Blue-ringed<unk>  (genus Hapalochlaena) is commonly cited venomous<unk> 
Venom contains tetrodotoxin, which inhibits voltage-gated Na+ channels --> paralysis
Potentially lethal
Becomes bright yellow with blue rings when provoked
Venom contains tetrodotoxin, which inhibits voltage-gated Na+ channels --> paralysis
Potentially lethal
Becomes bright yellow with blue rings when provoked
Octopus bite
Toxins
Armed spider bite
Ciguatera
Lizard bites
Scombroid
Shark bite
Tetrodotoxin 