Title: OSTREOBIUM DIVERSITY IN THE SCROLL CORAL, AGARICIA UNDATA, AT MESOPHOTIC CORAL ECOSYSTEMS FROM SAN ANDRES ISLAND, COLOMBIAOSTREOBIUM DIVERSITY IN THE SCROLL CORAL, AGARICIA UNDATA, AT MESOPHOTIC CORAL ECOSYSTEMS FROM SAN ANDRES ISLAND, COLOMBIA

Abstract: Endolithic algae have important functions in reef ecosystems and will have a critical role in how coral tolerate climate change and ocean acidification. Endolithic algal filaments dissolve CaCO3 crystals making reefs more susceptible to abrasion and dissolution and serve as food for bioeroders. These algae can also facilitate coral survival during bleaching events extending their survivorship without zooxanthellae. In the Caribbean, members of the family Agariciidae are commonly the dominant species in the deeper portions of coral reefs. Agaricia undata, inhabits deep reefs between 15 and about 90 m; this coral is associated with dinoflagellates of the genus Symbiodinium as well as endolithic algae (Ostreobium quekettii). A high abundance of Ostreobium sp. has been observed as depth increases. We took images of the Ostreobium and A. undata using light microscopy and SEM and we found a longitudinal growth and high density of the algae. Using the molecular marker rcbL, we examined the diversity of Ostreobium within A. undata from mesophotic coral ecosystems of San Andrés Island in Colombia to test if depth has an effect on Ostreobium composition. We identified five Ostreobium clades, but did not identify a depth-associated pattern. We have yet to determine if the different clades found in A. undata have an ecological significance. The genotypic diversity of Ostreobium, allows us to speculate that these algae could be physiologically diverse and have developed different adaptations that facilitate photosynthesis in low light environments.

Authors: González FL, Sánchez JA

Presentation: Poster (#130)

Session: 11

Date: 06/20/16

Time: 18:30 - 20:00

Location: Poster/Exhibit Hall

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