Bdelloid Rotifers

Bdelloid rotifers are microscopic, freshwater-dwelling metazoans notable for their asexual reproduction through parthenogenesis, having persisted without sexual recombination for tens of millions of years while maintaining genetic diversity through horizontal gene transfer and desiccation-induced DNA repair.

Their transparent, bilaterally symmetric bodies contain a corona of cilia used both for locomotion and for drawing food particles—mainly bacteria and detritus—into their mastax, a chitinous jaw-like organ that grinds ingested material.

Unique among metazoans, they can survive complete desiccation by entering anhydrobiosis, during which their metabolism halts and DNA fragments are later repaired upon rehydration, allowing them to colonize unstable microhabitats such as mosses, lichens, and temporary water films.