Stylet elemental signatures indicate population structure in a holobenthic octopus species, Octopus pallidus

摘要

Targeted trace elemental analysis was\udused to investigate the population structure and dispersal\udpatterns of the holobenthic octopus species Octopus\udpallidus (Hoyle, 1885). Multi-elemental signatures\udwithin the pre-hatch region of the stylet (an internal\ud‘shell’) were used to determine the common origins and\udlevels of connectivity of individuals collected from 5\udlocations in Tasmania. To determine whether hatchling\udelemental signatures could be used as tags for natal origin,\udhatchling stylets from 3 of the 5 locations were also\udanalysed. We analyzed 12 elements using laser ablation\udinductively-coupled plasma-mass spectrometry (LAICPMS).\udOf the 12 elements, 7 were excellent spatial\uddiscriminators. There was evidence of high-level structuring\udwith distinct groupings between all sites (the 2\udclosest being 85 km apart) within the adult O. pallidus\udpopulation, suggesting that all adults had hatched in or\udnear their respective collection sites. The hatchling signatures\udshowed significant spatial variation, and a high\udpercentage of individuals could successfully be traced\udback to their collection locations. However, they could\udnot be used to trace adults back to their natal site, due\udto significant differences in element concentrations in\udhatchling and adult stylets, which was likely the result\udof differences in Ca concentration. This study presents\udthe first insights into the population structure of a\udholobenthic octopus species using stylet elemental\udsignatures, which will have important implications for\udthe sustainable management of O. pallidus.