name all six larvae of phylum platyhelminthes
Answers
Answer:
Tapeworm
Planarian
Schistosoma
Blood fluke
Liver fluke
Taenia
Paragonimus westermani
Fasciolopsis buski
Dwarf tapeworm
Flatworm, also called platyhelminth, any of the phylum Platyhelminthes, a group of soft-bodied, usually much flattened invertebrates. A number of flatworm species are free-living, but about 80 percent of all flatworms are parasitic—i.e., living on or in another organism and securing nourishment from it. They are bilaterally symmetrical (i.e., the right and left sides are similar) and lack specialized respiratory, skeletal, and circulatory systems; no body cavity (coelom) is present. The body is not segmented; spongy connective tissue (mesenchyme) constitutes the so-called parenchyma and fills the space between organs. Flatworms are generally hermaphroditic—functional reproductive organs of both sexes occurring in one individual. Like other advanced multicellular animals, they possess three embryonic layers—endoderm, mesoderm, and ectoderm—and have a head region that contains concentrated sense organs and nervous tissue (brain). Most evidence, however, indicates that flatworms are very primitive compared with other invertebrates (such as the arthropods and annelids). Some modern evidence suggests that at least some flatworm species may be secondarily simplified from more complex ancestors.
General Features
Importance
Although some platyhelminths (flatworms) are free-living and nondestructive, many other species (particularly the flukes and tapeworms) parasitize humans, domestic animals, or both. In Europe, Australia, and North and South America, tapeworm infestations of humans have been greatly reduced as a consequence of routine meat inspection. But where sanitation is poor and meat eaten undercooked, the incidence of tapeworm infestations is high. In the Baltic countries much of the population is infested with the broad tapeworm (Diphyllobothrium latum); in parts of the southern United States a small proportion of the population may be infested with the dwarf tapeworm (Hymenolepis nana). In Europe and the United States the beef tapeworm (Taenia saginata) is common because of the habit of eating undercooked steaks or other beef products.
Parasites in immature stages (larvae) can cause serious damage to the host. A larval stage of the gid parasite of sheep (Multiceps multiceps) usually lodges in the sheep brain. Fluid-filled hydatid cysts (i.e., sacs containing many cells capable of developing into new individuals) of Echinococcus may occur almost anywhere in the body of sheep. In humans, hydatids of the liver, brain, or lung are often fatal. Infestation occurs only where people live in close association with dogs that have access to infested sheep for food. Mark it as the brainliest