Yellow Gorgonian, Eugorgia ampla

Yellow Gorgonian, Eugorgia ampla. Underwater photographs taken in Zihuantanejo Bay, Guerrero, November 2019. Photographs courtesy of Ron Woheau, Zihuantanejo.

Phylogeny: The Yellow Gorgonian, Eugorgia almpla, is an octocoral and a member of the Gorgoniidae Family of Gorgonians.   Eugorgia is one of thirteen genera in this family, and there are seventeen  species in this genus. In Mexico, this species is known as abanico de mar amarillo .

Morphology:  Yellow Gorgonians are yellow to orange-yellow in color and exist as a single plane with relatively large mesh that varies in shape with free-flowing branches. The polyps are evenly distributed around the branches. The branches are known to interweave with neighboring sea fans. They reach 90 cm (35 inches) in length.

Habitat and Distribution:  Yellow Gorgonians are found attached to hard surfaces including coral, rocks and wreckage at depths between 5 m (15 feet) and 30 m (100 feet). In Mexican waters, the  Yellow Gorgonian is found throughout the Sea of Cortez and south along the mainland. They are absent from the west coast of the Baja Peninsula.

Diet:  Yellow Gorgonians are suspension feeders, using the eight tentacles around each polyp to capture copepods, fish eggs, larva, and other zooplankton from the surrounding water.

Predators:   Information specific to predation of Yellow Gorgonians has not been published. Gorgonians in general are prey for fish, starfish, and gastropods.

Reproduction:  Reproduction in Yellow Gorgonians is sexual with mature gametes being shed into the coelenteron and spawned through the mouth. The zygote develop into planktonic planula larva and metamorphosis begins with early morphogenesis of tentacles, septa, and pharynx before larval settlement on the aboral end.

Ecosystem Interactions:  Yellow Gorgonians provide attachment structure for gorgonian anemones of the genus Antiparactis. Little is known about this relationship, but it appears that they harm the gorgonian.

Human Interactions:  Yellow Gorgonians have no direct impact on human activities. From a conservation perspective they have not been formally evaluated however they are fairly common with a relatively wide distribution and should be consider to be of Least Concern.

Synonyms:  Eugorgia ampla typica, Gorgonia ampla, and Leptogorgia ampla.