fauna (New Series) No. 5.]
King, P.E., 1986. Sea Spiders. A Revised Key to the Adults of Littoral Pycnogonida in the British Isles. Field Studies, 6, 493-516.
Picton, B.E. & Costello, M.J., 1998. BioMar biotope viewer: a guide to marine habitats, fauna and flora of Britain and Ireland. [CD-ROM] Environmental Sciences Unit, Trinity College, Dublin.
Ventham, D., 1990. The shore fauna of Brighton, East Sussex. Volume 1. Cnidaria, Annelida, Chelicerata, Crustacea and Uniramia. Peterborough: Nature Conservancy Council.
Centre for Environmental Data and Recording, 2018. IBIS Project Data. Occurrence dataset: https://www.nmni.com/CEDaR/CEDaR-Centre-for-Environmental-Data-and-Recording.aspx accessed via NBNAtlas.org on 2018-09-25.
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.
NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.
OBIS (Ocean Biodiversity Information System), 2023. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2023-12-09
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Last Updated: 03/07/2008