NOAA's Office of Ocean Exploration and Research
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Aquarists know that the color of colourful corals is largely determined by the zooxanthellae; these corals have aragonite as a stabilizing skeleton.
So where do azooxanthellate corals such as Placogorgia tenuis get their sometimes very bright coloration from?
Azooxanthellate corals can come from depths of several hundred meters or from underwater caves and have bright red colors (e.g. black corals that have been made into jewelry and keep them for many years, while zooxanthellate corals without their Symbiodinium dinoflagellates turn white extremely quickly.
These bright colors are caused by the uptake of carotenoids, which are permanently stored in the stabilizing calcite skeleton during the growth phases.
These carotenoids are absorbed by the coral in the form of astaxanthin, which is produced in the sea by phytoplankton, algae and aquatic plants.
More detailed information can be found in the texts “Pink-to-Red Coral: A Guide to Determining Origin of Color” and “Identification of reddish pigments in octocorals by Raman spectroscopy” under “Related links”.
Placogorgia tenuis was formerly known as Paramuricea tenuis.
Placogorgia tenuis is a medium-sized to large, typically yellow sea fan.
Synonym: Paramuricea tenuis Verrill, 1883
So where do azooxanthellate corals such as Placogorgia tenuis get their sometimes very bright coloration from?
Azooxanthellate corals can come from depths of several hundred meters or from underwater caves and have bright red colors (e.g. black corals that have been made into jewelry and keep them for many years, while zooxanthellate corals without their Symbiodinium dinoflagellates turn white extremely quickly.
These bright colors are caused by the uptake of carotenoids, which are permanently stored in the stabilizing calcite skeleton during the growth phases.
These carotenoids are absorbed by the coral in the form of astaxanthin, which is produced in the sea by phytoplankton, algae and aquatic plants.
More detailed information can be found in the texts “Pink-to-Red Coral: A Guide to Determining Origin of Color” and “Identification of reddish pigments in octocorals by Raman spectroscopy” under “Related links”.
Placogorgia tenuis was formerly known as Paramuricea tenuis.
Placogorgia tenuis is a medium-sized to large, typically yellow sea fan.
Synonym: Paramuricea tenuis Verrill, 1883
