Cuttlefish, Octopus and squid are all cephalopods.
Cephalopods communicate using their ability to control the pigment in their skin.
They flash messages in colorful spots and splotches.
This is due to chromatophores, surface cells, filled with red, yellow and black pigments that can expand or contract in a few thousandths of a second.
Caribbean Reef Squid can send one message via color patterns to a squid on their right, while they send another message to a squid on their left.
Cuttlefish add to this unique visual communication by gestures of their ten tentacles. There have been over 137 gestures catalogued. When researchers gesture to cuttlefish they have been know to gesture back.
octopus have some rather unsavory sexual habits. Although amazingly smart and emotional, they can be quite savage, you know. When a male gets sexually excited, he becomes striped and horny… literally horny: two fleshy knobs just rise right out of his head.
He doesn’t have a penis, poor dear, but that doesn’t stop him! One of his eight arms is hollow and he starts caressing the female all over–sometimes a tad violently. Then, he thrusts his hollow arm into the female’s breathing cavity, and his sperm packets slide down his arm into her throat. If she doesn’t like it, she may bite his arm off and swim around with it for days, until it absorbs into her body.
In some species, the copulatory arm loads itself up with sperm, detaches itself from the octopus, and swims off by itself in search of a mate. Can you imagine how the female must feel? There she is, trying to nap perhaps, when suddenly she awakens to find a strange arm trying to force its way down her breathing passage and father her children.
I have personal experienced this while 
in Thailand… a conversation with a Cuttlefish.
Hence I don’t eat them…. In Korea they shove live baby octopus is their mouths because they enjoy the sensation of suction as the creatures look for escape… but then that’s Korea…