Fish That Cannot Swim (And Fish That Swim Very Slowly)

Fish That Cannot Swim (And Fish That Swim Very Slowly)

Image of a fish that cannot swim

Batfish and Spiny Devilfish are fish that cannot swim. Instead, these fish walk across the ocean or seafloor with the help of their pectoral, anal, and pelvic fins that act as legs. Other than these two, there are slow swimming fish like Seahorses, Eels, Pipefish, Pufferfish, and Yellow Perch fish.

Let’s learn more about all these fish.

Fish Species That Can’t Swim

While all aquatic creatures are good swimmers, there are some exceptions.

In particular, there are two fish that can’t swim. Yes, you read that right!

Given below are the fish that walk on the seafloor instead of swimming in the water.



Scientific Name: Ogcocephalidae

Where are they found: Galápagos Islands.

Batfish are named after Charles Darwin and are primarily found in the Galápagos Islands.

However, if you can’t visit the Galápagos Islands to see these unique fish, you can find their closely related rosy-lipped Batfish around Cocos Island, off the coast of Costa Rica.

Batfish are popular for walking across the ocean floor. These fish don’t swim.

Instead, they walk to survey their surroundings. Also, these fish are known for their bright red lips.

When the Batfish mature, they use their highly adapted pelvic, anal, and pectoral fins to walk on the ocean floor.

They alternate their limb-like fins for walking.

Besides, their dorsal fin grows into a horn on their head like a unicorn’s horn. They use their horn to lure and catch prey.

Coming back to the red-lipped Batfish, they are mostly found at depths of 30 to 60 feet in the water.

However, they can also be found in deeper waters at around 400 feet.

The red-lipped Batfish prefer to hang out in the rocky and sandy bottoms that help them to blend into the seafloor.

Spiny Devilfish

Spiny Devilfish
Spiny Devilfish

Scientific Name: Inimicus Didactylus

Where are they found: Indo-West Pacific region.

Apart from Batfish, the other fish that are well-known for walking rather than swimming are the Spiny Devilfish.

Spiny Devilfish are the cousins of Stonefish and are equally venomous.

They are unusual fish with articulated fins that allow them to walk along the bottom of the sea.

Spiny Devilfish crawl slowly along the seabed, using their four lower rays of the pectoral fins as legs.

They usually dig themselves into the sand, with only their dorsal fin spines sticking out.

While catching prey, these fish stand still in the sand, camouflaging and quietly waiting to attack.

Once the prey approaches them, the Spiny Devilfish come out of the sand and strike with blinding speed.

They mainly feed on small fish, crustaceans, and invertebrates.

Alright! Now that you know of the fish that can’t swim, let’s also talk about the slow swimming fish.

Fish Species That Swim Slowly

Not all fish are similar in appearance, feeding habits, and behavioral characteristics. So their swimming speed also varies.

Some fish like sharks swim very fast. In comparison, some fish are slow swimmers and rely upon their other strengths for survival.

Given below are the most prominent fish that are slow swimmers.



Scientific Name: Hippocampus

Where are they found: Pacific waters from North America to South America.

Seahorses are mainly found in the shallow tropical and temperate saltwater of the estuaries, coral reefs, seagrass beds, and mangroves.

Their unique body shape makes them one of the slowest moving fish.

They have long-snouted heads and bent necks that resemble a horse.

Seahorses are slow swimmers as they just have a tiny fin in the middle of their backs to propel themselves in the water.

Unlike most fish, they don’t have a caudal (tail) fin.

These fish use their pectoral fins to steer in the water. Besides, they have a swim bladder that controls their buoyancy.

According to the Guinness World Records, Seahorses are the slowest moving fish with a top speed of about 5 feet (1.5 m) per hour.

Although Seahorses are slow swimmers, they can swim forward, backward, up, and down with equal ease.

Another unique feature of Seahorses is their prehensile tail, which is similar to that of a monkey.

They use their tail to grasp or hold onto the objects.

Moreover, Seahorses are very effective in catching highly evasive and fast-swimming prey.

They use their curved necks as springs to move their heads forward and capture the prey.



Scientific Name: Anguilliformes

Where are they found: Atlantic coastline from Venezuela to Greenland and Iceland, Great Lakes, and Mississippi River.

Eels are slow swimmers compared to other fish.

They swim in the anguilliform form by pushing themselves through the water wave-like fashion.

Their movement through the water resembles a snake crawling on the land.

This is a relatively slow motion, and hence a lot of energy is consumed while swimming.

Eels’ dorsal fin helps them move through the water by stabilizing them during the movement.

At the same time, their anal fin allows them to propel forward while swimming.

Most Eels are solitary during their juvenile and adult life.

They swim slowly with the help of sinuous lateral movements of their body and median fins.



Scientific Name: Syngnathinae

Where are they found: Tropical and subtropical regions.

Pipefish look similar to straight-bodied Seahorses with tiny mouths.

These fish are slow swimmers and swim in a leisurely fashion.

Pipefish swim slowly as they only have a tiny dorsal fin limiting their swimming speed.

They move through the water by swimming slowly using their dorsal fins like waves.

Also, these fish use gentle currents while swimming and get tired quickly.

Hence, they need to rest frequently.

Besides, Pipefish mainly reside in the shallow waters as they are not strong swimmers.

Although most Pipefish species are slow swimmers, some species like the Flagtail Pipefish are pretty strong swimmers.

This is because they have caudal fins that are more developed, which enable them to swim fast.

Yellow Perch

Yellow Perch
Yellow Perch

Scientific Name: Perca flavescens

Where are they found: Native to North America.

Yellow Perch are the most widely distributed members of the Perch family.

Since these fish are slow swimmers, they are often easy prey for the bigger fish in their natural environment.

However, Yellow Perch often swim in schools and protect the younger fish from predation.

The favored habitat of Yellow Perch is a weedy, warm water lake.

However, they also inhabit slow-moving freshwater streams, rivers, ponds, and brackish waters.

Initially, these fish were found in abundance.

However, their population has now declined due to the increasing pollution in the streams and other water bodies where they spawn.



Scientific Name: Tetraodontidae

Where are they found: Warm regions of the world.

Pufferfish are slow and clumsy swimmers.

They move by swimming sideways using their anal and dorsal fins while using their pectorals fins for balancing.

Since Pufferfish are slow swimmers, they seem to be easy prey for the larger fish.

However, they make an easy escape from the predators by using camouflage and inflation as their primary defense.

When Pufferfish are threatened, they inflate by taking a lot of water (and sometimes air) inside their stomach, turning into a large ball.

They puff and make themselves at least three times bigger. This makes them look challenging to eat.

Besides, Pufferfish have spines that stick out like needles once they puff.

In addition, these fish have excellent eyesight that helps them identify predators in advance so that they can either flee or puff themselves before being targeted.

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