The giant freshwater crayfish is a mere 6 mm long as a hatchling, and matures extremely slowly, living for up to 40 years (5). Reproductive maturity occurs at around nine years in males and 14 years in females, with females breeding just once every two years (2). Mating occurs in autumn and the eggs, attached to the female’s swimming legs during development, hatch the following summer, remaining attached to the swimming legs as hatchlings for another month. Such a long reproductive process means that females spend much of their life with their young attached to their legs – a good strategy as fully grown adults have no natural predators (2). However, fishing of adult crayfish by humans results in the removal of not only the adults but all their young as well (3).
The giant freshwater crayfish is omnivorous, eating primarily rotting wood and animal flesh, as well as leaves and insects that fall into the water. Juveniles tend to hide in shallow water where they are less at risk from their large predators including fish and platypuses. Adults hide under submerged logs in deep pools where they appear to tolerate each other, despite being aggressive elsewhere (5).