GSM hatching over two days?

[GregDoug]

I noticed that my GSM clutch hatched out about 30 babies on the 4th night, when the majority (almost all) always hatch on the 5th night. I do not know if I just never noticed the few babies before on the 4th night or if this is common? Do the 4th night babies live just as easily when fed rotifers or do they die as they are premature? I caught out the 30 babies and placed them in the fry tank but the next night mixed in all the other babies so I can not really track it but thought I might try again next week. Also, my GSM spawn and hatches a clutch every 10 days (from the hatch of a clutch to the hatch of the next one). I stuff the parents with highly HUFA foods and such... should I try to slow them down? I thought something like every 2-3 weeks would be more average.

 

[billsreef]

Has the water temp in your tank increased a bit?

 

[GregDoug]

Bill,

I thought temp and stress too. It ends up that I was on my fourth night, turned the flow off (its a system, so the water cooled from 82 to about 77 - I didnt think about it and made a mistake . Anyway, when only 30 or so hatched, I thought I made the mistake of chilling the water a little... but then when I wrote it down in my log, I was a night early.

I figure the temp change may have done it... just wanted to know if other people have a few early birds hatch a day early? I had about 3k and about 30 hatch early... so its only about 1%

 

[Fishboy42]

It happens sometimes that a hatch is split over two nights. I take it that they are "hedging their bets" on the survival of the larvae. For me they seem to survive equally well, unless on the 2nd night of hatch they don't have enough yolk left.

This can happen also if there is light in the room that prevents the nest from hatching properly (so it is delayed for the next night)--those hatches tend to be weaker since they really are a day late.


IME 4 days for maroons is pretty fast at 82. 10 days between nests is a good schedule though. HTH

Matt