Hobbies And Interests
Annelids
There are over 2,700 different types of earthworm. They are all a part of the wider family of annelids which encompasses most species of worm and similar creatures such as leeches. Most annelids can regenerate and go through several stages to do this.
Healing
The first step in any regeneration is the healing of the initial wound. Then, a blastema (a mass of cells capable of creating growth) forms beneath the surface. Hormones from the brain then help to create regenerative structures within the blastema.
Nerves
As the body structure re-grows, the worm's simple nervous system regenerates from the remaining nerve chord still attached to the brain.
Clitellum
To regenerate, the body of the worm must be severed below the clitellum. This is the distinctive band around the worm's body and contains the reproductive organs. All other organs are above the clitellum.
Laboratory Regeneration
In certain species it is theoretically possible to grow two worms from one bisected specimen. In addition, scientists have successfully encouraged the Tasmanian earthworm to grow a second head. In the wild, however, worms are generally limited to natural tail regeneration.