In this article, you’ll meet 12 of the ugliest fish that inhabit the sea. These ugly fish have such bizarre appearances that some look almost otherworldly. Many of them are so recently discovered by scientists that they don’t yet have official scientific names—let alone common ones. But shouldn’t ugly fish get the recognition they deserve? Common names are typically given to creatures frequently encountered, but when a species lurks deep in the ocean, evading capture, its identity remains a mystery. If a picture is worth a thousand words, then each photo of these 12 ugly fish is surely worth a thousand names.
01. Carpet Shark or Wobbegong
- Where they live: Tropical waters of the western Pacific Ocean and eastern Indian Ocean.
- What they like to eat: Mollusks, fish and crustaceans.
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The carpet or wobbegong sharks get their name from the strange ornate patterns that cover their skin, giving them the appearance of a carpet. This built in camouflage is further enhanced by little weed like whiskers that surround their mouths and act as sensory barbs. They are a bottom dwelling shark and mainly are seen on the ocean floor resting. They do not pose a threat to humans unless they are provoked.
02. Longhorn Cowfish
- Size: Up to 20 inches in length.
- Where they live: Around reefs of the tropical and subtropical Indo-Pacific ocean regions.
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Longhorn cowfish come in several colors ranging from yellow, orange and green with many having blue and/or white spots. Longhorn cowfish are poisonous to eat and have two natural built in defenses to ward off potential predators. First they have their horns, the two on top of their head and two more horns beneath their tail. This makes them difficult to swallow. And secondly, they release a poisonous toxin when startled by bright lights or loud sounds, or when threatened by a predator.
Cowfish are slow swimmers and may appear to be hovering in the water because of their unique way of using their dorsal and pectoral fins. This form of swimming is called ostraciform swimming. Because of their unique form of swimming cowfish are easily caught by divers and are known to make grunting sounds. This fish is seen on the cover of the book too.
03. Dogface Puffer Fish
- Size: Up to 13 inches in length.
- Where they live: Tropical waters of the Indian and Pacific Ocean.
- What they like to eat: Sponges, stony coral, algae and crustaceans.
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Now this fish lives up to its name, with its big sad puppy eyes, looks just like a cute little doggie. Not only appropriately named for its appearance, but also its behavior, the dogface puffer fish is rarely aggressive and tends to live in solitary among the tropical reefs.
They usually have random dark spots on a colored body, ranging in colors from browns, grays, bluish yellows, black and gold or orange. When frightened or distressed by potential predators, pufferfish can inflate their bodies to over two times their original size by swallowing air or water. They also secrete a toxic poison, a natural defense against predators.
04. Elephant Fish or Elephant Shark
- Size: Up to 5 feet in length.
- Where they live: Subtropical waters of the southwest Pacific Ocean around Australia and New Zealand.
- What they like to eat: Small fish, crustaceans and bottom living invertebrates.
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Elephant fish have a long “trunk like” snout that looks similar to an elephant’s trunk. They are found in the deep-sea were they like to feed off the muddy and sandy bottom of the ocean, eating shellfish and small fish.
Since they spent most of their time in deep waters up to 4500 feet, when captured and brought to the surface their eyes are a startling metallic green color. The elephant shark is harmless to humans.
05. Frogfish
- Size: 1 to 15 inches in length.
- Where they live: In coral and rock reefs of most tropical and subtropical oceans and seas worldwide.
- What they like to eat: Fish and crustaceans.
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Frogfish are the masters of disguise and can conceal themselves from both predators and prey.
Belonging to the anglerfish family they are equipped in front with a “rod” like dorsal fin that is topped with an esca, or “lure”. It is like having their very own, fishing rod and lure. Though the “rod” dorsal fin does not change much in appearance between different types of frogfish, the “lure” may.
It can mimic, that means to look like, a tubeworm, a shrimp or another fish, or simply just a lump of something.
As the frogfish hides himself among the coral and reef, it patiently waits for something to be attracted to its lure. Then when the prey gets close enough, it quickly snatches it into its mouth. The attack from the frogfish can be as quick as 6 milliseconds and they can swallow something up to twice their own size!
Frogfish can hide so well because they do not have scales like other fish and their bodies are covered with bumpy bifurcated spinules. Plus, they have many colors like red, green, yellow, white and black, even spots to help them blend into the coral reef. Many frogfish can even change colors. Can you pick out all the frogfish in the photos?
06. Monkfish or Allmouth
- Size: 4 to 5 feet in length.
- Where they live: Northwest Atlantic Ocean.
- What they like to eat: Fish.
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Monkfish are part of the anglerfish family and live on the bottom of the ocean. Like other anglerfish, monkfish hide on the ocean floor and then attract their prey with a lure. In their case it’s called the “esca”, which is a part of their spine which can be angled forward, so it can dangle over their mouth and wiggled like bait. Can you see the monkfish hiding in the picture?
Monkfish have very wide and flat heads that are as broad as the fish is long, with enormous mouths filled with long sharp teeth. That is why they are also called “allmouth” since the fish is mostly head, and almost the whole head is mouth. They have been known to eat prey nearly one-half their size, as well as eat water birds on the surface.
Monkfish are considered to be a very good tasting fish to eat. Their tail meat is known to taste like, and have the same texture of lobster tail meat, hence they’ve been nicknamed, “the poor man’s lobster”. The largest monkfish caught on record weighed 253 lbs. That had to be one big mouth!
07. Oar Fish
- Size: Up to 56 feet in length.
- Where they live: Oceans worldwide.
- What they like to eat: Jellyfish, crustaceans, squid and small fish.
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Seeing a living oarfish is a very rare occurrence since they spend most of their time in the deeper deaths of the ocean. When they have been seen near the surface it has been because they were dying or sick.
Oarfish are also known as “King of the Herrings” because they are part of the herring family and are the longest boney fish in the world.
Their “kingly” looking dorsal fin originates from above the eyes and runs the entire length of the oarfish; around 400 dorsal fin rays in all, the first 12 are elongated to varying lengths, forming a trailing crest with reddish spots and flaps of skin at the ends, giving the appearance of a kingly headdress.
Because of this silver tapering, ribbon like body, along with the impressive pinkish to cardinal red dorsal fin, give the oarfish the perception of majesty, and help explain how they became the center of many sea serpent tales.
08. Ocean Sunfish or Mola Mola
- Size: Up to 10 feet in length and 2200 lbs.
- Where they live: Tropical waters of all oceans.
- What they like to eat: Jellyfish, squid, eel grass, small fish and crustaceans.
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Sunfish look like a big fish head with a tail and can be just as tall as they are long. Sunfish are the heaviest bony fish in the world and received their name from being seen floating on the ocean surface sunbathing. Sunfish while basking in the surface sun, allow seabirds to feed on parasites that lodge within their skin.
They range in color from white, grey, silver and brown. Even though sunfish are very large they still have to watch out for predators that would like to have them for lunch, like the killer whale, sea lions and sharks.
They are known to be very friendly and docile around divers. Injuries from sunfish occur more to boats from accidently hitting the enormous fish basking on the surface. The largest sunfish caught on record is 3500 lbs. In comparison, a Toyota Camry weighs 3200 lbs.
09. Pinecone Fish or Pineapple Fish
- Size: Up to 12 inches in length.
- Where they live: The tropical and subtropical regions of the Indo-Pacific oceans.
- What they like to eat: Plankton, shrimp and fish.
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Pinecone fish have a yellow to orange colored round body that has large scales, with very prominent ridges on them. These ridges are outlined in black, giving the fish the appearance of a pinecone or pineapple; hence their name seems to fit very well.
Pinecone fish are very popular among public aquariums worldwide, not only because of their unique pinecone look, but their glowing smile due to the bioluminescent bacteria that live in the sides of their mouths. The color of the bioluminescence produces a glow, blue-green to yellow, that attracts plankton on which they feed on at night.
The pinecone fish is considered nocturnal and prefers to hide during the day.
10. Sarcastic Fringehead
- Size: Up to 12 inches in length.
- Where they live: Pacific Ocean off the coast of North America.
- What they like to eat: Crustaceans.
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This fish looks like it’s the star in a monster movie!
Sarcastic fringehead are ferociously territorial and very aggressive. When there is a turf war between two sarcastic fringeheads, the mouth wrestling begins! They begin wrestling with their large mouths fully extended against one another as if they were kissing, until one of them gains dominance.
You’ll find fringehead fish setting up house in empty clam or snail shells, abandoned burrows, and cracks in rock outcroppings. Primarily ambush predators, they like to hide within their shelter and then surprise prey swimming or moving by their hideout.
11. Stargazer
- Size: Up to 3 feet in length.
- Where they live: Tropical waters of most southern ocean regions of the world.
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Stargazers are unique in that they have their eyes, nostrils (nose) and mouth located on top of their head. They burrow themselves into the sand on the bottom of the ocean floor until only their eyes can be seen. Then wait for some prey to walk or swim by, then surprise attack their unsuspecting prey.
Stargazers do not have scales and are silver or pale in color, some with spots covering their bodies. They are equipped with a cirri on the edge of their mouth that helps prevent sand from coming in when their hiding and waiting for prey.
Stargazers not only look scary, but can deliver some scary pain to other predators with their poisonous spines located above the pectoral fin and behind the opercle fin. Plus they have the ability to deliver up to 50 volts of electric shock through their modified eye muscles!
12. Napoleon Wrasse or Maori Wrasse
- Size: Males can reach 6 feet, and females up to 3 feet long. And grow to over 400 lbs.
- Where they live: Around coral in the Indo-Pacific Ocean regions.
- What they like to eat: Fish, shellfish, starfish, sea urchins, mussels and worms.
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The napoleon wrasse is one of the biggest coral reef fishes in the world and can easily be recognized by its shape, size and beautiful color. The male wrasse, are a bright blue and green, to a purplish blue color, while the females generally range in a red-orange and white color. They have a hump over their head that grows with age and looks like a napoleon hat, hence their name.
Wrasses are equipped with protrusible mouths, which separate their jaw teeth and jut outward. This allows them to smash big chunks of dead coral with peg-like teeth to feed on the mussels and worms inside. They play a vital role in balancing the coral reef marine life by being one of the few predators of poisonous marine animals like the boxfish, sea hares and crown-of-thorns starfish.
The wrasse though large, are gentle giants, and on many occasions have been known to interact playfully with divers much like a pet dog would do, by brushing or nudging up against a diver to get attention, like a dog wanting to be petted.
Wrasse can live up to 30 years and are known to be “protogynous hermaphrodites” which means some of the female wrasse become male at around 9 years of age. The reason why or how this happens is still known.