Saltwater Aquarium Guide -- Fast Facts

Fast Facts (page 20)

Ultraviolet light is made up of three components; UV-A, UV-B, and UV-C. We are onl;y going to talk about the two that have a factor in either the home aquarium or in nature. Both UV-A and UV-B light waves have been found to cause destruction of the DNA and RNA within the coral's tissues. In response, many corals have made adaptations in reducing the effects of these harmful rays. Corals have developed protective pigments that are often blue, purple, or pink in color. Most corals that contain these pigments come from shallow waters where the amount of UV-A and UV-B light is higher than in deeper areas of the reef.

In an aquarium, we use glass over metal halide lighting to reflect any UV light before it enters the water. This is important to protect any corals that do not contain these pigments, and to protect the shallow water corals that may have lost their pigments in transportation. It is common for corals with these bright colors to adapt to the lower UV-A and UV-B conditions within the aquarium by losing their colorful pigmentation. This is not a sign of an unhealthy coral; it is simply the adaptation of the coral to its new environment.

In conclusion it is a common misconception among many hobbyists that when a newly received coral changes color in the home aquarium, the coral is not healthy. Many times the color change is merely due to the coral's adaptation to the new lighting intensity, spectrum, and change in UV light. With this in mind, it is important to consider the color of newly received corals and research their lighting requirements when placing corals in the aquarium.

<<Back>>

- - - -