Using desiccation-resistant eggs to explore the ecology of giant ostracods (subfamily Mytilocypridinae) in Australian salt lakes

Abstract

AbstractGiant ostracods in the subfamily Mytilocypridinae are an important component of the biota of Australian salt lakes, which are predominantly temporary, and often located in remote arid areas. Mytilocypridines produce desiccation-resistant eggs to persist in these habitats during unfavourable conditions. In this study, we used mytilocypridine eggs collected from sediments in salt lakes in Western Australia to analyse aspects of the ecology of these ostracods. We conducted two rehydration trials, where sediment was collected from dry lakes or the dry margins of lakes, rehydrated in a laboratory setting, and selected mytilocypridine species hatched and raised in cultures. The first trial found that the eggs of mytilocypridine species were unevenly distributed in a dry lake and could be hatched even after 27 months of dry storage with no discernible loss of viability. The second trial assessed the capacity of selected mytilocypridines to hatch and develop into adults under different salinity treatments. One species, Australocypris insularis, hatched and developed across a very wide salinity range (0–100 g/L). Egg/sediment samples provide a means for testing species’ tolerance to physical and chemical variables throughout their entire life cycle, as well as for surveying the mytilocypridines in remote lakes that rarely hold water.