Is Port Stephens, eastern Australia, a global hotspot for biodiversity of Aplysiidae (Gastropoda: Heterobranchia)?

ABSTRACT

Port Stephens, a large natural harbour on the central New South Wales (NSW) coast, provides ideal oceanographic and benthic conditions for the growth of marine algae and seagrasses, and this promotes a suite of herbivorous heterobranch sea slugs such as sea hares and sap-sucking sea slugs. In this article we document both historic and recent observations of sea hares (family Aplysiidae) from Port Stephens with the intention of recording species diversity. The western South Pacific region has the richest aplysiid fauna in the world, with 16 species now recorded in Port Stephens. This location is the most taxonomically diverse for this family in Australia. Despite this hotspot of aplysiid diversity, the taxonomy and nomenclature of 12 species is uncertain, a fact highlighted by a series of nomenclatural notes included in this article. We herein report the first observation of Petalifera sp. in Australian waters. Dolabrifera jacksoniensis Pilsbry, 1896 is newly synonymised with D. brazieri G.B. Sowerby II, 1870. Recent reports of southern range extensions for other heterobranch sea slugs, both in Port Stephens and elsewhere in NSW, highlight the importance of recording the existing aplysiid diversity in the port. Thus, any future alteration to species composition and range shifts driven by climate change may be detected.

KEYWORDS:

• Anaspidea
• census
• citizen science
• climate change
• New South Wales

Acknowledgements

The authors extend their gratitude to all participants in the Sea Slug Census programme, many of whom are members of the Combined Hunter Underwater Research Group. Meryl Larkin and Peter Davey provided photographs and observational data from their research and dive projects. Denis Riek kindly shared his records of aplysiids from northern NSW. We are grateful to Robert Burn (Geelong, VIC) for help with generating the entries for the type species and for detailed comments on the final manuscript. We are also grateful for critical comments from a reviewer which helped to improve the manuscript. Erwin Koehler (Cebu, Philippines) kindly informed RCW of the dates of postings on his Sea-slugs from the Philippine Islands website. This article was prepared from data collected as part of a BSc (Hons) research project undertaken by MJN.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCiD

Matt J. Nimbs http://orcid.org/0000-0003-3541-5727

Additional information

Funding

Funding and in-kind support was provided by Southern Cross University and a research grant from the Linnean Society of NSW, Joyce W. Vickery Research Fund.