Marcus’ Aeolid, Coryphellina marcusorum

Marcus’ Aeolid, Coryphellina marcusorum. An exceptional portfolio of underwater photographs taken in Zihuantanejo Bay, Guerrero, March 2022, courtesy of Ron Woheau, Zihuantanejo.

Phylogeny:   The Marcus’ Aeolid Coryphellina marcusorum (Gosliner & Kuzirian, 1990), is a member of the Flabellinidae family of Nudibranchs. The genus Coryphellina is one of six genera in this family and there are sixteen species in this genus. They are known in Mexico as Eólido de los Marcus.

Morphology: Marcus’ Aeolids are soft-bodied gastropods that lose their shells during their larval phase. They have elongate, deep bodies, with a tapering tail. The anterior end of their foot is angular. Their mantle forms a series of finger-like projections (cerata) along the entire back of the animal. These cerata function as gills, they assist with digestion, and they incorporate stinging cells, from their prey, as a defense mechanism. Marcus’ Aeolids have long rhinophores (horn-like projections) on their heads. Rhinophores are chemosensory organs help them to locate food and potential mates. These nudibranchs lack complex eyes, but have photoreceptors that sense light and dark. Marcus’ Aeolids have translucent orange to yellow-orange bodies with purple cerata and rhinophores. The cerata and rhinophores are tipped with white. The dorsal surface is covered with white specks. The oral tentacles are thin and longer than the rhinophores. This species reaches a maximum of 2.0 cm (0.75 inches) in length.

Habitat and Distribution:  Marcus’ Aeolids are found under rocks, in crevasses, and on rock walls. They live subtidally, and to depths up to 20 m (66 feet). They are a species of both the tropical Western Atlantic and the tropical Eastern Pacific. Some sources show this species being found along the east coast of Mexico, from the south side if the Yucatán Peninsula, south to Belize. Other sources show it being absent from Mexico’s east coast and located much further east. Along Mexico’s west coast they range from Cedros Island, Baja California, south to Guatemala. They are found throughout the Gulf of California.

Diet: Marcus’ Aeolids feed on the polyps of hydrozoans.

Predators: Predation upon Marcus’ Aeolids has not been documented. Other species in this genus are primarily eaten by other nudibranchs, and occasionally by fish.

Reproduction:  Marcus’ Aeolids are simultaneous hermaphrodites (having male and female reproductive organs). They reproduce sexually by hypodermic insemination. This occurs when both mating partners dart their penis toward each other to induce one to act as a male and the other as the female. The victorious one to penetrate the body wall is the dominant male. The eggs are laid as a bright pink mass, at the base of their hydroid prey. The eggs hatch into veliger larva and later metamorphose into adults.

Ecosystem Interactions: Marcus’ Aeolids are a poorly studied and understood species. There is no documentation of their involvement in commensal, parasitic, or symbiotic relationships.

Human Interactions:  Marcus’ Aeolids 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:  Flabellina marcusorum.