The ocean is mysterious, deep, and dark, hiding all kinds of fascinating creatures. Scientists have discovered many sea creatures with surprisingly big eyes, used for helping them see in the murky water, discover prey, and avoid predators. Not surprisingly, animals with the biggest eyes in the ocean often live in the darkest areas.
A sea creature’s large eyes can help them detect the bioluminescence of other sea creatures. This adaption is necessary for their survival and their dinner! Their large eyes also help them see any bit of natural light that comes from the surface, detect shadows, movement, and even colors.
Sea creatures with the biggest eyes in the ocean include the giant squid, the stubby squid, the mantis shrimp, swordfish, hammerhead shark, the colossal squid, the bigeye tuna, the cuatro ojos, and more. These sea creatures with large eyes are fascinating!
In this article, we’ll take a look at some of the most fascinating sea creatures with big eyes. In fact, we’ll be talking about animals with some of the biggest eyes in the ocean! Let’s get started.
1. The Giant Squid
According to the Smithsonian, giant squids have the largest eyes – not just in the ocean, but in the entire animal kingdom! So you might say a giant squid’s eyes are as big as a dinner plate, a bowl of fruit, or possibly even a human head!
A giant squid’s giant eyes help him spot small food and giant predators. These big eyes let in extra light so a squid can see the faintest shadows moving in the dark deep ocean.
For example, they can detect a sperm whale up to 394 feet away. But a giant squid doesn’t just have big eyes. It can grow up to around 40 feet long and weigh as much as a ton! These giant squids are surprisingly hard to find for their very large size.
2. The Stubby Squid
On the other extreme, a stubby squid isn’t very big at all. In contrast to the giant squid, a stubby squid will only grow to about 11 cm in length, total! You might be amaze by these little creatures. They have surprisingly large eyes for their tiny little bodies.
Also known as a Rossia pacifica, or the bobtail squid, this cephalopod lives in the northern Pacific Ocean. It has a purple body and large googly eyes. When it is scared, the stubby squid will freeze. When it does so, it looks far more like a child’s forgotten bath toy than an actual ocean squid, but it’s a real sea creature with really big eyes! You can find out more from National Geographic.
3. The Mantis Shrimp
Another sea critter with comically large eyes is the mantis shrimp. These creatures are tiny and look a little bit silly with their eyes perched on the tops of their heads. You might imagine they are straight out of a comic book or a cartoon.
However, there is nothing silly about these sea creatures! A mantis shrimp has the most complex eye structure in the world, giving them the ability to see UV, visible, polarized, and circular polarized lights.
Try not to laugh too hard at the antics of the mantis shrimp. While they look like a comic book critter, they also have the most devastating punch in the world. Their punch is as fast as .22 caliber bullet and can even break their aquarium glass. So beware, because they can give a nasty punch to people, too!
Find out more information about the mantis shrimp at Two Oceans Aquarium.
Swordfish are often the stars of crazy cartoons for their long sword-like bill, which they use for capturing their dinner. But don’t be deceived. A swordfish has other interesting characteristics, too. For example, the swordfish has special tissues that can insulate its brain from changes in water temperature, and of course, it has some of the biggest eyes in the undersea kingdom!
A swordfish’s eyeballs are about the size of softballs, way larger than a human’s! The same tissues that protect the swordfish’s brain also help to warm up the eyeballs, keeping its eyesight and central nervous system protected from problems that might happen in very cold water.
5. Hammerhead Shark
Hammerhead sharks get their name from their oddly-shaped head. No, they don’t hammer their prey with their hammer-shaped head, but they do use that head-shape for survival. But let’s not forget that their large, wide-set eyes make them even more special as sea creatures. And while most hammerhead sharks are small, the great hammerhead shark can grow up to 20 feet, giving it some really giant-sized eyeballs.
Interestingly, their large and wide-set eyes help them to see better than other types of sharks because they can scan more of the ocean at a time. They also have special organs on their head to help them find food. Some hammerhead sharks can even sense electrical fields created by their prey.
If you want to learn more about the hammerhead shark, you can visit the National Geographic website.
6. Colossal Squid
Would you believe the Colossal squid’s eyes are as big as soccer balls? This squid, not to be confused with the giant squid, is one of the world’s largest animals. This squid, however, lives in the ice-cold waters of Antarctica.
The Colossal squid is even larger than a sperm whale! It’s no wonder this sea creature has such big eyes! Even in the dark water, the squid’s gigantic eyeballs help it to see food and, of course, predators. In addition, the squid’s eyes face forward to give it better distance vision. It would see you coming long before you would see it in the ocean.
7. The cockeyed squid
Also known as histioteuthis heteropsis, this little squid is aptly named for its strangley mismatched eyes.
The cockeyed squid only has one large eye! So the cockeyed squid swims sideways, and its bulging yellow eye watches the water above, while the smaller, darker eye watches the water below. There is very little light in the water, so the sizeable yellow eye looks for little bits of sunlight, and the smaller dark eye can pick up the bioluminescence of other animals.
This fascinating critter makes the list for its one large eye!
8. Horse-eye jack
Squids aren’t the only animals with large eyes. In this case, the caranx latus, or horse-eye jack, is a large fish with huge eyes. These eyes are pretty special because they have adipose eyelids. An adipose eyelid is a transparent membrane that covers the fish’s eye, helping it to see better underwater.
These large fish weigh about 30 pounds or even more. These fish are considered game fish in the Panama area, making them popular with fishermen. They have good eyesight and will put up a big fight if you catch them!
Read more about the horse-eye jack here.
Squirrelfish, also known as holocentridae, are large carnivorous fish that swim in schools in coral reefs. Interestingly, these large-eyed fish are primarily nocturnal, so their large eyes help them to hunt and fight off predators at night.
Squirrelfish are sometimes thought to be a delicacy, but they are also frequently used in aquariums for their vibrant colors. You can read more about squirrelfish here.
10. Bigeye Tuna
Like its name says, the Bigeye Tuna has big eyes! Its scientific name is the Thunnus Obesus, referring to its large size! Of course, tuna is well-known for becoming sushi! But did you know it also swims in schools? You might not know that this commercial fish has been over-fished, and these sea creatures with large eyes are declining in numbers.
11. Cuatro Ojos
This fish from Brazil is known as the four-eyed fish, as its name says. But this fish’s name is a bit deceiving, after all. You see, instead of having four individual eyes, the cuatro ojos (which means four eyes) has two large eyes which are separated by a membrane. As a result, this unusual fish can see above water and below water at the same time! Its unique – and large -eyes get it an important spot on this list of sea creatures with big eyes.
The rockfish is an omnivore. When it’s underwater, its eyes seem normally sized for its body. However, when the rockfish comes to the surface, its eyes begin to bulge and look enormous, like a giant pair of binoculars!
This fish has a swim bladder that fills with gas to help it float. When the fish is underwater, the pressure in the swim bladder is equal to the pressure of the water. But when the rockfish comes up out of the water, the pressure of the gas inside the bladder is more than the air pressure, and it causes the fish’s eyes to swell up and bulge out!
The eyes of the rockfish help it to see at depths up to 9000 feet! Read more about this interesting fish here.
Pufferfish are famous for puffing up when they get scared! But they also have large eyes, which help them have very good eyesight. Their large eyes help them to find prey and avoid dangerous predators.
When scared, these smaller fish will puff up to twice their regular size by gulping in a whole bunch of water. This helps them appear larger – and scarier – to predators, but it also means they swim more slowly. But don’t worry too much about these crazy fish. There is enough poison in a single pufferfish to kill up to 30 people! They have plenty of ways to defend themselves.
Pufferfish are also known as globefish, fugu, and blowfish.
14. Telescope Goldfish
Another underwater creature with giant eyes is the telescope goldfish. Their eyes are so big. They look like they don’t belong! What’s different about these fish is that their giant eyes don’t help them see any better. In fact, they have very poor eyesight, making it hard for them to see their food and their predators.