Salty Slug Love

Slippery, slimy, oozy slugs; what’s not to love? Slugs can be small and slugs can be as long as your arm! Slugs can be sausage shaped and brown, or they can have leaves, legs, and lots of rainbow colours! They can live anywhere wet, and lots live under the sea. 

Salty Samples 

Sea slugs are a family of boneless animals that contain a particularly fancy looking molluscs called nudibranchs. Usually they’re small enough to fit on your hand, but they can be as long as a sheet of binder paper. Their shapes and colours result in names like “dragon” and “orange peel,” or “sea bunny,” “dancer” and “clown.” Start an image search and you could browse pictures of fanciful nudibranchs all day. There are more than 3000 kinds! 

Pantry Paint Packs 

Like flamingoes get their pink colour from their food, nudibranchs get their colour from their diet too. Check out this little creature that looks like a sheep that rolled in cut grass! It’s the leafy sheeps’ algae diet that makes them green. They store the chloroplasts from their food and that means photosynthesis happens inside their bodies like it does in plants. 

Nudibranch Brunch 

Nudibranchs are carnivorous! They eat algae, sponges, and even other sea slugs. Some also eat coral and even stinging jellyfish, and that makes them a bit toxic. Like the leafy sheep keeps some chloroplasts from its food, the jellyfish eating “blue dragon” keeps some of the stinging cells from its food. Like a lot of colourful things in nature, the bright hues warn us that they can hurt. Touching them can sting. 

Making Nudibranchs 

Any two nudibranchs can make babies together, because they all have both sex organs. They’re hermaphrodites, just like earthworms and most snails are. About 5 of every 100 animal species are hermaphroditic.

A gooey ribbon of fertilized eggs will hatch into nudibranchs that look just like their parents but smaller. Depending on the type, there can be 2 eggs or 25 million! Once they leave the nest, they’ll live just a few weeks to a year. 

Notice Nudibranchs 

To see a nudibranch in person, you’ll have to go out into the ocean because they don’t survive captivity for long. But you’ll find some of these saltwater slugs along every ocean coast — except in the Arctic and Antarctic circles. They love coral reefs. You will find nudibranchs in shallow water and way down in the deep. Look on the bottom, and remember they’re usually very small. Most photos of these creatures are taken with a close-up macro lens.

Chromodoris “ruffled” nudibranch image by Arhnue Tan from Pixabay. 

Orange peel nudibranch by Love to Dive, used under CC BY-NC-ND 2.0 license.

Leafy sheep nudibranch linked from FireFly Daily on Flickr. 

Nembrotha nudibranch on bottle by Florent Horn from Pixabay.