The ocean is one of the, if not the, largest habitats for life in the entire world, and unsurprisingly too. There are fish and marine animals in all of the different climates in the ocean, from the freezing temperatures of the arctic to the tropical areas of the great barrier reef, to even the darkest and deepest parts of the ocean. On the list, we’ve taken our pick of the weirdest and most unusual marine animals you’ll find in the ocean, under our waves.

Angler Fish

Why it’s unusual: Uses a bright lure to attract prey

Where is it found: The ocean floor

The angler fish has huge teeth on its lower jaw, and uses its fin ray to attract prey

The angler fish is a well-known marine creature thanks to the success of the film Finding Nemo. So while it may not be unheard of, it definitely earns the moniker of unusual. Using its fin ray as a lure it attracts and then devours its prey.

Interestingly the bioluminescence emitted from the lure comes from a symbiotic bacterium. These come in many shapes, some with an almost eel-like body but the one thing they have in common is their lure!


Why it’s unusual: They are shell-less and breath using devices outsite their body

Where is it found: The ocean floor

The spectacular Nudibranch with it’s beautiful colors

These are more commonly known as the sea slug. The fact that they are called slugs might make you envision an earthbound slug and therefore induce feelings of revulsion.

However, the aquatic versions are often beautifully colored. As with many creatures the colorings are to deter prey suggesting that they are venomous and many species are. While we joke that slugs are snails that have “lost their shell” that is literally the case with Nudibranchs which have evolved to ditch their shells.

Sea Hare

Why it’s unusual: Have an internal shell

Where is it found: Globally

The Sea Hare can shoot ink to ward off predators

Credit: Genny Anderson (CC BY-SA 4.0)

This creature looks more like a sea slug than a sea slug does, but it is actually an aquatic snail. Initially, this may seem unusual as it doesn’t appear to have a shell, but the sea hare has an internal shell and that alone makes it worthy of the list. They can shoot ink when threatened and have quite an engaging appearance.

Brine shrimp

Why it’s unusual: Type of shrimp that are millimetres long

Where is it found: Globally, in saltwater lakes and marshes

The brine shrimp can save without metabolizing at all

Credit: Hans Hillewaert (CC BY-SA 4.0)

The brine shrimp are commonly referred to as sea monkeys. Given their popularity, it might surprise you that they make an appearance on this list. But, these incredible tiny shrimp can survive without metabolizing. Metabolism is the sum of all the chemical processes in an organism and the brine shrimp can survive without any of that happening. It is not alone in this: Jellyfish polyps also can remain in that dormant state.

The Blue Whale

Why it’s unusual: The largest living creature on Earth

Where is it found: All oceans except the Arctic

Unusual for its size alone, the blue whale is remarkable that a creature this size can even exist

This gigantic mammal makes the list purely because of its size. Despite all of the dinosaurs that once roamed our earth, the blue whale remains the biggest creature to have graced our planet. They are massive. It is suggested that an adult man could swim in one of its arteries. Its tongue, incredibly, weighs as much as an elephant. Additionally, despite its humongous size, its diet consists mostly of tiny krill. In fact, they are so small that the Blue Whale has to devour more than 40 million of them per day.

Leafy Seadragon

Why it’s unusual: A master of camouflage, looking like seaweed

Where is it found: Australia

Leafy Seadragon
The Leafy Seadragon has near-perfect camouflage when around seaweed

The leafy seadragon is actually a member of the seahorse family, something that becomes more obvious when considering the shape of its head. Its bright colors and unusual shape make it one of the more interesting aquatic life forms. So interesting, in fact, that wildlife guru David Attenborough has commented that it is one of his favorite animals.


Why it’s unusual: One of the most inefficient swimmers in the ocean

Where is it found: Globally in tropical waters

Sea Horse
Seahorses have to continually feed to stay alive

The sea horse is a relative of the pipefish and as such it has a long thin digestive tract that is notoriously poor at absorbing nutrients. As a result of this, the seahorse is in an almost perpetual state of feeding. These well-known and often sought after animals are a wonderful addition to this list.

Red Handfish

Why it’s unusual: Can walk on the ocean floor with its fins

Where is it found: Southern Australia

The amazing Red Handfish uses its fins to walk across the ocean floor

Credit: CSIRO (CC-BY-3.0)

Unfortunately, the Red Handfish is on the brink of extension and is native to just two small reefs. It would truly be a loss to the ocean.

Despite its unique look, there are other reasons to include it on a list of the weirdest marine animals. Specifically, its unique travel style. They use their fins to move across the reefs in a way that makes them look like they’re walking. This is a technique used by certain members of the Goby family such as mudskippers.


Why it’s unusual: A deep sea fish with a perculiar face

Where is it found: Australia

The blobfish live at incredibly low depths in the ocean

Credit: Rachel Caauwe (CC-BY-SA-3.0)

The blobfish is also known as a Psychrolutes marcidus. Due to living in such great depths, the fish has an incredibly unusual shape. It’s gained some amount of fame due to its appearance and is mainly found off of the coasts of Australia, Tasmania, and New Zealand.


Why it’s unusual: Very colorful and incredibly venomous

Where is it found: Eastern Atlantic

The Lionfish is one of the most spectacular looking fish beneath the waves

The lionfish is one of the most distinctive-looking fish. It has an almost Samurai-like quality with its luxurious spiny-looking fins that flow from it like an ancient warrior’s robe. The lionfish is a vicious hunter and any marine aquarium keeper will tell you that you don’t want to keep these beautiful fish in a tank with another species otherwise you are just going to end up with some pretty expensive food.


Can you eat Lionfish?

Yes, in some parts of the world it is encouraged. For example, the species are not native to the Florida coast and have caused havoc to the natural food chain so removing them is encourages. A note of caution: they do have venomous spines, but if prepared properly they are delicious and sustainable.

How long have sharks been around for?

Around 450 million years. In fact, sharks have been on the earth longer than trees have. This is because life evolved in the sea before spreading to the land, but there is something about trees that make them seem eternal somehow like they have always been there.

What is the rarest marine creature?

There are many rare marine creatures but one of the rarest is the vaquita. It is on the edge of extinction with around 10 remaining individuals in the entire world.

What is the ugliest fish on earth?

Unfortunately for the blobfish, it is often labeled the ugliest fish on earth. This is due to its strange shape, indistinct color, and rounded face.