Range: Coastal waters of California and northern Mexico

Habitat: Marine, coastal waters up to 60 feet (18m) deep

Size: Up to 15.7 inches (40cm) long; Up to 5 pounds (2.3kg) in weight, but on average only half this

Diet: Red algae, sea lettuce, eelgrass, and more

Threats: Sea stars, sea anemones, lobsters, and more

Lifespan: One year on average

Transcript:

Today on Animal Fact Files we’re discussing California sea hares. The California sea hare is a mollusc, though it does not have an external shell. Instead, it has an inner shell which has the consistency of cardboard. The internal shell protects the animal’s internal organs like the heart. Sea hares are sea slugs and some of the largest alive in the world. The California sea hare is no exception. In size, these invertebrates can reach more than 15 inches (38cm) in length and weigh up to five pounds (2.3kg). That’s about half the size of Chester! Though on average they only reach half these metrics.

Sea hares get their common name from the tentacles atop their head. Don’t they look like little bunny ears?! These tentacles help a sea hare sense the surrounding water. The California sea hare is hermaphroditic meaning it has both male and female reproductive organs. These invertebrates gather together during northern hemisphere summer months and form breeding chains. The individual in the front receives sperm from the individual behind them, thus fertilizing their eggs. These chains can reach dozens of slugs long and go on for days! California sea hare eggs are laid in gelatinous strands. There may be millions laid at a time. These hatch about two weeks later into free swimming larvae. The larvae take just over a month to settle onto red algae, their main source of food. It takes three months before they become sexually mature.

As the name may imply, the California sea hare is found near California. They range from California’s northern shores to tidepools of northern Mexico. These are coastal animals. Juveniles are found in deeper water up to 60 feet (18m) deep, but adults are more common in the intertidal zone. California sea hares get their color from the food they eat. Red algae turns them a mottled red, but they also eat eelgrass and sea lettuce which can give them a brown or green hue. Like terrestrial snails, the California sea hare has rasping jaws with which to consume food. Though it might look frightening, these animals are herbivores.

Their body consists of the head region with rabbit ear tentacles and mouth, a foot with which they scoot around on the seafloor, as well as two flaps that cover their gills. These are called parapodia. They open and close to allow seawater across the gills, but they can also be used for swimming!

Like an octopus, California sea hares can produce an ink-like substance which may be used as a defense against predators. When it encounters a threat, a California sea hare will shrink and may expel this purple colored ink. Supposedly this substance tastes awful and deters predators, but it may also smell like cedar according to observations! Predators to sea hares include lobsters, anemones, sea stars, and other sea slugs. California sea hares are most active at night to help avoid predation, and they can live to be about a year old, though they are known to live longer in colder water!

For more facts on California sea hares, 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! Thank you to these viewers for today’s request! And thank you for watching Animal Fact Files!