An interesting observation

[auntiejude]

When one of my axies laid eggs I knew I couldn't raise them all, so I culled a whole bunch () and kept about 50. They were all laid in about 36 hours, a total of around 500 from a very young mother

I split these 50 eggs into 3 groups - I left some in the tank (18C), some in tubs in my living room (20C), some I put outside in my outhouse(7-15C). 2 were accidentally artificially hatched by damaging the eggs when they got sucked into my siphon.

The outhouse eggs have another week or 10 days to go (as expected), they haven't got gills yet and they are not wriggling.

But to my surprise the ones I had left in the tank have hatched first - I removed them on Sunday because I could see there were almost ready to hatch. I have about 20 babies and a few more to hatch from the tank eggs. The ones in the tubs look like they'll be hatching in a day or 2 - making them 3 days behind the tank eggs. Now logic dictates that the ones kept in a warmer environment should hatch first - any idea why it's happened this way round? Oxygen levels? Circulating water? Something else?

 

[Jennewt]

Are you measuring air temp or water temp? The tubs have no lid, so they evaporate more and are cooler. The tank has a lid and possibly some heat-producing appliances (lamp, filter). These factors could easily make the tank water warmer than the tub water.

If that's not the answer, then I think your other factors, like oxygen levels, might be the reason.

Sometimes they'll hatch earlier or later in development (slightly preemie, or overdue). So it's possible the ones in the tank are hatching sooner, but didn't actually develop faster.

 

[auntiejude]

Thanks Jen, I just found it a bit odd. Yes, I checked water temp rather than air temp, and the tub were kept right beside the tank. I left lids over the tubs to prevent too much evaporation, but loose enough for air exchange at the surface.

Another weird observation - I had 2 tubs of eggs that I removed as soon as they were laid - one tub has hatched this morning (8 out of 10 eggs) and only one hatched from the other tub (1 out of 12)!

And I have had my first casualty . One of yesterdy's hatchlings looked a bit sickly - quite small, all curved and gills missing on one side, and he didn't make it through the night.

 

[SariYappa]

Awww, I'm sorry for your loss... Probably not the last, but sad just the same

Very strange about the hatching... Mother nature likes to show us that we really aren't in control, we just think we are

 

[auntiejude]

All my 'inside' batches have hatched, a total of 36 survivors . The last ones hatched yesterday, I just have 20 'shed' eggs that I've kept cool outside to slow them down.

A few more casualties overnight, but not unexpected.

They took 7 days to hatch - most from day 13 to 17 - exactly as the text book says!

 

[auntiejude]

Today I had my first 'shed' babie! I brought in the batch I kept outside over the weekend as they were wriggling like mad, and I had 2 hatchlings this morning

So they are a week behind the others.

Mind you, it's interesting now that I have week-old larvae next to newly hatched babies I can really see how big the first ones have got! And their little orange bellies after a good dinner of brineshrimp is amazing (will post pics when I can).

 

[auntiejude]

Wanna see orange bellies?