Net Fire Coral, scientifically known as Millepora dichotoma, is a colonial cnidarian commonly found in tropical and subtropical waters. It is characterized by its intricate, net-like structure and its ability to sting, earning it the moniker “fire coral.” Although resembling corals, Millepora dichotoma is actually a hydrozoan, a group of animals closely related to jellyfish and hydroids.
Description & Characteristics
Millepora dichotoma forms branching colonies that can grow to considerable sizes, often reaching several feet in diameter. The colony’s skeleton is made of calcium carbonate, giving it a hard, rigid structure. Its surface is covered in tiny polyps, which are responsible for feeding and defense. These polyps have two distinct forms: feeding polyps, which are small and numerous, and reproductive polyps, which are larger and less common. The polyps have stinging nematocysts, which they use to paralyze prey and ward off predators. Despite their outward appearance, Millepora dichotoma is not a true coral, but a member of the hydrozoa class.
Habitat and Occurrence
Millepora dichotoma thrives in shallow, tropical and subtropical waters, typically found in reef environments and rocky outcrops. It is particularly common in the Indo-Pacific region, extending from the Red Sea to the eastern Pacific Ocean. Millepora dichotoma is a common sight in the tropical and subtropical reefs of the Indo-Pacific, where it plays an important role in the ecosystem. This coral prefers water temperatures between 20-28°C and can be found in depths ranging from the surface to 50 meters.
Taxonomy
Millepora dichotoma is classified within the phylum Cnidaria, which encompasses a diverse group of aquatic animals including jellyfish, corals, and sea anemones. It belongs to the class Hydrozoa, a group characterized by their polyp-like forms and a distinct life cycle involving both polyp and medusa stages. Millepora dichotoma is further classified within the order Anthoathecata, distinguished by their lack of a true medusa stage. Finally, it belongs to the family Milleporidae, which encompasses all fire corals. This family is characterized by its colonial nature and its ability to sting, due to the presence of nematocysts.
Feeding
Millepora dichotoma is a carnivore, feeding primarily on small invertebrates such as zooplankton, which it captures using its stinging nematocysts. Millepora dichotoma also relies on a symbiotic relationship with a type of algae called zooxanthellae. These algae live within the polyp tissues and provide the coral with energy through photosynthesis. In turn, Millepora dichotoma provides zooxanthellae with a protected environment and access to nutrients. This dual-feeding strategy allows Millepora dichotoma to thrive in a variety of conditions, from nutrient-rich waters to nutrient-poor environments.
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