Common name: Spine coral

General information

The Branching Hydnophora, scientifically known as Hydnophora grandis, is a species of SPS (Small Polyp Stony) coral that is popular among reef aquarium enthusiasts for its unique growth patterns and vibrant colors. This coral is characterized by its branching colonies with blunt, horn-like tips, which is where it gets its common name, Horn Coral. The polyps of Hydnophora grandis are small and extend during the day to capture food particles from the water.

Care

Hydnophora grandis requires stable water conditions to thrive, with consistent levels of calcium, alkalinity, and magnesium being particularly important for skeletal growth. This coral prefers strong lighting and moderate to high water flow, which helps to keep the polyps free of detritus and provides the necessary nutrients. It is important to place Hydnophora grandis in an area of the tank where it will not come into contact with other corals, as it can be aggressive and may sting its neighbors.

Symbiosis

While Hydnophora grandis does not have any specific symbiotic relationships that are notable in the context of home aquariums, it does host zooxanthellae, symbiotic algae that live within its tissues. These algae provide the coral with some of the nutrients it needs through photosynthesis, which is why strong lighting is important for the health of the coral.

Habitat

In the wild, Hydnophora grandis is found in the Indo-Pacific region, including the Red Sea, East Africa, and the central Pacific. It typically inhabits reef slopes and lagoons, where it can be found at various depths, often forming extensive colonies that contribute to the complex structure of coral reefs.