Southern range extensions for twelve heterobranch sea slugs (Gastropoda: Heterobranchia) on the eastern coast of Australia

A list of occurrence records of twelve species heterobranch sea slugs (Gastropoda: Heterobranchia) in Australian waters as part of a study of the extension of the southern distribution limit at Port Stephens, New South Wales. This adds to the growing list of marine taxa that are progressively extending their southern range, potentially as a result of climate change.