What Aquarium Fish Don’t Have Scales?

If you’re considering getting fish for your aquarium, you have a variety of possibilities to choose from.

Aquarium fish come in all sorts of colors and sizes, with some being exotic and others more common in everyday aquariums.

You can even purchase fish that come in different textures, like with or without scales.

Do All Fish Have Scales?

All fish have some kind of skin covering their body. This skin can be affected by exposure to different elements, like sunlight or sharp objects.

Sometimes, this skin has a covering over it as well, like a layer of scales that protect the fish’s organs from being damaged.

These scales can either be opaque or transparent and can be colored as well.

However, many fish are not covered with scales. These are certain species of fish that have evolved to have different coverings.

Fishes that don’t have scales include the clingfish, catfish, and shark family, among others. Instead of scales, they have other layers of material over their skin. They can have bony plates that are also covered by another layer or tiny, teeth-like protrusions covering their skin.

Their bodies can also be covered by a layer of mucus.

Which Pet Fish Don’t Have Scales?

Among the many fish that don’t have scales, let’s consider only the ones that you can keep in your aquarium.


Catfish get their name because of their whiskers and are a very diverse group of fish that can live in many different environments.

They can live in saltwater, freshwater, and even brackish water.

Some species of catfish prefer waking at night, while others do all their activities during the day.

How Do You Keep Catfish in an Aquarium?

You can add a catfish to your aquarium if this particular fish interests you.

However, many people also like having catfish in their aquarium because they keep the aquarium water clean.

They can be found in different sizes, with some of them staying the small size that you bought them in (like the corydoras) and others becoming much bigger (like plecos and Columbian sharks).

Catfish get along with other fish in the aquarium and do good in group settings. You might notice that they even get along with the fish that other fish have not been able to get along with so far, like a betta fish.

Depending on how big your aquarium is, you have to pick a catfish that will be suitable for that capacity.


Sharks not only don’t have scales, but they also don’t have any bones in their body.

Their entire skeleton is made from cartilage because it gives them the ability to grow to a size that is appropriate to your tank and be very agile as well.

Sharks don’t have scales, because they have dermal denticles, also known as placoid scales.

Denticles look like miniature teeth spread across their entire body, making their exterior surface feel rough but strong.

These are placed in the direction of the shark’s tail because this helps prevent friction against the water when the shark travels through the water.

This helps sharks move faster through the water. When a shark gets bigger, it does not grow more denticles.

The number of denticles on its surface just increases instead.

Sharks are also easy to take care of in the aquarium.

How Do You Keep a Shark in an Aquarium?

If you want to keep a shark in an aquarium, you’ll need to make sure you get a tank that’s big enough for the fish to swim comfortably.

Get a tank that is at least a hundred gallons in capacity.

If you’re getting a bigger type of shark, you will need to push that number up to three hundred gallons.

Most sharks prefer being in aquariums that have lots of plants because they like to hide among the greenery.

Have lots of rocks and crevices near the base of the tank, so that the shark can make a home for itself and see the area as its territory.

Another important factor to consider before getting a shark for your aquarium is the other kinds of fish that you already have.

Make sure you only get fish that aren’t small enough for the shark to eat, or you could risk making your fish become a small snack for the shark.

They should also be fish that aren’t too aggressive, or this could result in fights and injury among the inhabitants of the aquarium.


Another fish that does not have scales are stingrays, manta rays, electric rays, among other kinds of batoids.

While many people can choose not to have Rays in their aquarium, they can make an interesting aquarium dweller.

Rays can often grow to very large sizes and need bigger tanks to live in, which is why people need to have ample space in their house to install a tank with enough capacity for the ray to live in comfortably.

Many people choose rays like torpedo rays, electric rays, and whiptail stingrays when deciding on what batoid to get for their personal aquarium.

Not all batoids are suited for living in different kinds of environments, so make sure that the one you opt for has the kind of environment provided to it that it needs.

Torpedo Rays

Torpedo rays generally eat tiny fish for their diet, but they can also eat shrimp and squid.

They have distensible jaws, which gives them the ability to even eat fish that are similar to them in size.

When you’re deciding on what kind of fish to get along with your torpedo ray, you’ll have to keep in mind that it is capable of eating those fish, so keep fish that aren’t as aggressive and won’t push the Ray to eat them.

You might even have to keep the rays in a separate tank made only for them.

How Do You Keep Torpedo Rays in an Aquarium?

Torpedo rays can grow larger their tank, so if you don’t think you can keep investing in larger tanks as the fish grows, you might want to consider not buying this fish.

They like to bury themselves under the sand at the base of the aquarium, so make sure you have plenty of that in your tank at all times.

Torpedo fish also only prey on fish that are moving, so you have to feed them live fish or place the fish on a feeding stick to trick them into believing that it is moving.

Electric Rays

Electric rays do not do as well in an aquarium environment as other fish, so if you decide to keep them in a tank, you have to be extra mindful of what you feed them and what kind of setup you have in the tank.

They usually only eat annelid worms, which are difficult to get access to, so you’ll have to ensure you have a supply of those before finalizing your purchase.

How Do You Keep Electric Rays in an Aquarium?

Their tank base should have very fine sand so that it doesn’t injure their skin.

They have very sensitive skin and even a slight scratch can start the spread of infection.

Sometimes, the reactions to these infections can be so severe that the electric ray can die as well.

Avoid any kind of aquarium decoration if you want to protect your fish from deathly injuries.

Whiptail Stingrays

Whiptails look a lot like round stingrays and stingarees.

They usually eat different invertebrates and fish and they use their spines as a defense mechanism.

When feeling attacked, they can whip their tail onto the attacker and sting them because their tail is covered in a poisonous layer.

How Do You Keep Whiptail Stingrays in an Aquarium?

Whiptails should also be kept in aquariums with sand at the bottom, which helps keep them safe and allows them the opportunity to bury themselves underneath the sand.

They should not be kept with fish that are aggressive, which would trigger an attack within the aquarium.

Moray Eels

The last scale-less aquarium fish we will talk about are the moray eels.

Most people don’t consider getting a moray eel when they’re thinking of different eels to purchase, but investing in one of these can turn out to be a great decision.

How Do You Keep Moray Eels in an Aquarium?

These eels can be a bit picky about what they want to eat and can often grow to very huge sizes, but once you figure out how to manage them, they make a wonderful addition to a saltwater aquarium.

You’ll need to make sure that you get a big enough tank that will have enough capacity for the eels as it continues to grow.

They can be over several feet in length, so you’ll need that space to be available in your house.

You’ll also need a very good filter system because Moray Eels are known for producing a lot of waste.

This plays a role in what kind of company you decide to keep with the moray eel since many fish are sensitive to high levels of waste and can become sick if they’re forced to stay in an environment that is not safe for them.

Keep only anemones and corals, because these plants can withstand the waste. Don’t keep other fish inside the tank.

Moray eels prefer eating frozen food, so you’ll have to invest quite a bit of money in getting the right diet prepared for this fish.

They need food like fish, shrimp, crab, and octopus to stay healthy.

Final Words

Getting a fish can be a combination of hard work and investment.

You need to make sure that you get a fish that you will be able to take care of.

Tank fish come in all sorts of sizes, shapes, and textures, so whether you get a fish with scales or one without, as long as you’re mindful of its needs, they’ll be able to thrive in your aquarium.

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