What signs can I expect to see when a guppy is going to give birth?

[Lesley]

I have a few guppies, two male and four female. Sometimes I think the female are pregnant then I separate them into a breeding net. Soon after though they don't appear pregnant any more so I put them back with the others. Now three of the females look pregnant, but I don't know for sure. Is there any way to tell when they are ready to give birth. I have quite a bit of live plant in the tank so the fry would have a place to hide if I didn't isolate them. Does anyone have any suggestions as to what would be the best thing to do? Should I try isolating the females again or just leave them in the tank with the rest?

[shev]

I would let her give birth, then catch the fry into the net. guppies get a gravid spot near their ventral fin, which gets darker as she gets ready to give birth. she could be giving birth then eating the fry. guppies are \ live bearers, but they carry the eggs until they hatch, if you put the guppy in the net it could force her to prematurely give birth to unhatched guppy eggs.

[Lesley]

Hi Shev,

Thank you for your suggestion. I think it is the best thing to do as I can't keep putting the females in and out of the breeding net. I noticed the dark spot you are talking about, but so far no fry.

[fish_doc]

I made a breeding box out of the plastic craft mesh. The holes in that are big enough for fry to swim through. I leave this on my guppy tank all the time that way if I am not around when fry are dropped they can swim in there until I can move them to their own tank.

[doggydad38]

Fish doc is right, the gravid spot gets very dark when the female is about to give birth. The other thing to look for is when the female "squares off." Look at the vent area between the anal and ventral fins. During pregnancy this area has a nice smooth curve from the abdoment to the caudal peduncle. When the female is about to have or is having fry, that area looks square. It looks the same when she is going to the bathroom only even more exaggerated.
Unless you are breeding guppies on a large scale as I am, let them have their fry in the tank and save the remaining babies. These will be the fastest and healthiest ones and will give you good breeding stock later. Hope this helps.
Tony