The Cup Coral, also known by its scientific name Astrangia rathbuni, is a captivating and resilient species of stony coral found in the marine environments of the Western Atlantic Ocean. This coral exhibits a unique and alluring morphology, contributing to its popularity among aquarists and marine enthusiasts.
Description & Characteristics
The Astrangia rathbuni is a solitary coral, meaning it does not form colonies like many other coral species. It is typically characterized by a cup-shaped skeleton with a distinct central polyp. The skeleton of the Cup Coral is usually a whitish color, and the polyp itself can display a vibrant range of colors, including green, orange, pink, and even brown. These colors are a result of the coral’s symbiotic relationship with zooxanthellae algae, which provide nutrients through photosynthesis. However, Astrangia rathbuni is an azooxanthellate coral, meaning it does not rely on these algae for sustenance.
The Cup Coral can grow up to approximately 2 inches (5 centimeters) in diameter, making it a relatively small coral species. Its polyps extend from the central skeleton and contain tentacles, used for capturing prey.
Habitat and Occurrence
The Cup Coral is commonly found in the Subtidal, sublittoral, infralittoral, deep zone of the oceans from the lower limit of the intertidal zone (intertidal) to the shelf edge at about 200 m water depth. neritic. This signifies its adaptability to a wide range of depths, from shallow water near the shore to deeper environments along the continental shelf. The coral typically prefers hard substrates, such as rocks, piers, and even shipwrecks, where it can firmly anchor itself.
Taxonomy
The species Astrangia rathbuni belongs to the Class: Hexacorallia, Order: Scleractinia, and Family: Astrangiidae. This classification highlights its relationship to other coral species within the broader context of marine invertebrates. Hexacorallia represents the class of corals that possess six-fold radial symmetry, while Scleractinia is the order encompassing stony corals, which are characterized by their hard, calcium carbonate skeletons. The Astrangiidae family includes a diverse group of corals that exhibit a range of morphologies and ecological adaptations.
Feeding
The Cup Coral is a carnivorous predator, feeding primarily on small invertebrates like copepods, Daphnia salina, and zooplankton. Its tentacles, armed with stinging nematocysts, paralyze prey and draw it toward its mouth for ingestion. The coral’s ability to thrive without zooxanthellae further distinguishes it from many other coral species, showcasing its independence and resilience in various marine environments.
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