Phyllodesmium sp.

Image courtesy of Jim Black
Raja Ampat,West Papua, Indonesia
Nikon D-300 in Subal Housing with Ikelite strobes.
Copyright 2011, Jim Black

Phyllodesmium sp. (undescribed)

We refer to this beauty as Phyllodesmium sp. 10 in Indo-Pacific Nudibranchs and Sea Slugs

It is characterized by its long semi-coiled cerata with reddish-brown cores, and an opaque white line along each edge. Note the curly, spiraling ceratal core, and the absence of a cnidoblast (sacs for storing nematocysts) at the tip of the ceras. Members of the genus Phyllodesmium do not utilize nematocysts for defense, even though many of the octocoral species they prey on do.

Although we have not verified this, the ceratal cores of this new species appear to contain symbiotic zoozanthellae. These microscopic symbionts carry out photosynthesis, within the slugs body, converting water and carbon dioxide into oxygen and sugar for the slugs own nutrition.

To date specimens are recorded only from Bali, Indonesia and Raja Ampat, West Papua. Specimens my reach 20mm in length

Dave Behrens
Gig Harbor, Washington
May, 2011

WEBMASTER'S NOTES : Another great submission by Jim Black who continues to astound us with his uncanny ability to find and photograph slug images most of us probably aren't going to see in this lifetime!

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.

Send Jim email at

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!

As an added note, Jim was one of the keynote speakers at the Pittsburgh Scubapalooza, held Saturday, 5/14 at the Pittsburgh Scuba Center, 818 Ann St., Homestead, Pa.

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

Send Dave email at

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