Wow, check out this new find from the waters of Dubai, United Arab Emirates. Having not seen this beautiful creature personally, I will just have to stick my neck out and call it an undescribed Plocamopherus. Depending upon which systematic scheme you follow this phanerobranch dorid genus is placed in either the family Polyceridae or Triophidae. While the orange body coloration and white speckled papillae are somewhat similar to Plocamopherus imperialis Angas, 1864, this unique species' body is smooth in texture, not having the villous texture of P. imperialis, and it has large black spots, which no other Ploc' I'm aware of have. The photos of Plocamopherus imperialis shown in Opisthobranchs of Kerama Islands , pg 68, Opisthobranchs of Izu Penisula, pg 65 and Nudibranchs of Heron Island GBR, pg 207 all support my hunch. Carole and Leon found this specimen and several others (incidentally, these guys are huge, over 10 cm in length) crawling in a fisherman's net.
Bill Rudman's Sea Slug Forum gives an informative review of the biology of the members of the genus Plocamopherus stating that members have a series of paired papillae along the mantle edge of the body, some of which have a large bulb at the tip. When disturbed, the bulbs, and other patches on the side of the body, luminesce, producing flashes of light down each side of the body. As Bill points out, biologists are still uncertain how they do this and whether light-producing bacteria are involved.
Species of Plocamopherus are also able to extend the posterior end of their body/foot into a vertical "paddle". When disturbed they can swim by vigorously flapping their body from side to side. The paddle-like shape of the posterior end of the body provides necessary propulsion, to propel the slug through the water.
We'll hopefully be seeing many more of Carole and Leon's finds from this
region of the western corner of the Indian Ocean. Seeing new critters like
this one makes ya want to run right out and buy an airline ticket and go
dive with them right now.
Carole and Leon live in the United Arab Emirates and have been diving for over 13 years. One of Carole's favourite photography subject is nudibranchs, because as she says, she is almost guaranteed to get a fairly decent shot! Living in the UAE has proved to be a most diverse and unexpected smorgasboard of offerings from a wide range of unusual nudis to robust ghostpipefish, pipehorse, pygmy sea moths, hammerheads, and recently a pygmy sperm whale.
Carole is currently working on a UAE dive guide book which is expected to be published in December... Includes details of the most dived locations, colour photographs and dive-site maps.
She is also a very active member in the Emirates
Environmental Group, promoting underwater awareness to its members and the
public alike and has struck up a friendship with a reporter who shares the same
environmental eagerness and helps to highlight these matters in the local
Taxonomic information courtesy of Dave Behrens
David W. Behrens
Pacific Coast Nudibranchs
Send Dave mail at firstname.lastname@example.org