ABSTRACT
Acetic acid (in the form of vinegar) inhibits nematocyst discharge after contact with Chironex fleckeri, the deadly north Australian box jellyfish. Vinegar application has become accepted first aid not only for box jellyfish stings, but also for stings by other jellyfish (Fenner et al., 1993). However, in the case of stings by a newly differentiated species of Physalia found in Australian waters that can cause severe envenomation, vinegar was found to cause discharge of up to 30 % of nematocysts, and vinegar is therefore not recommended for the treatment of such stings as it may actually increase envenomation. Stings from the single-tentacled Physalia utriculus (the ‘bluebottle’) are not severe (tentacles with unfired nematocysts rarely adhere to the victim’s skin), and vinegar dousing is not required. Vinegar treatment is therefore an unnecessary step in the first aid management of any Physalia sting but remains essential first aid for all cubozoan (box) jellyfish stings (Fenner et al., 1993).
