Blue Bottles: are also known as Portuguese Man (or Men) O’ War. Their scientific name is Physalia physalis. The specimen illustrated was one of a large number washed up on a beach on the North Coast of New South Wales.Wildlife
These jellyfish-like organisms have a gas-filled blue float that supports a number of specialized tentacles. These tentacles may be up to tem metres in length. Although superficially similar to jellyfish, Blue Bottles differ in a number of ways. A Blue Bottle is not a single organism but is a complicated colony of different organisms. Zooid is the name given to the individual members and they co-operate to form a jellyfish-like organism. The zooids perform different roles. Some will sting and capture prey; others eat the prey whilst some are in reproductive department of this complicated colony. Even the gas-filled float is a modified member of the colony. There are two types of floats. Some face left whilst others are angled to the right. A wind will push left and right-angled floats in different directions. Thus not all Blue Bottles will become marooned on the beach and expire. We find this survival mechanism rather remarkable. In fact the whole Blue Bottle colony organisation is mind-boggling.
Blue Bottles are dangerous organisms. Their tentacles are able to deliver painful stings to swimmers. They are able to sting even when lying dead on the beach.
Much of this information was gleaned from the excellent Wildlife of Sydney site:
Follow the link to Invertebrates then Jellyfish, anemones and corals.
Please refer to this site for First Aid information.