Acropora humilis, commonly known as Finger Coral, is a species of stony coral belonging to the family Acroporidae. This coral is characterized by its distinctive finger-like branches, contributing to its common name. Its intricate structure and vibrant colors make it a captivating sight in the underwater world.
Description & Characteristics
Acropora humilis exhibits a branching growth form, with slender, finger-like branches extending outwards. These branches typically grow to a maximum size of around 1 meter in length. The coral’s surface is covered in numerous polyps, each with a central mouth surrounded by tentacles. The color of Acropora humilis can vary depending on environmental factors, ranging from pale brown to vibrant yellow and even green. The coral’s polyps are responsible for capturing food and contributing to the overall health of the colony.
Habitat and Occurrence
Acropora humilis is predominantly found in the subtidal, sublittoral, and infralittoral zones of the oceans, ranging from the lower limit of the intertidal zone to the shelf edge at approximately 200 meters water depth. These zones are characterized by a diverse array of marine life, making them ideal habitats for coral growth. The coral thrives in neritic marine environments, where sunlight penetration allows for the growth of its symbiotic algae. The finger coral’s distribution extends across various regions, making it a prominent member of these aquatic ecosystems.
Taxonomy
Acropora humilis belongs to the Class: Hexacorallia, Order: Scleractinia, and Family: Acroporidae. This classification highlights its evolutionary lineage and relationship to other coral species. The Hexacorallia class encompasses a vast array of corals, while the Scleractinia order specifically includes stony corals that form hard, calcium carbonate skeletons. The Acroporidae family encompasses a diverse group of branching corals, including Acropora humilis.
Feeding
Acropora humilis is a heterotrophic organism, relying on a combination of feeding strategies to obtain sustenance. Like other corals, Acropora humilis harbors symbiotic algae called zooxanthellae within its tissues. These algae provide the coral with a significant portion of its energy through photosynthesis, converting sunlight into usable energy. However, the coral also actively captures food particles from the surrounding water. This includes dissolved inorganic substances, such as sodium chloride, calcium, magnesium, potassium, and iodine phosphate, along with dissolved organic substances and plankton. The coral’s polyps, with their outstretched tentacles, filter these particles from the water, further contributing to its nutritional needs.
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