Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help
Researched by | Dr Keith Hiscock | Refereed by | This information is not refereed |
Authority | (Linnaeus, 1767) | ||
Other common names | - | Synonyms | Porcellana longicornis (Linnaeus, 1767) |
A small crab less than 10 mm across the carapace. It is reddish-orange in colour, frequently with patches of pearly white on the carapace or sometimes all of the carapace is white. Long claws and with only three pairs of walking legs apparent and a tiny fifth pair of appendages often concealed.
- none -
Phylum | Arthropoda | Arthropods, joint-legged animals, e.g. insects, crustaceans & spiders |
Class | Malacostraca | Crabs, lobsters, sand hoppers and sea slaters |
Order | Decapoda | Crabs, shrimps, prawns, crayfish and lobsters |
Family | Porcellanidae | |
Genus | Pisidia | |
Authority | (Linnaeus, 1767) | |
Recent Synonyms | Porcellana longicornis (Linnaeus, 1767) |
Typical abundance | Moderate density | ||
Male size range | <10mm | ||
Male size at maturity | |||
Female size range | 3mm | ||
Female size at maturity | |||
Growth form | Articulate | ||
Growth rate | Data deficient | ||
Body flexibility | |||
Mobility | |||
Characteristic feeding method | Scavenger | ||
Diet/food source | |||
Typically feeds on | |||
Sociability | |||
Environmental position | Epifaunal | ||
Dependency | Independent. | ||
Supports | None | ||
Is the species harmful? | No information |
Pisidia longicornis is the most numerically abundant decapod crustacean in sublittoral areas. It occurs in densities of up to 640 /m² (Robinson & Tully, 2000a). Smaldon (1972) suggests that it "may survive to breed for a second or third season" suggesting a lifespan of up to three years.
Physiographic preferences | Open coast, Strait / sound, Sea loch / Sea lough, Ria / Voe |
Biological zone preferences | Lower circalittoral, Lower eulittoral, Lower infralittoral, Mid eulittoral, Sublittoral fringe, Upper circalittoral, Upper infralittoral |
Substratum / habitat preferences | Large to very large boulders, Small boulders |
Tidal strength preferences | Moderately Strong 1 to 3 knots (0.5-1.5 m/sec.), Strong 3 to 6 knots (1.5-3 m/sec.), Very Strong > 6 knots (>3 m/sec.) |
Wave exposure preferences | Exposed, Moderately exposed, Sheltered, Very sheltered |
Salinity preferences | Full (30-40 psu) |
Depth range | intertidal to depth unknown |
Other preferences | |
Migration Pattern | Non-migratory / resident |
Reproductive type | Gonochoristic (dioecious) | |
Reproductive frequency | Annual episodic | |
Fecundity (number of eggs) | 100-1,000 | |
Generation time | Insufficient information | |
Age at maturity | Insufficient information | |
Season | March - September | |
Life span | 2-3 years |
Larval/propagule type | - |
Larval/juvenile development | Planktotrophic |
Duration of larval stage | 1-2 months |
Larval dispersal potential | Greater than 10 km |
Larval settlement period | Insufficient information |
The MarLIN sensitivity assessment approach used below has been superseded by the MarESA (Marine Evidence-based Sensitivity Assessment) approach (see menu). The MarLIN approach was used for assessments from 1999-2010. The MarESA approach reflects the recent conservation imperatives and terminology and is used for sensitivity assessments from 2014 onwards.
Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
Intermediate | High | Low | Moderate | |
Pisidia longicornis occurs on a variety of substrata especially in the subtidal. Although at least some individuals will be destroyed by the removal of substratum, displaced individuals are likely to find alternative homes. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Low | High | Low | Moderate | |
Pisidia longicornis, being mobile, may escape from smothering events but siltation may remove suitable habitats by clogging underboulders and undergrowth. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Tolerant | Not relevant | Not sensitive | Moderate | |
Pisidia longicornis most likely feeds as a scavenger and active carnivore so that increase in levels of suspended sediment are unlikely to affect it. However, settlement of suspended silt is addressed in 'Smothering'. | ||||
Tolerant | Not relevant | Not sensitive | Moderate | |
Pisidia longicornis most likely feeds as a scavenger and active carnivore so that decrease in levels of suspended sediment are unlikely to affect it. | ||||
High | High | Moderate | Moderate | |
Pisidia longicornis lives in habitats that are protected from desiccation and would most likely, because of its mobility, be able to escape desiccation situations such as boulder turning. However, if exposure to air occurs, desiccation effects are likely to be severe. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Low | Very high | Very Low | Moderate | |
Pisidia longicornis lives in shaded damp habitats on the mid to lower shore. If emergence regime changes so that crabs are exposed for longer to dry conditions, the vertical extent of habitat suitable for the crab is likely to be reduced although individual crabs will survive by moving further downshore. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Tolerant* | Not relevant | Not sensitive* | High | |
Pisidia longicornis is a species that lives in damp places and fully submerged habitats so that decrease in emergence will favour the species. | ||||
Low | High | Low | Moderate | |
Pisidia longicornis lives in habitats where water flow rate may be from very strong to weak. However, as a cryptic species protected by bryozoan turf, kelp holdfasts etc in the sublittoral, it is unlikely to be affected by 'wash out' which might however occur from under boulders. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Intermediate | High | Low | Moderate | |
The communities in which Pisidia longicornis live are particularly well developed in areas subject to strong tidal flow or strong wave action. In the absence of strong wave action, decrease in water flow rate will lead to siltation of habitats and reduction of the bryozoan turf that Pisidia longicornis favours. A decline in abundance would therefore be expected. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Tolerant | Not relevant | Not sensitive | Moderate | |
Pisidia longicornis occurs in a wide range of temperature regimes from Norway to Angola and it is not therefore expected that crabs would be adversely affected by increase in temperature at the level of the benchmark. | ||||
Intermediate | High | Low | High | |
Long-clawed porcelain crabs were adversely affected by the 1962-63 winter in Britain. Crisp (1964) records that many hundreds were found dead on the strandline at Oxwich, south Wales. In other locations, they were not found on the shore (although could have migrated offshore). Overall, it seems that some mortality is likely and an intolerance of Intermediate is suggested. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Low | High | Low | Moderate | |
Pisidia longicornis is a scavenger and is only likely to be adversely affected by increased turbidity through visual impairment. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Tolerant | Not relevant | Not sensitive | Moderate | |
Pisidia longicornis is a scavenger and is unlikely to be adversely affected by decreased turbidity. | ||||
Intermediate | High | Low | Moderate | |
Pisidia longicornis lives in locations where it could be displaced by strong water movement. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Intermediate | High | Low | Moderate | |
Pisidia longicornis lives underboulders, in kelps holdfasts and amongst bryozoan turfs especially. A decrease in wave exposure may allow silt to settle thus removing suitable habitats by clogging underboulders and undergrowth. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Tolerant | Not relevant | Not sensitive | Moderate | |
Pisidia longicornis is unlikely to react to noise as it has no appropriate organs. It will most likely react to vibrations resulting from noise but is probably tolerant at the benchmark level. | ||||
Low | Immediate | Not sensitive | Moderate | |
Crabs scuttle away when boulders are overturned - most likely as a response to increased light levels but also, since they have eyes, visual presence. The crabs are mobile so that recolonization/recovery is likely to be very rapid. | ||||
High | High | Moderate | Moderate | |
The crabs are easily crushed by abrasion by mobile cobbles and larger substrata or by mooring chains. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Low | Very high | Very Low | High | |
Displacement is unlikely to adversely affect Pisidia longicornis unless it is trapped in a new unsuitable location. The species can move to a suitable area. |
Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
Intermediate | High | Low | Very low | |
No information has been found specifically on Pisidia longicornis but crustaceans in general are fairly tolerant. Bryan & Gibbs (1991) report that crabs appear to be relatively resistant to TBT although some deformity of regenerated limbs has been observed. In the early 1960's in Washington, experimental application of a broad range of pesticides was tested for use on shrimp-infested oyster grounds identified carbaryl (1-napthol n-methyl carbamate; sold under the trade name Sevin) to be an effective method to control burrowing shrimp (Feldman et al., 2000). Carbaryl, a non-persistent organocarbamate pesticide that is extremely toxic to arthropods, was applied at 9kg/ha to remove shrimps from oyster grounds. In view of the equivocal results from different studies and with different chemicals, an intolerance of intermediate is suggested with a very low confidence. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Intermediate | High | Low | Low | |
No information has been found specifically on Pisidia longicornis but crustaceans in general are fairly tolerant. Crompton (1997) reports that the concentrations above which mortality of crustaceans can occur is 0.01-0.1mg/l for mercury, copper and cadmium, 0.1-1mg/l for zinc, arsenic and nickel and 1-10mg/l for lead and chromium. Crustaceans are generally regarded as being more intolerant of cadmium than other groups (McLusky, 1986).The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Intermediate | High | Low | Low | |
No information has been found specifically on Pisidia longicornis but crustaceans in general are fairly tolerant. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Tolerant | Not relevant | Not sensitive | High | |
No information has been found for radionuclides adversely affecting crustaceans. | ||||
Tolerant | Not relevant | Not sensitive | Moderate | |
No information has been found for nutrients adversely affecting crustaceans. | ||||
Intermediate | High | Low | Moderate | |
Long-clawed porcelain crabs are apparently not recorded in low salinity conditions but do occur in the lower reaches of estuaries suggesting that they require full or variable salinity. Mortality may therefore occur in events where salinity falls significantly. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
High | High | Moderate | Moderate | |
Long-clawed porcelain crabs are apparently not recorded in low salinity conditions but do occur in the lower reaches of estuaries suggesting that they require full or variable salinity. A reduction in salinity, especially if it occurs in already estuarine conditions, is likely therefore to have a significant adverse effect. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
Intermediate | High | Low | Low | |
The crabs live in areas which are well oxygenated so that decrease in oxygen levels below ambient may be adverse. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. |
Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
No information | No information | No information | Moderate | |
Insufficient information | ||||
No information | Not relevant | No information | Not relevant | |
Insufficient information | ||||
High | High | Moderate | Moderate | |
Extraction of this species is not known to occur. The crabs are mobile and have a planktonic larva so that recolonization/recovery is likely to be fairly rapid. | ||||
No information | Not relevant | No information | Not relevant | |
Insufficient information |
- no data -
National (GB) importance | - | Global red list (IUCN) category | - |
Native | - | ||
Origin | - | Date Arrived | Not relevant |
Bryan, G.W. & Gibbs, P.E., 1991. Impact of low concentrations of tributyltin (TBT) on marine organisms: a review. In: Metal ecotoxicology: concepts and applications (ed. M.C. Newman & A.W. McIntosh), pp. 323-361. Boston: Lewis Publishers Inc.
Crisp, D.J. (ed.), 1964. The effects of the severe winter of 1962-63 on marine life in Britain. Journal of Animal Ecology, 33, 165-210.
Crompton, T.R., 1997. Toxicants in the aqueous ecosystem. New York: John Wiley & Sons.
Crothers, J. & Crothers, M., 1988. A key to the crabs and crab-like animals of British inshore waters. Somerset, England: Field Studies Council. [AIDGAP guide, no. 155.]
Feldman, K.L., Armstrong, D.A., Dumbauld, B.R., DeWitt, T.H. & Doty, D.C., 2000. Oysters, crabs, and burrowing shrimp: review of an environmental conflict over aquatic resources and pesticide use in Washington State's (USA) coastal estuaries. Estuaries, 23, 141-176. DOI https://doi.org/10.2307/1352824
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Ingle, R., 1997. Crayfishes, lobsters and crabs of Europe. An illustrated guide to common and traded species. London: Chapman and Hall.
Lindley, J.A., 1987. Continuous plankton records: the geographical distribution and seasonal cycles of decapod crustacean larvae and pelagic post-larvae in the north-eastern Atlantic Ocean and the North Sea. Journal of the Marine Biological Association of the United Kingdom, 67, 145-167.
McLusky, D.S., Bryant, V. & Campbell, R., 1986. The effects of temperature and salinity on the toxicity of heavy metals to marine and estuarine invertebrates. Oceanography and Marine Biology: an Annual Review, 24, 481-520.
Robinson, M. & Tully, O., 2000. Dynamics of a subtidal population of the porcellanid crab Pisidia longicornis (Decapoda: Crustacea). Journal of the Marine Biological Association of the United Kingdom, 80, 75-83.
Robinson, M. & Tully, O., 2000. Seasonal variation in community structure and recruitment of benthic decapods in a sub-tidal cobble habitat. Marine Ecology Progress Series, 206, 181-191.
Smaldon, G., 1972. Population structure and breeding biology of Pisidia longicornis and Porcellana platycheles. Marine Biology, 17, 171-179.
Bristol Regional Environmental Records Centre, 2017. BRERC species records recorded over 15 years ago. Occurrence dataset: https://doi.org/10.15468/h1ln5p accessed via GBIF.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.
Cofnod – North Wales Environmental Information Service, 2018. Miscellaneous records held on the Cofnod database. Occurrence dataset: https://doi.org/10.15468/hcgqsi accessed via GBIF.org on 2018-09-25.
Environmental Records Information Centre North East, 2018. ERIC NE Combined dataset to 2017. Occurrence dataset: http://www.ericnortheast.org.ukl accessed via NBNAtlas.org on 2018-09-38
Fenwick, 2018. Aphotomarine. Occurrence dataset http://www.aphotomarine.com/index.html Accessed via NBNAtlas.org on 2018-10-01
Fife Nature Records Centre, 2018. St Andrews BioBlitz 2014. Occurrence dataset: https://doi.org/10.15468/erweal accessed via GBIF.org on 2018-09-27.
Fife Nature Records Centre, 2018. St Andrews BioBlitz 2015. Occurrence dataset: https://doi.org/10.15468/xtrbvy accessed via GBIF.org on 2018-09-27.
Fife Nature Records Centre, 2018. St Andrews BioBlitz 2016. Occurrence dataset: https://doi.org/10.15468/146yiz accessed via GBIF.org on 2018-09-27.
Isle of Wight Local Records Centre, 2017. IOW Natural History & Archaeological Society Marine Invertebrate Records 1853- 2011. Occurrence dataset: https://doi.org/10.15468/d9amhg accessed via GBIF.org on 2018-09-27.
Kent Wildlife Trust, 2018. Biological survey of the intertidal chalk reefs between Folkestone Warren and Kingsdown, Kent 2009-2011. Occurrence dataset: https://www.kentwildlifetrust.org.uk/ accessed via NBNAtlas.org on 2018-10-01.
Kent Wildlife Trust, 2018. Kent Wildlife Trust Shoresearch Intertidal Survey 2004 onwards. Occurrence dataset: https://www.kentwildlifetrust.org.uk/ accessed via NBNAtlas.org on 2018-10-01.
Manx Biological Recording Partnership, 2017. Isle of Man wildlife records from 01/01/2000 to 13/02/2017. Occurrence dataset: https://doi.org/10.15468/mopwow accessed via GBIF.org on 2018-10-01.
Manx Biological Recording Partnership, 2018. Isle of Man historical wildlife records 1990 to 1994. Occurrence dataset: https://doi.org/10.15468/aru16v accessed via GBIF.org on 2018-10-01.
Manx Biological Recording Partnership, 2018. Isle of Man historical wildlife records 1990 to 1994. Occurrence dataset:https://doi.org/10.15468/aru16v accessed via GBIF.org on 2018-10-01.
National Trust, 2017. National Trust Species Records. Occurrence dataset: https://doi.org/10.15468/opc6g1 accessed via GBIF.org on 2018-10-01.
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: 2023-04-02
Outer Hebrides Biological Recording, 2018. Invertebrates (except insects), Outer Hebrides. Occurrence dataset: https://doi.org/10.15468/hpavud accessed via GBIF.org on 2018-10-01.
South East Wales Biodiversity Records Centre, 2018. SEWBReC Myriapods, Isopods, and allied species (South East Wales). Occurrence dataset: https://doi.org/10.15468/rvxsqs accessed via GBIF.org on 2018-10-02.
South East Wales Biodiversity Records Centre, 2018. Dr Mary Gillham Archive Project. Occurance dataset: http://www.sewbrec.org.uk/ accessed via NBNAtlas.org on 2018-10-02
Yorkshire Wildlife Trust, 2018. Yorkshire Wildlife Trust Shoresearch. Occurrence dataset: https://doi.org/10.15468/1nw3ch accessed via GBIF.org on 2018-10-02.
This review can be cited as:
Last Updated: 03/06/2008