Britannica Sources used in this answer

How do stonefish dorsal spines deliver venom?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Stonefish (Synanceia verrucosa). — scorpaeniform Stonefish (*Synanceia verrucosa*).

Stonefish, which belong to the family Synanceiidae within the order Scorpaeniformes, are highly venomous marine fish. These bottom-dwelling creatures possess dorsal fin spines that are equipped to deliver venom when the fish is disturbed or stepped on.12

The delivery mechanism functions through specialized grooves located along the length of these dorsal spines. When pressure is applied to the spines—such as by a predator or an unsuspecting human—the venom is injected through these grooves, often resulting in wounds that are intensely painful and potentially fatal. While other members of the related Scorpaenidae family also possess spiny fins that can inflict severe wounds, the stonefish is particularly notorious for its potent venomous defense.1234