Parasite shows how the jellyfish ‘devolved’

Devolved over centuries to become microscopic parasite.

Myxozoan spores from Kudoa iwatai, left. Each spore is approximately 10 micrometres in width. The jellyfish Aurelia aurita – moon jelly (right). The bell is approximately 25 centimetres wide or 2,500 times larger than a myxozoan spore. Credit: A. DIAMANT (LEFT), P. CARTWRIGHT (RIGHT)