The giant squid is literally a blue blood of the marine world. Its blood has a bluish color because of a copper compound in it. When it has been depleted of oxygen, it is cycled through the gills by two hearts, pumping it into one gill each. Then a systemic heart serves to pump the fresh blood through the tissues. So, the squid actually has three hearts!
The giant squid is also equipped with an ink sac. This releases large amounts of black fluid for camouflage, shooting out a blob approximately squid-size to confuse pursuers. It is, in effect, an underwater smoke screen.
Also helping the squid to elude attackers are small colour cells that give it the ability to change colours. These cells are so efficient that they can closely match the colour of their background, even causing a wave of colour to flow across the body of the squid as it swims from one background to another.
The giant squid is also equipped with an ink sac. This releases large amounts of black fluid for camouflage, shooting out a blob approximately squid-size to confuse pursuers. It is, in effect, an underwater smoke screen.
Also helping the squid to elude attackers are small colour cells that give it the ability to change colours. These cells are so efficient that they can closely match the colour of their background, even causing a wave of colour to flow across the body of the squid as it swims from one background to another.
