What Causes an Ora Bird of Paradise Coral to Lighten?

Coral Bleaching

• Bleaching occurs when environmental stressors compel corals to release their zooxanthellae. Zooxanthellae maintain a symbiotic relationship with corals and also give them their color pigmentation by feeding on and trapping algae from the water column, which provide photosynthetic strength to the coral. When a coral colony lacks nutrients to sustain the zooxanthellae, and the zooxanthellae can no longer provide support in return, the plankton are released and the coral turns white in color.

Causes of Bleaching

• In the environment and sometimes in an aquarium, heat stress can cause coral to release its zooxanthellae and turn white. Like all Seriatopora species, Bird of Paradise which is available from the ORA (Oceans, Reefs & Aquariums) hatchery, are particularly susceptible to heat stress due to their fine branching habit. In a study conducted near Papua, New Guinea and published by the Planetary Coral Reef Foundation, Seriatopora species were the least resistant to bleaching and their high rate of bleaching may have been due to warm waters. They had a bleaching rate of 65.87 percent in waters at a temperature of 86 Fahrenheit.

Fading

• Corals may lighten or fade in response to changes in light exposure. A fading coral may benefit by a new placement with more light exposure, such as with higher placement in the aquarium, or with a stronger light. If the coral is turning completely white, bleaching may be to blame. Some corals are more susceptible to temperature and light changes than other corals. After some time and the chance to acclimatize to environmental changes, a coral may change to a desirable bright color.

Bird of Paradise Care

• Bird of Paradise has both pink and green colors. It is naturally a dull color that prefers low light, but in moderate lighting it can produce more vivid bi-colored show. Under such conditions, the base turns lighter green or cream and the polyps are pink. When caring for the Bird of Paradise, provide 5 watts of lighting per 1 gallon of water in a tank. If food variety is limited, you may want to provide supplemental food to keep your coral healthy. This species is not adept at capturing prey due to its small polyps. Provide food of small particle size, such as oyster eggs.