Pleurobranchus mammalatus

Image courtesy of Jim Black
Anilao, Philippines
Nikon D-300 in Subal Housing with Ikelite strobes.
Copyright 2011, Jim Black

Pleurobranchus mammalatus Quoy and Gaimard, 1832

This is one of our ocean's largest sea slugs. No wonder it was described back in 1832 - heck it's so huge how could they miss it? Pleurobranchus mammalatus first came to our attention back in 2001 when Carole Harris and Leon Betts reported it from the United Arab Emirates.

Of all the side gilled slugs, Pleurobranchus mammalatus . is the only species with tall elevated tubercles on the dorsum. Between the long tubercles, there are clusters of smaller tubercles. The color varies greatly as can be seen in comparing Jim's specimen with that of the Harris and Bett's find. Jim's specimen has beautiful pale lavender marks and crescents encircling the tubercles.

Jim's series of photos have captured several parts of the species biology. We see that like many other species, Emperor's Shrimp , Periclimenes imperator, hitch a ride occasionally in hopes of picking up a few tidbits of food left behind by the slug.

More importantly, he has captured a specimen laying an egg ribbon . Excellent. Wow. This is a wonderful documentation of the similarity of this species egg ribbon to other species of Pleurobranchus.

In Indo-Pacific Nudibranchs and Sea Slugs, we do not report this species from the Philippines. Once again, Jim's keen eyes have added to our knowledge of these fascinating species. Nice extension of the geographic range from Tanzania, United Arab Emirates, South Korea, and Japan. Thanks Jim.

Dave Behrens
Gig Harbor, Washington
Aug. , 2011

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.

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.

Send Jim email at

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!

The 12 Annual San Diego UnderSea Film Exhibition is set for Friday and Saturday evenings, September 9 and 10, 2011 7:00 pm at Irwin M Jacobs' Qualcomm Hall.

Thirty-two short underwater films, produced by leading professional and amateur videographers from around the world, will be highlighted at the 12 Annual San Diego UnderSea Film Exhibition in Irwin M Jacobs' Qualcomm Hall big screen auditorium!

Starting at 7:00 pm, each evening will feature 16 different films, most in high definition, limited to 5 minutes each of fast-paced action. A state-of-the-art digital projection system will bring the world beneath the surface to the eyes of the audience.

This exhibition is unique because there are no entry fees and no prizes, except for the prestige of having a film chosen. An independent panel of three distinguished judges will select the best films among many international entries.

Each year the bar is raised in terms of quality and excitement. From the kelp forests of California to the coral islands of Indonesia, from the sperm whales of the Caribbean to the mantas of the Maldives, there will be something for everybody.

Also shown for the first time will be the winner of Capture the World, an international video competition. Tickets are available for $15 per evening online at SDUFEX . SDUFEX is a 501c3 nonprofit organization.

A portion of the proceeds will go to Birch Aquarium , San Diego Coastkeeper, and the Chula Vista Nature Center. Previous shows have been sellouts, so get your tickets early. A limited number of tickets may be available at the gate.

Seating is open, and doors open 30 minutes prior to the show. Parking is free on the Qualcomm campus. Further information is available online at Contact information: Pete Fowler, Mary Lynn Price , or Eric Hanauer .

A Film Trailer of the forthcoming event is now up on YOU Tube !

Send Pete email at
Send Mary Lynn email at
Send Eric email at

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

Send Dave email at

© The Slug Site, Michael D. Miller 2011. All Rights Reserved.