Norris’ Chromodorid, Felimida norrisi

Norris’ Chromodorid, Felimida norrisi. Underwater photographs taken in coastal waters of Los Cabos, Baja California Sur, May 2018. Photographs courtesy of Bob Hillis, Ivins, Utah.

Phylogeny: Norris’ Chromodorid, Felimida norrisi (Farmer, 1963), is a member of the Chromodorididae Family of Nudibranchs. The genus Felimida is one of eighteen genera in that family, and there are twenty-eight  species in this genus. This species is also known as the Sea of Cortez Chromodorid and the Clown Nudibranch and in Mexico as chromodórido de Norris.

Morphology:  Norris’ Chromodorid has an elongated oval profile. They vary in color from grayish, lavender, pink or white and they are covered with maroon and yellow spots that vary in size and number. The gills and rhinophores are tipped in orange. The mantle has an orange margin that may be continuous or interrupted. They reach a maximum of 6.3 cm (2.5 inches) in length.

Habitat and Distribution:  Norris’ Chromodorid is found on and under rocks. They reside intertidally and can be found at depths up to 15 m (50 feet). They vary seasonally in their abundance. In Mexico Norris’ Choromodorid is found in all waters of the Pacific, including throughout the Sea of Cortez, with the exception that they are absent from north of Guerrero Negro, Baja California.

Diet:  Norris’ Chromodorids prey on sponges.

Predators: Norris’s Chromodorids are preyed upon by other nudibranchs, crabs, polychaetes, and sea stars. Other potential predators are deterred by this species’ ability to secrete chemical defenses that make it taste bad or even toxic. Norris’ Chromodorids obtain this toxin from the sponges that they eat.

Reproduction:   Norris’ Chromodorids are simultaneous hermaphrodites. 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 mass on the bottom stratum. The eggs hatch into veliger larva and later metamorphose into adults.

Ecosystem Interactions:  Very limited information regarding interspecies relationships for Norris’ Chromodorids has been documented.

Human Interactions:  Norris’ Chromodorids 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: Chromodoris norrisi and Glossodoris norrisi.