Platy - Xiphophorus maculatus

Scientific Name : Xiphophorus maculatus

Common Names : Many types and usually based on the color patterns - Southern Platy fish, Red Wagtail, Red, Mickey Mouse, Red Tuxedo, Moon Fish, Topsail Rainbow, Sunset, Golden, Calico, Salt and Pepper, Coral Red, Black, Blue, the list goes on.

Care Level : Easy, good first fish for freshwater fish beginners

Size : 2 inches (5 cm)

pH : 7 - 8

Temperature : 65°F - 77°F (18°C - 25°C)

Water Hardness : 10° to 25° dH

Origin / Habitat : Central America

Lifespan : How long do they live for? This depends on a lot of different variables (food, aquarium water parameters, etc), but on average they live for 2 - 3 years.

Temperament / Behavior : This is a good tropical fish for the beginner. A common question on the forum is "are platies aggressive". In general, they are a very peaceful fish. Males might pester females and it can be a good idea to have two females for every one male. Doing this will prevent the male from harassing a single female.
Another common question is "what kind of fish can live with them?" The answer to that question is: many! Mollies, swordtails, various tetras, etc. Just keep in mind the male/female ratio.

Breeding : They are livebearers which means that the babies can swim immediately after birth. Usually, not much effort is required to get them to breed. If you have a male and a female, chances are they will breed. The parents must be separated from the young after birth. For more information on breeding them, please read the breeding livebearers article. That article talks about guppies and swordtails but the process is similar with Platies.
If you want to try and raise the fry, get a breeding box or breeder net like these:

Breeding Box or Breeding Net

Breeding Frequently Asked Questions (credit: aylad on the Fishlore forum) :

Is my platy pregnant?

1. She has been in a tank with a male or swordtail within the last 6 months.
2. She is an adult, more or less (rough estimate, maybe 3/4 of an inch long).
3. She is a she. See the gender ID section on this page.

When will she drop her fry (give birth)? Or how long are they pregnant for?
Platies normally stay pregnant for roughly a month. Having said that, the water chemistry and temperature in your tank may shorten or extend the pregnancy, and if they pregnant platy is heavily stressed out due to the water chemistry, incompatible tank mates, or similar reasons, she may terminate the pregnancy. If you don't know how long she's been pregnant, it's not always easy to give a simple answer to this question. The classic sign is a large, dark "gravid spot" above and slightly in front of her anal fins; she may also "square off," which means to have a somewhat square-shaped belly. Younger platies, however, may not square off noticeably, and certain color patterns may make the gravid spot harder to see.

In any case, if she squares off, she's ready to start dropping fry any second now. If the other fish are chasing her around the tank, she may already have started giving birth. When her fry start dropping, the other platies will tend to see her as a vending machine with fins, dispensing free snacks. See "will the other fish eat her fry" below.

How many fry will she drop?
Again, it's hard to say, because depending on her age, health, water conditions, how many times she's given birth, etc. etc. etc., it may be 3-4 or 30-40. Leave mom in the breeder net for 6-12 hours, although she probably won't take that long.

If your breeding container doesn't separate mom from the fry, she might be able to eat some of her little babies during this time period (I've read that she won't eat them for a few hours after giving birth, but I have seen them swallow a fry IMMEDIATELY after birthing it. Its total lifespan was less than 5 seconds). If you see as many fry in the breeder as you want (or can take care of), go ahead and move her back into the tank. If you miss a couple, well, she'd probably have eaten at least that many anyway.

Will the other fish eat her fry?
Yes, absolutely. Few fish will be able to resist the sight of a fresh, juicy fry swimming past their noses. Even the mother will eat her own young. If you want to save as many as possible, invest a few dollars/euros/whatever in a breeder box or breeding net. Read the directions and use it as directed. The general idea is that the mother is placed in the breeding trap, she gives birth, she is removed, and the fry are kept inside until they are big enough to fend for themselves (in a species tank, this may be as brief as a couple of weeks). If you want to do things the "natural" way, just have lots of hiding places where the fry can go to escape the other fish. This is probably your best bet if you don't have the tank space for dozens of adults.

What other dangers will my fry face?
Filter intakes, larger fish, gravel vacuums, poor water quality, some species of invertebrates, starvation... it's tough being a tiny tiny fish. Cover your filter intakes with a prefilter sponge (Fluval makes a nice one that fits on many of the most common filter designs, or you can search for instructions to DIY one). You can also use never-used and never-washed nylon stockings. Vacuum your gravel with care, or cover the end of the vacuum with a stocking.

Larger fish and freshwater invertebrates, including (reportedly) ghost shrimp, crabs, and crayfish, are a threat, but hiding places or breeding traps can protect your fry from them. See the question above.

Do water changes every day or every other day and run activated carbon in your filter. This will prevent the accumulation of toxins in your water and also dilute fish hormones in the water that slow your fish growth rates.

How do I feed my fry?
Normal flake food can be crushed up into a fine powder and sprinkled into the water. I like to put a pinch of food inside a plastic sandwich bag and work it between my fingers. This lets me crush the food into ever-smaller pieces without getting it all stuck to my fingers. This is not an ideal fry food, though. It works, but it may not have the nutrients that growing fish need.

Special fry foods are available that are already tiny and nutritionally balanced for healthy fry. There are other options like baby brine shrimp that may interest you as well.

If your fry are in a breeding trap, you may find that the food sits on the water's surface until it starts to look nasty. I have noticed that fry are often unwilling to come to the surface to eat, especially in the first few days of life. Try dripping a few drops of water onto the fry powder to break the surface tension and drive the food down into the water column. Your fry will be excited to eat food drifting past their faces!

If your fry are not in a trap, sprinkle the food in front of your filter's outflow (if possible). This should drive the powder down into the tank and disperse it where fry can reach it from their hiding places.

You will probably find that you are feeding much more food than they are eating, simply because they won't see the food if you only put in enough to fill their tiny bellies. Frequent cleanings are important to remove excess food buildup.

They may not want to eat for the first 24-48 hours, but sprinkle a little food in, just so it's there when they're ready. Feed them 2-3 times per day.

Help! My fish gave birth early and I hadn't put her in the breeding trap yet!
This has happened to me SO many times. You'll probably lose some fry to the bigger fish, but you can save others. You can use a turkey baster (never washed) to suck up fry and deposit them into the breeding trap. The hard part is sneaking up on them, but you'll get the hang of it. Just have a comfortable stool in front of your tank to sit on. ;)

The first time I did this, I had a bubble wall on one end of the tank. When the fry swam into the bubbles, they were disoriented by the strange currents and struggled against the flow. They were very easy to snatch with the turkey baster that way. You might give it a shot if you are having trouble catching them otherwise.

How soon can I put them with the adult fish?
They should be large enough to be left alone by adult platies around 2 weeks after birth. This is not to say that they're ready to be put in the main tank. Bigger fish might still go after them, and they may still have trouble swimming against the rougher currents outside the breeding trap. On the other hand, keeping 20 fry in a small breeding box is a situation you want to end as quickly as possible. Consider your tank environment and weigh your options.

How long will it take them to reach maturity?
That depends on the tank environment and available food. With frequent water changes and healthy, protein-rich food, they can grow fairly quickly; with less frequent water changes and lots of other fish in the tank, they will grow slowly.

How can I stop my platies from breeding?
I've got a deadly parasite in one of my tanks that apparently sterilizes the fish several weeks before it kills them. I don't recommend it, though. Seriously, though: Keep all males or all females. Be aware that an all-female tank may include females impregnated before you got them, and if they give birth to males, they can and will breed with their own offspring. Consider an egg-scattering species if you don't want fry. If you love your co-ed tank, just don't intervene with the fry... the adults will eat many of them, often leaving you with no surviving fry at all.

Aquarium Size : 10 gallon or larger.

Compatible Tank Mates : They make an excellent fish for a community tank given their peaceful nature. The list of fish that can live with platies is large. Make a post in the aquarium stocking forum with possible tank mate considerations and Fishlore members will give you good advice and opinions on your stocking scheme.

Fish Disease : Freshwater Fish Disease - Diagnose, Symptoms and Treatment

Diet / Foods : Give them a varied diet consisting of flakes, live and freeze dried foods for optimum health. Feeding them spirulina has been shown to increase growth rates, fertility and coloration. Perhaps due to the amount of protein in spirulina. Overall, the linked study shows that spirulina is a very good thing to add to their diet.

Tank Region : All over the aquarium

Gender : The female is usually bigger than a male of the same age. The male also has a modified anal fin called a gonopodium.

Fish Lore Forum : Platy Forum

Photo Credit : Photos copyright JJPhoto.dk

References :
fishbase.se - Xiphophorus maculatus
Tamu.edu Commercial Production of Xiphophorus.