Man-of-War Essay, Research Paper

Man-of-War

The Portuguese man-of-war if a member of the Kingdom Animalia, phylum

Cnidaria(1), class Hydrozoa, order Siphonophra, the genus Physalia, and the

species Physalia(2).

The man-of-war is not an actual jellyfish, but a Siphonophor. Also the

man-of-war is not a single organism. It is made up of many different organisms

that work together. These organisms are called polyps.

The Portuguese man-of-war is usually found in the Northern Atlantic gulf

stream. It can also be found in the tropical and subtropical regions of the

Indian and Pacific Oceans.

The man-of-war will usually travel in groups, that may contain up to one

thousand members.

The main portion of the man-of-war’s body is an oblong gas-filled

bladder. The bladder is usually nine to thirty centimeters long, and is a

translucent pink, blue, or purple. On top of the bladder is a crest. This is to

catch the wind, and move the man-of-war along. Below the bladder, hang long

stringy tentacles, that can reach a length of up to fifty meters. The tentacles

are made-up of three different types of polyps. The names of these three polyps

are: dactylozooid, gonozooid, and gastrozooid. The polyps are the parts that:

capture prey, digest prey, and reproduce. The dactylozooids have cells called

nematocysts(3). The nematocysts release a toxin(4) into anything that they come

into contact with. The gastrozooids then attach to the dead/stunned victim, and

spread over it. They digest it, and transfer food to the rest of the man-of-war.

Last, the gonozooids create other polyps. The means by which the man-of-war

reproduces, however, is not yet understood.

The fish Nomeus gronvii lives among the tentacles of the man-of-war.

This fish, which is eight centimeters long, is mostly immune to the man-of-war’s

toxin. It will eat the tentacles, which will grow back, as its main source of

food. Although it is mostly immune to the man-of-war’s toxin, the man-of-war

will sometimes end up eating it.

The enemies of the man-of-war are the Nomeus gronvii, and the loggerhead

turtle.

If you were to get stung by a man-of-war, you would experience a very

painful sensation where you got stung. The toxin that the man-of-war uses blocks

nerve conduction. This causes a severe systematic syndrome. This is accompanied

by a fever, possibly shock, and interference with heart and lung functions.

Bibliography

“Portuguese man-of-war,” Encyclopedia Britannica. 1988, University of Chicago:

Vol. IX, p.634-35

“Portuguese man-of-war,” Animal Kingdom. 1972, United States of America: Vol.

XVIII, p.88-93

Caras, Roger. Venomous Animals of the World. United States of America: 1974, p.

17-18

hillside.sowashco.k12.mn.us,

http://hillside.sowashco.k12.mn.us/kaipo/invertebrate/welcomeinv.html, United

States of America: hillside.sowashco.k12.mn.us, 1997

Microsoft Encarta 1996. Silicon Valley Ca., Microsoft Corporation, 1997

1 Cnidaria and Celenorates are two interchangeable names for this Phylum.

2 Multiple sources were researched including the Encyclopedia Britannica, World

Book, Encyclopedia Americana, Microsoft Encarta, and Internet searches through

Yahoo, Altavista, and HotBot; however, no reference to Family was provided.

3 A capsule within specialized cells of certain coelenterates, such as jellyfish,

containing a barbed, threadlike tube that delivers a paralyzing sting when

propelled into attackers and prey.

4 A poisonous substance, especially a protein, that is produced by living cells

or organisms and is capable of causing disease when introduced into the body

tissues but is often also capable of inducing neutralizing antibodies or

antitoxins.