June 21, 2011
Being a sea slug may not sound like a very glamorous station in life, but they are among the most colorful animals on Earth. This beauty is known as a Spanish Shawl (Flabellina iodinea).
Actually, sea slug is the casual name we often use, but this is technically a nudibranch, which means "naked gills." They come in many different shapes and colors, live in huge numbers in shallow waters near the shore, and they are invertebrates, which means that they do not have a spine.
Nudibranchs lost their shells through the course of evolution, which required them to develop a whole range of other kinds of protection. Most species have poisonous appendages sticking out from their bodies, as you see in this photo. They also tend to have very intense, bright coloring - "warning coloration" - which alerts other animals to the fact that they either taste bad, or may even be poisonous if eaten. Others are camouflaged because they look very similar to the plants around them. And if that weren’t enough, their skin releases a slimy, sour liquid when they are touched by another creature. Sea slugs are definitely a "look but don’t touch" kind of animal!
Here is another beauty, a black-spotted nudibranch (Phyllidiopsis papilligera). This one was photographed in shallow waters off the coast of Haiti.
Readers often ask me which is my favorite book of all the ones I have written. I can never say which I like the best (that’s like choosing among your children!), but my favorite at any given moment tends to be whatever animal I am writing about. These days I am working on a new book called CORAL REEFS. So, I am fascinated by all these marine animals who live in the vast "cities under the sea" that we know as the coral reefs. They are some of the most diverse, and certainly among the most magnificent, ecosystems on Earth.
Spanish Shawl photo: Magnus Kiaergaard
Black-Spotted Nudibranch photo: Nick Hobgood
Posted by: Seymour Simon
