eggs at night...

[Angie Lanie]

Our lab was wondering if anyone knows a trick to get your fish to 
lay eggs in the night.  Will a little bit of light flashed on at the time 
you want work?  Or must the fish's whole internal clock need to be 
reset (ie: gradually rotate the light cycle from day-light to night-
light)?  We're trying to avoid coming in periodically throughout the 
night to look at the eggs at different time stages.   Before I rig 
something up, I thought maybe someone could enlighten me on 
anything they've tried.  

Thanks,
Angie Lanie
Zebrafish Room Manager
University of Minnesota