Fat Guppies Then Back Skinny?

[mrsdoubtfire]

I have 2 guppies that appear to be very fat and gravid in the morning before first feeding of the day. I move them to a birthing tank along with 3 preg. female platies and then within a few hours they are right back skinny showing no signs of being preg. and the gravid spot goes from black back to light brown... so then I put them back in the main tank and this has been going on for about a week now. Why are they doing this Tomorrow morning Im gonna try to post a picture of them before their first feeding and then another picture of them several hours later so you ca see what I'm seeing. Usually the best time to tell if a guppy is really preg is in the morning before they get any food for the day as they will still be huge. This is so confusing and I dont want to keep moving them but I dont want them to be in the main tank and out come the fry only to be eaten just like one of my Marigold Swordtails did a few weeks agon The very day I decided to take her out...she dropped the fry the night before. Any suggestion before I post pics would be greatly appreciated.

 

[HCpetraitis]

Well, what you said about them being more pregnant in the morning is true. The babies eyes are easier to see because the mother is calmed down in the night and then all the babies feel relaxed. Then, during the day the mom moves alot and is very active which makes the baby's eyes less easy to see.