Fig 1.
A cell culture flask and xenon lamp were used to assess the phototaxis of Symbiodiniaceae cultured strains.
a) 250-mL cell culture flask with black PVC tape attached in a grid shape. b) Eight types of band-pass optical filters (ø 25 mm) were attached with double-sided tape. c) The cell culture flask with band-pass filters was placed in front of the xenon lamp source. d) A specific wavelength of light passed through each band-pass filter into the cell culture flask. To count the symbiodiniacean cells, 1 mL of medium was collected from each grid using a Pasteur pipette inserted from the mouth of cell culture flask.
Fig 2.
The phototaxis patterns of cultured Symbiodiniaceae strains.
The 100% line indicates constant cell densities before and after irradiation. The mean and standard deviation of triplicate measurements (error bar) are shown. Asterisk on the shoulder of the strain name indicates significant relationship between wavelength and positive/negative phototaxis from GAM analysis.
Fig 3.
Fluorescent micrographs of A. tenuis larvae taken under blue-violet excitation (Ex. 400–440 nm, Em. ≥475 nm).
Micrographs of one to three-day-old larvae were taken with an exposure time of 500 ms, whereas those for four-day-old or older larvae were taken with an exposure time of 50 ms and without any digital black balances. Although micrographs for one to three-day-old larvae had a slightly different color than those for four-day-old or older larvae, changes in larval fluorescence at four- to 21-days-old could be confirmed visually.
Fig 4.
Fluorescence spectrum of A. tenuis larvae under blue-violet excitation (Ex. 400–440 nm, Em. ≥475 nm).
Peak wavelength at which the maximum intensity was recorded is shown in each graph. Fluorescence intensity in one-day-old and two-day-old larvae was almost at the same level as in the background. The y-axis values for the 16- and 21-day-old larvae are different from the others.
Fig 5.
Fluorescent micrographs of A. tenuis larvae taken under UV-A excitation (Ex. 330–385 nm, Em. ≥420 nm).
The micrographs of one to three-day-old larvae were taken with an exposure time of 500 ms, whereas those for four-day-old or older larvae were taken with an exposure time of 50 ms and without any digital black balances. Although, the micrographs of larvae aged one to three days and those older than four days are slightly different in color, changes in larval fluorescence between four-day-old larvae and 21-day-old larvae can be confirmed visually. The brightness of micrographs for larvae aged four days old and over are increased. The original figures are shown in S2 Fig.
Fig 6.
Fluorescence spectrum of A. tenuis larvae under UV-A excitation (Ex. 330–385 nm, Em. ≥420 nm).
Peak wavelength at which the maximum intensity was recorded is shown in each graph.
Fig 7.
The symbiodiniacean cell numbers within larvae under red LED light source.
Acquired cell numbers are shown in a sunflower plot for each experimental cup separately. Number of leaves (petals) indicating that individual larvae harbored the same numbers of symbiodiniacean cells. Five individual six-day-old larvae were observed in each experimental cup.