Is it true that if you cut an earthworm in half, you will get two viable individuals?

Many of us have known the story since childhood that if an earthworm is cut in half, then each half will regenerate into a whole organism and live its own life. We decided to check if this is true.

Users ask this question on websites And forums, and some even claimthat teachers told them about this ability of worms in biology lessons at school. 

Rain (earth) worm - an invertebrate representative of the order of annelids, living on all continents except Antarctica. The animal's body consists of segments, their number varies from 80 to 300. The annelid worm has a head and tail ends of different structures. The circulatory and excretory systems are located along the entire body, and breathing occurs through the skin. It is because of skin respiration that worms crawl to the surface during and after rain, since there is not enough oxygen left in the waterlogged soil.

Closer to the head end of the worm there is a “belt”, scientifically called the clitellum, a thickening responsible for the reproduction of the worm. “Belt” and the following segments (from 9 to 15) play key role in animal regeneration. If, as a result of injury, the clitellum remains at the head end, then this part, under favorable conditions, is capable of regeneration and can grow a new tail. At the same time, the second part of the cut animal is not capable of “growing” a new mouth. If the wound heals, then another tail will appear in place of the head with the mouth opening and the body will die of starvation.

It is important to note that among the worms there are those who are capable of real miracles of regeneration. These are flatworms and their representative is planaria. It is an aquatic carnivore that lives in both fresh and salt water. capable grow your body from a fragment that is only 1/300 the size of an adult animal. Planarians can restore not only their entire body, but even their memories. Scientists installedthat as a new head grows, neurons “remember” everything that happened to them before.

Thus, earthworms, unlike planarians, have a very limited ability to regenerate. If the cut is made after the 15th segment, the head end can grow a tail. But there can be no talk of any two independent individuals, since the tail end, if separated from the head, inevitably dies.

Not true

What do our verdicts mean?

Read on the topic:

1. Why do worms crawl onto the road after rain?
2. Earthworms are gigantic and can mate for hours
3. Remember everything: worms restore memory along with their heads