[Killietalk] Re: Fry rearing basics

["Mary Ludwig" <mary at rockytop_net>]

Here's some more info that perhaps can shed light on the problem:

   >  Add a couple of pond snails to the container with the fry to help
   >  clean things up.
I have not been keeping snails or Java moss in the fry containers, but I can start doing this with the next batch.
   
   >  Wonder just how warm the container of water got after you put the
   >  light over it.
Heat from the lamp should not have been a problem.  The fry and egg containers are kept partially immersed on a shelves in heated 2.5gal incubation tanks.  So they are maintained at tank temp, which after running the light for ~8hrs yesterday was 70degF.  I was more concerned about possible trauma from the sudden environmental change, as I have read of this occuring in fry of other species.
 
   >  Next question, might there be Velvet in the water anywhere?
I doubt it, only because I have not had any disease yet in my small fish room (knock on wood).  If I'm not mistaken, Velvet is not the kind of thing that would go unnoticed for very long in any of the main tanks.  I suspected some kind of disease when my largest group of 9 fry all perished within about 48 hrs of each other.  I bleach-sterilized anything that came in contact with these fish.  If disease is to blame, I just don't know the source, unless something could be dormant/otherwise unnoticed in the parent tank???
 
> were there any extra microscopic brown spots on the fins or body of the
   >  fry?
Unfortunately I don't yet have a microscope to examine the fry under.  Nothing strange was visible to my naked eye.  Before being given the ice bath, the two most recent fry (and the oldest one that lived to 6 weeks) showed signs similar to oxygen depravation, with spinning and hanging out at the surface.  Oxygenation of the water and water changes didn't help so I put them down.

   >  Most mortalities come from poor water conditions, too much Chlorine,
   >  decaying food, etc. and secondly from disease such as Velvet. We need
   >  to take a closer look at your conditions.
   >  
   >  Send more data . . .
I tested water in the fry container last night and it was showing undetectable ammonia and nitrite.  Only chlorine coming in is a minute amount from brine shrimp being rinsed in tap before feeding.

Thanks again for the help all.
Mary Ludwig
Elkton, Maryland

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