Rock Lobster Biology

Southern rock lobster are distributed widely across southern Australia from northern New South Wales, around Tasmania, across to Dongara in Western Australia and are also present throughout New Zealand waters.

Southern rock lobster live in a variety of reef habitats, ranging from shallow rock pools, out to the continental shelf. Lobsters vary in colour from usually reddish-purple in shallow water, to purple and creamy-yellow in deeper offshore waters.

Mating occurs during the months of April to July, with most eggs hatching between September and October. The eggs are extruded from a genital opening at the base of the third pair of walking legs. Fertilisation occurs externally and the fertilised eggs are carried under the tail of the female for 4-6 months. A large female can carry up to 400,000 eggs.

Female lobsters carrying eggs are known as ‘in berry’ or ‘buried’.  These lobsters are totally protected in South Australian waters. They must be handled with care and returned to the water immediately.

A Female Lobster


Rock lobsters have several recognisable life stages. After hatching, the planktonic larvae (phyllosomes) disperse widely with the ocean currents and have been located hundreds of kilometres offshore.
This phase of the lobster life cycle lasts between 9 and 20 months, after which the phyllosomes change (metamorphosis) into transparent puerulus, which resemble miniature lobsters in shape. Puerulus settle in inshore reef areas and, soon after settling, moult into bottom dwelling juvenile lobsters.


Distinguishing male and female lobsters

Characteristic Female Male
Fifth or last pair of walking legs (counting from the front to back) Terminate in a small claw, used to tend to the eggs under the tail during the spawning season No claw, fifth walking leg ends as a single point
Image examples
 A Female Lobster Underside
 A Male Lobster Underside
Location of the genital pore Genital pore is at the base of the third pair of walking legs, where the eggs are released Genital pore is at the base of the fifth walking leg
Pleopods (swimmers) under the tail Inner and outer pleopods, used to carry eggs Four pairs of single pleopods