Human blood, as you know, is a beautiful crimson red – that’s a result of the iron content found in our hemoglobin. But not all creatures have red blood. The range of colours found in the animal kingdom is determined by the chemistry of the molecules that each species has developed to transport oxygen throughout their bodies. For example, the horseshoe crab has copper in its blood which produces blue-coloured hemocyanin. Proteins, minerals and evolution have all contributed to the many colour variations that exist. Here’s a list of blood colours and the animals they are found in:
BLUE horseshoe crabs / lobsters / octopi / spiders
GREEN leeches / marine worms / skinks
YELLOW beetles / sea cucumbers
WHITE cockroaches
CLEAR ocellated icefish