I had two turtles (male and female) and five goldfish in one 2.5 x 1.5 ft (around 46 x 61 cm) aquarium, which was filled with water up to 1 ft (around 30 cm) height. I fed all of them once a day, everyday in morning with protein Toya food (fishes also like it). But one evening one of my turtles ate one of the goldfish and left its corpse behind (few months ago even corpse wasn't found in water, when fish was small).

Why are they attacking the fish when I am feeding them daily? How can I stop it? I don't have a place to fit another aquarium for either the turtle or for the fish. Should I bring another bigger species like a frog or bigger fish that can guard the goldfish? The turtle who ate the fish also attacks the other turtle's feet and neck.

  • 2
    Are you referring to a water turtle? Tortoises are strictly land based reptiles and shouldn't be kept in water.
    – Jestep
    Jun 25, 2014 at 13:31
  • For confusion between the difference between turtles and tortosies
    – Spidercat
    Jun 25, 2014 at 14:29
  • If the aquarium is somewhat square, I would put a screen in the middle (or wherever) to separate them.
    – J. Musser
    Jun 25, 2014 at 15:03
  • Screw the turtle problem, the goldfish are what I'm worried about. Goldfish need a lot more room than more commonly thought. The way I have been taught is that you need 10 gal/goldfish. They produce insane amounts of waste. You should probably have your water tested. Your best bet would be to get a much larger, second tank for your goldfish.
    – NealC
    Mar 4, 2017 at 2:03
  • turtels are loner, they meet only to make little turtles. If you do not have a tank spaced like a little room, they will not get their own area for each. even one single turtle should have a tank 7 times its shell long, 2-3 times its shell wide and with a water level at a high equal to 1-2 times the shell length. May 12, 2020 at 13:37

3 Answers 3


First, the turtles are eating the fish because fish are food, not friends. Turtles are omnivores and fish make up part of their natural diet. There's absolutely nothing you can do to stop it other than separating them from each other. You cannot train turtles to treat food as anything but food. You may get lucky, and have a turtle that's content with the food you provide rather than the fish, but that's no guarantee. The turtle could get bored and hunting alleviates boredom.

Second, that tank is way too small for even the fish. The reason the turtles are lashing out at everything in the tank, is that they want more space, and the easiest way they can make more space is to kill the other occupant that are taking up that space. That will include each other, as you're already noticing with the one attacking the other.

If you don't get a larger aquarium for the turtles, you will end up only having one turtle.

As a rough guide, to tell what size of tank you need, measure your turtles from head to tail. For each inch you measure, you should have about 10 gallons of water.

As far as adding more animals to 'protect' the fish. Even if there was room in the tank, turtles will eat amphibians too. If you got a frog large enough that the turtles didn't eat it, it would happily join the turtles in eating the fish. The same goes for larger fish really.

  • And if the fish are big enough, they will eat the turtles!
    – Oldcat
    Jun 25, 2014 at 21:38
  • 4
    I would also note that once an animal has eaten a type of prey and found it palatable it is more likely to seek out that type of food in the future
    – Critters
    Jun 26, 2014 at 13:36

Turtles love eating goldfish and lots of things that fit into their mouths.

I had the same problem: I had 3 newborn koi and 4 goldfish that were less than an inch long in the same tank, and one day I saw my turtle trying to eat my koi. What I did was to divide the tank so that the goldfish would be on one side and the turtle on the other.

You can do the same, but not with the tank you have. That tank is way too small for those turtles. Alternatively, you could make a pond and put either your fish in there or put your turtle in there. And if you divide to put your goldfish in there they will grow three times bigger than they would in that small tank

  • I edited your post to make it a bit clearer but I wasn't sure about the final sentence. Are you talking about the goldfish growing bigger if you put them in a divided tank or if you put them in a pond? Jul 14, 2014 at 10:16
  • fish do not follow their tanks in growth, this is a myth. The grows depends on the amount of food they get and the temperature they life in. We get a goldfish from a pond for our tank (smaller than the pond ...) and after 2 years we give it back and it was the biggest goldfish in that pond blubb May 12, 2020 at 13:33

This is one trick that worked with my turtles, I got my turtles at a really young age but this may also work with older turtles. Buy about four dozen mosquito fish (very cheap) and dump them into the tank. If the turtles eat them then keep buying more, eventually your turtles will become uninterested in the fish and you can start adding other fish, in your case goldfish. Also, you do know the sizing in that tank is horrible. Here let me help you out. Assuming that you keep your turtles until adulthood you will need at least and 80-100 gallon aquarium Goldfish need lots of space too contrary to popular beleif One comet (common) goldfish: 30 gallons add ten gallons for each goldfish added after that One fancy goldfish: 20 gallons add ten gallons for each fish added after that Please get the right sized aquarium, no matter how small the animal it's still considered abuse.

  • 1
    Could you please add some references for the sizes you've quoted? That would make this answer much better.
    – Kate Paulk
    Sep 26, 2016 at 11:55

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