The organism which reproduces by the method of fragmentation is

Fragmentation is a form of asexual reproduction in which an organism is split into fragments. Each of these fragments develop into mature, fully grown individuals that are clones of the original organism.
Fragmentation is seen in many organisms such as filamentous cyanobacteria, molds, lichens, filamentous algae like Spirogyra and many plants and animals like sponges, acoel flatworms, some annelid worms and sea stars.