Asexual Reproduction in Animal - Regeneration

Regen­eration:

• Regen­eration is regrowth in the injured region.
• Regeneration was first studied in Hydra by Abraham Trembley in 1740.
• Regeneration is of two types, morphallaxis, and epimorphosis.

A) Morphallaxis:

In morphallaxis, the whole body grows from a small fragment e.g. Hydra and Planaria. When Hydra is accidentally cut into several pieces, each piece can regenerate the lost parts and develop into a whole new individual. The parts usually retain their original polarity, with oral ends, by developing tentacles and aboral ends, by producing basal discs.

Regeneration in Hydra

B) Epimorphosis:

Epimorphosis is the replacement of lost body parts. It is of two types, namely reparative and restorative regeneration. In reparative regeneration, only certain damaged tissue can be regenerated, e.g. human beings whereas in restorative regeneration severed body parts can develop. e.g. starfish, tail of wall lizard.