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

Abstract

Port Stephens, on the central New South Wales coast, provides ideal oceanographic and benthic conditions for the settlement and growth of larvae of tropical species delivered from the north by the East Australian Current. The popularity of the bay for recreational and scientific diving has facilitated extensive documentation of the biota over several decades, confirming its high biodiversity. Of the 313 species of heterobranch sea slugs recorded from Port Stephens to date, 30 are not known to occur further south. Our observations increase the number of taxa with a southern distribution limit at Port Stephens by 12 species and add to a growing list of marine taxa that are progressively extending their southern range, potentially as a result of climate change.

Spatial and temporal variation in subtidal molluscan diversity amongst temperate estuarine habitats

“…Higher within habitat Alpha h diversity (measured as species richness) was linked to habitat complexity (i.e., varied benthic assemblages, and sizes and shapes of bottom structures) with higher diversity, especially of heterobranch sea slugs, occurring in habitats containing complex benthic assemblages (e.g., filter feeders, branching algae). The high proportion of heterobranch species occurring within Port Stephens has been attributed to varied oceanographic conditions, topography and benthic assemblages (Nimbs et al., ). Many mollusc species are known to consume filter‐feeding organisms or algae (McDonald & Nybakken, ), and complex benthic assemblages provide niches for numerous molluscs that have specialized dietary requirements (e.g., Smith, ), thereby promoting increased diversity.…”

“…Higher within habitat Alpha h diversity (measured as species richness) was linked to habitat complexity (i.e., varied benthic assemblages, and sizes and shapes of bottom structures) with higher diversity, especially of heterobranch sea slugs, occurring in habitats containing complex benthic assemblages (e.g., filter feeders, branching algae). The high proportion of heterobranch species occurring within Port Stephens has been attributed to varied oceanographic conditions, topography and benthic assemblages (Nimbs et al, 2016).…”

First Survey of Heterobranch Sea Slugs (Mollusca, Gastropoda) from the Island Sangihe, North Sulawesi, Indonesia

“…Because marine Heterobranchs are also very attractive to tourists, additional data are and will be available through citizen science due to documentation in websites or personal information and provision of images on personal bases. This was shown lately by Nimbs et al [16] and Nimbs and Smith [17] where long-term documentation of scientists and recreational divers led to the identification of new tropical species introduced in Port Stephens, on the central New South Wales coast of Australia, and Tasman Sea. In order to monitor potential damage to the environment around Sangihe, irrespective of its original cause, we have started with a first survey in 2016, focusing on marine Heterobranchia.…”

Intersection of historical museum collections and modern systematics: a relict population of the Arctic nudibranch Dendronotus velifer G.O. Sars, 1878 in a Swedish fjord

“…Nudibranch molluscs are important model subjects for various disciplines, including phylogenetics, neurophysiology and also the emerging field of marine natural products (Nuzzo et al, 2012;Goodheart et al, 2015;Katz, 2016). They are now routinely included in wellillustrated field guides (Picton and Morrow, 1994;Malmberg and Lundin, 2015;Hayward and Ryland, 2017) and owing to their attractiveness they have recreational importance in national parks and other conservation areas (e.g., Bertsch, 2014;Garcia-Mendéz and Camacho-Garcia, 2016;Mehrotra and Scott, 2016;Nimbs et al, 2016). The species of the nudibranch genus Dendronotus occur in the Northern European and Arctic seas, generally on rocky and stony habitats in shallow waters less than 50 m deep (Thompson and Brown, 1984;Thollesson, 1998;Korshunova et al, 2016).…”