is it safe to eat a blue lobster?
http://upload.wikimedia.org/wikipedia/commons/6/62/Blue-lobster.jpg

lol
yes :)
and, contrary to what many people think, lobsters are not really red. They only get that way after you cook them.

Blue crabs are blue but also turn red after you cook them.

I remember when they caught that particular blue lobster. It was an unusual colour morph but not impossible. Usually that species is grey/blue mottled. Lots of them have been spotted with blue parts or white parts (albino). It's just usual to see one entirely blue, so this guy got famous. It happens to other crustaceans as well.

Next week's lesson - Gynandromorphous crabs:male on one side, female on the other (pics included)

Wow I have learned a lot in this post.

Is it true that blood turns red when it hits oxygen?

blood is red or blue depending on the oxygen levels, oxygen = red deoxygenated blood = blue

yes, the colour of blood is determined by haemoglobin. When there is no oxgen to bind to it, it reflects the blue end of the colour spectrum. When oxgen binds to the haemoglobin, it reflects red because of the iron.

Crabs have haemomyocin so their blood is green - they use copper instead of iron.

I want to eat it?