Just Accepted

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A grey nurse shark from the Northern Territory of Australia shares a mitochondrial haplotype only recorded from the west Australian population

Sara Krause , Adam Stow

Abstract

The critically endangered grey nurse shark (Carcharias taurus) is a widely distributed coastal to near coastal species. Overexploitation has resulted in severe global population declines, including in Australian waters, where two genetically distinct populations are known to exist in temperate to subtropical waters of the east and west coasts of the continent. However, occasional sightings of C. taurus have been reported in the Timor Sea and Northern Territory waters. In this small-scale study, we aimed to evaluate whether a single C. taurus individual captured in waters off the Northern Territory of Australia belongs to the critically endangered east Australian population. Based on previously identified mitochondrial haplotypes for this species, we align the mtDNA control regions of the Northern Territory individual with sequence data from eastern and western Australian samples. The sequence alignment revealed a haplotype unique to West Australia (haplotype E), confirming genetic compatibility of the individual caught in Northern Territory waters with the west Australian population. These data suggest that C. taurus occurring off the Northern Territory do not represent an extension of the critically endangered east coast population and also highlight the need for future research on the understudied grey nurse shark in tropical waters off northern Australia.

MF24162  Accepted 01 February 2025

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