Acropora, literally a porous branch or stem, is a type of coral commonly referred to as staghorn or table coral. Unlike other species of staghorn coral that branch out in a way similar to a tree or antlers, table coral branches out horizontally like a flattened bush, also resembling the top of a table. Due to the support provided by a connected coral stem attached to the sea floor, table coral creates a shaded shelter to numerous species of fish.
Generally, coral is divided into two categories, soft coral and hard coral. Soft corals referred to as “non-reef builders” are composed of soft “finger-like” extensions. Table coral is a hard coral, also known as a “reef builder,” which produces skeletons of calcium carbonate that become the infrastructure of all coral reefs. Depending on the environment, coral can grow into many different shapes. Some species of coral are round or flat, some resemble a bush or plant, while many have extensions that branch out like trees.
The outside composition of coral consists of coral polyps. Polyps are small invertebrates covering the entire surface of coral, responsible for providing the organism with nutrients. Some species of coral contain polyps with the ability to capture small fish using tentacles covered with stinging cells.
Living inside of the coral's tissue is a type of algae. This algae is responsible for the wide array of colors associated with coral. Algae can also provide nutrients to coral. For hard corals, the main sources of food are zooplankton and photosynthetic algae called zooxanthellae.
The distinct shape of table coral is key to its survival. This coral relies on zooxanthellae algae as a primary food source. As the algae provides food through the process of photosynthesis, the horizontal surface of table coral allows for maximum exposure to sunlight, which results in an abundance of nutrients.
Similar to other coral species, table coral thrives in shallow, warm waters as part of a coral reef community. A famous example is the Great Barrier Reef in Australia — due to its vast amounts of coral it can be considered the largest living organism on the planet. Hundreds of species of coral, including table coral, play an important role in the reef’s construction and the surrounding ecosystem. Around the world, reefs are in peril and are dying off at an alarming rate due to the effects of global warming and pollution.