Immaculate Conception In My Fish Tank

Any idea what they are? I know it can be a bit  tricky as baby fish often don't look like they do when they're grown up.

Is the isolation tank a separate tank or one of those that fits inside the main tank?
If it's a small separate tank, you can do lots of water changes in there while still cycling the main tank, but with one that gos inside the main tank you'll need to stop cycling and get any ammonia and/or nitrite down to zero and continue with a fish-in cycle. Which could take a long time with tiny fish.......

I should have checked your other posts before my last reply. I see you are using an NTL labs bottled bacteria product. I'm afraid to tell you that is unlikely to have done much. It might contain the right species of ammonia eaters but not the right nitrite eaters - use of those has been copyrighted or registered or whatever the right term is so they aren't allowed to use the correct species. And without adding ammonia the ammonia eaters don't have any food so won't multiply.

You are now doing a fish-in cycle. Three tiny fish won't make much ammonia so you might not even see a reading for that or nitrite. But keep an eye on those two levels and do a water change if necessary to keep them below 0.25. The bad news is that it will take a long time to cycle the tank with three baby fish. The other bad news is that if they are actually dwarf rainbows, they'll need a bigger tank as they grow. Seriously fish reckons 60cm long minimum, but having had some in my 107cm long tank, I would suggest bigger than 60cm as they are very active fish. And dwarf rainbow eggs are apparently attached to surfaces by a small thread so yuor guess could well be right.

This immaculate conception is catching 

In May 2013 I had 8 male endlers. No females. 1 tiger, 1 black neon, 2 black bar and 4 snake chest. Details from this thread reply #10.
In Feb 2014 I had 5 or 6 male endlers according to this thread reply #3, though I didn't make a note of which pattern types they were.

I am now down to 2 snake chest endlers.



And a half sized black bar type. But my black bars had orange dorsal fins and orange swords on both edges of their tails. This fish has a white dorsal fin with black spots and there is just a bit of colour at the top edge of his tail fin. His body colours are also muted. This fish is displaying all the signs of being a juvenile - small in size, muted colours, swords still developing colour.

Where did he come from? There have been no females in the tank for 18 months. The only thing I can think of is that a tiny fry stowed away when I got the rice fish on 4 September. I didn't see anything like a fry in the bag but the dates are right. Only there were no endlers in the same tank as the rice fish in the shop........