These are known as man-of-war, blue bottle, floating panic, etc. In Hawaii they are called 'ili mane'o, palalia etc. The name "Man o 'war" comes from the 16th century warship "man-of-war". They are found in the warm and almost warm waters of the Atlantic, Pacific and Indian Oceans. Scientific name "Physalia physalis". They belong to the genus Cnidaria, to the genus Hydrozoa, to the class Siphonophorae, and to the sub-class Cystonectae.
They have many toxic microscopic nematocyst tentacles. A nematocyst is a special type of cell like a cut or poisonous coil thread. The tiller can be 10-30 m (about 30-100 feet) long. Tortoises remain active for a few hours or days after death or detachment from the body and can sting at the same power as the living. Its venomous bite is sufficient to paralyze and kill various species of fish and in some cases even kill humans. They use tillers to paralyze the prey and digest it by rotation.
They are responsible for biting around 10,000 people every summer in Australia. The sting usually causes scars on the skin, which usually lasts for 2/3 days, but the pain starts to subside within 1-3 hours. However, if the toxin enters the lymph nodes, it can cause allergies, laryngitis, heart pain, breathing problems, etc. They are different from single organisms, such as jellyfish, because they are colonial organisms that are made up of different, but genetically distinct, parts called "zooids". These "zooid" gula are so physically connected that they cannot survive on their own. They reproduce through asexual reproduction. They cannot move actively. Floating by the force of the wind or the current of the waves. They are also preyed upon by Loggerhead turtle, Blanket Octopus, Blue sea slug "Glaucus atlanticus", Ocean Sunfish.
References: https://en.m.wikipedia.org/wiki/Portuguese_man_o%27_war