Fish Are Not What We Assumed
The tusk fish picks up a clam, swims to a rock, and smashes it open, repeatedly, deliberately, with the same stone it has used before. This is tool use. It was filmed in the wild, published in the journal Coral Reefs in 2011, and it still hasn't fully landed in the public conversation about what fish are capable of. Most people who eat fish daily have never heard of it.
