You’ve most likely heard of squid and octopii, but have you ever seen their close relative, the Cuttlefish (Order: Sepiidae)?!  There are about 120 species of cuttlefish around the world, exhibiting an amazing array of behaviors and fascinating physiological adaptations.

Like other cephalopods, cuttlefish are marine animals with at least 8 arms and a beak. They are thought to be very intelligent and have complex nervous systems with sophisticated eyes.  If you’ve ever owned a pet bird, you might have heard of the cuttlefish’s unique internal shell that it uses to help keep it afloat. This is because the cuttlebone was once used in toothpaste, but now it’s given to many pet birds as a dietary supplement due to being high in calcium.

Despite it’s welcoming name, you might not want to cuddle with a cuttlefish.  At least three species of cuttlefish have toxic salivary gland which can be used to kill crabs.  Another species, the Flamboyant cuttlefish, was discovered to have extremely toxic muscles.

And if these traits don’t make the cuttlefish awesome enough, wait until you see their camouflage. Cuttlefish can rapidly change the color of their skin, the shape of their body, and even the polarization patterns of light on their body!   There is some evidence that male cuttlefish can use coloration patterns as a way to signal aggression to other males. When meeting other males, a male cuttlefish can exhibit the “intense zebra display” where it dons black and white stripes and extends its 4th arm towards the opponent.  Scientists think that males use this to identify themselves as male and also signal their intention to attack.  In encounters where cuttlefish actually attacked each other, both males adopted darker facial color patterns than in encounters when no physical contact occurs.

You can learn more about coloration in cuttlefish by watching the documenary below.