And I think that one's been around a few times, with variations in who stands in as the shark (or whatever) bait. Making it an Englishman is lot better than some versions...

Nothing wrong with passing on good stuff we come across - it's how jokes travel, the same way songs do. But I think, when it's a cut and paste of a specific text, it's good manners to indicate so, and maybe give a link to the immediate source.