Water-Insoluble Black Pigment Released from the Octocoral Sinularia flexibilis

Coral reefs are the most diverse and productive marine ecosystems on earth. The National Museum of Marine Biology Aquarium has cultured more than 35 species corals for research. When we conducted asexual propagation corals, octocoral Sinularia flexibilis released a black pigment that stained operator’s hands black. This is first reported case skin being dyed while propagating corals. We quantified blackness stain by using RGB value color. longer coral contacted skin, darker became. Incubating tentacles S. in high-salinity filtered seawater increased amount released. However, collecting 100% was exceedingly challenging because it very sticky constantly entangled with Symbiodiniaceae. Furthermore, were unable to identify any solvents could dissolve pigment. structure function merit further study as potential become new dye human industries.