Meeting Abstract
Ocean acidification reduces the level of calcite saturation in the water column, making it more difficult for pluteus larvae of Arbacia punctulata to lengthen the ciliated arms they use to suspension feed. A reduction in skeletal size could negatively impact larval growth as well as adult size and reproductive success. Adults from a population near from Woods Hole, Massachusetts were crossbred in a 3×3 mating design with sibships reared under either current CO2 or 2.5x current CO2. Larval skeletal measurements were used to estimate genetic variation for resistance to elevated CO2. Larvae subjected to higher CO2 exhibited less skeletal growth overall, particularly in the post oral arm rods, and also demonstrated increased asymmetry. Significant genetic variation was estimated for differences in post oral arm length between low and high CO2. These results indicate that near-future ocean acidification could negatively impact A. punctulata larval growth and development, but that populations may have the capacity for an evolutionary response to increasing CO2. Future studies will need to examine responses of genetically distinct populations of A. punctulata along its latitudinal range.
