Clown Nudibranch (Triopha catalinae)

Clown nudibranch at the surface of the water (photo credit: Molly Sultany)

Clown nudibranch under water (photo credit: Dani Nielsen)

Description: The clown nudibranch, or sea-clown, is overall white in color and slightly opaque. They have multiple orange spots on their body, including on raised papillae and the rhinophores. The gills are also orange at the tip and mostly white below. This species is unique in having a row of orange tentacles around the front of their body that are also an orange color! In the intertidal, these individuals can be around 7 cm. In deeper waters, individuals can get up to 15 cm long.

Habitat: From the Aleutian Islands, Alaska to the Gulf of California, Mexico, these clown nudibranchs are found on rocks and in tide pools around kelp. They can be seen in the mid intertidal down to depths of 80 m in the subtidal.

Diet: Clown nudibranchs feed on bryozoans.

Tide Pool Tidbits:

  • This is one of the largest nudibranchs capable of crawling on the underside of the water. They crawl upside down with their foot against the surface of the water.

  • It is thought that clown nudibranchs exhibit some sort of chemical repellant as tide pool fish are often seen avoiding them.

  • The population in the Gulf of California may be different from the populations living on the open coast.

References: Walla Walla University, The New Beachcomber’s Guide to the Pacific Northwest by J Duane Sept