some of them have blue blood because they have copper rather than iron in it.
how interesting.

(, Wed 20 Oct 2004, 1:10, archived)
spiders have blood, do they?
They have some kind of fluid, which fills their exoskeleton, and that's why, when you kill em, their legs all curl up, cos there's no pressure....or something
(, Wed 20 Oct 2004, 1:12, archived)
They have no circulatory system and simply absorb oxygen through their spirocles(sp?).
*edit* Not sure about the leg curling bit, but it sounds reasonable.
(, Wed 20 Oct 2004, 1:13, archived)