The document summarizes a study that investigated how the pigmentation of the sea anemone Condylactis gigantea changes under thermal stress. Six C. gigantea were placed in either a control or treatment aquarium tank, with the treatment tank increasing in temperature by 1 degree Celsius every other day. Photos of the anemones were taken and their colors were measured and analyzed using a colorimetry method. The results showed that while the data wasn't statistically significant, there was a trend of the anemones in the treatment tank becoming lighter in color over time compared to the control tank anemones. Future research with improved controls and a longer study period could provide more definitive results on the temperature threshold at
1. Change in Pigmentation of
Thermally Stressed
Condylactis gigantea
Kelsey Beachman
Under the supervision of:
Dr. Eric Hochberg
2. Introduction
Condylactis gigantea is symbiotic
with zooxanthellae
C.gigantea have been observed
to totally bleach at 32ºC
Venn et al 2008 study
Zooxanthellae give C. gigantea
its coloration
Change in pigmentation of
C.gigantea under thermal
stress measured using
colorimetry
(Perez et al 2001, Venn et al 2008)
3. Introduction: Colorimetry
science that puts numerical value on
colors that we see
Digital camera uses RGB color space
Human eyes see XYZ color space
Camera may pick up colors that we
don’t see yet - bleaching
What is chromaticity?
Little x & y
represent chromaticity; used to plot(Mobley 1994)
4. Hypotheses
H₀: The pigmentation of
Condylactis gigantea will
remain constant over time
under thermal stress
H₁: The pigmentation of
Condylactis gigantea will
become lighter over time
under thermal stress
5. Methods
Six Condylactis gigantea were
collected across from Rogue
Island
3 in each flow-through aquaria with
pumps
Initial water temperature 23ºC for
both tanks
Treatment tank heat was increased
by 1ºC every other day
Fed zooplankton twice a week
6. Methods
Photos of each anemone were
taken with a ColorChecker
Photos were calibrated to
ColorChecker in MatLab program
Calibrated colors were applied to
each photo
Colors of anemones were
measured in MatLab program
(RGB & XYZ)
Graphs and statistical analyses
were made (x & y).
8. Results: Chromaticity for Each Anemone
Day 1
Day 5
Day 1
Day 5
Day 1
Day 5
Day 5
Day 1
Day 1
Day 5
Day 1
Day 5
ControlTank:
Anemones1-3
TreatmentTank:
Anemones4-6
9. Discussion
Camera captured what we wanted:
golden-brown chromaticity
Data wasn’t statistically significant, but
there was some trend
Errors in experiment:
Control not kept at “ambient”
temperature
Fluctuations in temperature of
treatment tank
Time period not long enough
● Future research?
○ Low temperature threshold for
C. gigantea
○ Controlled temperatures to get
accurate results
○ Longer duration
10. References
Fujise L, Yamashita H, Suzuki G, Sasaki K, Liao LM, Koike K 2014. Moderate Thermal Stress Causes Active and
Immediate Expulsion of Photosynthetically Damaged Zooxanthellae (Symbiodinium) from Corals. PLoS ONE
9(12): e114321. doi:10.1371/journal.pone.0114321
Mellas RE, Mcilroy SE, Fitt WK, Coffroth MA 2014. Variation in symbiont uptake in the early ontogeny of the upside-
down jellyfish, Cassiopea spp. Journal of Experimental Marine Biology and Ecology. Vol 459. 38-44.
Mobley CD 1994. Light and Water: Radiative Transfer in Natural Waters. San Diego: Academic Press. 47-58.
Lirman D, Schopmeyer S, Manzello D, Gramer LJ, Precht WF, Muller-Karger F, Banks K, Barnes B, Bartels E, Bourque A,
Byrne J, Donahue S, Duquesnel J, Fisher L, Gilliam D, Hendee J, Johnson M, Maxwell K, McDevitt E, Monty J, Rueda
D, Ruzicka R, Thanner S 2011. Severe 2010 Cold-Water event Caused Unprecedented Mortality to Corals of the
Florida Reef Tract and Reversed Previous Survivorship Patterns. PLoS ONE 6(8):
e23047.doi:10.1371/journal.pone.0023047
Perez SF, Cook CB, Brooks RW 2001. The role of symbiotic dinoflagellates in the temperature-induced bleaching
response of the subtropical sea anemone Aiptasia pallida. Journal of Experimental Marine Biology and Ecology.
Vol 256. 1-4.
Sachs JL, Wilcox TP 2006. A shift to parasitism in the jellyfish symbiont Symbiodinium microadriaticum. Proc Biol Sci.
Vol 273. 425-429.
11. References
Shick JM 1991. A Functional Biology of Sea Anemones. First Edition. 88-89.
Siebeck UE, Marshall NJ, Kluter A, Hoegh-Guldberg O 2006. Monitoring coral bleaching using a color
reference card. Coral Reefs. Vol 25. 453-460.
Titlyanov EA, Titlyanova TV, Yamazato K, Woesik R 2001. Photo-acclimation dynamics of the coral
Stylophora pistillata to low and extremely low light. Russian Journal of Marine Biology. Vol 263. 211-225.
Venn AA, Loram JE, Trapido-Rosenthal HG, Joyce DA, Douglas AE 2008. Importance of Time and Place:
Patterns in Abundance of Symbiodinium Clades A and B in the Tropical Sea Anemone Condylactis
gigantea. Biological Bulletin. Vol 215. 243-252.
Venn et al 2008: tested bleaching in C. gigantea, found that clade B bleaches at 32C and clade A is more thermally tolerant (inshore locations)
Zooxanthellae give anemone coloration because of the pigment in their chlorophyll
can we observe change in chromaticity through colormetrically analyzing photographs?
describe color spaces as computer colors vs. printer colors (CMYK) - cyan magenta yellow and black
Total of 30 photographs taken (5 for each anemone)
Figure 1: the chromaticities for all the anemones fell into the golden-brown to white chromaticity
Figure 2: no major difference between the chromaticities of the anemones in the control and in the treatment tank
Control Tank: did not stay consistent in anemones 1 & 2, anemone 3 stayed the most consistent (none of this data is statistically signficant)
Treatment Tank: anemone 4 showed the largest change in chromaticity over the course of the experiment. Was also the only data that highly correlated with the increasing temperature. However, all of the data collected in the treatment tank was not statistically significant
