Among sushi delicacies is 'uni', made of sea urchin gonads. Why anyone would eat squishy orange stuff, much less enjoy it and ask for more, is explained on The Echinoblog.
Possibly MORE than what you wanted to know about 'uni'.
Warning: it's a post that will make you go 'ooo' AND 'eehwww' at the same time.
Collection pressure on the poor pricklies as well as chemistry issues also considered (including effect on 'potency' of human beings) in Why Sea Urchin sushi (uni) tastes SO frakking good!