Marcuses’ Aeolid, Coryphellina marcusorum

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

Phylogeny: Marcuses’ Aeolid, Coryphellina marcusorum (Gosliner & Kuzirian, 1990), is a member of the Flabellinidae Family of Nudibranchs. The Coryphellina genus is one of six genera in the Flabellinidae Family and there are sixteen species in the Coryphellina genus. They are known in Mexico as Eólido de los Marcus. The  genus name Coryphellina comes from the Greek words meaning “little crown” or “little peak” and refers to the crown of cerata on these nudibranchs. This species was named in honor of the Brazilian husband and wife zoology team Ernst Marcus and Eveline du Bois-Reymond Marcus. After fleeing Nazism in Germany the couple settled in Brazil and became prominent invertebrate zoologists specializing in opistobranch mollusks.

Morphology: Marcuses’ 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. Marcuses’ 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. Marcuses’ 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. Marcuses’ Aeolid reaches a maximum of 2.0 cm (0.75 inches) in length.

Habitat and Distribution:  Marcuses’ Aeolids are found under rocks, in crevasses, and on rock walls. They live in the subtidal zone, and to depths up to 20 m (66 feet). Marcuses’ Aeolids are found in both the tropical Western Atlantic and the tropical Eastern Pacific. In Mexican waters of the Atlantic Ocean they are found along the east coast of the Yucatán Peninsula south to Belize. In the Pacific Ocean they are are found in all Mexican waters with the exception that they are absent from north of Cedros Island, Baja California, along the central and northwest coasts of the Baja Peninsula.

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

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

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

Human Interactions:  Marcuses’ 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