Little is known bout the mating system of these animals.

In general it has been noted that species within the genus Lagenorynchus have gestation periods of ten to twelve months. Calving season for L. australis usually occurs between the southern spring and autumn but a calf can be born as early as October. Females tend to have only one calf per birth (maybe two) and they also move more inshore to do this. Some records show that when two of these dolphins were spotted together in the past, they were only considered a mother and calf if the smaller of the two animals was one third or less the size of the adult accompanying it. On visual sightings alone, this is probably still the most common way to tell a calf from an adult.

Although data are not available for this species, in another member of the genus, L. acutus, young are between 90 and 125 cm at birth. They nurse for about 18 months, and become independent of their mothers around the age of 2 years. It is not known whne these animals mature sexually.

Breeding season: It is not known for certain when mating occurs, but births occur during the Southern Spring to Autumn.

Range number of offspring: 1 to 2.

Average number of offspring: 1.

Range gestation period: 10 to 12 months.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization (Internal ); viviparous

Young are precocial and swim along side of their mothers from birth. The mother provides her calf with milk for approximately 18 months, although the calf may remain dependent upon her for an additional 6 months. It is not known what role males play, if any, in the parental care of this species.

Parental Investment: precocial ; pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence; extended period of juvenile learning