Description of a new species of Bursatella Blainville, 1817 (Gastropoda, Aplysiida, Aplysiidae) from southern Australia

ABSTRACT

Currently, the sea hare genus Bursatella contains two species, the circumglobal B. leachii and the recently re-erected B. ocelligera which is restricted to the central Pacific. Among circumglobally-distributed aplysiid species there is often considerable intraspecific morphological variation. This diminishes the reliability of using only morphology for species delimitation. In these cases, the inclusion of molecular data as part of an integrated taxonomic approach is particularly useful. Although Australian Bursatella have a near circum-continental distribution, animals from the western and southern coasts exhibit a distinct morphology that warrants investigation as to whether or not they represent a separate taxon. Specimens of B. leachii and the putatively novel taxon were used in an integrated taxonomic study with delimitation based on a consensus protocol. Combined molecular and morphological data supported the presence of a separate species, Bursatella hirsuta n. sp., which is described herein. Although adult animals may be readily distinguished from other sea hares by their overall appearance, juveniles may be mistaken for unstriped forms of the small sea hare Stylocheilus striatus.

KEYWORDS:

• Flindersian endemic
• integrated taxonomy
• ontogenic variation
• Stylocheilus

Acknowledgements

Gratitude is extended to Adrian and Sophie Brown, Janine Baker, Naomi Strong and Beth Evans for specimens and information, Dr Richard Willan for early guidance, staff of the AM and WA Museum for assistance, particularly Mia Hillyer (WAM) for sequencing, and Maxine Dawes from Southern Cross University (SCU) for help with SEM. Thanks are also extended to Professors Patrick Krug, Stephen D. A. Smith, Kirsten Benkendorff, Dr Bill Rudman and two anonymous reviewers who provided feedback on the manuscript which improved it considerably. Specimens from NSW were collected under permit issued by NSW Department of Primary Industries (P14/0014-1.1), from SA by citizen scientists under the Fisheries Management Act (SA) 2007, and from WA under permit issued by the Department of Parks and Wildlife (Regulation 17- 08-000214-2) and Department of Fisheries Exemption 2756. This study was supported by the Net Conservation Benefits fund (WAM), National Marine Science Centre, SCU Marine Ecology Research Centre, and the Malacological Society of Australasia. This work has been undertaken as part of a PhD project (MN) titled ‘Taxonomy and systematics of the Australian Aplysiidae (Mollusca: Heterobranchia).’ This project is supported through funding from the Australian Government’s Australian Biological Resources Study National Taxonomy Research Grant Programme.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Australian Biological Resources Study: [Grant Number CT217-17]; Malacological Society of Australasia and the Net Conservation Benefits Fund.