Two new records of octocorals (Anthozoa, Octocorallia) from north-west Australia

WA Museum Records and Supplements | Updated 7 years ago

INTRODUCTION – In 2012 and 2013 the Western Australian Museum (WAM) undertook a comprehensive biodiversity survey in the Sahul Shelf Bioregion, which encompassed the intertidal and shallow subtidal reef communities of the outer shelf atolls of Ashmore and Hibernia Reefs, and several submerged midshelf shoals. While the outer shelf has seen some octocoral sampling effort in the past, there was no information from the midshelf region (Marsh 1986, 1993; Griffith 1997; Kospartov et al. 2006, Fabricius 2008; Bryce and Sampey 2014).

The eastern section of the Sahul Shelf Bioregion between longitudes 123°20’ and 130°46’E is characterised by three platform coral reefs and a series of submerged shoals (Wilson 2013). These structures are true bioherms, built by the accumulation of marine biogenic carbonate during periods of submergence in the Pliocene. While the Kimberley coast is mainly characterised by a low energy wave regime, turbid coastal water conditions, and local tidal currents, the Oceanic Shoal Bioregion has a high wave regime, clear water conditions and is influenced by the Indonesian Throughflow and Holloway Currents (Wilson 2013).

Examination of octocoral species from these recent surveys, paired with unidentified historic material from the WAM collection has revealed the occurrence of Plumigorgia hydroides Nutting, 1910 and Coelogorgia palmosa Milne-Edwards and Haime, 1857 in Australian waters. Our intention here is to report on the distribution of these octocorals in Australia and support our findings with molecular analyses for DNA barcoding.