P3.108 Friday, Jan. 6 Developmental effects of ocean acidification on porcelain crabs CEBALLOS, L*; CARTER, HA; MILLER, N; STILLMAN, JH; San Francisco State University email@example.com
Intertidal zone organisms, like porcelain crabs of the genus Petrolisthes, naturally experience daily pH fluctuations with extremes values lower than the predictions for future ocean acidification (OA). Porcelain crabs spend their embryonic stage in the intertidal zone, then hatch as planktonic larvae, and spend several months in the plankton living under stable conditions before returning to the variable intertidal zone as juveniles. In order to understand the response to an acidified environment, the physiology of P. cinctipes under future OA conditions at different life-history stages was studied. P. cinctipes embryos and newly hatched larvae were acclimated to two different pH conditions, ambient (pH~8.0) and acidified (pH~7.6, achieved by bubbling water with CO2). Heart rate and morphology were measured in both stages after 8-10 days exposure to acidified water. Hatching success and yolk consumption rate was assessed in embryos. Larval heart rate was 21% lower in the individuals kept at low pH compared to the ambient pH. Embryonic heart rate was 36% lower in the individuals kept at low pH. Body size and shape of both stages were not affected by acidification. The results show non-significant effects of low pH in hatching success (~60% +/- 26% hatching in both conditions). Changes in heart rate may suggest larval and embryonic metabolic depression under continuous acidification, which in the long-term has the potential to affect growth and developmental timing.