Some Questions About Guppy And Platy Fry

[kuri33]

I have somewhere around 17 guppy fry and around 10 platy fry. The guppy fry are almost a month old and the platy fry around 3 weeks. The guppy fry are also at least 1/4 of an inch big and the platy fry that are with them are quite small, but I didn't catch all of the platy fry. I have at least 2 still in my 29 gallon tank and they have grown pretty big, also around 1/4 of an inch.

So my questions are:
1. How soon will guppy and platy fry mate?
2. How soon will I be able to tell males from females?
3. How soon should I separate males from females?

 

[KrystaK]

1: Typically they are ready to mate at around three months if they are fed properly and are taken care of.
2: You should be able to sex them at around a 4-6 weeks the males should obviously become males, their anal fins will turn into a gonopodium (Which basically looks like a stick ) The females will keep their anal fins the same fan shape and may develope a gravid spot, which is a dark patch around their anal fin. Though I couldn't tell the gender of a recent batch of dropped fry until they were almost two months old.
3: I would separate them as soon as you can tell their gender, as some fish mature faster than others and will try and breed as soon as they can, it's best to separate them from as soon as you can positively gender them so they don't have a chance.


Also, the reason for the size difference in your tanks could be due to a number of factors; how big is the fry tank compared to your community tank? What is the temperature in each tank?
The size of the tank is important, if the tank is small it will stunt the growth of the fry.
If the temp is 80F or above the fry will grow faster.
Also the amount and type of food you feed will affect their growth.
The fry I left in my community tank grew much more quickly that the ones I had in my nursery, probably from a combination of the factors above.

 

[kuri33]

I can kind of see a gravid spot on some of the guppy fry, but i don't think they have their "sticks" yet lol

My 29 gallon is around 80 degrees F, my 5 gallon fry tank is around 82degees F. I don't put any food that is specifically for fry in the big tank, but I put crushed up flakes in the fry tank about 5-10 times a day.

I take it the platy fry will be more difficult to tell apart? They all have black fins. The mom is a golden wag platy, not too sure about the dad.

 

[kuri33]

Also, what is the preferred why of separating them? I have 4 fish tanks, a 29 gallon, a 20 gallon, my 5 gallon tank that i dedicated for fry, and my 2.5 which i turned into a birthing tank. I have two floating breeder traps, should I put split one gender of fry in those?

 

[OldMan47]

If you want to prevent breeding among related fish, separate them by gender as soon as you can tell them apart. I am not a serious line breeder so I never bother doing that. Sibling crosses are really not a problem but a proper breeding program to fix a particular strain would require about 10 tanks to hold males, females, selected breeders of each sex, fry growth, etc. If you are like most of us, you just want some fry to survive and keep your tank population up without spending tons of money. For that you really only need 2 tanks, one good sized one for fry growth and the other for juveniles and adults. It can even be pared down to a single tank if you provide adequate cover and are not concerned about maximizing fry survival. A fry grow out tank should be large enough for the number of fry you are trying to raise if they were all adults. (If you have 30 fry, put them in a tank big enough for 30 adults.) That often means the grow out tank is larger than the adult tank, not the other way around.

This tank gives me a nice scoop of adult guppies every few months to sell at club auctions and is self sustaining. It does have a nice dense cover crop of java moss and the fish are mostly fed daily.

For guppies or platies a tank temperature of 74F, 23C, is plenty. Higher temperatures will give slightly faster growth, and maturity and death. The whole life cycle will speed up, but you sacrifice fish quality when you do that. When the fish have adequate time to mature they end up being better adult specimens.

 

[kuri33]

I think i can pretty much tell some of them apart now. I think the ones that are starting to get color are males.. does that sound correct? The ones getting color don't have any hints of ether a gravid spot or a gonopodium. However i think over half have ether noticeable or possible hints of a gravid spot.

I want to separate them so I can control how many fish I have. I don't want the babies to have babies because the adults are already having them. I plan to separate all the adults as well. and I'll put two fish together for a short period of time if i want more fry after the females stop having them, which is about 6 months after she's separated from a male, right?

Sorry for all the questions