Ocean acidification impacts on sperm mitochondrial membrane potential bring sperm swimming behaviour near its tipping point

摘要: ABSTRACT Broadcast spawning marine invertebrates are susceptible to environmental stressors such as climate change, their reproduction depends on the successful meeting and fertilization of gametes in water column. Under near-future scenarios ocean acidification, swimming behaviour invertebrate sperm is altered. We tested whether this was due changes mitochondrial activity by investigating effects acidification metabolism sea urchin Centrostephanus rodgersii . used a fluorescent molecular probe (JC-1) flow cytometry visualize (measured change membrane potential, MMP). Sperm MMP significantly reduced ΔpH −0.3 (35% reduction) −0.5 (48% treatments, whereas less sensitive with only slight (up 11% decrease) observed overall. There significant inter-individual variability responses acidified seawater. suggest it likely that exposed these pH close tipping point terms physiological tolerance acidity. Importantly, substantial variation may increase scope for selection resilient phenotypes, which, if heritable, could provide basis adaptation future acidification.