Stonefishes

Synanceiidae, the stonefishes, are a family of ray-finned fish in the order Perciformes, found in the Indo-Pacific region. They are close relatives of the scorpionfishes, with both placed in the suborder Scorpaenoidei. Many members of this family, most famously the subfamily Synanceiinae, are venomous. A majority of species in this family are marine, but some such as Notesthes robusta inhabit freshwater habitats.

All synanceiids share the unique defense mechanism of a "lachrymal saber", a switchblade-like spine found under each eye (being attached to the lachrymal bone) that can be projected forwards via movement of the maxilla.