Do Neon Tetras Play Dead?

So I’m writing about a topic that seems to divide some people. For most hobbyists who keep these awesome little fish, the neon tetra this topic is a no-brainer. What are we going to explore in this article yep do neon tetras play dead? (.)

Come with me as we discover that they do indeed play dead.

Neon tetra has become popular and rightfully so in my opinion. Super cool personality mixed with a cheeky, playful attitude and some stunning color. How do neon tetra get so colorful click to see? Although very nice fish some say they are too hard to keep and die easily could they just be playing dead? (.) 

We know neon fish like particular water parameters and need to be kept in the right-sized tanks for their ability to shoal and school.  If they get stressed and neon tetra are prone to stress well too much stress for these little guys causes illnesses such as neon tetra disease and also symptoms of diseases such as dropsy.

Even the odd bit of play like chasing each other or boisterous behavior tetra fighting can cause some stress. All that being said would a neon tetra be able to play dead? (.)

Neon Tetra Playing Dead

So the question is

Do neon tetra play dead?

The neon tetra is able to play dead when stressed they release cortisol via their internal renal cells located in the head and kidneys of the fish. These cells pass cortisol directly to the fish’s bloodstream.

How Neon Tetra Play Dead

Now we know these little fish are able to play dead. The next logical question would be how this is possible. As touched on above cortisol this chemical is secreted when the fish is overly nervous or stressed.

When this occurs and the fish has stressed a process, involving activation of the hypothalamo–pituitary-adrenal/interrenal axis or  (HPA/I).

Ok, let’s break this down and make it easier to understand. Our fish the neon tetra gets stressed. Those stress signals are sent to both the central nervous system and the sympathetic nervous system.

The sympathetic nervous system is the head and kidneys. Right with me so far ok the head and kidneys go on to produce catecholamine hormones via Chromaffin cells and this produces adrenaline.

While this is happening the stress was also sent to the central nervous system. Ok, once there the central nervous system uses the hypothalamus and pituitary glands to make cortisol.

Find out more about the systems involved in the making of cortisol for fish in the link. And

adrenal chromaffin as well as hypothalamus and pituitary glands. I’ll try to explain in more simple terms here.

Hopefully, we are all still together after that science expedition. Anyway, after those processes have taken place the stress is turned into cortisol and adrenaline. Those are then passed into the bloodstream and the fish has a fight or flight moment.

Usually resulting in the fish playing dead for a bit.

Why Play Dead

Let’s recap we now know for sure this happens. I’ve seen it many times and have spoken to many hobbyists who can confirm yes neon tetra plays dead. We also now know the mechanism for how they are able to play dead. (sorry for the overly scientific exploration) but felt it was needed for this article. 

Why does the neon tetra play dead? This seems to be solely a genetic defense system. They appear to be born with the ability purely to confuse possible predators.

Neons are very fast fish and can wriggle and dart out of most problems. They are pretty good at hiding and staying out of trouble too. But it seems if these two options don’t work they can just play dead and hope the predator leaves them alone.

Does Playing Dead Work

Not much is known about how they survive in the wild. If anything it’s surprising how many survive after hatching as the parents seem to care very little for their young and even eat them. What neon tetra eat each other (cannibals) I know strange but true they will indeed eat eggs and newborn fry as well as each other after death.

I don’t think it would work long-term I feel it’s a short-term tactic if in a pinch. It would need to be as if they play dead too long one of their mates might eat them. Joking aside they are very good at it I’ve heard of hobbyists nearly flushing them down the toilet before they saw them move.

I’ve also heard of hobbyists who did flush them and then wondered what if after discovering they are able to play dead. So it didn’t work for those that were flushed.

I’m guessing the reason it works in the wild and in our tanks, to a certain extent if you take us out of the equation the reason it works is the cortisol. 

Hear me out cortisol is released via the gills and skin of the fish. So I believe this may leave a scent in the water around this fish while it’s playing dead. This scent must prevent the other fish or predators from eating our little buddy.

Obviously doesn’t work on us humans we just flush them away. But now you know better and hopefully, you won’t lose any.

In Conclusion Yes Neon Tetra Do Play Dead

As I finish writing this article id say to any new hobbyist looking at keeping neon tetra. Be vigilant as these little fish will from time to time play dead. Especially when you try to net them or move them from one tank to another.

Don’t panic give them time and make sure you put them into the other tank as quickly and stress-free as you can. Chances are no matter how careful you are they may play dead it’s fine they will recover just give them a quick gentle nudge once in the new tank and away they go.

I’ve had this happen many times Sometimes they look like their sleeping heads down floating this may be because the temperature is lower than the main tank. It does seem as though water temperature changes can induce this strange sleeping-playing dead behavior.

Just don’t flush them away before you know they are dead as they might just be playing dead. Thanks for reading hope you learned something and please feel free to look around the site for more good information.