Body Of The Portuguese Man Of War example essay topic

Portuguese man-of-war One kind of jellyfish found in the oceans is commonly called the Portuguese man-of-war. The scientific name for this species of jellyfish is Physalia physalia. The Portuguese man-of-war is in the phylum Cnidarian. Species in this phylum have a tissue level of organization and two layers of cells form the body. The species also has radial symmetry, which is where related parts of the body are set and continual around a central axis. Cnidarians have and oral surface where the mouth is and aboral surface on the opposing side.

The mouth is centrally positioned and opens into a gut. Tentacles border the mouth. The basic form in this phylum is medusa or upside-down polyp, which is customized for swimming. Hydrozoa is the class that the Portuguese man-of-war belongs to.

Hydrozoa include feathery or bushy colonies of small polyps. The polyps are made for feeding, defense and reproduction. They also have tiny see-through medusa that discharges gametes, which grow into larvae. The larva of planula phase is the flagellated stage containing two layers of cells.

Planula's resolve on the bottom of the ocean and change into polyp. Polyp will separate and grow into a colony of polyps. Some Hydrozoa do not have this stage and grow into medusa, others directly generate gametes. The Portuguese man-of-war is in the order Siphonophors. Siphonophors make up wandering colonies and may be specialized floats. The floats may be gas filled.

Siphonophors also have elongated tentacles. The family name for the Portuguese man-of-war is Physaliidae. The characteristics of this family are almost identical to the characteristics of the Portuguese man-of-war. The Portuguese man-of-war ranges in color from blue to pink.

It has a semi-transparent body called a pneumatophore. The body of the Portuguese man-of-war can be anywhere from 3-12 inches long, with a crest only a few inches tall that aids in locomotion. The stinging tentacles of this type of jellyfish may be 165 feet long. The colony has four types of polyps: a float, tentacles, feeding zooids, and gonozooids, which manufacture gametes for reproduction. Nematocysts, or stinging cells, are positioned in the tentacles. Sensory cells are abundant and are situated in the epidermis of the tentacles and area in the region of the mouth.

The Portuguese man-of-war lives and feeds in the benthic zone, the bottom of the ocean. It also lives and feeds in the pelagic zone, or water column. The Portuguese man-or-war may also be found in the open oceans, and bays and beaches through tough onshore winds. This species of jellyfish's key resource of food is fish fry, or young fish, and little adult fish. In addition to young fish and small fish it feeds on shrimp, other crustaceans, and little animals in the plankton.

However, virtually 70 to 90% of their food is fish. The Portuguese man-of -war will really eat just about anything that comes into its tentacles. Some fish and crustaceans, like the sand crab, eat this species of jellyfish. The Portuguese man-of-war does not have any unusual habits. The dangerous behavior the Portuguese man-of-war has towards humans is they can painfully sting humans. The sting is capable of causing serious side effects, such as fever, shock, and obstruction of heart and lung action.

After this type of jellyfish stings a person there are red curvy, whip-like, stringy welts on the skin. The long tentacles of the Portuguese man-of-war may be considered its defense mechanisms. The dangerous structures of the Portuguese man-of-war are tentacles of dactyl zooids that have stinging nematocystic structures that paralyze little fish and additional prey, along with harming humans. The poison of the Portuguese man-of-war is secreted from the tentacles of the dactyl zooids. The nematocystic sting poison is a neurotoxin about 75% as strong as cobra venom. The toxins include catecholamines, histamine, hyaluronidase, fibolsins, kinin's, phospholipase's and other hemolytic, cardio toxic and dermatonecrotic poisons.

Primarily Physalia reproduce sexually. During sexual reproduction the sperm of one adult colonial hydroid fertilizes the egg of an additional reproducing larva. The Portuguese man-of-war asexually reproduces itself by mitotic, asexual reproduction to make genetically similar offspring with and onto itself.