StonefishesSynanceiinae

The most venomous fish in the sea has no way of using that on anything bigger than itself. The venom sits in the spines along the back, each one a stiff needle with a pair of glands at its base under a sheath of skin, and the whole apparatus is passive. Nothing is aimed and nothing is decided. Weight pushes the sheath down the spine, the glands compress, and the dose goes in under the pressure of whatever stood on it. Press harder and you get more of it. The spines are stiff enough to go through the sole of a beach shoe.

A sting is immediate, severe pain far out of proportion to a wound that may be two small punctures, spreading up the limb, with swelling that can last weeks. Bad cases bring vomiting, breathing trouble and a drop in blood pressure, and they belong in a hospital. The main toxins are large proteins, which is why heat is the first move: hot water, as hot as the hand can stand, while somebody arranges the transport. This is also the only fish sting anywhere with an antivenom behind it, made from horse serum since the 1950s and given in a hospital, not on a beach.

None of it is aggression and none of it is about you. The fish has no swim bladder, it spends its life on the bottom, and it does not leave when something comes near, because leaving was never the plan: whatever arrives from above is supposed to meet the spines and reconsider. A person's foot was not in the design.

So the injuries happen where people walk rather than where people dive: reef flats, the shallows off a beach, the few meters between the shore and the boat. Shuffle instead of stepping, keep something on your feet, and look before you put a hand down for a photograph. Four species are listed here and two of them are not Synanceia at all, including a small stingfish that lives half buried in soft mud and the devil scorpionfish, which walks on two free rays under each pectoral fin and flashes bright color in them when something pushes it too far.