Greetings! What would you say if I told you that the nudibranch is a rather high-class fashion model roaming around in our seas? What? Well it’s true! This is how famed National Geographic photographer David Doubilet described nudibranchs. Okay – now what-in-the-world is a nudibranch?
A nudibranch (pronounced NEW-dee-bronk), is a soft-bodied, shell-less marine mollusk or sea slug. Their scientific name, Nudibranchia, comes from the Latin word nudus and the Greek word brankhia, which together means “naked gill,” a reference to the exposed, plume-like extremities that most nudibranchs wear on their backs. They’re found in seas around the globe, from the tropics to the Southern Ocean, to Canada’s three coastlines.
And get this – new nudibranch species are still being discovered each year! It’s with a passion that scuba divers always hope to get lucky and encounter a nudibranch they’ve never seen, or photographed, before! Non-scuba divers are no less enthralled whenever they are shown pictures of these enchanting sea creatures.
It’s of particular interest that in British Columbia, nudibranchs inhabit the emerald depths in such high concentrations; the province is considered Canada’s hotspot for these extremely colorful creatures.!
There are actually two distinct types of nudibranchs: aeolids and dorids. Okay – so what’s the difference between the two? Aeolids absorb oxygen through their skin and have a series of horn-like projections, which are called cerata, on their heads and backs. This allows them to take in more oxygen. Dorids, on the other hand, are the most common type of nudibranch. They breathe through a tuft of external feathery gills that they can retract into their body for protection if it is needed. Nudibranch gills come in many shapes and sizes and are used for breathing, digestion, and defense. While in other parts of the world the average length for nudibranchs is just under an inch (2 centimeters). However in British Columbia, their nudibranchs are giants by comparison, and they generally reach an impressive 5.9 to 11.8 inches (15 to 30) centimeters in length!
It doesn’t matter which part of the world you are in, cold-water nudibranchs like those found in the waters of British Columbia are no less exotic looking than their riotously colored tropical counterparts. All nudibranchs derive their coloring from the food they eat and the terrain they inhabit. Because they lack any outer protective shell, nudibranchs have evolved several different ways for defending themselves against predators. Some employ camouflage to blend in with their surroundings, while others use their vibrant and contrasting colors to deter predators from devouring them. Many nudibranchs make themselves unpalatable to predators by absorbing foul-tasting toxins from sponges into their body tissues, and some even recycle stinging cells from sea anemones into the tips of their cerata.
Now here’s where it gets rather interesting – nudibranchs can soak up their prey’s pigment into their tissue, which allows them to actually be camouflaged while they’re feeding atop the very animals they eat! Since nudibranchs are harmless to humans, people in Chile and some islanders in Alaska and Russia consider them a delicacy to be eaten boiled, roasted, or raw. And for the uninitiated, this dining experience is a much like you chewing on a rubber pencil eraser.
Scientists are interested in nudibranchs for mainly two reasons. One is they believe the chemicals these sea animals store could actually be used to develop new medicines for use in humans. One compound stored by nudibranchs called Latrunculin A is the subject of ongoing research to develop new treatments for cancer and neurodegenerative diseases.
Secondly, the DNA of nudibranchs may offer insights into ocean conditions relative to climate change. Global warming threatens the genetic diversity of some marine species and compromises their ability to evolve as undersea environments change. A population explosion of any one-nudibranch species may serve as an early warning system for further problems.
If you are in Florida and you see a sick or injured manatee, please call the Florida Fish and Wildlife Conservation Commission at: 1-888-404-FWCC. They are the folks who are responsible for rescuing us in Florida.
Here’s the Save the Manatee Club link to learn more about manatees …
Here’s a cool link for you to learn more about how we’re rescued and brought into rehabilitation …
~ Kobee Manatee