second fail attempt at raising the eggs

[rapitts]

Hi All,

I'm attempting to raise the clown fish eggs from a pair of ocellaris clowns (7 years old).

However so far I've failed, I've got my green water and rotifers (within reason) ready but I've noticed only a few fry (4-5) actual emerge from the egg, at the moment the timing is roughly 7 days before the first emerge.

The clutch turns silvery so I normally then transport these to the hatching tank which is fed using the same tank water and mini pump (behind some filter mesh) however I'm stuck trying to resolve why the complete clutch doesnt emerge.

The pipe feeding the hatching tank is gravity fed so I did aim this over the eggs to attempt to replicate the male clownfish.

I did leave a small light on overnight so prehaps this is playing a factor or perhaps the eggs aren't strong enough to breakout?

 

[Uncle99]

The flow over the eggs must be gentle but changing.
The fish "fan" the eggs so not a constant flow.
Eggs only hatch in the complete darkness.

I found it easier to hatch in a separate tank but with parents, they take the best care.
The tank has a plastic wall full of 1/8" holes. Eggs and parents on the top half of the tank.
The bottom half is the safe area for fry.

When eyes silver, lights out, I shine a flashlight in the bottom half for 4 hours, then turn it out.
I repeat each night till hatched. After a hatch, Once light returns hatching stops.

Fry run and stay with the light, on the bottom safe half so parents can't have dinner.

As soon as, I carefully remove the fry to a black 5g for rearing...

 

[rapitts]

hmmm, maybe I move the parents next time however guess this will cause a bit of stress.

Going to increase the feeding in case the quality of the eggs isnt 100%.

Does all your fry hatch over two nights?

 

[Uncle99]

Yup, small first night, other 80% second

 

[BonsaiNut]

Uncle99 knows what he's talking about

You can also keep the nest in your main display tank and remove the fry when they hatch. This is actually pretty dependable if you use a light timer so that the lights turn off on the same cycle each night. Wait until the nest is about to hatch, and then turn off your filter a minute before the light goes out. Place a flashlight so that it shines in an upper corner of the tank. Do not have it pointing down in the tank so that it shines on your substrate. Rather, have it go in from the side and out the front panel so that the light beam only passes through the water in the upper corner of the tank. Make sure the room is dark with no other lights visible (i.e. no television or kitchen light shining in the background). Then simply wait for the fry to swim up to the light and scoop them out.

It is critically important that when I say "scoop" I mean with a cup or similar instrument. You CANNOT touch the fry physically with anything or you will see a huge spike in mortality. NO NETS. Simply use a glass or other vessel that is already full of water, and maneuver the glass so some fry swim into it, and lift glass out, and place the fry in your rearing tank using the same method in reverse.

As is apparent, the fry are strongly photo-positive in the beginning and you are trying to emulate the moon If you can have a single diffuse light over the middle of your rearing tank for the first couple of days, I have found it tends to help keep the fry off the walls of your tank and reduces head injuries (bulldog nose, broken jaw).