You’ve all heard the adage that one man’s crab meat is another man’s poison, right? OK, so maybe that rendition isn’t all that universal, but it has become quite apropos over in Ireland, where one Ruth McManus recently happened upon a strange, rather colorful “mystery crab” washed up among seaweed on Dollymount Strand in Dublin. It was such an odd and unfamiliar crustacean that she hurried a photo off to Dave Wall at the National Biodiversity Data Centre in Waterford, Ireland.

Truth be told, all that Ruth would have needed for an instant ID was a passing Yank from Jersey – as in New Jersey – to…