Few areas which i have taken note to improve subsequent batches as i re-learn ....
Issues with Frys
1. Infertile Eggs
Inexperience young female
2. Insufficient Eggs Collected
Likely eaten by other species of corydoras like C. atropersonatus who is known to eat their own eggs. I have seen a dying fry got eaten up today when i let it down into the main tank.
3. Dies inside it's shell before hatch
Occur in my first batch. Suspect too early retrieve of eggs and fungus.
5. Unable to detach it's head from the shell.
Do not attempt to help remove it. At this stage the fry is very fragile and may cause more harm.
6. Fry refuses it or swirl around
Brine shrimps are not clean enough from salt. Rinse many many times.
7. Blood streak in the stomach
Looks healthy but will die suddenly. Suspect constipation from brine shrimp eggs.
8. Weak Frys and turn white
Suspect poor ventilation. I moved the floating hatchery nearer and ensure the sides are open to flow.
9. Feed too early
Will wait till Day 11 next time for closer observation.
10 Major water change
Even on main tank, 50% seems ok and will not impact frys. Cutting down on food to the adults will help.
Daily changes even small amount may helps.
11. Day 14-17 period, Frys are truly free swimming and observed to eat external foods.
This may mean prior weeks to avoid feeding unless necessary as rotting or fungus foods will weaken the frys.
12. Oil formation on the the surface
Hatchery without it tends to product more active frys. Just enough floating plants and ensure near to filter turbulence will minimize their formation.
This list will be updated subsequently.
28th April 2012
3rd May 2012 on point 11 and 12.