Rainbow Coral, Leptogorgia iridis
Rainbow Coral, Leptogorgia iridis. Underwater photographs taken in Bahía de Banderas, Puerta Vallarta, Jalisco, July 2026. Photographs and identifications courtesy of Greg Timms, youtube.com/@Coralmasterdives-PuertoVallarta/videos.
Phylogeny: The Rainbow Coral, Leptogorgia iridis (Hernández, Gómez-Gutiérrez & Sánchez, 2021), is an octocoral member of the Gorgoniidae Family of Soft Corals. The Leptagorgia Genus is a large genus with ninety-four recognized species, and it is one of thirteen genera in the Gorgoniidae Family. The genus name Leptogorgia comes from the Greek words meaning “slender gorgonian”, or “delicate gorgonian”. This refers to the delicate, snake-like branches. The species name iridis comes from the Latin word meaning “of a rainbow”, and refers to the variety of colors this species displays. They are known in Mexico as Gorgonia Arcoíris, which also reflects its historical designation as Leptogorgia sp. ‘arcoíris.
Morphology: Rainbow Coral colonies grow as a plane, branching laterally. They attach to the bottom substrate by use of a holdfast, which can reach 5 mm in diameter. It can often be found growing aorund the base of larger gorgonians and sea fans and along side the similar sized Diffusa Sea Fan, Leptogorgorgia diffusa and the Ena Sea Fan, Leptogoria ena. The branches reach up to 7.0 cm (2. 8 inches) in height and 8.1 cm (3.2 inches ) in width. They are semi-rigid in structure. The branches are 1 mm to 2 mm in diameter, and have blunt ends. The branches may be red, purple, or yellow, with yellow or white stripes running along the entire length of the branches. Oval shaped polyp mounds run, in two rows, along the branches. The polyp mounds are slightly raised and reach 1.0 mm in length. Paratypes within this species can have morphological differences, such as thicker branches, but most of these differences are not discernable in the field. Rainbow Coral colonies can be distinguished from the similar looking Leptogorgia obscura which have pointy branch ends.
Habitat and Distribution: Rainbow Corals are found attached to rocky reefs. They live in the subtidal zone to depths up to 20 m (66 feet). Rainbow Coral is a tropical Eastern Pacific species that is ENDEMIC to Mexican waters of the Pacific Ocean, where they range from the Islas Marías Archipelago, Nayarit, to Bahía Banderas, Jalisco.
Diet: Rainbow Coral are azooxanthellate suspension feeders. The polyps use their eight tentacles to capture micro plankton and suspended organic matter from the surrounding water.
Predators: Detailed predator information for the Rainbow Coral has not been formally documented. Other species in the Leptogorgia Genus are preyed upon by coralliferous reef fish, gastropods and nudibranchs.
Reproduction: Rainbow Coral is gonochoric (male or female for life). They reproduce sexually through broadcast spawning with external fertilization. The zygotes develop into planktonic planula larva and metamorphosis begins with early morphogenesis of tentacles, septa, and pharynx before larval settlement on to the bottom substrate.
Ecosystem Interactions: Rainbow Corals provide structure and camouflage to small small fish and invertebrates such as brittle stars, crabs, and shrimps.
Human Interactions: Rainbow Coral have limited direct impact on human activities. From a conservation perspective they have not been formally evaluated.
Synonyms: None