MacFarland’s Chromodorid, Felimida macfarlandi

MacFarland’s Chromodorid, Felimida macfarlandi. Underwater photographs taken in the coastal waters off San Diego, California, March 2018. Photographs courtesy of Bob Hillis, Ivins, Utah.

Phylogeny:  MacFarland’s Chromodorid, Felimida macfarlandi (Cockerell, 1901), 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 Three-stripe Doris and in Mexico as Chromodorido de MacFarland. 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 Frank Mace MacFarland. MacFarland was a malacologist and professor of histology at Stanford University for more than 60 years. He was considered to be the early 20th century’s leading authority on Eastern Pacific nudibranchs.

Morphology:  MacFarland’s Chromodorid has an elongate oval outline, with a long, tapering tail. They are lavender to bluish purple in color. They have three bright yellow lines running the length of their back. The margins of the mantle are also yellow. The rhinophores and gills are darker colored. MacFarland’s Chromodorid reach a maximum of 6.0 cm (2.3 inches) in length.

Habitat and Distribution:  MacFarland’s Chromodorids are found on and under rocks. They live in the low intertidal zone and can be found at depths up to 23 m (75 feet). They are a temperate Eastern Pacific species. They have a limited distribution in Mexican waters of the Pacific Ocean, only being found north of Magdalena Bay, Baja California Sur, along the central and northwest coasts of the Baja Peninsula.

Diet:  MacFarland’s Chromodorids prey on sponges of the genus Aplysilla.

Predators: MacFarland’s Chromodorids are preyed upon by crabs, sea stars, polychaetes 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. MacFarland’s Chromodorids obtain this toxin from the sponges they consume.

Reproduction: MacFarlands’ 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:   The interspecies relationships of MacFarland’s Chromodorids has not been documented.

Human Interactions: MacFarland’s 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 macfarlandi