Coral is divided into two main subtypes, hard and soft. These animals
grow incredibly slowly, and in symbiosis with many other types of
sealife.
Types of Coral
There are around 6,000 types of Coral, and a few of the common ones are:
Staghorn Coral
Elkhorn Coral
Brain Coral
Pillar Coral
Great Star Coral
Bubble Coral
Fluorescence
Three types of smaller coral surrounded by fish
Algea that lives inside corals absorb much of the suns energy. As the
oceans get warmer, some of the algea cannot survive leaving the coral
exposed to the suns energy. Some coral are capable of producing a
vibrant pigment which acts as sunscreen for them, this is why some coral
looks fluorescent.
As Wikipedia states:
Fluorescence serves a wide variety of functions in coral. Fluorescent
proteins in corals may contribute to photosynthesis by converting
otherwise unusable wavelengths of light into ones for which the
coral's symbiotic algae are able to conduct photosynthesis. Also, the
proteins may fluctuate in number as more or less light becomes
available as a means of photoacclimation. Similarly, these fluorescent
proteins may possess antioxidant capacities to eliminate oxygen
radicals produced by photosynthesis. Finally, through modulating
photosynthesis, the fluorescent proteins may also serve as a means of
regulating the activity of the coral's photosynthetic algal
symbionts,(source).