Invertebrate atlas

Geographical Origin and Habitat: The Torch Coral (Euphyllia glabrescens) is a highly prized, spectacularly beautiful Large Polyp Stony (LPS) coral natively endemic to the warm, sunlit coral reefs and sheltered lagoons of the Indo-Pacific Ocean, Australia, and the Red Sea. Their natural biotope is defined by expansive reef slopes and turbid lagoon environments where they anchor their heavy skeletons into the rockwork, exposing their long, flowing tentacles to moderate, rhythmic tidal currents.

Taxonomy: Scientifically classified within the Euphylliidae family, they are an LPS coral featuring a heavy, branching, calcified skeleton (corallite). Morphologically, they are instantly identifiable and breathtaking. At the tip of each skeletal branch is a fleshy polyp that extends dozens of extremely long, thin, flowing tentacles. Defining Feature: unlike the Hammer or Frogspawn coral, the Torch Coral's tentacles end in a single, perfectly round, ball-like tip (resembling a lit torch).

Social Behavior: They are sessile invertebrates, but they are exceptionally aggressive and territorial. They require significant real estate. Critical Behavior: at night, the Torch Coral will deploy specialized sweeper tentacles that can reach 10-15 cm beyond its normal polyp extension. These sweepers are heavily loaded with potent stinging cells (nematocysts) designed to biologically burn, sting, and kill any competing corals within their radius.

Coloration and Sexual Dimorphism: New color morphs exhibit intense, glowing neon yellow and orange hues and command premium prices. The long, fleshy tentacles are typically deep purple, rich brown, or striking green. The rounded tips are highly contrasting, presenting in blinding neon green, electric yellow, or bright pink. Sexual dimorphism is non-existent.

Tank Setup: The aquarium architecture must accommodate their aggressive nature and massive tentacle extension. A minimum 110-liter marine aquarium is required. Critical Requirement: they must be given extreme isolation. Leave at least 15 cm of completely open space around the coral in all directions to prevent its sweeper tentacles from damaging neighboring corals. Securely epoxy the skeletal base to the rockwork to prevent it from being knocked over.

Diet and Feeding: They are highly autotrophic, deriving most of their daily energy from the photosynthesis performed by their symbiotic zooxanthellae algae under moderate to high lighting. However, they are also active, carnivorous feeders. Target feeding is highly recommended and accelerates skeletal growth and tentacle extension. Gently feed the polyps 1-2 times a week with Mysis shrimp, krill, or specialized LPS coral pellets using a turkey baster.

Water Quality: As heavily calcified LPS corals, they are sensitive to water chemistry and require stable parameters. They demand stable temperatures (24-27°C) and salinity between 1.024 and 1.026. Critical Requirement: they must have highly stable Calcium (420-450 ppm), Alkalinity (8-10 dKH), and Magnesium (1300-1400 ppm) levels to grow their branching skeletons. Fluctuations in Alkalinity will cause rapid polyp bailout or tissue death.

Compatibility and Tankmates: Compatibility requires caution due to their aggression. They will sting and damage SPS corals, soft corals, and even other LPS corals. While they are often compatible with other Euphyllia species (like Frogspawn), Torch Corals are known to occasionally sting even close relatives. They are a suitable surrogate host for Clownfish, which may wallow in their long tentacles.

Aquarium Breeding: Propagating (fragging) the Torch Coral is straightforward but requires tools. Because they possess a branching skeleton, aquarists can use a Dremel tool or bone shears to cut through the dead, calcified stalk well below the fleshy polyp. Critical Warning: never cut into or tear the fleshy polyp tissue itself, as this will result in a lethal bacterial infection. The severed skeletal branch is glued to a frag plug.

Risks and Diseases: Critical Disease Risk: Euphyllia corals are highly susceptible to Brown Jelly Disease (BJD), a rapid ciliate/bacterial infection that turns the fleshy tentacles into a rotting brown mass. It can destroy a colony in 24 hours. The second major risk is inappropriate flow; flow that is too strong will tear the delicate tentacles against the sharp skeleton, causing infection. They require moderate, gentle, chaotic flow.