It grows to 1.5 m (5 ft) tall and is variable in colour, being whitish, yellow, or pale purple.

[3][4] The purple sea fan is found in the western Atlantic and Caribbean, with a range extending from Bermuda and Florida and the Gulf of Mexico to Curaçao.

Its tissues contain symbiotic dinoflagellate Symbiodinium spp., which are photosynthetic and use sunlight to create organic carbon compounds which are then available to the host coral.

Several epizootics have occurred in the Caribbean on corals growing in stressful conditions such as in low-salinity water in estuaries which seem especially susceptible.

[7] A study done in the U.S. Virgin Islands has shown that G. ventalina has a high ecological resilience with populations maintaining their densities after two hurricanes in 2017.