Figure 1

Experimental setup and representative experiments on small and thin coral fragments. (a) Picture of recently obtained S. pistillata fragments settled back in the aquarium; the black bar indicates 5 mm. (b) Schematic representation of the setup used for simultaneous analyses of chlorophyll a fluorescence yield and oxygen exchange. (c) Disposition and orientation of a coral fragment into a 1 cm² glass cuvette relative to the light guide and the detecting photodiode in the JTS-10 spectrophotometer. Drawing in (b) and (c) were created using PowerPoint of Microsoft Office 365 ProPlus. (d,e) Representative records of chlorophyll a fluorescence yield measurements and oxygen concentration changes. Each light step (represented by the upper bar with a grey scale) lasted three minutes and saturating pulses were given each 30 s (r.u. = relative units). (f) Representative record of Photosystem I primary donor (P700) photo-oxidation upon five seconds of illumination (210 µmol photons m⁻² s⁻¹) followed by a saturating pulse of light (SP), in presence of PSII inhibitor (DCMU at 20 µM).