Fragmentation: In Plants and Animals

Students studying Biology would have come across the topic of asexual reproduction. Fragmentation is one of the most common forms of asexual reproduction. It is a form of cloning in which one organism is broken into smaller fragments. These fragments can be reassembled into fully grown organisms.

Fragmentation is also known as splitting method of reproduction. It can be seen in many organisms like cyanobacteria and fungi as well as in animals such as flatworms, sponges and annelid worms.

Fragmentation in various organisms

Fragmentation in Plants

Fragmentation is a common type of sexual reproduction. The most common form of vegetative reproduction is fragmentation. Fragmentation is when a shoot that has been rooted becomes detached from the main group. There are many other mechanisms that plants use to fragment their cells. Natural fragmentation can also occur in other plants.

Specialised structures (Reproductive). Very few plants can form adventitious plants on their leaves. These plantlets would then detach and become individual plants. Some plants produce organs such as turions or bulbils.

Fragmentation can occur even in non-vascular plants. This is common with liverworts and mosses. The wind, animals, and water carry moss stems or leaves. When the moss fragment is in a suitable environment, it will root itself to become a new plant.

People use fragmentation to artificially propagate plants by cutting, layering and grafting. Many plants can be artificially propagated by fragmentation, including layering, cuttings and grafting.

Fragmentation in Animals

Natural fragmentation and reproduction occur in animals such as coral colonies and sponges. Different species of sponges and coral colonies can reproduce using this method.

This reproduction method is used by flatworms and annelid species.

While certain developmental changes can cause splitting, terms like architomy and paratomy are widely used. Paratomy is the process whereby an animal splits into two pieces. Each piece would have its own tissues and organs. Architomy is where organisms are split into fragments that then become mature organisms.

Furrows may develop at the area of splitting before the animal splits. A fragment must not have a head to be able to regenerate a head.

Paratomy is a split where the anteroposterior is perpendicular to the anterior axis. This allows for the pre-generation of anterior structures in the posterior. As their body’s axis is properly aligned, both organisms will develop head to tail. Paratomy and budding are very similar, with the exception that their body’s axis is not correctly aligned.