species mud crab native atlantic coast north_america established outside native range living mediterranean_sea 1970s north_sea black_sea reach width black tips unequal claws feeds turn eaten predators including atlantic blue crab eggs produced spring autumn offspring reach sexual maturity following summer individuals live years closest relative lives gulf_of_mexico species differ subtle features pair walking legs description small crab similar appearance reaches maximum width millimetres sexually mature females having millimetres roughly times wide long strongly convex finely surface light covering hair especially sides claws unequal right left narrower olive green brown tips claws black distribution natural range extends des eastern canada south eastern united_states lives zone depths metres wide range temperatures recorded number locations europe sighting docks united_kingdom scientist reported believed doubt species arrived shipping record mediterranean_sea species discovered north eastern italy thought living late 1970s recorded north_sea coast netherlands discovered black_sea living harbour romania delta western mediterranean_sea ecology lives predominantly muddy bottoms predator native environment hides colonies avoid preyed atlantic blue crab important predator delaware bay adriatic_sea observed feed striped venus introduced asian date life cycle life cycle begins normally takes place shortly female soft spawning occurs hours days eggs female ready hatch females found carrying eggs april october study crabs caught gloucester point virginia females observed carry eggs number eggs increases width according power law power law suggests largest females capable carrying eggs eggs days develop increases days temperatures young crabs hatch larvae pass stages juveniles juveniles thought reach maturity summer hatch total lifespan individual years taxonomy species noticed american zoologist thomas formed species called cancer junior cancer junior synonym described seven new species genus including addition species placed genus time common names species include mud crab mud crab smith noted similarity species described years earlier smith considered species edwards independently remained moved taxa genus established smith taxon subspecies argued taxa considered subspecies hybrids occurred specimens saw thought examined concluded good species elevated rank species placed separate genus close relationship occurs gulf_of_mexico distinguished form fifth walking leg male
Dyspanopeus sayi