“I study leeches called branchiobdellidans that live on crayfish. These leeches are just millimetres long and are symbionts — meaning they live in a close, long-term association with their host. They ...

Protecting some of Australia's smallest freshwater critters such as the spiny crayfish is a top priority for ecohydrologist Sarah O'Hea Miller. "I personally find them cute," she said. "Some people ...