Abalones are either male or female but lacking accessory reproductive organs necessary for copulation, they are spawners. An adult female may lay up to 500,000 eggs which are released into the sea water when induced by the presence of male sperm. Fertilisation takes place in the sea and the eggs then float for one to five days as they develop into veligers with a minute shell. The veligers sink to the sea bed attaching themselves to lithothamnion, a red seaweed covering rock, and begin to grow at a rapid rate. Growth rates depend entirely on the food supply available but it can be as much as 40 millimetres per year.
Young abalone remain vulnerable to natural predators, making a tasty dish to many varieties of fish and crabs. As such, they live by day concealing themselves within tiny crevices between rocks emerging only at night to feed. Yet as they grow larger and become more sexually mature (about three years of age) they may remain out in the open while still avoiding the occasional deadly foe such as octopus, crabs, fish, sharks, stingrays and of course man.