Range: Cosmopolitan (absent from Arctic ocean)

Habitat: Rocky shores, reefs, deep habitats like hydrothermal vents, and more

Size: Less than 1 inch to over 6 inches (2.5-15cm)

Diet: Algae, sea grasses, and detritus

Threats: Fish, crabs, sea stars, shore birds, small reptiles, mammals, and even humans

Lifespan: Two to twenty years

Transcript:

Today on Animal Fact Files we’re discussing limpets. Not all animals with the common name “limpet” are closely related. These are great examples of convergent evolution! The facts in this episode will be focused on the "true" limpets, but you may see different types throughout just to give you an idea of their diversity.

All limpets are molluscs and gastropods. They're a type of snail with a non-spiraled, conical shell and strong muscular foot. In fact, they're so tough that naval mines have been designed after them and given the same name! Unlike other molluscs, like mussels, which remain fixed in a single place their entire lives, limpets move around. At the same time, these animals need to be able to hold fast to a surface during strong wave action, so they have adhesive mucus and strong suction-cup-like abilities to make them almost impossible to remove. In fact, removing a limpet from where it's stuck often ends in death for the limpet!

All true limpets are marine, though there are other limpets that live in freshwater, as well. A limpet's shell is known as a "patelliform" - or plate-like shell. This gives them a similar appearance to acorn barnacles with whom they may share habitat, but, as we discussed in our barnacle episode, barnacles are not molluscs, they're arthropods! True limpets are most frequently seen in areas that experience the effects of oceanic tides but they also live in the deep sea in habitats such as hydrothermal vents and whale falls. In areas that experience tides, during high tide limpets move around and search for food, and during low tide they'll return to a single spot on the rocks or other hard substrate. This is known as a “homescar'' and it's created by the limpet's shell and their chewing on the rock. This spot allows them to suction to the substrate and retain moisture during hot parts of the day. Limpets live in all oceans around the world except the Arctic ocean. They have a preference for hard surface areas like rocky shores or reefs. 

Like chitons, limpets have a radula they use to scrape food from hard surfaces. They eat algae, sea grasses, and detritus. Their “teeth” are arranged in a conveyor belt-like fashion where the “teeth” in front are worn down by this scraping and replaced with “teeth” from the back. These are continuously grown and replaced! Limpet teeth are strong. In fact, they're considered stronger than spider silk in terms of tensile strength which is how much stress a material can stand without breaking! Don't worry, you can’t be bit by a limpet. Their toothy tongue might scrape your skin, but it's not large enough to cause harm. Fascinatingly, some limpets are territorial! They have “garden” patches of algae that they defend from other limpets by ramming intruders with their hard shells. Predators to limpets include fish, crabs, sea stars, shore birds, small reptiles, mammals, and even humans!

Limpets often blend in with their environment and can be difficult to spot. In size, they range from under an inch to over half a foot (2.5-15cm) in length, though most are less than half this size. Depending on the species, the sexes are separate, individuals appear hermaphroditic, or they begin life as a male and transition to a female as they grow. Spawning is mostly external in the water column and the eggs hatch into larvae which develop through a few stages before settling to substrate. Depending on where they live, limpets can live 2 to 20 years!

For more facts on limpets, check out the links below. Give a thumbs up if you learned something new today. Thank you to our Patrons SpikeSpiegel93, Dad, and everyone else for their support of this channel! And thank you for watching Animal Fact Files!