Physaliidae Family of Hydrozoans
One Man-of-War of the Physaliidae Family can be found in this website:
Portugese Man-of-war, Physalia physalia. A representative of the Physaliidae Family of Hydrozoans.
Phylogeny: Hydrozoans of the Physaliidae Family, like sea anemones, hard corals, and jellyfish, are in the Phylum Cnidaria. They are in the subphylum Medusazoa, the class Hydrozoa, the subclass Hydroidolina, the order Siphonophorae, and the suborder Cystonectae. The Physaliidae Family is one of two families in this suborder. The Physaliidae Family is comprised of one genus and four species. The name Physaliidae comes from the Greek word meaning “bubble” or “bladder”, and refers to the gas-filled pneumatophore. Species in the family are variously known as Man O’ Wars, Man o’ wars, and Blue Bottles. In Mexico they are called Aguamala or Frigata Portuguesa.
Morphology: Man-of-wars appear to be a single organism but they are actually a colony of four types of multi-cellular, interdependent, animals (zooids). Man-of-Wars consist of an oval shaped, gas-filled, bladder (pneumatophore) that provides buoyancy, and long tentacles. The pneumatophore has a sail-like structure on top to catch the wind. The sail may be right handed or left handed, which determines which direction they blow in the wind. The tentacles are muscular and contractile, and can reach up to 50 m (165 feet) in length. The tentacles are equipped with nematocysts (or cnidocysts) that deliver a toxic sting that is utilized to capture prey or repel predators. The bladder and tentacles are translucent blue to violet giving rise to the common name “Blue Bottles”. The bladder can reach up to 30 cm (12 inches) in length.
Habitat and Distribution: Man-of-wars are primarily found on the surface of the open ocean, though they are sometimes pushed on to beaches, and into bays and harbors. Man-of-wars are unable to swim or dive and are at the mercy of the wind for locomotion. They can form large groups that are sometimes pushed ashore by the wind. Once ashore, they begin to die, although the nematocysts can remain active for days, or even weeks. Man-of-wars are found worldwide in subtropical to tropical seas. At least two species from this family are found in Mexican waters.
Reproduction: Each individual Man-of-war colony is gonochoric (male or female for life). Reproduction is sexual, via broadcast spawning with external fertilization. The fertilized eggs develop into larvae which then reproduce asexually by budding to form a new colony.
Ecosystem Roles: Man-of-wars feed primarily on fish and planktonic invertebrates. Once the tentacles sting their prey, the tentacles retract to pull the prey toward specialized digestive cells. In turn they are preyed upon by the Loggerhead Sea Turtle, Caretta caretta, Nudibranchs of the Glaucus genus, Ocean Sunfish, Mola mola, and the Violet Sea Snail Shell, Janthina janthina. Several fish species have a commensal relationship with Man-of-wars; the fish gain protection by maintaining a close proximity to the stinging tentacles and the fish may attract prey for the Man-of-war.
Caution! Man-of-war Stings and Treatment. These are extremely dangerous animals that can generate serious envenomations and may require advanced medical treatment. The nematocysts from a Man-of-war can deliver excruciatingly painful stings to humans, and on rare occasions, may be fatal. Not all of the nematocysts fire their venom on first contact. Care should be exercised to avoid activating these remaining nematocysts. Usually fatalities require that a large amount of tentacle come into contact with a large surface area of skin, especially on the torso with small children being the most susceptible. Generally, the stings appear as welts. Treatment should not involve flushing with fresh water or alcohol as these have been shown to cause additional nematocysts to fire. The application of copious amounts of vinegar is recommended, leaving the affected area immersed for at least 30 seconds. An alternative, but second choice, is a seawater flush to remove the tentacles and then immerse the affected area in hot seawater for 20 to 30 minutes.