Thorunna daniellae

Image courtesy of Jim Black
Anilao, Batangas, Philippines
Thorunna daniellae (Kay & Young, 1969)

UW Master Shooter, Jim Black, has noticed we are missing a few common Indo-Pacific species on Mike's site. Yes, there are probably 100's, so it will take some time catching. So we start today with a tidy little (to 15 mm) chromodorid nudibranch, Thorunna daniellae.

Easily identified because of its white body and smudged purple submarginal band on the mantle and along the edge of the foot. The gill and rhinophores are orange-red.

While this species is only slightly aposomatic in coloration, it is interesting to note that it has no mantle glands containing toxic chemical metabolites . Unlike other acid secreting dorid nudibranchs, the absence of mantle glands suggests that maybe the dorid/flatworm - model/mimic relationship for this species is reversed. Is it possible that Thorunna daniellae gains its protection by mimicking an acid secreting flatworm, such as the similarly colored Pseudoceras gamblei, which it co-exists with? I think likely so. Comments?

This species has a wide distribution, from South Africa, across the Indian Ocean to Australia and north to Okinawa, the Marshall Islands and Hawai'i.

Dave Behrens
Gig Harbor, Washington
Dec., 2009

Jim Black on location in Thailand with friend

Jim is retired from US Airways after 27 years as a pilot..., flying Captain on an Airbus 330 Internationally.

Diving since 1970...with over 5200 dives logged. Shoots Nikon D-300 in Subal Housing with Ikelite strobes. Macro Mate on 105mm for supermacro

Jim's photography has been featured in a number of books and publications including Helmut Debelius' Nudibranchs and Sea Snails of Gosliner, Behrens and Williams Coral Reef Animals of the Indo-Pacific. A photo of Jim petting a shark in "Sleeping Shark Caves" off Isla Mujeres Island, Mexico, taken by Amy Foster his significant other, recently appeared in Dave Behrens' Diving Guide to Cozumel, Cancun & The Riviera Maja.

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Jim has been a solid supporter of the Slug Site since day one. His countless contributions put him near the top of the list of photographers who have greatly expanded our knowledge of sea slugs. There are a lot of kids in the formative stage of their education who are getting their first introduction to our sea slug friends via the great photographs Jim and other contributors have made to the site. My hat is off to Jim for making this presentation possible!

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

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