Stonefish

Stonefish are the most venomous fish on Earth, 13 dorsal spines loaded with a neurotoxic-myotoxic cocktail powerful enough to kill an adult human if untreated. They sit motionless on coral rubble, fully camouflaged as encrusted stones, and even local guides need a trained eye to spot them.

The risk is stepping on one, almost every sting in scuba history is an accidental kneeling or hand-down event. Antivenom exists and is held by every major dive resort in stonefish territory, but the pain and tissue damage are severe regardless.

Found across Indo-Pacific reefs: Andaman, Maldives, Bali, Komodo, Red Sea. Local guides know the resident individuals and point them out, once you see one, the camouflage becomes obvious. Photograph from the front; never reach to position your gear near them.