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Despite its reputation for being sociable, the Platy fish isn’t always so patient and placid.There are a few things that can make your Platy bad tempered and even aggressive.
So what’s likely to turn your friendly little fish into a bully?
Do Male Platys Compete For Females?
When it comes to mating the Platy has a voracious appetite. And like all livebearers Platys produce a lot of fry from each mating. This can take you unawares if you’re not prepared for the amount of baby fish that are likely to populate your aquarium.
Even if you’ve got the male to female ratio right (1 male to 3-4 females) there’s still likely to be some competition between the males for the attention of your female Platys.
This competition for female attention is probably the most common reason for signs of aggression in a Platy tank. Or any other mixed sex fish tank for that matter. It’s just part of nature for the males to vie for the attention of the females when it comes to procreation.
And when you think about, it It’s not only male fish that exhibit their fitness to mate. It happens all over the animal kingdom, no matter what the species is. Whether it’s done by brute force, showing off or looking the most attractive, males will do their utmost to mate with the female of the species.
So while it does help keep the male to female ratio right, don’t be surprised if your male Platys still compete with each other when it comes to improving their chance to breed with the females.
Can Pregnant Female Platys Be Aggressive?
Platys don’t have a protective instinct towards their fry. The males, and also other females in the tank, often hang around a female who’s giving birth waiting for a tasty snack. And a mother Platy will also eat her own fry after giving birth to them. Again, it’s just part of the natural scheme of things when it comes to Platy fish and often with other livebearers too.
During her pregnancy though a female Platy often becomes very defensive.
As she doesn’t have a protective instinct for the fry she’s carrying, her defensiveness is more likely to be a self preservation move on her own part. She probably feels more vulnerable with her belly full of babies. And she isn’t going to tolerate the male Platys chasing her around in their continued effort to mate with her when she’s already carrying fry.
One of my pregnant females in particular developed a strong aversion to having other fish anywhere near her.
She claimed the ‘sunken boat’ tank ornament for herself and regularly went there to rest under the tunnel-like canopy of the boat.
Whenever another fish came near, or even got remotely close to the boat, she shot out and chased the fish away. Then she went back to her hidey-hole again for a bit of peace. Even after coming out to feed, once she’d eaten enough, she went back to the boat and kept guard for intruders.
Oddly though, she had no problem tolerating the company of the Amano shrimp. The pregnant Platy and the shrimp were often found sharing the canopy of the boat without any problems at all.
Do Platy Fish Fight Over Food?
The Platy is always on the lookout for food. In fact it’s a rather greedy little fish and often looks like it’s begging for a meal every time you go near the tank. Don’t let it fool you though. If you know that your Platys have all had their fair share of the day’s supply of food it’s not a good idea to give them a bit more.
Overfeeding can cause digestive problems and also foul up your aquarium water quality.
But even if you know that your fish are well fed it doesn’t mean that you won’t see any competition for food.
I’ve noticed a distinct ‘pecking order’ when it comes to meal times since I started keeping Platy fish.
The largest female in my original four Platy fish (affectionately named Big Momma) was always first to get to the food. And woe betide the others if they tried to beat her to it!
Although usually a very laid back fish she would aggressively shunt her tank mates out of the way when it came to meal times. And because she was a lot bigger than they were they soon learnt not to push their luck.
Once she had taken the edge off her appetite the other Platys got the chance to eat. But even that was done in order. My smaller female was then allowed to join Big Momma. The males had to wait until last. But I always made sure that they got their fair share of the food.
And even now that I have other Platy fish as well there’s still a distinct hierarchy when it comes to meal times. Especially if the meal is a fresh veggie treat such as a lightly steamed broccoli floret.
It’s definitely ‘ladies first’ in my aquariums.
Making sure that your fish get the correct amount of food to feed them all adequately does help to avoid a food fight. But even so you may notice a distinct feeding order in your Platy tank.
Can One Platy Fish Dominate The Others?
As I just mentioned, my larger female Platy, Big Momma, became dominant when it came to getting the first bite of the food. For the rest of the time she was a gentle sociable fish. In fact she was rather inactive in between meal times and liked to rest in the afternoons.
And despite an occasional bit of push-you-shove-me from the males competing for the female’s attention, the atmosphere in the tank was generally relaxed and non-aggressive.
However, it’s not unusual to find that one Platy in the group becomes the dominant fish. Although this is probably less common if you have a large amount of Platy fish in your aquarium. Higher numbers do seem to dilute aggressive tendencies.
But you may still find that one of your Platy fish decides to be boss.
It’s not always a male fish that tries to dominate the tank. Females often do this too. And as female Platys are usually larger than the males they have more clout when it comes to the aggressive side of things. Being physically bigger and stronger is useful if you’re a bully or just want to be in charge.
You’ll only know if you have a dominant Platy in your tank by watching how your Platy fish interact on a daily basis. You’ll soon get to know who’s in charge of your Platy group even if you also keep other types of fish together in a community aquarium.
Being dominant doesn’t necessarily mean being a bully. But keep an eye out for genuinely aggressive behaviour. Bullied fish become stressed and can end up developing illnesses, or injuries, that can lead to fatalities
No fishkeeper wants to lose fish unnecessarily. So spending time each day to check what’s going on in the tank is well worth the effort.
Does Illness Make Platy Fish Aggressive?
As people we often avoid the company of others when we’re unwell, in pain, or just feeling down. There are simply times when we just want to be left alone.
And a poorly fish is no different.
So illness is another one of those things that can lead to defensiveness and even aggression in Platy fish. And also in other breeds of fish too.
A Platy that’s unwell is likely to keep itself apart from the rest of its tank mates. Finding a quiet place to rest and not wanting to interact with the other fish. And depending on the type of illness the Platy fish may stop eating too.
When another Platy, or tank mate comes close, a poorly Platy may well react by pushing or even chasing it away before going back to its chosen resting spot.
Checking for signs of ill health and disease is something that, as fishkeepers, we need to do on a regular basis. After all, the sooner you spot that something’s wrong the better. You’ll have more chance of getting it sorted and saving your fish from further distress, or worse.
How Does A Platy Bully Other Fish?
Bullying can show itself in different ways. But there are a few common things to watch out for when you’re spending time observing your Platy tank.
Firstly it’s important not to confuse mating behaviour with bullying. While the males can harass the females in their efforts to breed it’s just part of the Platy cycle of life. As long as you have your male to female ratio right your females shouldn’t get overly stressed because of the attention of the males.
Also a bit of pushing when it comes to feeding time can be harmless. The Platy is rather a greedy fish and each one wants to get to the food first. As long as all the fish are eating enough it’s not a problem.
However, if you notice unnecessary and prolonged pushing and shoving, continuous chasing with one fish not allowing the other one to escape and rest, fin nipping or nips aimed at the eyes, then you’ve likely got a bully fish on your hands.
What Are The Consequences Of Bullying?
A Platy that is continually bullied will suffer both physically and psychologically. And it’s not just Platy fish that suffer the consequences of bullying. No matter what species of fish you keep in your tank, if there’s a bully among the group, it’s going to be bad news for the victim..
Physical exhaustion from being chased for long periods each day will take its toll healthwise. Especially if the fish hasn’t been getting a fair share of the food. And an injury from being nipped, or catching itself on tank decor in a bid to escape, can lead to infection.
On top of that there’s the stress that comes with being the victim of a bully. Being under constant threat can lead to depression. And, although it may sound odd, fish can get depressed just like people can.
While physical injury and infection are more obvious causes of death in fish, stress is generally considered to be the biggest killer of aquarium fish. Not only does continued stress make your fish’s life miserable it can also kill them.
My understanding of the reason for this (and I’m no expert) is that stressed fish are more prone to developing serious illnesses. If fish are brought low by stress they can’t fight off illness and parasitic infection as effectively as they would if they were more relaxed in their everyday life.
Stress in fish can present itself in different ways. But there are a few signs to look out for in general, and in particular if you think that a fish is being bullied.
- Loss Of Appetite
- Hiding Away/lethargic – when usually active
- Loss Of Interest In Tank Mates And Surroundings
- Breathing Fast (hyperventilating) – even when appearing to be at rest
- Loss Of Colour
Because you know your fish better than anyone else you’re best placed to spot changes in behaviour and appearance that could indicate bullying and stress. This means you might notice other things than the ones I’ve mentioned that don’t seem right to you when it comes to your Platys and their tank mates.
How Can You Deal With A Bully In The Tank?
The simplest way to deal with a bully fish is to return it to the Pet Store or Dealer that you bought it from. I know this isn’t always possible but it’s worth asking them. Even if they can’t, or won’t, take the fish back they may be able to advise you on what to do with your rogue fish.
Another solution is to remove the bully from the aquarium and keep it in a smaller tank on its own. If you don’t already have a spare/emergency tank it’s worth investing in one, especially if you still want to keep the fish.
Having a spare tank is handy anyway, because you never know when you might need to separate a sick or injured fish. Having a spare is also useful as a nursery tank to keep fry safe from the adults until they’re big enough to return to the main aquarium.
But what can you do in the meantime?
Well, you could put the Platy bully into a breeder box/hatchery inside the main tank. It will be isolated from the other fish and unable to carry on bullying its tank mates.
Platys get to a fair size though, so using a breeder box will probably only work temporarily while you sort out a more permanent solution.
It may be possible to find someone locally who will take the fish off your hands despite it’s temperament. Maybe a local breeder, or someone who keeps a community tank that has larger, but compatible fish, in their aquarium.
It’s definitely worth asking around and searching fish rehoming options online if your Pet Store or Dealer are unable to help you.
Although it’s not your fault if one or more of your fish turns out to be a bully there are a few things that can help to reduce the likelihood of unnecessary aggression in your aquarium.
Keeping your tank conditions healthy and water parameters steady can make a difference. Also make sure that all your fish, whether it’s the Platys or their tank mates, get adequate food.
Another thing that helps to reduce bullying in the tank is to provide lots of hiding places amongst the plants and decorations. Being able to escape for a while reduces the stress put on your gentler fish because it lets them take some time out to rest.
However you choose to deal with a bully it’s important to solve the problem as soon as possible. An aggressive fish will upset the balance of your tank community and put all your hard work at risk
Are Some Varieties Of Platy More Aggressive Than Others?
There are so many different varieties of Platy fish that a fishkeeper can be spoilt for choice. The range of colours and markings that Platy fish display is astounding. And we naturally all choose the varieties that appeal to us most.
But are some varieties more aggressive than others?
Apart from a general consensus about the Swordtail Platy being a little more aggressive than others, I haven’t found any hard and fast evidence about other varieties when it comes to the pushing and shoving.
Like a lot of things in the fishkeeping hobby it often comes down to personal experience.
I have come across a couple of opinions though, that crop up often when it comes to aggressive tendencies in Platy fish.
One is that mixing different varieties of Platy in the same aquarium seems to increase the chance of dominant or bullying behaviour.
And the other is that an all male tank is more prone to infighting than an all female or mixed sex tank.
On the flipside though, both the Marigold and Red Wagtail Platy fish have a reputation for being more docile and less inclined to argue even if they’re kept together in the same aquarium.
But like I say, personal experiences do vary.
I Lost Big Momma Because Of A Bully
If you’ve read this far you’ll remember I told you about Big Momma. My easy going but ‘first to the food’ female Platy.
One of the other female Platy, a fairly new addition to the aquarium, had decided she was going to be number two in the tank hierarchy.
Not a problem at first. She wasn’t aggressive to the other fish and was content to follow Big Momma’s lead.
The problem started after Big Momma had given birth to a batch of fry and was feeling tired. She needed time and space to rest and recover. After all, it wasn’t her first batch of babies and at 14 months old she wasn’t a young mum.
I kept an eye on her and made sure she fed well.
But after a couple of days she started to go downhill. Although she’d always been a rather lazy Platy between meal times, she now hardly bothered to move at all. Her colour started to fade and her vibrant ‘blood orange’ fins turned into a pale peachy hue.
Then she stopped eating.
Big Momma, always the first one to the food, had lost her appetite. I knew then that I was going to lose her.
I just couldn’t figure out why.
She’d had other fry and recovered fine. There were no obvious signs of illness that I could see.
So what was going on?
Then one evening I was up later than usual, watching the fish as I sat drinking a glass of wine at the kitchen table.
The female Platy that had decided it was number two in the tank, started to chase Big Momma around once the light had dimmed.
It was a continuous onslaught. Big Momma couldn’t escape even for a minute. The other female Platy found her out and continued the attack.
And it wasn’t just the relentless chasing either.
Things got a whole lot nastier than that.
Whenever Big Momma got tired and slowed down the other female shunted her about. Knocking Big Momma off course.
The final straw for me came when the bully started going for Big Momma’s dorsal fin and then nipping at her eyes.
I couldn’t stand any more.
So I grabbed a hatchery box, (like this one on Amazon), put it in the tank, and netted the bully fish into it.
If Big Momma was going to die she should be allowed to do it in peace.
I lost her two days later.
Needless to say it was a sad day in my house.
Big Momma was one of my four original Platy fish. The Platys that got me into the fishkeeping hobby in the first place.
I’ve no idea how long the bullying had been going on. I’d never seen it happen before despite spending time every day watching my fish.
Maybe it only happened during the night and so I’d missed the signs.
Oddly though, when I released the rogue Platy back into the tank she didn’t bully anyone else. She didn’t try to assert her dominance in any way over the other fish.
Maybe it was because she now felt she was the number one Platy fish and didn’t need to prove anything.
Or perhaps she didn’t fancy another spell in solitary confinement!
I’ve kept a close eye on her ever since though, just in case.
