Acanthodoris lutea
Largest northeastern Pacific onchidorid with aposematic orange coloration.
The orange-peel doris, *Acanthodoris lutea*, is a shell-less marine gastropod mollusk, a type of nudibranch in the family Acanthodorididae. It is the largest of the northeastern Pacific onchidorids and is easily spotted due to its bright, warning coloration. The species name *lutea* is Latin for an orange-yellow color, while the genus name *acantho* comes from the Greek for spiny, and *doris* refers to an ancient Greek sea nymph.
This nudibranch reaches about 30 mm in length. Its dorsum is bright orange, papillated, and dotted with yellow specks. As with many nudibranchs, this vivid coloring is aposematic, warning predators of its distastefulness. However, paler color variations occur in British Canada, and individuals in the Salish Sea are extremely variable—ranging from nearly white to brown with whitish papillae—depending on habitat and diet. When handled, these slugs often emit a sandalwood-like scent.
First described from Cayucos, California, the species lives along the Pacific coast of North America from Cape Arago, Oregon to northern Baja California, Mexico. Specimens from Duxbury Reef, California, and Puget Sound, Washington, have been sequenced for the 16S ribosomal RNA, Histone H3, and CO1 genes. It inhabits intertidal and subtidal zones on rocky shores.
*Acanthodoris lutea* feeds on bryozoans of the genus *Alcyonidium*. It converts chemicals from its prey into a noxious metabolite toxic to potential predators, reinforcing its aposematic warning.
Quick Facts
- Taxon
- Acanthodoris lutea
Facts from the source article.
Lore & Background
This species was described from Cayucos, San Luis Obispo County, California. The generic name 'acantho' comes from the Greek word meaning spiny, and 'doris' is the name of an ancient Greek sea nymph. The species name 'lutea' is a Latin word meaning an orange-yellow color.
Acanthodoris lutea grows to about 30 mm in length and has a bright orange papillated dorsum covered with yellow specks. This bright coloration is thought to be a reminder to would-be predators of its distasteful nature, an example of aposematic coloration. However, paler color variations exist in British Canada, and individuals in the Salish Sea are extremely variable in color, ranging from almost fully white to brown with whitish papillae, due to different habitats and diets. When handled, these slugs often smell of sandalwood.
The orange-peel doris feeds on bryozoans of the genus Alcyonidium. It turns the chemicals taken from the bryozoan food into a noxious metabolite which is toxic to possible predators. This species is aposematically colored, warning predators of this toxic deterrent.
Reader's Guide
Acanthodoris lutea is significant as the largest of the northeastern Pacific onchidorids, making it a prominent species in its range. Its bright orange coloration with yellow specks serves as an aposematic signal, warning predators of its distasteful nature derived from chemicals in its bryozoan diet. The species exhibits notable color variation, particularly in British Canada and the Salish Sea, where individuals range from almost fully white to brown with whitish papillae, attributed to different habitats and diets. This variability highlights the influence of environmental factors on nudibranch appearance. The species also produces a distinctive sandalwood odor when handled. Specimens from Duxbury Reef, Marin County, California and Puget Sound, Kitsap County, Washington have been sequenced for the 16S ribosomal RNA, Histone H3 and CO1 genes, contributing to genetic studies of the group. Its common name, orange-peel doris, reflects its bright coloration and texture. The species' ability to convert bryozoan chemicals into a noxious metabolite underscores its ecological role in chemical defense.
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