When one thinks of coral, one usually thinks of a flowing underwater garden filled with colorful, hard flowers. Those gorgeous coral reefs are actually composed of many corals. The corals are the “flowers” of the reef. Scientists call this form of coral a polyp. A polyp is a body form of a cylinder glued to a hard surface. One of the most striking characteristics of corals is how they interact with photosynthetic algae called zooxanthellae. With a cooperative partnership, corals construct the limestone reefs that are home to a great number of animals and plants. Corals do not even cover 1% of the Earth’s surface, but they still can be called home by 25% of marine fish. In fact, corals are the second most productive ecosystem, just behind rainforests. It is no surprise that corals are often known as the “rainforests of the ocean.” Indeed, a single patch of Caribbean reef 10 feet across can have over 75 different fish species. Coral reefs have higher rates of photosynthetic carbon fixation, nitrogen fixation and limestone deposition than any other ecosystem, even though tropical waters are low in nutrients and concentrations of nitrates, ammonia and phosphates. The unique coral biology allows an abundance life, which has become vital for the structure, ecology, and nutrient cycling in the reef community.
Here you will learn about vital functions of corals, their taxonomy and classification.
History of Reefs
The word “reef” originated from German word “ref”. This word was introduced by mariners and signify underwater ridge or rock derivation organic as well as inorganic, being a danger to ships. Today this term refers only to organic structures, originated from accumulation of reef-builders’ skeletons (today the main reef builders are corals – that’s why the most common reefs are coral reefs). For more information on the history of reefs, just enter this section.
Types of Reefs
As coral reefs are built, they go through different stages of growth. Throughout development, coral reefs characteristically sink into the water. Each of the following three stages describes a step the reef goes through while it sinks.
Corals belong to a classification of Cnidarians. This section will present to the reader the various anatomical features of Corals.
The study of coral symbiosis physiology has become what it is today thanks to C. M. Younge ‘s work during the Great Barrier Reef Experiment in 1929. Through his experiments, Younge showed that corals get phosphates and ammonia from seawater during the day and release these chemicals at night.
Living organisms must be able to reproduce. Otherwise, the species would no longer exist after the organism dies. When all the same types of organisms die so that the species no longer exists, it is called extinct. This means that it is gone forever and can never come back. The ways in which corals reproduce are as follows:
Corals can reproduce asexually through a processes of division budding or fragmentation. Through sexual processes, corals make free-swimming larvae that land away from the parent to form new coral. Just during the 1999, July 4th holiday weekend, spawning was observed at the Stephen Birch Aquarium-Museum, Scripps Institute of Oceanography, UCSD. This is significant because this event is extremely rare while in captivity.
Topics on coral aggression patterns are a particular area of interest. Corals, like many other animals, must compete for food and space in order to live. Interesting ways of fighting with other corals and even other animals have been created through gradual evolutionary improvements.