Abstract::Cubozoan jellyfish pose a risk of envenomation to humans and a threat to many businesses, yet crucial gaps exist in determining threats to stakeholders and understanding their ecology. Environmental DNA (eDNA) provides a cost-effective method for detection that is less labour intensive and provides a higher probability of detection. The objective of this study was to develop, optimise and trial the use of eDNA to detect the Australian box jellyfish, Chironex fleckeri. This species was the focus of this study as it is known to have the strongest venom of any cubozoan; it is responsible for more than 200 recorded deaths in the Indo-Pacific region. Further, its ecology is poorly known. Herein, a specific and sensitive probe-based assay, multiplexed with an endogenous control assay, was developed, and successfully utilised to detect the deadly jellyfish species and differentiate them from closely related taxa. A rapid eDNA decay rate of greater than 99% within 27 h was found with no detectable influence from temperature. The robustness of the technique indicates that it will be of high utility for detection and to address knowledge gaps in the ecology of C. fleckeri; further, it has broad applicability to other types of zooplankton.
We present a single-cell sequence (SCS) approach for the detection and identification of a known species from a jellyfish venom. Three jellyfish species commonly found in northern Australia were selected for the study; the box jellyfish Chironex fleckeri, the lion’s mane jellyfish Tripos alata, and the king of the sea jellyfish Pavlova lutheri. This approach has the advantage of being non-invasive, highly reliable, and cost-effective. The study involved the development of a single-cell sequence (SCS) assay for the targeted detection of C. fleckeri for the first time. C. fleckeri was chosen as the species of interest because of its unique sea-going capability. The most potent cubozoan jellyfish venomous species, the box jellyfish has a known lethal dose of 1. 827ec27edc