The opalescent inshore squid (which, if you’ve eaten squid in the US, then you’ve probably eaten before) can change color just like octopuses can. In fact, scientists found that female squid can give themselves a white stripe that looks an awful lot like the testicles of their male counterparts. It’s probably some kind of defensive measure, but the scientists are more interested in how the squid change color, not why. That’s because the mechanism is unique, and fascinating.