Mottled Sea Hare: 15 Facts You Won’t Believe!

Mottled sea hare facts about the unique Atlantic species

Sea hares, known by their scientific name Aplysia fasciata, are a type of mollusks species of animals that resides close to the reefs in the water body. Hares usually refer to fast-running, long-eared mammals and are herbivorous in nature. Sea hares however are a different species underwater and have an internal shell that is covered in tissue. They are also called sooty sea hares or the black sea hare based on their appearance or characteristics. Another popular name for these species is the sea slug. They don't have an outer shell or mantle.

Sea hares are used to removes unnecessary algae out and their appearance makes them blend in with the coral reefs. These species are hardly identifiable if observed from a distance owing to their structure and shape. They have short lifespans and mate multiple times before they die. They have good swimming ability and are efficient in most of their tasks. This article will analyze some fun and interesting facts about mottled seahorses. For more relatable content, check out these ghost shrimp facts and Asian lady beetle facts as well.

Mottled sea hare

Fact File

What do they prey on?

Algae and seaweed

What do they eat?


Average litter size?

Millions of eggs

How much do they weigh?

2.20 lb (1 kg)

How long are they?

15.74 in (40 cm)

How tall are they?


What do they look like?

Dark brown and black with spots

Skin Type

Wet, Slimy Scales

What are their main threats?

Lobsters, Starfish

What is their conservation status?

Not Evaluated

Where you'll find them

Coast, tide pools, regions with algae growth and seaweed


France, Spain, Portugal, Great Britain, West Africa





Scientific Name

Aplysia fasciata





Mottled Sea Hare Interesting Facts

What type of animal is a mottled sea hare?

Mottled sea hare aplysia fasciata is a type of Mollusca lacking outer shells that reside near coral reefs and belong to the kingdom Animalia.

What class of animal does a mottled sea hare belong to?

The mottled sea hare, aplysia fasciata, is a Mollusca species that resides in similar habitats to other fish but belongs to class Gastropoda, family Aplysiidae, and genus Aplysia. They are hermaphrodites and can be both male and female at the same time.  

How many mottled sea hares are there in the world?

Mottled sea hares' exact population in the world has not yet been evaluated. They are region-specific species and cannot survive in extreme climates. Their conservation status is not evaluated hence their exact distribution is not known. There are a total of 35 species of sea hares.

Where does a mottled sea hare live?

Mottled sea hares swim in the ocean, tide pools rocky terrain, seagrass beds, seaweed, and along the coast. These species are seen in France, Spain, Portugal, Great Britain, and West Africa.

What is a mottled sea hare's habitat?

Mottled sea hares, aplysia fasciata, are seen near coral reefs, rocky terrain, seaweed, and rocky terrain. They feed on underwater vegetation hence they reside close to their source of food.

Who does the mottled sea hare live with?

A mottled sea hare is a solitary being however, if you spot one it's likely to spot others as well in similar regions since they live close to where they can find appropriate food.

How long does a mottled sea hare live?

Mottled sea hare aplysia fasciata live up to one year hence they mate multiple times before they pass away.

How do they reproduce?

Mottled sea hares, aplysia fasciata, mate multiple times, and lay eggs post-mating. They are estimated to lay up to 26 million eggs. The eggs hatch in a period of 15 days. The juveniles develop through a process of metamorphosis and develop into young sea hares. Spotted sea hares are hermaphrodites meaning they are both male and female at the same time.

What is their conservation status?

Mottled sea hare aplysia fasciata conservation status is not evaluated by the International Union For Conservation Of Nature (IUCN).

Mottled Sea Hare Fun Facts

What does the mottled sea hare look like?

Mottled sea hares are species that reside on the bottom of the water body and have a long stretched body as per description.

Mottled sea hares have a long, dark, stretched body including their head, neck, and wings. It has wings which when spread appear circular in appearance. Their color varies from dark brown to black with lighter spots with its edges being red. A mantle covers its gills and internal organs. They have both female and male reproductive organs. A black flap covers the gills. They have no outer shell or mantle. They have oral tentacles. The tentacles are present on the neck. They also have a tail that is short in appearance, is rounded, and has a flap on its back.

How cute are they?

These sea slugs are unique and extremely exotic beings in description seen swimming along the bottom level of the water body. They are seldom seen by humans unless they are specifically placed in an environment to feed on unwanted algae since they dwell and are seen swimming in the bottom levels of the water body.

How do they communicate?

Mottled sea hares communicate via pheromones, chemical, and tactile means. They communicate primarily during mating season. In most instances, they are commonly seen on seagrass beds near coral reefs as solitary beings.

How big is a mottled sea hare?

A mottled sea hare is 15.74 in (40 cm) which is ten times bigger than the apple snail which is 3-5 in (7.62- 12.7 cm).

How fast can a mottled sea hare move?

Mottled sea hares move by flapping their wings and have slow sluggish movements. They utilize their purple ink to blind the eyes of the predator and escape safely.

How much does a mottled sea hare weigh?

Mottled sea hares weigh around 2.20 lb (1 kg). The black sea hare is the largest species in the family of sea hares.

What are the male and female names of the species?

Males and females are not addressed differently.

What would you call a baby mottled sea hare?

There are no specific names for juvenile sea hares.

What do they eat?

They are primarily herbivores and feed on red algae and seaweed. They feed on algae. Once they digest their food they excrete their wastes into the water body as well. They reside close to their source of food where they can find red algae easily so they can feed on algae easily.

Are they poisonous?

When they are threatened they tend to release a purple ink similar to an octopus. This is done in order to mislead their predators and blinding their sight in order for them to escape into the nearest shelter. Predators include lobsters and starfish. They are not dangerous toward humans however, it's likely that they release their purple ink if you try to touch or catch them.

Would they make a good pet?

No, these species are innately wild beings and survive in oceans with coral reefs. They are however placed in certain water bodies to get rid of unwanted algae and clean the waterbody.  

Did you know...

The purple ink that these species produce as a self-defense mechanism was used by Native Americans to dye clothing.

Research on these species has greatly benefited humans in cancer-related studies as well as understanding human development in terms of sex hormones.

While mating sea hares or sea slugs form circles and each animal inseminates the one in front. This circle is sometimes referred to as the Roman circle.  

The sooty sea hare is also called a slug. These sea slugs move slowly and rarely swim. They glide through the water hence it cannot exactly be considered a swim.

Why is the mottled sea hare also known as sooty sea hare?

The mottled sea hare gets its name from the direct translation of its Latin word Lepus Marinus owing to the fact that its existence was recorded since Roman times. Their name also is a reference to their shape which resembles the ears of a hare.

How does the mottled sea hare defend itself?

Mottled sea hare similar to other species releases a purple ink when threatened and escapes slowly since its slow while moving and has a sluggish movement. The ink helps the sea hare get out of difficult situations, but they do not bite.  They move forward by flapping their wings which is an essential part of their body. It is rare to come across these species unless you visit parks, conservation centers, and other regions where you can find them easily.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! Learn more about some other arthropods including seahorse facts and slipper lobster facts.

You can even occupy yourself at home by coloring in one of our free printable coral reef coloring pages.



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