Astacidae
Guides
Pacifastacus
Pacific Crayfish
Pacifastacus is a genus of freshwater crayfish endemic to western North America, comprising six species including the widespread signal crayfish (P. leniusculus) and two extinct species. The genus has gained significant conservation attention due to the invasive spread of P. leniusculus in Europe and Japan, where it transmits crayfish plague and displaces native species. Within its native range, several Pacifastacus species face population declines from habitat degradation and competition from invasive crayfishes.
Pacifastacus gambelli
Pacifastacus gambelli is a species of crayfish in the family Astacidae. The genus Pacifastacus is native to western North America, with species distributed across freshwater habitats in the Pacific Northwest and Rocky Mountain regions. P. gambelli is closely related to other Pacifastacus species including the widely studied signal crayfish (P. leniusculus), which has become a notorious invasive species in Europe. The species epithet 'gambelli' honors William Gambel, an American naturalist and explorer of the western United States in the 19th century.
Pacifastacus leniusculus
Signal Crayfish
The signal crayfish is a large North American freshwater crayfish introduced to Europe in the 1960s to replace declining native fisheries. It has become one of the most ecologically impactful invasive decapods in Europe, outcompeting native crayfish and serving as a carrier of crayfish plague (Aphanomyces astaci). The species establishes self-sustaining populations rapidly, with six age cohorts documented within a few years of introduction. It shows sex- and size-specific coloration patterns, with males displaying more saturated and brighter ventral claw surfaces than females, suggesting a role in intraspecific communication.
invasive-speciescrayfish-plague-carrierdecapodfreshwater-crustaceanconservation-concernspecies-of-Union-concernearly-detection-rapid-responseark-sitesecosystem-engineerbioaccumulationsexual-dimorphismnocturnal-activityinvasion-gradienttrappingelectrofishingeradicationMediterranean-invasionheadwater-threatnative-crayfish-displacementfisheries-introduction1960s-introductionEuropeJapanCalifornia-nativePacifastacusAstacidaeDecapodaMalacostracaArthropodaAphanomyces-astaciwhite-clawed-crayfishsignal-crayfishcontrol-planningremoval-actionscatch-per-unit-effortcolor-variationcarotenoidscamouflageconspicuousnessintraspecific-communicationelemental-accumulationcontaminanttrophic-levelmacroinvertebrateplant-detritusrifflestreamriverlaketributaryinvasion-frontcore-populationexploratory-behaviormigration-patternsontogenetic-color-changekick-samplingdetection-protocolfalse-negativeCataloniaItalyPortugalSpainPolandScandinaviaBritish-IslesSegura-RiverClitunno-RiverValla-streamRabaçal-RiverFosso-VecchioUnion-concernLIFE-IMAGINEeradication-attemptbiosecuritypathway-action-plansINNS-inspectorateenvironmental-DNAeDNAhost-pathogen-dynamicsconservation-translocationark-siteaggregates-levyenvironment-agencyBBC-wildlife-funddefrahabitats-directivefavourable-conservation-statusunfavourable-badextinction-riskfunding-cutsecosystem-serviceskeystone-specieswoodlandpollinationdecompositionnutrient-cyclingpredationwater-purificationcitizen-scienceex-situ-conservation-rearingzoosaquariaFen-Raft-SpiderPond-Mud-SnailLarge-Marsh-GrasshopperFreshwater-Pearl-MusselMarbled-White-ButterflySmall-Skipperclimate-changeassisted-colonizationrange-marginbiotic-responseabiotic-driverwarmingpollutioneutrophicationfunctional-traitthermal-limitembryogenesiscompetitive-advantagealien-aquatic-speciesartificial-light-at-nightnutrient-enrichmentbrown-troutbiological-controlclearance-rateparasite-loadsympatryglobal-invaderpredatory-interactionexperimental-approachepiphytic-algaesubmerged-plant-communitymolecular-toolsinformaticssocial-mediapooled-samplingintegrative-taxonomyhybridbryozoancost-efficient-methodologypolicy-effectivenesslegislative-toolsLIFE-INVASAQUAnetworkingpreventionawarenessmarine-protected-areacitizen-science-datanon-native-freshwater-fishknowledge-gapsinvasive-alien-freshwater-plantsnaturalised-plantsaquatic-habitatspot-plantshorticultureNew-Guinea-flatwormPartula-tree-snailsLob-wormLumbricus-terrestrisHarlequin-ladybirdOak-processionary-mothNew-Zealand-flatwormAustralian-flatwormLily-beetleRosemary-leaf-beetleSpanish-slugGirdled-snailAustralian-landhopperLight-brown-apple-mothAsian-hornetArgentine-antLinepithema-humileVespa-velutinaash-diebackHymenoscyphus-fraxineusFloating-PennywortGiant-HogweedChinese-Mitten-CrabEriocheir-sinensisBallast-Water-ConventionOffice-for-Environmental-ProtectionEnvironmental-Improvement-PlanGlobal-Biodiversity-Frameworkdelistinglistingrapid-responseGreat-Britain-Non-native-Species-StrategyNature-2030Wildlife-and-Countryside-LinkBuglifeinvertebrateconservationreintroductionreinforcementassisted-colonisationhabitat-managementgenetic-diversitydonor-stockstakeholder-collaborationNatural-EnglandeNGOlandownerpublic-engagementmedia-attentiontabloidsensationalismspidersize-of-ratsMarvellous-Mud-Snails-CornwallCitizen-ZooHop-of-Hopevolunteerex-situ-rearinglong-life-cycleglochidiasalmonid-fish-hostFreshwater-Biology-Associationjuvenile-musselhabitat-restorationmicro-habitatField-CricketWart-biter-Bush-cricketBarberry-Carpet-MothMarsh-Fritillary-ButterflyFisher's-Estuarine-MothSouthern-DamselflyWhite-faced-Darter-DragonflyPine-HoverflyDark-bordered-Beauty-MothMedicinal-LeechTadpole-ShrimpNetted-Carpet-MothLadybird-SpiderNarrow-headed-AntCumbriaDorsetDevonmicrohabitatlow-mobilitynatural-colonizationshort-haired-bumblebeeBombus-subterraneussub-optimal-managementBarberry-bushPaul-WaringBenoit-Guénardconservation-fundingvertebrate-biasinvertebrate-neglectbeaverCastor-fiberpine-martenMartes-martesbird-of-preyLarge-Blue-ButterflyPhengaris-arionChequered-SkipperCarterocephalus-palaemonmainland-Europenational-reintroductionlocal-reintroductiondonor-populationreceptor-sitecounty400-misolated-habitatEngland-Species-Reintroduction-Task-ForceKarim-Vahedhalf-a-centurydiverse-specieslogistically-easierguidelinescodegovernmenthabitat-conditionssite-conditionstargeted-habitat-managementmobilityrecoveryunsuccessful-caselack-of-genetic-diversityoptimal-managementestablishment-failurecareknowledgefunding-allocationPNASthreatened-species80%6%species-numbersimbalancelegislationwild-releasehigh-profilemain-imageDecticus-verrucivorusDr-Sarah-HenshallshareFacebookLinkedInTrinity-AudiotweetNEOBIOTA-2024Lisbon421-participants47-countriesinvasion-scienceaquatic-studiesmarinefreshwateroral-sessionposterworkshopNeoBiota-Special-IssueeditorialPedro-AnastácioFilipe-RibeiroPaula-Chainho23-papersfive-themes100th-issueZooKeysdigital-taxonomyenvironmental-stressorinvasion-successsalinitysea-level-riseAlternanthera-philoxeroidesstress-toleranceavoidanceescapeGonçalvesphysiological-performanceCallinectes-sapidusclimate-warmingPhymactis-papillosaenvironmental-toleranceecological-impactPortuguese-intertidalsynergistic-effectZhangecological-interactioninvasion-impactpopulation-dynamicsSalmo-truttaMatosbivalvecapture-efficiencynatural-sestonCabralEupercariaTkachenkoglobal-aquatic-invaderReshetnikovPontederia-crassipesPistia-stratiotesShendetectionmonitoringsurveillanceearly-detectionDiasXenopus-laevispooled-eDNAEvertsSqualiusGkenasChilean-SE-PacificRechmanagementpolicylegislative-toolEU-policysectoral-impactMagliozzifreshwater-turtleRatoCarosihabitat-usetrapping-efficiencyhypersaline-lagoonHerrero-ReyesIberian-PeninsulaLópez-CañizaresAfrican-marine-protected-areaglobal-databaseAcklandIndian-freshwater-fishevidence-gapKumarEuropean-freshwater-plantecosystem-impactDi-Lerniaglobal-synthesisnaturalised-plantaquatic-habitatKortzinterdisciplinaritytranslational-relevanceissue-4930Blueskyscholarly-publishingecologyinvasion-ecologyaquatic-ecosystemflatwormsnailgang-attackextinctionpot-plantsoil-sterilizationfumigationhot-water-immersionbiosecurity-measureinternational-tradeHirudo-medicinalisNeil-PhillipsSteven-FalkSarah-Henshallomphiscola-glabraCornwallScotlandBlera-fallaxEpione-vespertariaTriops-cancriformisEustroma-reticulatumEresus-sandaliatusFormica-exsectaGryllus-campestrisDecticus-verrucivorousPareulype-berberataEuphydryas-auriniaMargaritifera-margaritiferaGortyna-borelii-lunataDolomedes-plantariusCoenagrion-mercurialeLeucorrhinia-dubiaStethophyma-grossumMelanargia-galatheaThymelicus-sylvestrisFormica-rufaKielder-ForestNorthumberlandLiz-OldringStephen-WillsDurham-Universityclimate-suitabilitylimited-fundingbiased-fundingvertebratenature-positive-trade2024-General-ElectionManifesto-for-Bugsseven-actionscommitmentshalting-nature-lossreversing-invertebrate-declineAndrew-WhitehouseSouth-West-ManagerLord-De-Mauleywildlife-ministermineral-extractionTreasuryGeorge-Entwistle50%-cutbadger-cullriver-dredging£100K£12.75£420£1,6162012201421-projects2-projectsreportingBedstraw-hawk-mothnational-prideleadershipDavid-SmithSocial-Change-and-Advocacy-OfficerLisa-ManningPolicy-and-Engagement-OfficerFebruary-2024GB-Non-Native-Species-Strategyone-year-anniversarymeasurabilitytimelineoff-track2030time-lagestablishmentRed-Imported-Fire-AntSolenopsis-invictaworld's-worst-invasive-speciesPaPsdraft-formconsultation-delay2023-State-of-Nature-ReportEnvironmental-Audit-Committee£6-millionanimal-healthplant-healthresourcinglong-term-futureslipped-timelinesinefficient-processfully-resourced-implementation-plansgeneral-electionmanifestosmallest-creaturesfoundationshealthy-environmentecosystem-functionnature's-declineactioncommitmentEngland-Managerdeliberate-movementreleasewildconservation-purposefeatheredfurredmultitudelarge-scale1980s1990s2018Englandsmall-sizesmall-scaleregion2005200720082010-201520092010201920222023isolatedhigh-reproductive-potentialcost-effectivezooaquariumcollaborationten-different-zoosthousandsspiderlingsfour-new-populationsNorfolkSuffolkmedia-response2024headlinehomeownerurgent-warningrelatively-easy-to-rearlocal-schoolscollegesvolunteerssmall-aquaria500-snailsfour-new-sites6,00047-volunteerslong-complex-life-cyclelong-livedmany-years50,000specialised-facilitieshundredsjuvenile-musselsageing-populationsNorthern-Englandnatural-rangeconservation-status2000climatically-suitablenine-yearspest-speciesForestry-EnglandWood-Antkeystone-woodland-speciesrescueimmediate-dangerAustropotamobius-pallipesNorth-American-Signal-CrayfishPacifastacus-leniusculusoutcompetesfungalCrayfish-Plaguesusceptiblesuccessful-reintroductionrigorous-planningappropriate-guidelinesreintroduction-codenatural-habitatrestorationmicro-habitat-requirementslife-cycle-stageconservation-tool-kittargeted-habitat-restorationmobile-speciesspecies-specialistpublic2010s2004thousands-of-caterpillarsmultiple-attemptspublic-attentionvertebrate-relative2025opposite-patterncelebration