The purpose of this report is to discuss corals. Different types of coral reefs and reef corals will be mentioned in this report. Also to be included is discussion of the reef environment. Discussion of the reef environment will include some of the reef inhabitants other than the corals.
Coral reefs are known for the wealth and diversity of their flora and fauna. Problems in coral reef biology include accounting for the species diversity, explaining the high biomass productivity of coral reefs, distribution of coral reef organisms, and the growth and recruitment of coral colonies, to name but a few of the problems in coral reef biology.
The larvae of corals settle out of the plankton and undergo a period of growth and development on a hard substrate prior to the attainment of sexual maturity. Corals at Low Isles on the Great Barrier Reef (at latitude 16 degrees south) developed numerous gonads when reaching a size of more than 10 centimeters in diameter. These Favia doreyensis corals grew at the rate of 1.3 centimeters in diameter per year, and took an estimated 8 years to reach sexual maturity.
At latitude 7 degrees north Fungia actiniformis corals gave birth to larvae only when reaching a size greater than 7 centimeters in diameter. Branching corals tend to grow faster and die sooner than these massive species. Some species (such as Pocillopora brevicornis, Manicina areolata, Diploria labyrinthiformis, Favia fragum, Favia doreyeniss, and Lobophyllia species) may actually self-fertilize. Only eggs or only sperm have been seen for many other species. This suggests the presence of unisexual colonies or colonies that undergo sex change as they age. This indicates cross-fertilization for species such as Acropora durvillei, Turbinaria species, Sphneotrochus rubescens, Coenopsammia species, Acropora plamata, Isophyllia sinuosa, Montastrea cavernosa, Sideratrea radians, and Symphyllia recta, as well as Pavona cactus.<...