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.

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