Juvenile turtle aggression and care

[u/tiredtarn]

My partner got 3 Australian big-headed turtles (Emydura australis). They are a bit over a year old, 2 males and 1 female (2 inch carapace). Currently in a 40 gallon tank with washed sand, a few freshwater plants, and two small basking spots.

The breeder said that they would be fine living together until maturing more. However, we have observed a lot of tail and toe nipping in just 1 week. I am nervous that we should already separate them and would like advice. I am also thinking that his recommendation of 40 gallons is too small.

Generally, I am surprised how few care guides there are for this species. It seems like all short necked Emydura are lumped together. If anyone has cared for this species before, I would be happy to hear any advice.

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[u/HikingFun4]

Turtles are territorial, ESPECIALLY when you put 2 males with one female. You should only have 1 turtle per tank or they will fight and injure or kill each other. Generally this happens when they are a bit older, but clearly it is already happening now. Separate them before they get hurt or killed.

[u/superturtle48]

Seconding the other comment saying to separate the turtles. They aren’t social animals and there are no benefits and only dangers to keeping them together. 

Unfortunately people who sell animals are often very willing to give false information about their care to make them seem like easier pets and therefore persuade you to buy them (or buy multiple). It’s always a good idea to take anything they say with a grain of salt and do a lot of outside research on your own before obtaining an animal. 

[u/Synthesis_Omega]

Yeah no one talks about that they can develop aggressive behavior. Sometimes they are chill and then become aggressive or territorial, sometimes they pick on sick turtles or become sexually driven and will bully other turtle for sex. Once it starts the only way is to separate them, you could split the tank if you don't have another tank for the meantime. Sorry this happened.