Dataset: Abundances of phytoplankton and non-pigmented bacteria determined by flow cytometry from water samples collected on R/V Roger Revelle cruise RR2201 in the Eastern Indian Ocean during February and March 2022

Flow cytometry samples were collected from each CTD rosette or individual Go-Flo bottles. All samples were analyzed on board the ship with a Beckman Coulter CytoFlex S flow cytometer, equipped with 4 lasers (375 nanometers (nm), 405 nm, 488 nm, and 536 nm) and CytExpert software. Preserved (0.5% paraformaldehyde final) samples (500 microliters (µL)) were stained with Hoechst 34580 (1 microgram per milliliter (µg mL⁻¹)) and run (50 microliters per minute (µl min⁻¹)) within 3 hours of collection (Selph 2021). The data presented here for all populations, except heterotrophic eukaryotes (HEUK) and potential mixotrophs (MEUK), are from these preserved samples. At many stations, a live sample (500 µL) was also analyzed after staining with Hoechst (1 µg mL⁻¹ final) and Lysotracker Green (LTG, acidic vacuole stain, 75 nanomolar (nM) final, Rose et al. 2004) to obtain estimates of HEUK and MEUK. Data files (Lismode 3.0) were generated and analyzed using FlowJo software (Tree Star, Inc.).