Platies are excellent beginner fish as they are hardy creatures and don’t require high maintenance to thrive. The Southern platy, variatus platy (Xiphophorus variatus), and the Southern platy (Xiphophorus maculatus) are fascinating creatures that give birth to live young. If you are new to this breed of the genus Poeciliidae, you might wonder if they breed easily?
Platies are very easy to breed as long as their water parameters are correct. Female platies have a short gestation of between 24-28 days and may hatch a brood of 20-100 fry every time, so be prepared for a rapidly filling tank.
Not only are they relatively easy to keep in your freshwater aquarium, but these fish are also excellent breeders. In fact, they breed so well that they are considered an invasive species in some areas of the US. If you wish to breed your platies, please read on to discover
How To Breed Platies Easily
- Get a large tank of at least 20 gallons, keep your tank water clean, and make regular water changes.
- Provide your platies with temperatures from 70-82°F.
- Feed your platys regularly with commercial feed and meat and vegetable supplements
- Keep your male-to-female ratio at 3:1 to prevent stress to your female fish.
- Look out for mating behaviors and gravid spots on your females.
- Remove your female from the tank before giving birth, or provide tank vegetation for the fry to hide inside.
- Feed your fry commercial fry feed and baby brine shrimp.
How Do Platies Breed?
Platy females breed by giving birth to live young and are ovoviviparous, meaning that they carry their eggs internally through their gestation. Unlike viviparous vertebrates, the female platy does not provide many nutrients to her young but rather safely carries the brood within her abdomen until they are ready to hatch.
Platies reproduce pretty simply by the male using his modified anal fin called a gonopodium to insert sperm package into the female platy’s reproductive opening. The gonopodium is swung forward in the direction of the female and, with the side pelvic fin, forms a tube to the transfer of the sperm.
In a scary-sounding adaptation, the male platy has several claw-like structures on the tip of his gonopodium to hold the female fast during copulation. Mating is usually a short affair, with only a few seconds of interaction.
Male platies transfer sperm in spermatophores, which are bundles of sperm about 50 micrometers wide containing several thousand spermatozoa. The male releases hundreds of these bundles, but only one is necessary for fertilization. Fertilization occurs in the ovarian follicle, and ovulation and fertilization occur simultaneously.
The female indulges in multiple matings or polyandry. As the male platies may be sexually aggressive, they may suffer stress from being in a tank with a high male ratio. Although the platy males tend to perform short courtship displays, they often indulge in sneak copulations or forced mating with an unreceptive female.
Like most fish of the Poeciliidae genus, female platies can store male sperm from multiple matings in a process called superfetation. The female can access this stored sperm for several months to fertilize multiple broods of fry.
The female guppy stores their embryos inside their yolk-rich egg casings, where they receive nourishment from the yolk until they are ready to hatch. The female can give birth soon after hatching her last brood and can give birth almost every month if conditions are perfect.
How Do I Know My Platies Are Mating?
You will know your platies are mating due to the males making an S curve, swimming backward in front of the female, and pushing its gonopodium forward. The male will swim alongside the female with his dorsal fin erect and either thrust his gonopodium or copulate. Copulation lasts 2-3 seconds.
Male platies may be sexually aggressive towards unresponsive females, so keeping your male-to-female ratio at 3:1 is best. Female platies may suffer stress in tanks with a high male ratio as they have a high mating frequency.
Males may exhibit a thrusting and peck at unresponsive females who avoid their advances and engage in sneak copulations where they thrust into the female with no courtship display. However, the signs of platy courtship are as follows.
- S curving. The male distorts his body into an S shape for a couple of seconds
- Retiring. The male folds his dorsal and caudal fins and slowly swims backward away from the female
- Gonodium swing. The male moves his gonopodium forward towards the female.
- Lateral displays. The ale swims alongside the female with an erect dorsal fin and a stiff body posture.
- Thrusting. Although this appears similar to proper mating, the male rarely transfers sperm during this courtship display.
- Copulation. The male connects his gonopodium with the female for 2-3 seconds, and after contact is broken, the male usually swims rapidly around the tank.
When Will My Platy Give Birth?
Your platy will give birth 24-30 days after mating and deliver a brood of between 20-100 fry. Look out for a darkening area near the anal fin called the gravid spot and a square-shaped bulge under the female’s gills.
Platies reach sexual maturity reasonably early, between 3-4 months old. However, the platy sexual maturity is genetically controlled and varies from 10 to 32 weeks, and the period between births is temperature-dependent.
Once sexually mature, the female platy will mate with multiple males and store their sperm in the folds of her oviduct, sometimes for several months. The pregnant platy will swell and present a gravid spot near the base of her anal fin.
Gestation usually occurs between 24-30 days, when the female develops a bulge below her gills, and the gravid spot enlarges and darkens. When the fry mature, they lie curled in a circle within their egg casings and are delivered one by one over several hours.
Once the female hatches a fry, they fall through the water and shark-free of their casings. Then they will remain on the substrate or swim to foliage to escape predation. The platy breed is known to devour their young, so typically, the female is removed from the main tank to breed and then removed.
But considering that the hatchlings are already mature enough to feed and swim, a fair amount will survive predation if adequate plant cover is provided in their tank.
The platy is an excellent choice if you plan to breed fish, although you might find they breed a little too well! If your platies are breeding up a storm, you can always give your fellow fishkeepers extra fry or sell them to local pet stores for some extra cash.