An illustrated inventory of the sea slugs of New South Wales, Australia (Gastropoda: Heterobranchia)

Abstract

Although the Indo-Pacific is the global centre of diversity for the heterobranch sea slugs, their distribution remains, in many places, largely unknown. On the Australian east coast, their diversity decreases from approximately 1000 species in the northern Great Barrier Reef to fewer than 400 in Bass Strait. While occurrence records for some of the more populated sections of the coast are well known, data are patchy for more remote areas. Many species have very short lifecycles, so they can respond rapidly to changes in environmental conditions. The New South Wales coast is a recognised climate change hot-spot and southward shifts in distribution have already been documented for several species. However, thorough documentation of present distributions is an essential prerequisite for identifying further range extensions. While distribution data are available in the public realm, much is also held privately as photographic collections, diaries and logs. This paper consolidates the current occurrence data from both private and public sources as part of a broader study of sea slug distribution in south-eastern Australia and provides an inventory by region. A total of 382 species, 155 genera and 54 families is reported from the mainland coast of New South Wales.

Assessing cryptic marine fauna diversity as underwater macrophotography (UMP) objects in Sempu Strait, Indonesia

“…The identification process is carried out by comparing the morphological details of each specimen from the photograph with material source like books and journals, and also got its taxon verified by the World Register of Marine Species' website [18]. The fishes identifications are mainly compared to identification books [19][20][21], while the sea slugs are compared to various sources like book [22], scientific publications [23][24][25][26][27], and additionally the Bill Rudman's Sea Slug Forum [28]. The polyclad flatworms identified by comparing to journals [29][30][31][32], while the arthropods (crustacean) identifed by comparing to book [33].…”

Beyond Capricornia: Tropical Sea Slugs (Gastropoda, Heterobranchia) Extend Their Distributions into the Tasman Sea

“…Metadata are included for each image, including location, date, and depth. The establishment of a hub for photographic submission and discussion not only provides sharing of recent discoveries, but often uncovers information about the historical presence of species [5]. In this way, previously unpublished observation records for Lord Howe Island were recognised as a result of the development of a social media page for that location.…”

“…They noted a concomitant decline in the abundance of other nudibranch taxa with subsequent dietary analysis and feeding experiments indicating predation by P. hiltoni as a likely cause. On the eastern and southern coasts of Australia, the introduction and rapid spread of the aeolid nudibranch Spurilla braziliana on intertidal rocky reefs [5,31], has anecdotally been linked to a reduction in the abundance of an indigenous aeolid species, Austraeolis ornata (SDAS, MN, pers. obs.…”

“…The central eastern Australian coast is a known climate change hot-spot where warming conditions are proving favourable for gradual poleward shifts in southern range limits for several marine taxa (e.g., Harasti; Scott, et al; Davis [37][38][39]). Since early 2014, we have identified and reported 28 species of sea slug south of their previously known range [5,[40][41][42][43] (Figure 1). The distance of such shifts varies from a regional scale at distances of 100s of km to a bioregional scale of >1000 km.…”

“…On the Australian east coast, diversity attenuates from the northern Great Barrier Reef (GBR), Queensland (QLD), where approximately 1000 species have been recorded [3], to the southern tip of the mainland with 400 species recorded from Victoria and Bass Strait [4]. The subtropical region of New South Wales (NSW) supports both tropical and temperate taxa representing a biogeographic ecotone, as well as several endemic taxa restricted to this overlap zone [5].…”