Meeting Abstract

37.1  Friday, Jan. 4  The Effect of Temperature on the Settlement Choice and Photophysiology of Larvae from the Reef Coral Stylophora pistillata EDMUNDS, PJ*; PUTNAM, HM; FAN, TY; California State University, Northridge; California State University, Northridge; National Museum of Marine Biology and Aquarium, Taiwan peter.edmunds@csun.edu

To better understand the consequences of global climate change for scleractinian corals, Stylophora pistillata was used to test the effects of temperature on the settlement and physiology of coral larvae. Freshly released larvae were obtained from corals in Taiwan, and were used in manipulative experiments designed to create temperature treatments of 23 oC, 25 oC (ambient) and 29 oC at light intensities of ?150 �mol photons m2 s-1. After 12 h exposure, the effects were assessed as settlement to crustose coralline algae (CCA) versus limestone, and dark-adapted quantum yield of PSII (Fv/Fm) in the larvae versus their parents. Regardless of temperature, 50-73% of the larvae metamorphosed onto the plastic of the incubation trays, or in a few cases were drifting in the water, and 14% settled on limestone. However, elevated temperature (29 oC) reduced the percentage of larvae swimming by 81%, and increased the percentage choosing CCA nearly 7-fold, both relative to the outcomes at 23 oC. Because temperature did not affect settlement to limestone or plastic, increased settlement to CCA reflected temperature-mediated choices by larvae that otherwise would have remained swimming. Interestingly, Fv/Fm was unaffected by temperature, but it was 4% lower in the larvae compared to the parents. These results are important because they show that temperature can affect the settlement of coral larvae, and reveal photophysiological differences between life stages that might provide insights into the events associated with larval development.