Petta Malmgren, 1866 is a small and poorly known genus of the annelid family Pectinariidae Quatrefages, 1866. Prior to this study, the genus comprised four species. The authors have revised the genus by re-examining the types and providing updated illustrated re-descriptions of its species, except for P. assimilis of which the type material has been lost. Two species P. investigatoris n. sp. and P. williamsonae n. sp. are described from deep water off the coast of southeastern Australia and represent the first records of this genus in Australian waters. These two species were collected from the RV Investigator voyage IN2017_V03 - see IN2017_V03 for voyage details, maps, other data and publications.

If this data has been used in any products, please acknowledge with the following: We acknowledge the use of the CSIRO Marine National Facility (https://ror.org/01mae9353) in undertaking this research.