Acanthodoris pilosa

Whidbey Island, Washington
Photo courtesy of Jan Kocian

Acanthodoris pilosa (Abildgaard, 1789)

Named way back in the eighteenth century, this species occurs in cold temperate and boreal seas around the globe. This species looks like a typical Acanthodorid in shape and texture on the dorsum. In fact the species name “pilosa” denotes the presence of the long conical dorsal papillae. The primary difference is that this species lacks any of the striking color pigments seen in sister species such as Acanthodoris rhodoceras , or A. lutea . Some Atlantic specimens do have background coloration, however. Additionally, the rhinophores of A. pilosa bend backwards.

Like other Acanthodorids, this species feeds on bryozoans, seen encrusting the substrate here. Jan has also captured the egg mass in his photo. As you can see it is quite typical, an undulating spiral ribbon attached to the substrate along one edge.

Dave Behrens
Gig Harbor, Washington
July. 2006

Jan Kocian

I was born in landlocked Czechoslovakia, but diving became my love early in life, getting my certification in the fresh cold waters of old quarry, before wet suits were available to the diving public behind the “ Iron Curtain ”.

After emigrating from there in 1968, the sea stayed close to my heart. I worked on research ships in the Pacific, enjoying the warm waters of the tropics for many years.

Not until I retired to Whidbey Island in Washington State I started to pay closer attention to the smaller creatures of the underwater world. And what a wonderful realm it is. After caves, wrecks and grand vistas, I am just beginning to discover the beauty of macro world.

My camera rig consists of a Nikon Coolpix 5400 digital camera in a Epoque housing with a single Epoque ES-150 DEX strobe.

WEBMASTER'S NOTES : Jan is quite a critter watcher which is evidenced by a special page set up for him at Well worth taking the time to visit!

Send Jan email at

Puerto Vallarta, Mexico
March 2005

Ali Hermosillo and Dave Behrens

Author: Pacific Coast Nudibranchs
Co-Author Coral Reef Animals of the Indo Pacific
Proprietor of Sea Challengers Natural History Books

Send Dave mail at

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