Working paper/research report

Publication year: 2020

URL: http://hdl.handle.net/1992/44558

Abstract: 

The euendolithic chlorophyte algae genus Ostreobium comprises one of the most pervasive agents responsible for reef dissolution. However, under low light conditions, Ostreobium changes the chlorophyll b:chlorophyll ratio and in addition, uses coral metabolic waste to translocate fixed carbon to the coral host during bleaching, thermal stress, and disease events. If this is beneficial for the coral host, an emergent mutualistic symbiosis between bioeroders and corals is likely. Within a closed coral microcosm system, we tested if Ostreobium may associate mutualistically to a reef-building coral under low light conditions, i.e., providing photo assimilates to its host. The primary productivity, using pulse amplitude modulated (PAM) and respiration, of acclimatized coral fragments (Porites rus) was assessed under red light, blue light and control conditions. The results for PAM showed no significant differences in photosynthetic activity between different light treatments, suggesting photosynthesis was possible no matter what type of light the holobiont is being exposed. Oxygen measurements showed significant differences in the red-light treatment (p <0,0001 dark incubation; p<0,001 light incubation). This means that, under low light environments, Ostreobium is capable of photosynthesize but it is not enough for the coral to compensate respiration needs. Under those conditions the holobiont need both autotrophy and heterotrophy.

Harvard Citation style: Ballesteros, F., Puntin, G., Schubert, P., Ziegler, M., Wilke, T. and Sanchez, J. (2020) Contribution of euendolithic algae to holobiont productivity in the reef-building coral Porites rus. Bogotá: Universidad de los Andes. http://hdl.handle.net/1992/44558

APA Citation style: Ballesteros, F., Puntin, G., Schubert, P., Ziegler, M., Wilke, T., & Sanchez, J. (2020). Contribution of euendolithic algae to holobiont productivity in the reef-building coral Porites rus. Universidad de los Andes. http://hdl.handle.net/1992/44558