Acid-base regulation in the sea urchin Parechinus angulosus during CO₂-induced seawater acidification

摘要: Ocean acidification is predicted to have adverse effects on the physiologies of marine organisms, particularly those that produce calcified structures. Extracellular homeostasis considered be critical mediating ocean acidification. Due their low metabolic rates and weak ability regulate ion exchange, sea urchins are thought acid-base regulators. Recent findings showing species-specific capacities for extracellular pH regulation however suggest species currently exposed natural CO2 elevations, such as upwelling events, may a higher capacity tolerate elevated CO2. The urchin Parechinus angulosus experiences variations within Benguela system therefore possess compensate moderate disturbances. Urchins were submitted control (8.0), intermediate (7.7) (7.4) seawater treatments 14 days investigate status. changes induced by exposure (pH 7.7) fully compensated through accumulation approximately 2.0 mmol l -1 bicarbonate. bicarbonate was only sufficient partially status during pH. Results from acute (24 hour) reveal accumulation, despite being evident 24 hours, not This study provides further support variability limited P.angulosus already adapted deal with reduction in 7.7, but lacks iono-regulatory accumulate 7.3. Long-term studies needed assess role mediator broader physiological tolerance acidification, its consequences at level whole organism. Un ive rsi ty Ca pe To wn