Blackworms have both male and female sex organs, but sexual reproduction is uncommon, at least under laboratory conditions. Reproduction is most commonly by fragmentation. That is, worms simply break apart and each fragment becomes a new worm by growing a new head and/or tail. This amazing process is called regeneration.

Reproduction

Fragmentation is a form of asexual reproduction or cloning 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.

Regeneration is the process of renewal, restoration, and growth that makes genomes, cells, organisms, and ecosystems resilient to natural fluctuations or events that cause disturbance or damage.