Nudibranch Behavior

by David W. Behrens

Nudibranchs are among the most beautiful creatures on the reef, with colors and shapes that dazzle and delight. Unlike fish that may disappear before our eyes in a flash, the showy nudibranch glides slowly along the substrate, allowing us the time to savor this extraordinary sight. With their shell-less unprotected bodies how do they survive in seas filled with hungry mouths? How do these sightless creatures navigate the reefs to find food and mates? What and how do they eat? How do they reproduce? What special relationships have they developed with other reef inhabitants? These and many more questions are answered in this informative and lavishly illustrated new book. You will never look at nudibranchs the same way again.

Genres: Nonfiction

176 pages, Paperback

First published October 5, 2005

Reviews

[Bill Leach · Rating 5 out of 5]

Nudibranchs are marine sea slugs making up a major group of the Gastropods. The nudibranchs are notable for their colors, being perhaps some of the most decorative marine organisms. Behrens observes that "... sea slugs dip deeper into nature's palette of colors than almost any other group of animals on earth."

While it appears that significant taxonomic changes have been made since the book's last printing in 2012, this book portrays the sea slugs as being made up of the headshield slugs, sapsucking slugs, seahares, sidegill slugs and the true nudibranchs. The author cautions that the term nudibranch is often used to refer to all sea slugs.

The book covers many areas where little information is found elsewhere:

Feeding - Various species have evolved to feed on seemly everything in the marine environment including algae, diatoms, bacteria, sponges, hydroids, jellyfish, soft and hard corals, gorgonians, sea pens, anemones, bivalves, flatworms, bryozoans, barnacles, crustaceans, tunicates and possibly fish and other species of nudibranch. Notable are the "solar powered" sea slugs that host single celled zooxanthellae which produce nutrients through photosynthesis.

Defense - All sea slugs are hermaphrodites with genital openings on the right side of the body. When they mate, both animals generally receive sperm and subsequently lay egg ribbons. Two-thirds of the species produce planktotrophic lavrvae which float in the open sea before settling to the bottom.

Defenses - Many nudibranchs rely on chemical defences or host nematocysts; their bright colours advertising their danger to potential predators. The nematocysts are obtained by eating cnidarians - hydroids, fire corals and anemones - the nudibranchs being immune to their toxins. Internally, they transfer the immature nematocysts to cnidosacs on their cerata where they mature to become active defence mechanisms.

Color - Many species are varied in their color and decoration, making identification difficult. While many are brightly colored, some species use camouflage or protective resemblance and can be very hard to see. Notable are Ceratosoma allenii which looks exactly like a clump of soft coral but for the well hidden rhinophores and gills, and Phyllodesmium rudmani that appears to be a small clump of Xenia coral.

The book is illustrated with a great many photographs of the various species.

[Sea Slug · Rating 5 out of 5]

This book has given me a a lot of insight over Nudibranchs' in the past. When I gone back over it let me regain those memories. As studying Nudibranchs and cancer is my job. This serves a reasonable and reliable book for informational purposes. Don't mind going back to it in a few years~

[Anne Freitag · Rating 5 out of 5]

Great introductory book on sea slug anatomy and behaviour, with beautiful pictures

[Don'tLookAtMe [Trudi]]

Sounds lude.
I'm in.

[Andrea Renfrow · Rating 5 out of 5]

Read through quickly once, but will perusing it thoroughly over the next few months for research purposes. The photographs are exquisite. I absolutely adore these little creatures!