Amazing in its variety, flatworms are very interesting creatures, this is a fact. True, this point of view is mainly shared by biologists who study them, and not by simple people, who naturally treat most of these creatures as parasites, which many of them, in fact, are. Nevertheless, it is impossible not to be surprised at the whims of the evolution that created such vitality.
Of all their classes, only ciliary worms live on their own, mostly in water, both salty and fresh. But all the other flatworms are parasites. They have no circulatory or respiratory system. They receive oxygen by assimilating it to the entire surface of the body. Flatworm parasites get rid of unprocessed food debris by mouth opening. Planar flatworms are able to assimilate knowledge at the genetic level, eating their fellows. The worms that fed the crushed bodies of the relatives who had previously successfully passed the experimental labyrinth, passed it without problems, as if they had already been to it.
In total, about 12,000 species of flatworms are now known, but from time to time scientists discover new ones. The life cycle of many flatworms begins in the reservoirs where their larvae live. Then they get into the bodies of livestock or fish, where they develop. Some of them are in the human body. The bovine tapeworm, perhaps the best known of flatworms, lives in the intestines of livestock or humans. If the patient is not treated, this roommate may exist in human guts up to 20 years. During its long life, the bullish tapeworm is able to lay up to 11 billion eggs. The special structure of the body gives most flatworms the opportunity to turn inside out if necessary.
From a biological point of view, flat worms schistosomes are very interesting. They are bisexual and monogamous, and the females are much smaller than the males, and they spend their entire lives in a pocket on the body of “their” male. In this case, the vast majority of all types of flatworms are hermaphroditic. The largest of the flatworms is the flat tapeworm parasite, which is 22-25 meters long. The length of the aforementioned bovine tapeworm can be 8-10 meters.
Planar worms have amazing regenerative abilities. They can fully restore their body, even if 95% of it was lost. As it was once calculated, the total mass of parasitic flatworms in a sheep herd of 100 thousand individuals reaches approximately 9 tons. The length of adults of most species of flatworm does not exceed 1 mm.
