The common sea fan is a species of soft coral, emblematic of tropical reefs in the western Atlantic Ocean and the Caribbean Sea. It is easily recognizable by its fan-shaped structure that gently sways with the ocean currents.

The common sea fan is identifiable by its fan-shaped structure, which can reach up to 5 feet tall and 3 feet wide, deployed perpendicular to the current and gently swaying with the water movement. Its delicate branches often display pale shades of purple, lavender, or yellow depending on environmental conditions, while its base attached to the substrate shows a deeper color.

The skeleton of the common sea fan is made of gorgonin, a collagen-like protein and calcite. Numerous tiny polyps are arranged in two rows along the branches and have eight tentacles that they extend, mainly at night, to capture zooplankton when feeding activity is at its peak.

The common sea fan is found in the tropical waters of the western Atlantic ocean and the Caribbean sea. It occurs in Florida, particularly in the Florida Keys, in the Bahamas and on reefs around many Caribbean islands such as Bonaire, the Cayman islands and the Turks and Caicos islands, as well as along the coasts of Central American countries bordering the Caribbean sea, such as Belize.

The common sea fan inhabits shallow waters of tropical reefs, generally between 6 and 33 feet deep, but sometimes down to 100 feet. It prefers areas exposed to moderate to strong currents, such as reef slopes, outer reef edges and crevices, where it can anchor securely.

Exposed to ocean currents, the common sea fan filters seawater to feed primarily on zooplankton.

It also hosts symbiotic algae called zooxanthellae, which live in its tissues and provide nutrients through photosynthesis. This symbiotic relationship is essential for its survival, especially in nutrient-poor waters.

The common sea fan reproduces sexually by releasing gametes into the seawater, where fertilization occurs. The larvae then settle on the substrate to form new colonies.

The common sea fan can also reproduce asexually through fragmentation, a process in which a piece of the fan detaches and establishes itself to grow into a new colony.

Although the common sea fan shows notable ecological resilience, especially after hurricanes, it remains vulnerable to fungal diseases such as aspergillosis, parasites and environmental impacts like pollution and climate change.

The visually striking common sea fan is a highly popular subject for underwater photographers.