Turtles and Fishes (Their relationship)

In this post, we will learn more about the relationship between freshwater Turtle and Fish. We will also discuss a little about their biology and requirements. 

Turtle and Fish

In general, fish and turtles may live together without major issues. However, there are exceptions. The tiger tortoise is carnivorous and it can prey on smaller fish or even harass larger ones.

If you choose to raise turtles and carp together, opt for a baby turtle, as that way they will grow together, especially if the pond/aquarium has favourable dimensions to these animals.

In the case of the Kinguios fish, that swim slowly, it is not recommended to keep them with turtles. They are considered easy prey for turtles and the turtle will start pinching mainly the tails of the smaller fish.

Fish and turtles number must be limited by the amount of water in the aquarium, as a very crowded environment can harm them due to toxins from their waste (urine and faeces). These toxic conditions can cause many discomforts to the animals, so you must keep the tank toxin-free. A great aquarium water filtration system for the survival of the species is strongly encouraged.

Can Turtle tanks have fish?

Yes, turtles tanks can have fish. There is no problem with that, as long as the turtle in question is not carnivorous.

This is because, if it is a carnivore one, the fish will be a great temptation for the turtle and it will easily become the turtle prey. 

So, in case the turtle is carnivorous, it can even live with the fish for a while, but at some point, the turtle will end up devouring your fish.

Which fish species are most recommended for as Turtle tanks?

The most important thing when trying to keep some fish and a turtle side by side is to have the correct amount of space. Space is everything in an animal’s life and you will certainly be harmful to both there is not enough space for them to thrive.

It may be that, over time, the fish and the turtle will change their territories and leave each one of their spaces gradually, but you need to give the animals the freedom to do this in a natural way.

Thus, there is not a specific fish species more or less recommended for living with turtles. It is only necessary to avoid the obvious: large carnivorous fish. As expected, large carnivorous fish can have problems with small turtles.

Although there is no recommended fish for turtle tanks, some potential turtle mates are 

·      Tetra fish

·      Zebrafish

·      Yellow cichlids

How to feed Turtles?

Considering that you already got the message and will opt for a non-carnivorous turtle for your aquarium, it is recommended that you have fruits and vegetables available for the turtle.

The diet can include melon, pear, apple, lettuce, radish, cucumber, beetroot, watermelon, banana, and many other natural items. 

The most important thing is that you keep the herbivorous turtle always fed, as this will avoid stress and also prevent the turtle from harassing the fish. In any case, the most important thing is to keep both of them very well fed. 

Turtle x Heat and temperature

Turtles need sunlight for approximately 12 to 14 hours a day, for vitamin D3 production. You can set a high-quality UV lamp in your tank with an automatic timer.

Ideal temperatures range between 82 and 84 degrees Fahrenheit. Turtles take a long time to adjust to changes in temperature. If you take it out of the aquarium to play with it, make sure the room is at relatively the same temperature as the aquarium.

Sudden changes may cause stress and possibly weak their immune system. In addition, they should not be handled for a long time, as this also provokes stress for this type of animal.

Setting a turtle-fish tank

You will need a tank/aquarium with enough space, around 100-gallon for pet turtles. Three-quarters of the tank area must be water. The water must be as deep as the turtle is wide. Design a small area where the turtle can be under a heat lamp to keep itself warm.

Turtles do grow, so make sure the space is adequate for the potential maximum size of the adult turtle.

Bricks or wooden planks are excellent land areas as they can be cleaned easily. Just make sure they are dry and slope gently towards the water for easy access.

Woody structures can become mouldy or grow fungus. If the turtle ingests anything like this could cause severe problems, so avoid using this type of material.

If you place plants inside the aquarium, do a quick check to make sure they are compatible and that your turtle will not get sick if it decides to eat some leaves. Live plants are good, but they may be eaten in a few days. Unless you have a place where you can grow plants, consider using artificial (or a combination of live and artificial) for decoration.

Do not use tap water for your tank as it usually contains chlorine and possibly fluorine, which can affect your system’s pH balance and your animals. Dechlorinated water is the one used for swimming purposes and filtered water is for drinking.

Adding salt to the water (1 teaspoon of salt/gallon) will reduce the development of dangerous bacteria and defend the turtle from some diseases.

Turtles can carry Salmonella. Thus, always wash your hands after handling them. 

Do not ever feed your Turtle with fishy material (fish feeder)

It is very disseminated the story about a lion that ate human flesh and became more dangerous to humans because it started seeking more. Turtles and fish are the same stories. 

Once they taste the fish, they will “develop” a taste for it. Thus, the turtle will probably seek more, and if it has a fish companion, the fish will probably become the next meal.

Test compatibility before populating the Turtle tank with fish

If you have decided to give turtle and fish combinations a try, opt for introducing a few fish before getting a load of them to populate the entire tank. It is recommended to test their compatibility first with one or two fish from different species, to see which of them is more compatible with your turtle and tank.

Choosing the right Turtle

This is something that a lot of people do not even think about, but it will affect your fish’s chances of survival. It is very important to consider different turtle species before choosing and picking one.

Some turtle species are way more adept and skilled at hunting down and eating fish than others.

In particular, red-eared sliders, painted turtles, and cooters are extremely good at hunting and devouring fish.

Dangerous fish for Turtles

Avoid any fish that is too aggressive, or that may wound, damage, or murder your turtle. Thus, you should avoid:

·      Large catfish

·      Hooker

·      Electric eels

·      Lobsters


In this post, we learnt more about the relationship between freshwater Turtle and Fish. We also discussed a little about their biology and requirements.

If you have any thoughts or doubts, feel free to drop us in a comment below!

Frequently Asked Questions (FAQs): Turtle and Fish

How to raise a turtle in an aquarium?

Place the aquarium in a bright environment, but avoid the sunlight being directly on it. Vitamin D3 is very important for the development of the turtle. If the spot does not have close sunlight availability, you can purchase lamps that contain the UV ray.

Can you put turtles and fish in the same tank?

In general, yes. Fish and turtles can live together in the same tank together. Your tank must be large enough to accommodate both turtle and fish. Your filtration system must be strong enough to get the extra load from the fish.

Do pet turtles eat fish?

Sometimes and depending on the turtle species, yes. Some turtle species have developed a hunting behaviour more than others. Thus, they can feed on fish.

Can turtles live in tap water?

Turtles can live in tap water, but you may need to treat the water first. Tap water may have chlorine amounts. For humans, this can be beneficial, but for turtles, it can cause damage.

What is the best tank condition for a tiger turtle?

By keeping the water clean at pH 7, enough healthy food, a little sun daily (or UV -a and UV -b lighting) and a minimum temperature of 74 you will have a turtle that will grow fast and healthy.

How to feed a small turtle?

Feed your pet two to three times a week in a small storage compartment that is separate from your normal aquarium, as leftover food can attract disease.


Janzen, F. J. (2011). Turtles: The Animal Answer Guide.

Britson, C. A., & Gutzke, W. H. (1993). Antipredator mechanisms of hatchling freshwater turtles. Copeia, 435-440.