How do slugs protect themselves

Melibe leonina is a marine snail that lacks a protective shell. These critters live on eelgrass and use a large tentacled oral hood like a Venus flytrap to feed on small planktonic shrimp. While such a snail has back appendages - scientifically called cerata - that simply "pop off" its body easily, each is much more vulnerable in the area of its oral hood, according to a news release. This self-amputating behavior is similar to how lizards and amphibians shed body parts when caught by a predator.

Posted on March 10, What is a slug? Where do slugs come from? How are they born? Where do they live? How are they beneficial? Slugs play an important role in nature, breaking down decaying matter and recycling it back into the soil.

Overall, slugs are scavengers. They eat substrate, or decaying organic matter that includes dead and rotting plants, leaf litter, fallen fruit, fungus, old wood animal droppings, toadstools and compost. Occasionally you might see them nibbling on a leaf, but it is probably already damaged or diseased. Slugs can be predators by eating snails, worms, maggots and other insect larvae that are harmful to garden and flower bed plants. Slugs are part of the great circle of life as many different animals feed on slugs.

People tend to call something a slug if it looks like a snail but has no shell. However, many distantly related critters among the gastropods—the group that contains snails and slugs—have independently evolved a sluggy, shell-free shape. And then there are the in-betweeners.

So-called semi-slugs have tiny shells on the outside of their bodies that are way too small for them to retract into. Honestly, they look pretty ridiculous. First, check out the tentacles. Two are for seeing and smelling, and they can be operated independently: a slug can gaze at you or smell you and a friend simultaneously.

The other two are for touching and tasting. Slugs also have thousands and thousands of teeth. And in case that doesn't seem weird enough, slugs essentially breathe through a blowhole that opens up on one side of their bodies. This round pore is called a pneumostome. Sea slugs have their own incredible features. The kahalalides, originally discovered in the early s , also protect a sea slug, Elysia rufescens , that consumes it. The sea slugs accumulate the toxins from the algae, which then protects them from predators.

The discovery of a symbiosis between a bacterium and a seaweed to produce a chemical defense is noteworthy. There are many examples of bacteria living inside the cells of invertebrate animals like sponges and manufacturing toxic chemicals, but a partnership involving a bacterium living in the cells of a marine seaweed to produce a toxin is unusual.

The finding adds a new dimension to our understanding of the types of ecological relationships that produce the chemicals shaping coral reef ecosystems. Our lab is home to an enthusiastic multidisciplinary team of marine chemists, microbiologists and ecologists who strive to understand how chemicals facilitate interactions between species in the marine environment.

We also use ecological insights to guide discovery of novel pharmaceuticals from marine organisms. Chemicals used by marine organisms to interact with their environment, including toxins which protect them from predators, often show promising medical applications.