126 TWO-LAYERED ANIMALS— PHYLUM COELENTERATA 



water and resembles the sails of the old men-o-war. Also, no fighting ship 

 in history, in comparison to its size, was more heavily armed than the Por- 

 tuguese man-o-war with its thousands of powerful nematocysts which 

 are able to inflict an extremely painful and sometimes dangerous sting 

 on persons that happen to contact the tentacles in the water. This is a 

 colonial form in which the individuals adhere together after budding and 

 assume different tasks in the group. Just under the float are quite a 

 number of feeding polyps that are concerned primarily with digesting 

 and absorbing food for the colony. Some are specialized to take care of 

 sexual reproduction, while others trail out in the water and bear the 

 nematocysts, capture other animals for food, and defend the colony against 

 any possible enemies. Here we see that the division of labor among 

 polyps, which we first studied in obelia, has been carried to the extreme. 

 This is known as polymorphism, a word meaning "many forms," and can 

 be compared to modern society where each man learns a different trade 

 and only a few actually raise food to eat. Portuguese men-o-war are 

 often left on the beach after the tide goes out, and bathers may step on 

 them to make them pop like a paper bag full of air. Bathers must 

 always wear shoes, however, to avoid retaliation by the stinging cells. 



An average sized Portuguese man-o-war will have a float about six 

 inches long with tentacles trailing down for several feet. The float glis- 

 tens with beautiful iridescent shades of pink, blue, and purple, making a 

 beautiful sight which belies the deadly nature of the tentacles hidden 

 beneath. This animal does not actively swim, but is carried by the tides 

 and the wind blowing its float which actually does act as a sail. A fish, 

 unfortunate enough to contact the deadly tentacles, is enclosed and stung 

 into insensibility ; then the tentacles contract and draw the fish up under 

 the float where the feeding polyps can go to work on it. These reach 

 down and spread their lips over its body and secrete their digestive fluid 

 on it and suck up the digesting bits of food as they break off. 



One of the most interesting relationships between two animals in the 

 whole animal kingdom occurs between the Portuguese man-o-war and a 

 small fish, Nomeus. Whereas to venture within reach of the deadly ten- 

 tacles usually means sudden death to most animals, Nomeus not only 

 ventures within reach, but actually swims in and out among the tentacles 

 in perfect safety and is protected from his enemies that do not enjoy this 

 privilege. However, the relationship is not a one-sided affair; the little 

 fish will sometimes swim out and offer himself as a temptation to larger 

 fish and, when the larger fish give chase, Nomeus will dart through the 

 tentacles. Then, as the victim attempts to follow, he finds himself en- 

 snarled and soon he is serving as a square meal for the Portuguese man- 

 o-war and its friend, Nomeus, who swims around and picks up the pieces 



