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One of the first things that baffled me about my new little fish was how to tell if they were male or female. I’d never kept Platys before so I didn’t know what to look for. And they all look pretty much the same – don’t they? So I did a little research on how to tell if my Platy fish are male or female and whether it was important to know this.
To tell if a Platy is male or female you need to look at the shape of the anal fin. Just as it sounds, the anal fin is the last fin on the underside of the Platy before you reach the tail fin. If the anal fin is a pointy stick shape it’s a male Platy. If the anal fin is wider and fan shaped it’s a female Platy. And there are several reasons why it is important to know the gender of your Platy.
Platy Fish Male Female Ratio
Knowing the sex of your Platy fish is important when it comes to working out the correct ratio of male to female Platys in your aquarium. Getting the balance right between male and female Platys will make a huge difference to how happy and healthy your Platys’ lives will be.
The ideal ratio of male to female platy is 1 male Platy to either 2 or 3 female Platys. But 1 male to 3 females is probably best.
The reason for this is that the Platy fish are prolific breeders. So if you have too many males to females in your ratio the females can become stressed because the male Platys will be constantly chasing them around the tank in an effort to breed. And stressed fish are more prone to illnesses. Some of which can be serious and even life threatening.
Another point about having too many males in the tank is that they will be in competition with each other for the attention of the females. This competition can lead to fighting amongst the males who are all trying to gain dominance of the aquarium in their quest to breed with the females.
Although the Platy is a peaceful fish in general, a shortage of females can lead to some serious fighting which can cause stress and injury to the losing male Platy. Also the harmony in your aquarium will be spoilt. Leading to unhappy and possibly unhealthy fish.
Can I Keep All Male Or All Female Platys?
A ratio of 1 male to 3 female Platys is ideal if you want your Platys to breed. Even if you don’t want to intentionally breed them, but it won’t cause you worry if they do, then this is the perfect combination of male/female Platy for your aquarium.
However, you may not want them to breed. You may just be happy to keep to the same number that you started with. Or you don’t have a particularly large tank and are not planning on upsizing any time soon.
The surest way to avoid being overwhelmed with lots of baby Platys (fry) is to keep only one sex in your aquarium.
All Male Platy Tank
If you keep all males you run the risk of quite a bit of in-fighting. Male Platys in an all male environment are likely to become territorial. Fighting for dominance of the aquarium by aggressive chasing and pecking. You’re likely to end up with a tank full of stressed and injured fish if the fighting gets out of hand or is continuous.
All Female Platy Tank
Female Platys are generally more docile than the males. There’s less chance of all that pushing and shoving, chasing and pecking. That’s not to say that the female Platy is never a bully. There are dominant females that like to assert themselves. But you have a better chance of of keeping a harmonious single sex aquarium if it’s all female.
Can Platy Fish Change Gender?
When I was researching how to tell the gender of my Platys I came across this question. While it sounded like an odd question to me at the time I was amazed at how many people were searching for an answer.
So, being a bit of a nosey type, and also because it linked into the question that I was looking for an answer to, I carried on reading.
Strange as it may sound, many people believe it’s possible for a Platy to change its gender depending on the circumstances. Others believe that live bearers can’t change their sex.
I’m in the ‘don’t know for sure’ category. I also don’t want to get into an argument about it. But because I found some interesting views on this, and the fact that the question intrigued me, I thought it was worth mentioning.
The main circumstance that I came across involves a dominant female in an aquarium with a male or males that are older and not interested in breeding. The dominant female may change its gender to male and will then breed with the females in the aquarium. However, a dominant female Platy can’t change sex if she’s carried young herself. It’s believed that once a female Platy has had young her gender is set.
Another reason why it can appear that a female has changed her sex to male is the difficulty in telling them apart when they are still very young. Platy fry all tend to look female at first. It’s not until they are about 3-5 months old that you can be sure about their gender. And even then some Platy may not display their true anal fin shape until they are a little older still.
So if you think that your female Platy has become a male it could just be that he took his time to reach sexual maturity.
Are Platys Good Community Fish?
Although Platys are not considered a schoaling fish they do like to live in small groups. As long as you get the male female ratio right your Platys will be happy living together in the tank. You can have just Platys in your aquarium if you choose to. And because there are lots of variants you will end up with a colourful and lively aquarium.
But if you want a variety of different fish to build up your community tank Platys are a great little fish to start your community with.
Because Platys are a peaceful easy going fish they are happy to live in an aquarium with other species of fish that have the same kind of temperament. This makes the Platy a good tank mate for Guppies, Danios and Mollies for example, and also for non-aggressive shrimp and snails.
So as a community fish the Platy is ideal as they are peaceful, sociable, non-aggressive and easy to care for. By adding other peaceful community fish to the tank you will have a harmonious, colourful aquarium, full of movement and interest.
