Mycetophyllia

Lore & Background

Mycetophyllia coral colonies have flat disc-like or dome structures with scalloped edges, and corallites covering the surface radially toward the center. Depending on the species, they may have a pattern of valleys and ridges on their surface. They are often brown, green, or grey in color and are identified by their thin plates and irregular ridge pattern. There are five known species within Mycetophyllia, each with unique morphological features. Mycetophyllia aliciae is characterized by a thin, scalloped plate without defined valleys and ridges, reaching a maximum diameter of 1 meter. Mycetophyllia danaana is the smallest species, with a diameter of 30 centimeters and thick plates with deep narrow ridges. M. ferox has thin plates with distinctive ridges and valleys, also reaching 1 meter. M. lamarckiana forms small, round mounds with valleys across the surface, usually light brown or grey. M. reesi has the thinnest plate of all Mycetophyllia species, with no ridges and a smooth surface.

Mycetophyllia is native to the Caribbean Sea, southern Gulf of Mexico, southern Florida, and the Bahamas, between the Tropic of Cancer and the equator at latitudes 10–25°N and longitudes 60–80°W. These stony corals occupy benthic rocky substrates and are most abundant at depths of 10–25 meters, though distribution varies by species. M. reesi occupies the greatest depths, found in deep-water fore reefs from 20 to 76 meters.

Like many stony corals, these corals are hermaphroditic, with some species possessing both male and female reproductive organs. Sexually mature corals produce gametes through meiosis. They begin their life cycle as polyps. When environmental conditions are favorable, polyps release sperm into the water column, allowing fertilization through external fertilization. Coral spawning occurs once a year during a full moon. After fertilization, the zygote drifts and undergoes cell division in mitosis, developing into a planula larva that moves with tiny cilia until it finds a hard substrate suitable for settlement.

Reader's Guide

Mycetophyllia is notable as a genus of hermatypic, reef-building corals within the family Mussidae, contributing to Caribbean reef ecosystems. Their symbiotic relationship with zooxanthellae provides nutrients, and they also feed passively on suspended organic matter. The genus comprises five recognized species, each with distinct morphological traits—from the thin, scalloped plate of M. aliciae to the ridgeless, smooth surface of M. reesi. These corals are found across a broad geographic range in the Caribbean, Gulf of Mexico, Florida, and the Bahamas, typically on benthic rocky substrates at depths of 10–25 meters, though M. reesi extends to 76 meters. Their life cycle involves hermaphroditic reproduction, external fertilization, and annual spawning during a full moon. However, widespread threats such as habitat loss, disease, warming ocean temperatures, and physical destruction are causing population declines. White band disease, identified by peeling tissue and exposed white skeleton, has led to coral deaths in the region, though its cause remains uncertain. Localized threats include human development, invasive species, unsustainable fishing, and pollution. The genus's ecological role as a reef builder and its vulnerability to environmental stressors underscore its significance in Caribbean marine ecosystems.

Did You Know?

• The smallest species, Mycetophyllia danaana, has a maximum diameter of 30 centimeters.
• Coral spawning in Mycetophyllia occurs once a year during a full moon.
• White band disease, which affects these corals, is identified by peeling tissue and an exposed white skeleton, though its cause is still unknown.