Austropotamobius pallipes

{{Short description|Species of crayfish}} {{Speciesbox | name = White-clawed crayfish | image = Austropotamobius pallipes.jpg | status = EN | status_system = IUCN3.1 | status_ref = <ref name=iucn/> | taxon = Austropotamobius pallipes | authority = (Lereboullet, 1858) | synonyms = *''Astacus pallipes'' Lereboullet, 1858 *''Astacus pallipes'' var. ''flavus'' Lereboullet, 1858 *''Astacus fontinalis'' Carbonnier, 1869 | synonyms_ref = <ref name=CranDeGr17>{{Cite journal |first1=Keith A |last1=Crandall |first2=Sammy |last2=De Grave |date=2017 |title=''An updated classification of the freshwater crayfishes (Decapoda: Astacidea) of the world, with a complete species list'' |journal=Journal of Crustacean Biology |volume=37 |issue=5 |pages=615–653 |doi=10.1093/jcbiol/rux070|doi-access=free }}</ref> }}

'''''Austropotamobius pallipes''''' is an endangered<ref name=iucn>{{cite journal|author=L. Füreder|author2=Gherardi, F.|author3=Holdich, D.|author4=Reynolds, J.|author5=Sibley, P.|author6=Souty-Grosset, C.|title=''Austropotamobius pallipes''|journal=The IUCN Red List of Threatened Species|volume=2010|page=e.T2430A9438817|year=2010|doi=10.2305/IUCN.UK.2010-3.RLTS.T2430A9438817.en|doi-access=free}}</ref> European freshwater crayfish, and the only crayfish native to the British Isles.<ref>{{cite web|url=http://www.arkive.org/freshwater-white-clawed-crayfish/austropotamobius-pallipes/|title=Freshwater white-clawed crayfish (''Austropotamobius pallipes'')|publisher=ARKive.org|access-date=28 January 2015|archive-url=https://web.archive.org/web/20150124011243/http://www.arkive.org/freshwater-white-clawed-crayfish/austropotamobius-pallipes/|archive-date=24 January 2015|url-status=dead}}</ref> Its common names include '''white-clawed crayfish''' and '''Atlantic stream crayfish'''.

==Description== ''A. pallipes'' is olive-brown, with pale undersides to the claws (whence its specific Latin epithet ''pallipes'', "pale feet"). It may grow to {{convert|12|cm|abbr=on}} long, and adult sizes below {{convert|10|cm|abbr=on}} are more common. It typically lives in rivers and streams about 1 m (3 ft) deep, where it hides among rocks and submerged logs, emerging to forage for food, and in lakes.

==Distribution== It is found from the easterly Balkan Peninsula to Spain and reaches its northerly limit in Great Britain, as well as Ireland (where it is considered introduced), where it is limited to some regions only: its highest densities are in chalk streams. ''A. pallipes'' is the only crayfish found in Ireland, occurring over limestone areas in rivers, streams, canals, and lakes. In France, ''A. pallipes'' is found in streams such as the Mornante and Sellon, two small tributaries of the Dorlay in the Loire department, where it is protected as a heritage species.<ref>{{cite web|url=http://www.rhone-mediterranee.eaufrance.fr/docs/gestion-quantitative/EEVPG/Gier/EVP_Gier_rapport_phase1_mars2010.pdf|page=6|author=CESAME |date=March 2010|title=Prélèvements et gestion quantitative de la ressource sur le bassin versant du Gier Phase 1|publisher=Saint-Etienne Metropole|access-date=20 August 2012|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304073258/http://www.rhone-mediterranee.eaufrance.fr/docs/gestion-quantitative/EEVPG/Gier/EVP_Gier_0rapport_phase1_mars2010.pdf|url-status=dead}}</ref> It is also among the emblematic species of many French Natura 2000 sites as it tends to be less and less common in France while it used to be present in most rivers before North American crayfish species were introduced during the 20th century.<ref> https://grosne-clunisois.n2000.fr/le-site-grosne-clunisois/les-especes</ref> It has also been introduced to Corsica, Liechtenstein, and Portugal (from where it is now extirpated).

It was once found across most of Great Britain; however its distribution is rapidly shrinking, and it is recorded in Yorkshire, central and northern England, east Kent, eastern Wales, the Candover Brook that flows into the Itchen in Hampshire;<ref>{{cite book |last=Peay |first=Stephanie |author-link=Stephanie Peay |title=Monitoring the white-clawed crayfish ''Austropotamobius pallipes'' |publisher=English Nature |year=2003 |isbn=978-1-85716-727-6}}</ref> parts of Essex,<ref>{{cite news |title=Endangered crayfish colony found |url=https://news.bbc.co.uk/2/hi/uk_news/england/essex/5359464.stm |publisher=BBC News |date=19 September 2006 |access-date=18 December 2019}}</ref> and several long headwaters of the River Thames, where it competes with the introduced noble crayfish, itself also facing competition from the introduced signal crayfish. Dowdeswell Reservoir, Gloucestershire, has the species, and during works of 1998, Severn Trent ensured its protection.<ref>‘''Conservation of the native crayfish population at Dowdeswell Reservoir during engineering works''’, March 1998, for Severn Trent Water.</ref> Disease from invasive species has wiped it from the naturally alkaline River Frome, Bristol, 2007–08.<ref>{{cite news|last=Gray |first=Louise|title=Crayfish breeding programme to save native species from American invader |url=https://www.telegraph.co.uk/news/earth/earthnews/5872979/Crayfish-breeding-programme-to-save-native-species-from-American-invader.html|work=The Daily Telegraph|date=21 July 2009|access-date=18 December 2019}}</ref>

==Ecology== thumb|left|Eggs on abdomen It is absent from more acidic waters<ref>{{cite book|author1=Catherine Souty-Grosset|author2=David M. Holdich|author3=Pierre Y. Noel|author4=Julian D. Reynolds|author5=Patrick Haffner|year=2006|title=Atlas of Crayfish in Europe|publisher=Muséum national d'histoire naturelle|location=Paris|pages=188|isbn=978-2-85653-579-0|series=Collection Patrimoines Naturelles 64}}</ref> and occurs in streams with a moderate flow alongside other freshwater invertebrates such as caddis fly, mayfly, and mollusc species. Trout and three-spined stickleback also occur in the same habitat. Tree roots and rocks in the banks provide shelter. Juveniles shelter in vegetation such as watercress and grass mats growing out of the bank.

==Conservation== Two main reasons for decline are: *Introduction of the invasive North American signal crayfish (''Pacifastacus leniusculus'') and red swamp crayfish (''Procambarus clarkii''):<ref>{{cite journal |author=Manenti, R. |author2=Ghia, D. |author3=Fea, G. |author4=Ficetola, G.F. |author5=Padoa-Schioppa, E. |author6=Canedoli, C. |title=Causes and consequences of crayfish extinction: Stream connectivity, habitat changes, alien species and ecosystem services |journal=Freshwater Biology |volume=64 |issue=2 |pages=284–293 |year=2019 |doi=10.1111/fwb.13215|bibcode=2019FrBio..64..284M |s2cid=91259855 |hdl=2434/617418 |hdl-access=free }}</ref> The former is a carrier of crayfish plague, an infectious disease to which it has resistance, while ''A. pallipes'' has none. Consequently, ''A. pallipes'' tends to be more and more restricted to upstream sections of small rivers and rivulets, which can be more prone to summer draughts, creating a domino effect for this fragile species. *Water pollution: Many local extinctions are caused by surface runoff of insecticides and of bleached, insufficiently treated, or illegal untreated wastewater.

==Further reading== Sweeney, N. and Sweeney, P. 2017. Expansion of the White-clawed Crayfish (''Austropotamobius pallipes'' (Lereboullet)) population in Munster Blackwater. ''Irish Naturalists' Journal''. '''35'''(2) pp. 94–98.

==References== {{reflist|32em}}

==External links== {{portal|Crustaceans}} *{{Commons category-inline|Austropotamobius pallipes|''Austropotamobius pallipes''}} *{{Wikispecies-inline|Austropotamobius pallipes|''Austropotamobius pallipes''}} *{{cite web|url=http://www.crayfish.org.uk/|title=UK Crayfish Website|publisher=Buglife – The Invertebrate Conservation Trust|access-date=2012-01-26|archive-date=2020-10-25|archive-url=https://web.archive.org/web/20201025050954/http://crayfish.org.uk/|url-status=dead}}

Category:Astacidae Category:Freshwater crustaceans of Europe Category:Crustaceans described in 1858 Category:Habitats Directive species