FIG 3 .

Photosynthate accumulation into coral glycogen granules. (A) Representative TEM micrograph of the coral oral epiderm with a higher-magnification view of glycogen granules (inset). (B and C) Corresponding NanoSIMS ¹³C/¹²C (B) and ¹⁵N/¹⁴N (C) isotopic images. (D) Merged image between the TEM micrograph and the NanoSIMS ¹³C/¹²C isotopic map. An enlarged view is provided in Fig. S7 in the supplemental material. (E) Fluctuations of both ¹³C (in red) and ¹⁵N (in blue) enrichments along the NanoSIMS profile depicted in panels B and C. Standard deviations of the mean are based on Poisson statistics. Black arrows point to areas rich in glycogen granules. av, autophagic vacuole; cn, cnidocyte; is, intercellular space.