A sea urchin is a sea urchin the word "sea" is used to differentiate between a normal urchin and also to show where their habitat is, I would imagine. Gulls don't spend a huge time at sea. I once ate sea horses at a wedding in Taiwan.
Big difference between a spikey yoke and a child with no shoes but will pass it on,thanks for your help.
Of course there is a huge difference, that is why they call them sea urchins. Could you imagine the confusion if somebody had 20 sea urchins to sell and they just said they had 20 urchins to sell? Fagin would be there like a shot trying to enrol kids with no shoes on into his pick pocket gang. Not to mention all the bloody Romanians etc. No, Mick, I think it is for the best if sea urchins are called sea urchins, there will be a lot fewer unsavoury incidents that way
One lives in the sea, one lives up a chimney encased in a protective gor’ blimey hat. Jesus, don’t you guys watch The Natural History Channel ?