Cranch's spider crab (Achaeus cranchii)
|Researched by||Emily Wilson & Eliza Gibson-Hall||Refereed by||This information is not refereed|
|Other common names||-||Synonyms||-|
A spider crab with characteristic swellings on each side of the carapace, bearing groups of bristles or small spines (hook-setae). The carapace is relatively smooth, narrowed, and grows up to 12 mm long and 8 mm wide. The frontal region produces a small, short, prolongation of the head (rostrum) with a U-shaped incision. Colouration is pale to a reddish-yellow, with lighter chelipeds and pereiopods. The abdomen is separated into 2-5 sections (somites). The pincered legs (chelipeds) are spiny and the walking legs (pereiopods) are covered with long bristles. Chelipeds are spiny, equal and larger in male crabs. The eyestalks are especially long and are always visible.
Recorded distribution in Britain and IrelandRecorded from the south and west coasts of Britain.
Global distributionScattered records from the British Isles along the northern coast of France to Brussels. Also recorded in the eastern Atlantic and Mediterranean.
HabitatFound from 5-70 m on hydroids, bryozoans, ascidians and on undersides of raised boulders, often masked with algae.
Depth range5-70 m
- Dorsal surface of carapace relatively smooth with distinctive, swollen, outline.
- Colouration pale to reddish-yellow
- Chelipeds spiny, equal.
- Second to fifth pairs of walking legs slender and covered with long, hook-shaped, setae.
Additional informationThe pereopods are shorter than those of Inachus spp.
- none -
Hanson Aggregates Marine Limited 1998. 1998 Hastings shingle bank : southern England, biological and habitat survey. [on-line] http://www.marlin.ac.uk, 2003-02-22
Hayward, P.J. & Ryland, J.S. (ed.) 1995b. Handbook of the marine fauna of North-West Europe. Oxford: Oxford University Press.
Ingle, R.W., 1980. British Crabs. Oxford: British Museum (Natural History), Oxford University Press.
Ingle, R.W., 1996. Shallow-water Crabs, (2nd edn). Shrewsbury: Field Studies Council. [Synopses of the British Fauna, no 25]
Sanderson, W.G., 1996. Rare benthic marine flora and fauna in Great Britain: the development of criteria for assessment. Joint Nature Conservation Committee, Peterborough. JNCC Report, no. 240.
This review can be cited as:
Last Updated: 01/08/2018