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  the Chromodorididae Family, and there are twenty-eight  species in the Felimida genus. They are also known as the Clown Nudibranch and the Sea of Cortez Chromodorid and the and in Mexico as Chromodórido de Norris. The genus name Felimida is thought to be derived from the Latin word for cat, but no one seems to know why. This species is named in honor of Kenneth S. Norris, who was a marine biologist known for his work in Baja California.

Morphology:  Norris’ Chromodorid has an elongated oval profile. They may be grayish, lavender, pink or white in color, 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. Norris’ Choromodorids are a subtropical to tropical Eastern Pacific species. They are found in all Mexican waters of the Pacific Ocean with the exception that they are absent from north of Guerrero Negro, Baja California, along the central and northwest coasts of the Baja Peninsula.

Diet:  Norris’ Chromodorids prey on sponges.

Predators: Norris’s Chromodorids are preyed upon by crabs, sea stars, polychaete worms and other nudibranchs. 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