shore crab crabs common crab widespread invasive species listed world worst alien invasive species native north east atlantic_ocean baltic_sea similar habitats australia south_africa south_america atlantic pacific coasts north_america grows width millimetres feeds variety worms small crustaceans potentially number fisheries successful occurred variety mechanisms ships hulls packing materials moved known different names world british isles generally referred shore crab green shore crab north_america south_africa bears green crab european green crab australia new_zealand referred european green crab european shore crab description millimetres long wide larger outside native range reaching wide british_columbia short teeth rim eye eyes eyes simplest means distinguishing closely related invasive species lacks extends forward eyes characteristic distinguishing species form second collectively straight parallel curve colour varies greatly green brown grey red variation genetic component largely local environmental factors particular individuals delay red coloured green red individuals stronger aggressive tolerant environmental stresses low juvenile crabs average display greater adults native introduced range native european north african coasts far baltic_sea east iceland north common crabs range mediterranean_sea replaced closely related species observed east coast north_america massachusetts found south_carolina northwards species extended range northwards newfoundland species found california pacific_coast united_states able extend range reached oregon state washington british_columbia extending range kilometres years extended south_america specimens discovered australia reported late 1800s port bay victoria species probably introduced early 1850s spread south eastern south western reaching new_south_wales south_australia tasmania specimen found western_australia discoveries area reached south_africa table docks area near cape_town spread far north camps bay south kilometres apart appearances recorded brazil panama hawaii madagascar red_sea pakistan sri_lanka resulted invasions remain isolated findings japan invaded related crab hybrid believed based ecological conditions eventually extend range pacific_coast north_america baja california alaska similar ecological conditions found world coasts large potential area invaded new_zealand new_zealand government taken action including release marine pest guide effort prevent ecology live types protected semi protected marine habitats including habitats mud sand rock submerged aquatic vegetation marsh soft bottoms preferred meaning tolerate wide range survive temperatures wide range allows survive lower found wide temperature range allows survive extremely cold climates beneath ice winter molecular biological study gene found genetic north_sea strongly populations iceland suggests unable cross deeper water females produce eggs larvae develop offshore stages final juvenile crabs zone young crabs live reach adulthood ability disperse variety mechanisms including ballast water ships hulls packing materials ship live marine organisms moved migration crab larvae ocean currents movement submerged aquatic vegetation coastal zone management initiatives found dispersed australia mainly rare long distance events possibly caused human actions predator feeding organisms particularly small crustaceans primarily nocturnal activity depends tide crabs active time day california predation native resulted decline native increase previously introduced gem implicated destruction soft shell fisheries east coast united_states canada reduction populations commercially important northern prey includes young fish effect predation winter minimal substantial negative impacts local commercial recreational fisheries young species crab competing resources control potentially harmful effects ecosystems efforts control introduced populations world massachusetts bounty levied catching protect local tons caught evidence native blue crab eastern north_america able control populations numbers species negatively found chesapeake_bay frequent west coast north_america appears limited upper habitats predation native rock crabs cancer competition shelter native shore crab host testing recently conducted parasitic potential biological control agent laboratory settled infected killed native california crabs including crab cancer shore crabs crabs vulnerable tested native species settlement infection parasite mature native crabs developing reproductive observed inside potential benefits control west coast north_america need weighed potential non target impacts use food east_coast united_states restaurant chain arranged purchase green crabs season local fishermen known commercial use crabs food industry legal plans test crab shrimp crab spring vegetables crab green crab stock test kitchen winter offer dishes restaurant locations crab season fishery small scale north east atlantic_ocean approximately tonnes caught annually france united_kingdom northwest atlantic subject fishery 1960s tonnes caught annually taxonomic history given cancer 10th edition earlier description published work calling species cancer starting point nomenclature number later synonyms published cancer cancer cancer cancer cancer chosen species came sweden assumed lost writing erected new genus hold species making type species genus described distinct subspecies occurring mediterranean_sea recognised distinct species
Carcinus maenas