|
|
|||||||
|
|||||||
|
| . | ||||||||||||||||
|
|
Portuguese Man-of-War (Bluebottle - Physalia spp. - Hydroid) |
|
 |
The portuguese man-of-war "jellyfish" - is actually any of various invertebrate, jelly-like marine animals of the family: Physaliidae, order: Siphonophora, class: Hydrozoa, and Phylum: Cnidaria. These pelagic colonial hydroids or hydrozoans are infamous for their very painful, powerful sting and are very common in Caribbean waters. The man-of-war ranges or occurs most commonly in the tropical and subtropical regions of the Pacific and Indian oceans, and the northern Atlantic Gulf Stream, although found in warm seas throughout the world. It is sometimes found floating - some even say "swarming" - in groups of thousands. And it is not a single animal but a colony of four kinds of highly modified individuals [polyps]. The polyps are dependent on one another for survival. |
|
Man-of-war's body consists of a gas-filled (mostly nitrogen), bladder-like float (a polyp, the pneumatophore) - a translucent structure tinted pink, blue, or violet - which may be 3 to 12 inches (9 to 30 centimeters) long and may extend as much as 6 inches (15 centimeters) above the water. Beneath the float are clusters of polyps, from which hang tentacles of up to 165 feet (about 50 meters) in length. The tentacles of the jelly fish contain hundreds of stinging cells, nematocysts. These on touching discharge a small dart into the prey, the dart is attached by a fine tube to a capsule that contains toxins. The toxins are discharged into the prey (usually small fish) and stuns or kills them. |
|
|
Sometimes a large "jelly fish",
the Portuguese Man of War, Physalia, is found stranded on beaches in the UK.
Physalia has a 30cm purple float filled with air that supports it on top of
the waves. Below the float are feeding and reproductive units and up to 50
meter long tentacles containing thousands of nematocysts. If the tentacles are touched, the nematocysts are discharged. Sailors and fishermen in the 17th Century were aware of the dangers of Physalia and accounts are given of fishermen who caught Physalia in their nets and were stung on their arms by contact with the tentacles. They tell of the intense burning pain that followed and their arms were left with strands of wheals that came up in blisters. The pain was so great that one sailor wanted to cut off his arm and others jumped in the water and preferred to drown rather than suffer the pain.
|
|
|
