Behold the humble water flea, locked in a battle of mythological proportions

Biologists sized up an unlikely natural phenomenon: when parasitism actually causes the number of hosts to increase, an effect known as a hydra effect. A study of common water fleas and their fungal parasites includes laboratory components and an analysis of 13 fungal epidemics in nature. The scientists use consumer-resource theory to explain why -- and in what types of systems -- the hydra effect can occur.

source https://www.sciencedaily.com/releases/2021/09/210920121803.htm