Further names: Portuguese: Caravelas
Prey: Mainly fish and crustaceans
Habitat and range: They are found in all warm regions of the world’s oceans. They most commonly occur in the tropical and subtropical regions of the Pacific and the Indian Ocean, and in the Gulf Stream in the Northern Atlantic.
Distinctive features: The Portuguese man o’ war looks like a large bladder with very long tentacles. This large bladder, also called the “sail”, reaches a considerable length ranging from 9 to 30 cm and a width of 10 cm. It is filled mostly with carbon monoxide and nitrogen. There are tentacles on the underside of the bladder which can be stretched out horizontally and can reach a maximum length of 50 metres. However, they are usually not longer than 10 metres.
Taxonomy: Class: Hydrozoa; Order: Siphonophorae; Genus: Physalia
Enemies: Despite their powerful venom, Portuguese man o’ wars are eaten by other animals. These include the Loggerhead sea turtle (Caretta caretta), a nudibranch known as the Blue Dragon (Glaucus atlanticus), the Common violet snail (Janthina janthina) and the Common blanket octopus (Tremoctopus violaceus).
Venom: Touching the tentacles often causes intense pain in humans. Red welts appear on the skin which usually only fade after 2 to 3 days. The pain subsides after about an hour. If the venom gets into the lymph nodes, the pain may be more severe. Contact with the stinging cells may also trigger an allergic reaction, which can have serious effects, such as fever, shock or rapid heartbeat. In rare cases, the sting may be lethal. Medical treatment is important especially in cases where severe pains persist and/or a red streak develops between a swollen lymph node and the sting or if the affected area is red and warm to the touch.