In July, during a lunch in a seafood restaurant in Sai Kung, I discovered there is a tank of few horseshoe crabs, which have blue blood. Later on, a pair of the elderly intended to buy it for brewing medical soup, to my surprise, the restaurant did not have a thought to sell them, claiming the horseshoe crabs are lack of meat, egg and so on. This prehistoric creature is only for display to catch people attention perhaps, for instance, an idle person like me standed there in attempt to make a lot of assessment of them.