Portuguese Man-of-War By: Amanda Warren

Phylum: Cnidaria

Class: Hydrozoa

Common Habitats

These organisms are infamous for their very painful, powerful sting and are very common in Hawaiian ocean waters.The man-of-war occurs in the tropical and subtropical regions of the Pacific and Indian oceans, and the Northern Atlantic Gulf Stream.They are commonly found in the open ocean and in bays and beaches during strong onshore winds.

The Man-of-War

These creatures are sometimes found floating and some are found “swarming” in groups of thousands.

This animal is not a single animal but a colony of four kinds of highly modified polyps. These polyps are dependent on one another for survival. These polyps are concerned with detecting and capturing prey, reproducing, and feeding.

Body StructureTheir body consists of a gas-filled (nitrogen) bladder-like float.This bladder-like float is a translucent structure tinted pink, blue, or violet, which may be 3-12 inches long and may extend 6 inches above the water.Beneath the float are clusters of polyps from which hang tentacles of up to 165 feet in length.

Reproduction

Physalia reproduce sexually. The sperm of one mature Man-of-War fertilizes the egg of another reproducing larva.The larval Physalia reproduces itself by asexual reproduction to grow identical colonial offspring in and on itself.Asexual reproduction leads to rapid growth and sexual reproduction produces genetic differentiation, combined, both lead to rapid increase in species numbers.

TentaclesThe tentacles bear stinging nematocysts. These are coiled thread-like structures that paralyze their prey.

These structures attach themselves to the victim and then digestion takes place.

This creature will eat anything that it comes in contact with.

Sting Effects

Fever, shock, and interference with heart and lung action.

The toxin secreted consists of a mixture of enzymes which is a neurotoxin that is about 75% as powerful as cobra venom.

When stung, carefully pick off any tentacles and rinse with fresh or salt water. For severe pain apply heat or cold, whichever feels better to the victim.

To avoid being stung watch for warning signs, which are posted as needed.

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