Platy fry...not growing

maxw47

On my ten gallon, there is a little refugium on the back (only about a gallon). I keep about 20 at a time in there until they get big enough to sell, and the mom has the rest in the tank. At least, that was the original idea. They have just kind of stopped growing. And based off of pictures of other fry and their age, thay should be a lot bigger. I am kind of thinking that it is the small space, but I am not entirely sure, and if it is that, I am worried that they will get stunted...not what I want. I feed them crushed up flake food (omega one) and there is Java Moss in there as well (the really tiny ones supposedly eat the little micro-organisms). I feed about a half a pinch in the morning and a whole pinch in the evening, sorry that that is a little hard to picture. What could it be??? Thanks in advance.

zof

There are a few major contributing factors to stunted growth and fish health in general, first being tank space/crowding, second water quality, third nutrition, fourth stress. I'm actually going through the same thing you are I had a couple good batches of platys then I got a stunted group, got some stunted rams and angels too. In my case I believe the factor is tank size and possibly water quality, some people swear by a daily to every 2 day water change with fry. While I've also kept the batches in a 10 gallon area, when I redo my tanks my parent angels will be moved to a 36 gallon bow front and will use my 50 gallon as a fry grow out to see if that helps but if I get a batch before then I will try and do a water change every couple of days to see if that helps.

Its just all about those 4 factors I mentioned and to research and play around until you find something that works.

maxw47

All right, that is really helpful. I think my problem is space. I looked on the package for the refugium and it said it is only 1/2 gallon. For 20 Platy fry, that seems like a lot. Water quality couldn't be an issue b/c my params are as follow: ammonia-0, nitrites-0, nitrates-<10, ph-8.2 (a little high but fine for platies from what I have heard). I do not think, although correct me if I am wrong, that nutrition is a problem either. I really like Omega one for its ingredients/quality. I forgot to add that I give mini Hikari wafers about every 2-3 weeks. If space is a problem then stress is sure to be as well. With all of that said, where should I go from here? If space is the problem, then the most reasonable would probably be to get a 5 gal. fry tank. The only problem, I am thirteen and my financial situation doesn't look like it is ready for a new tank. What would you guys recommend from here? Thanks!

jgraf

My suggestion would be to let the fry stay in your main tank from birth. Get a fish that hunts fry. Put some hiding spots in all four corners of your tank and let nature take its course. 99% will die or get eaten which is a better chance than what they have in nature. The survivors will be bigger, stronger, smarter, and faster. Adjusting your hiding spots is key to setting a survival rate but you want to cull the weak. I have fry that grew up with an angelfish, barely any survive to a safe size but the survivors are impressive* specimens. If not for some important issues that I don't quite understand, I would get into breeding platies myself.

Sure this doesn't sound like a typical breeding program but it's a start to getting a strong genetic line. Breeding platies to sell isn't very profitable (so many people have Platy population problems) unless you get that extra special Platy trait that becomes desirable. If you want to do this at thirteen, start mowing lawns, babysitting kids, or begging the parents, because you will need multiple tanks and a good understanding of selective breeding.

Additionally, I was told that growing swordtails release a hormone which inhibits the growth of other swordtails. Platies and swords are closely related and mostly hybridized so it isn't a stretch if platies secrete the same hormone. A larger tank, and/or less fry will dilute this hormone.

*My surviving Platy and Swordtail fry that made it to sexual maturity are ALL female and highly aggressive for livebearer standards. They always spar with each other and nip at adults (including the large angel) to steal food.

maxw47

Thanks! I was actually thinking about doing that when I first started breeding, but I decided to take the other course. I think I am going to switch to the method you were explaining. Would you recommend putting all of the Platy fry that are safe right now back in the main tank? Another quick question, my male will only mate or even pay attention to one female in the trio, how can I make him breed with the other one (if that is possible). I have already tried taking out his preferred female for while, but that didn't work.

fish monger

Actually, I don't think that platys are big fry eaters. I'd leave them with the parents in the breeding tank without the refuge. Just have a lot of floating plants for them to hide and make sure the parents are well fed. Removing the parents would be the best option; however, that depends on your resources.