Hermaea oliviae

Photo courtesy of Terry Strait
La Jolla Shores, San Diego, Calif
Oct., 2008

Hermaea oliviae, (MacFarland, 1966)

Originally, Frank Mace MacFarland placed this species to be named after his wife Olive Hornbrock MacFarland in the genus, Aplysiopsis . Since then it has been more appropriately moved to Hermaea .

Frank and Olive MacFarland

While it looks very much like an aeolid, this slug is a member of the Order Sacoglossa , or as we generically refer to them, the Sap-suckers. Sacoglossans get this name because of their unique feeding mode. All but two genera feed on algae, by puncturing the algal cells with a single pointed rachidian tooth, on their radula, followed by sucking the cellular contents, or sap.

Hermaea oliviae has a distinctive mahogany brown V on its head that starts at the tip of the rhinophores, and joins at the midline of the body. Additionally, the rhinophores have a distinctive, sickle shape to them.

Although seen here in Terry’s photo crawling on a small sand dollar, the species is more commonly found grazing on filamentous green algae. Known from Seymour Inlet, British Columbia, Canada to Islas Cedros, Baja California, Mexico.

Dave Behrens
Gig Harbor, Washington
Dec., 2008

Terry Strait at La Jolla Shores

I was certified in 2002 as a Christmas present for my girlfriend and I. After my first open water dive I was hooked. Now 4 years later I have over 600 dives and no plans on slowing down. Most of my diving is right here off the San Diego coast where I have ample opportunity to pursue my passion of searching for and photographing nudibranchs. I didn't even know what a 'branch was until Sean Kearney opened my eyes to the amazing world of the sea slug. Thanks to Sean I have spent way more money than was prudent on dive boats, dive gear and cameras.....all so I can say...."look what I found".

I am presently shooting a Nikon D40x with a Nikkor 60mm macro lens in an Ikelite housing. Two DS125 strobes.

Send Terry email at divinman@sbcglobal.net

From left to right, Terry Gosliner, Angle Valdes, Dave Behrens La Jolla, Calif.

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