Meeting Abstract
The keystone species Pisaster ochraceus plays a fundamental role in preserving biodiversity in Pacific intertidal ecosystems. Unfortunately, the increasing frequency and intensity of low salinity events in places like the Salish Sea is of growing concern for developing P. ochraceus larvae. Previous studies have shown that larvae reared in low salinity conditions become short and wide and their swimming ability is impaired. To further characterize how P. ochraceus larvae are affected by low salinity, I investigated how single and multiple low salinity events affect protein expression and feeding. Coomassie stained NuPAGE™ gels revealed that several proteins were expressed at equal levels regardless of salinity treatment; these included anion transporters and Na+/K+ ATPase. Other proteins, such as NADPH oxidase and Ca2+ ATPase, were up-regulated when larvae were exposed to multiple low salinity events, especially after four low salinity events. After a 24-hour low salinity event, larvae consumed fewer algal cells, demonstrating a reduced feeding ability. The difference in expression for the various osmoregulatory proteins and observed effect on feeding ability has implications for how P. ochraceus larvae can respond to frequent hypoosmotic stress.
