Confocal laser scanning microscopy monitoring symbiosis stability of Symbiodiniaceae in the foraminifera Sorites orbiculus

The long-term stability of newly established symbiotic associations in Sorites orbiculus specimens was assessed with Confocal Laser Scanning Microscopy (CLSM), measuring the percentage of host area covered with symbionts, in a 14-day cultivation following menthol-DCMU bleaching and re-inoculation with Symbiodinium microadriaticum (strains KB8 and CCMP2467) and Fugacium kawagutii (strain F2) individually and collectively. The final re-inoculation measurement also served as the initial stability measurement. Accordingly, this measurement is included in both data tables and is provided here under the experimental treatment label "re-inoculation." Specimens were cultivated in 6-well plates, with 2 samples containing 2 replicates per treatment / control. The medium, supplemented with a Nannochloropsis food mixture, was exchanged twice weekly. Control groups included non-bleached specimens and bleached specimens maintained with or without 5 µmol L-1 DCMU in artificial seawater (ASW). Environmental conditions were maintained at 22 - 24°C temperature, 37.5 - 40.5‰ salinity, and 46 - 63 µmol photons cm-2 s-1 illumination under a 12:12 h light-dark cycle.