Struggling Molly Fry

[campbellmay]

While doing a water change this afternoon, I discovered two stray Molly fry (from a batch I suspected had been born but were eaten before I got a chance to see them, let alone rescue any) hiding in the tank. I only managed to catch one of them, and have added him to a fry tank with seven other babies from a different Molly.

Ever since I took him out of the main tank (and maybe before that, I'm not sure), he seems unable to swim. He sank straight to the bottom of the fry tank, though he's able to move his fins and wiggle around when he wants to change positions. Some of the other fry have lightly nudged at him, and he was able to dart away (only to fall immediately back to the bottom). He seems to be breathing heavily, though I can't really compare it to the others, since they are so small and move so quickly. He's been this way for about six hours with no change. I know there's nothing wrong with the fry tank, since he acted this way even in the container I took him home in, and the other seven have been living quite happily in the tank for several days. Even with a magnifying glass, I can't see any signs of damage to his fins.

Could he have been somehow harmed by the net when I took him out? Is he merely stressed from the switch? Has he just grown accustomed to lying as still as possible in the gravel to keep from getting eaten?

I know it's just one little fry, but I hate to watch him struggle, especially if there's something I can do to help him. Any advice you guys can offer is much appreciated, even if it's bad news.

 

[WILDER]

He's not going to make it sorry, sound like swim bladder with a second infection of finrot, don't know if the swim bladder was damaged during birth.
Did you match ph and temp when you added him to the other tank.

 

[campbellmay]

That's what I figured...it doesn't really look like a fixable problem, unless he fixes himself. You're right, a swim bladder issue seems very likely. Is it possible for them to get fin rot that fast? He's just a little more than a day old, and there's no apparent damage to his fins. But it's very possible that he got nibbled on before I got him out, and the injury is too small to see.

And no, I wasn't able to do anything special to the fry tank besides fill half of it with water from the main tank. It has the basics, but I can't really afford a whole new set-up for the babies. I'm a bit of a beginner, and the fry caught me a little by surprise, even though I knew the fish were pregnant. As a result, I didn't have the equipment needed on hand to isolate them properly. I have since invested in a tank divider, but the other fry seemed to be quite happy in their new tank and so I figured it was better not to bother them. If they start showing signs of distress, I suppose I'll go ahead and move them back.

Oh, well. You save some, you lose some. Thanks for the advice.