ABSTRACT
The only octopuses clearly capable of causing severe toxin induced morbidity or mortality in man are small species of the genus Hapalochlaena, found in the Indo-Pacific region, predominantly in the coastal waters around Australia. The venom of the blue ringed octopus is produced in the paired posterior salivary glands. The venom is inoculated into the victim during the process of biting. The symptoms and signs of envenoming by the blue ringed octopus are those of tetrodotoxin (TTX) poisoning. The octopus must be in contact with the skin to bite the victim and cause envenoming. As bites only occur when the octopus is molested, and almost invariably, only after it has been removed from the water and placed on the victim's skin, all bites are preventable. Due to the rapidity of onset of life threatening sequelae of envenoming by the blue ringed octopus, prompt and appropriate first aid will often be crucial in securing a favourable outcome for the patient.
