Nudibranchs—Photo Gallery—National Geographic Magazine

Current Issue August 2008
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Living Color

Toxic nudibranchs—soft, seagoing slugs—produce a brilliant defense.

/2008/06/nudibranchs/img/1-green-striped-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-01.jpg Photograph by David Doubilet Nembrotha kubaryana
Size: 2.4 inches (6 centimeters)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162562 /2008/06/nudibranchs/img/2-pink-slug-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-02.jpg Photograph by David Doubilet Halgerda batangas against predators. Any that persist learn that the sponge-eater also exudes a toxin.
Size: 1.6 in (4 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162570 /2008/06/nudibranchs/img/3-orange-circle-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-03.jpg Photograph by David Doubilet Asteronotus cespitosus
Size: 8.7 in (22 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162580 /2008/06/nudibranchs/img/4-horns-striped-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-04.jpg Photograph by David Doubilet Chromodoris sp.
Size: 2.4 in (6 cm) ]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162565 /2008/06/nudibranchs/img/5-blue-yellow-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-05.jpg Photograph by David Doubilet Chromodoris annae compensate for their tiny size with loud, contrasting hues—warning predators of a toxic snack.
Size: 0.8 in (2 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162564 /2008/06/nudibranchs/img/6-horns-brown-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-06.jpg Photograph by David Doubilet Bornella anguilla flees danger by folding in its appendages and swimming like an eel.
Size: 2.8 in (7 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162563 /2008/06/nudibranchs/img/7-tufts-red-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-07.jpg Photograph by David Doubilet Cuthona sp.
Size: 0.7 in (1.8 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162585 /2008/06/nudibranchs/img/8-horns-back-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-08.jpg Photograph by David Doubilet Flabellina exoptata
Size: 1.2 in (3 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162572 /2008/06/nudibranchs/img/9-brown-solar-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-09.jpg Photograph by David Doubilet Phyllodesmium longicirrum—farms zooxanthellae algae within its own body. Feeding on the soft coral Sarcophyton, the nudibranch pilfers algal cells and hoards them within its digestive system, which fills the paddle-shaped appendages called cerata. Stored just beneath the skin, the algae capture light energy, producing nutrients that can sustain the nudibranch for months. The same chemicals that feed the animal are also exuded from its skin as a defensive shield.]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162615 /2008/06/nudibranchs/img/10-tentacles-clear-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-10.jpg Photograph by Jennifer Hayes Phyllodesmium iriomotense houses its branching digestive gland within tentacle-like cerata—outgrowths the animal can shed if under attack. This species is one of the few colorless nudibranchs.]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162587 /2008/06/nudibranchs/img/11-zebra-striped.jpg /2008/06/nudibranchs/img/nudibranchs-60-11.jpg Photograph by David Doubilet Armina, a genus that ranges to 8 inches long, plays tug-of-war with its sole prey, the burrowing sea pen. A tiny blenny bystander picks the safer perch.]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162569 /2008/06/nudibranchs/img/12-mating-stripes-475.jpg /2008/06/nudibranchs/img/nudibranchs-60-12.jpg Photograph by David Doubilet Hypselodoris whitei mate head to tail through a genital aperture. Equipped with both male and female reproductive organs—as are all nudibranchs—each fertilizes the other, and both produce eggs.]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162577 /2008/06/nudibranchs/img/13-yellow-dotted-475.jpg /2008/06/nudibranchs/img/nudibranchs-60-13.jpg Photograph by David Doubilet Hypselodoris kanga, 1.6 inches long, uses its sticky foot to secure an egg ribbon extruded from an oviduct on its side; hatchlings by the thousands will soon disperse with the currents.]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162579 /2008/06/nudibranchs/img/14-eggs-shrimp-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-14.jpg Photographs by David Doubilet (Periclimenes imperator) feeds—perhaps on sea debris or fecal pellets—where its host, a Ceratosoma nudibranch, has laid a ribbon of eggs. The shrimp benefits from the relationship, gaining a ride and access to food, but scientists don't know whether the slug profits from the shrimp's cleanup behavior.]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162617 /2008/06/nudibranchs/img/15-spanish-dancer-475.jpg /2008/06/nudibranchs/img/nudibranchs-60-15.jpg Photograph by David Doubilet Hexabranchus sanguineus can flee danger by taking to the open sea—a skill many of its cousins lack. Known as the Spanish dancer, the species is a giant among nudibranchs; some grow to a foot and a half, on a diet strictly of sponges. When not flashing its contrasting mantle colors to distract predators, the animal is actually camouflaged in its habitat.]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162584 /2008/06/nudibranchs/img/16-gills-shrimp-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-16.jpg Photograph by David Doubilet Periclimenes imperator, which at 0.7 inch long can nestle in the gills of a Spanish dancer, finding safe harbor and bits of food. Whether the tag-along shrimp benefit their host is uncertain—one of many nudibranch puzzles yet to be solved.]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162588 /2008/06/nudibranchs/img/17-fish-eating-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-17.jpg Photograph by Jennifer Hayes Ceratosoma nudibranch appears to attack a stock-still variable sabretooth blenny (Petroscirtes variabilis). But this was not a bite (the nudibranch eats sponges), just happenstance in the night. Sea slugs crawl over whatever lies in their path, and many bottom-dwelling fish tolerate being crossed.]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162619 /2008/06/nudibranchs/img/18-sidegill-slug-475.jpg /2008/06/nudibranchs/img/nudibranchs-60-18.jpg Photograph by David Doubilet Euselenops luniceps—swims freely by flapping its "wings" through dark seas. Though built with the tools to travel in open water, this animal, a close relative of the nudibranch, spends most of its life burrowed in the sand.]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162616 /2008/06/nudibranchs/img/19-group-trailing-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-19.jpg Photograph by David Doubilet Risbecia tryoni nudibranchs show the beginnings of trailing behavior, in which the animals follow one another's slime trails, each hot on the tail of the next. (It often occurs in pairs.) Scientists once thought trailing was related to mating, but evidence is thin; its true purpose remains unknown.]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162618 /2008/06/nudibranchs/img/20-red-horns-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-20.jpg Photograph by David Doubilet Hypselodoris sp.
Size: 2 in (5 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162566 /2008/06/nudibranchs/img/21-godiva-red-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-21.jpg Photograph by David Doubilet Godiva sp.
Size: 1.6 in (4 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162567 /2008/06/nudibranchs/img/22-grey-slug-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-22.jpg Photograph by David Doubilet Phyllidiella pustulosa
Size: 2.4 in (6 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162561 /2008/06/nudibranchs/img/23-white-horns-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-23.jpg Photograph by David Doubilet Phyllidia ocellata
Size: 2.4 in (6 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162571 /2008/06/nudibranchs/img/24-orange-centipede-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-24.jpg Photograph by David Doubilet Pteraeolidia ianthina
Size: 5.9 in (15 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162582 /2008/06/nudibranchs/img/25-green-dotted-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-25.jpg Photograph by David Doubilet Nembrotha cristata
Size: 4.7 in (12 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162581 /2008/06/nudibranchs/img/26-orange-pair-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-26.jpg Photograph by David Doubilet Ceratosoma gracillimum
Size: 4.7 in (12 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162574 /2008/06/nudibranchs/img/27-brown-circles-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-27.jpg Photograph by David Doubilet Jorunna funebris
Size: 2 in (5 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162568 /2008/06/nudibranchs/img/28-yellow-horns-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-28.jpg Photograph by David Doubilet Chromodoris sp.]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162744 /2008/06/nudibranchs/img/29-orange-trim-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-29.jpg Photograph by David Doubilet Glossodoris averni
Size: 2.4 in (6 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162575 /2008/06/nudibranchs/img/30-orange-tails-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-30.jpg Photograph by David Doubilet Thecacera pacifica
Size: 2.4 in (6 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162578 /2008/06/nudibranchs/img/31-pink-dotted-714.jpg /2008/06/nudibranchs/img/nudibranchs-60-31.jpg Photograph by David Doubilet Mexichromis mariei
Size: 1.2 in (3 cm)]]> http://pictopia.com/perl/ptp/natgeo?photo_name=1162576