Range extension of Czeblukov’s true sea snake Hydrophis czeblukovi (Elapidae:Hydrophiinae) southwest to Exmouth Gulf, Western Australia

Our understanding of the biology and ecology of many Australian marine snakes is inadequate to inform the conservation and management of their populations. Czeblukov’s true sea snake Hydrophis czeblukovi (Elapidae:Hydrophiinae) is an example of this, with an IUCN classification of “Data Deficient”. It is a wholly marine, ovoviviparous snake that is distinguishable by its dark colouration and unique pale banding forming dark pentagons on its dorsal surface and flanks. A recent biological survey in Exmouth Gulf, Western Australia found a recently dead H. czeblukovi specimen. This extends the species geographical range by approximately 300 kilometres southwest (minimum seaward distance). The stranding likely arose from the persistent onshore winds observed prior to the discovery or from self-stranding due to illness. This discovery brings the total number of marine snake species recorded from Exmouth Gulf to 11 out of ~24 known to occur in WA waters, which highlights the importance of this location for marine snake conservation. Here we compile the scarce knowledge for this data deficient species. We discuss the conservation implications of our findings in context of the dense industrial activity across the range of H. czeblukovi. We indicate the need for further research to inform conservation and management actions.