On Friday evening, I noticed that she was acting a bit strange, following behind and below the goldfish, near the bottom. Like she was cowering or trying to hide behind them. I was also concerned that when she tried to eat the food flakes, they seemed to come back out of her mouth, as if she couldn't swallow them.
On Saturday morning, she was very skinny, as if half her stomach was missing, and seemed to be again hiding from the other fish, and not even making much attempts to eat. I was concerned enough to move her into a small tank, and drop in some food for her, in case she was not able to compete with the others for enough food. But my reading on the 'net indicated that these signs may point to a female who has given birth.
Sure enough, by the evening, she was acting fairly normally, so I introduced her back into the aquarium again. Since then, I've noticed that when the other swordtails swallow the flakes, some portion often comes back out again, so this seems normal. A few days later, our orange female swordtail is still quite skinny, but otherwise seems fine:
Now I'm looking for signs from the other female swordtail. I read that before giving birth, there is often a dark spot in the anal area, and even some chance of seeing the eyes of the babies inside. Or perhaps I'll note some change in behaviour, and attempts to hide from the other fish.
I am thinking to get a second smaller tank set up, for the offspring, if I am able to retrieve any before they are devoured. (Wow, not much chance of that, since the goldfish are always hungry, and very quick!) That, or a birthing apparatus. We'll see.
A few more photos... My mom gave me two cool lava rocks which she found. I boiled and set them in the tank, and they not only look good, but they hold down the plants (which get otherwise dislodged from the gravel too easily:
I was also excited to get a photo of my pleco in "action" tonight, feeding along the bottom. He looks even more cool, when he has his fins stretched out like this:
I got a photo of his underside a couple of days ago, this guy looks quite amazing from every angle: