Why do I loose my postmetamorphosis juv?

[Bidadari]

I have initially 17 onyx percula babies. I've never lost any of them since day 3. Today they're 23 day old, and I only have 14 left. Between day 19 to 23, I've lost 3 of them.
They're in a 2 1/2 gallon tank with hydro-sponge filter in it (I'm thinking of transfering them to a 10 gallon, but I'm afraid it will cause too much stress that I'll loose most of them. So I think I'll wait transfering them until they're older).
I do roughly 10% water change daily & siphon out all uneaten food after every feeding. I started feeding them pulverized flake a couple of days ago, and I introduced cyclopeeze yesterday.
I still feed them with bbs since I'm not sure that all of them have taken the flake or cyclop. yet.
I know I'm kind of late introducing the flake or cyclop., but this is my first time trying to raise the babies, so I'm still learning along the way.
My questions are:
- Is it normal to loose postmetamorphosis juvies? I would think that it's not since by this time they should be much more hardy.
- Also my babies do not seem hungry when I feed them at night, and I usually only feed them twice (morning & night). There're usually still left over bbs until mid-afternoon, so my guessing is that's the cause that they're not too hungry at night?

Any input will be much appreciated! Thanks.

 

[firebirdbandit]

Babies eating just brine shrimp are know to suffer from sudden shock which makes them very skittish and just a little shock can cause them to die suddenly. Try to ween them off of the brine shimp or at least gut load the shrimp until you can.

 

[Bidadari]

Firebirdbandit, I'm trying to wean them off of bbs. I've read Joyce Wilkerson's book which also said the same thing about bbs causing shock. I've been giving them flake food & cyclopeeze for a couple days now. Some of the babies eat them, but not all of them yet; therefore, I still give them bbs.
What do you gut load the shrimp with? Phyto & selcon?
Do I better off skipping bbs, and jump directly from rotifers to pulverized flake? How long does it take on average for the babies to start eating the new food when you switch their food?

 

[billsreef]

Do you keep phyto growing in your rearing tank? Instead of pulverized flake food, you might want to look into trying Otohime larval rearing foods from Reed Mariculture. They are excellent nutritionally, and sprinkling a little bit of the Otohime A (the small size) a couple of times per day makes a real difference in growth and larval survival. You can generally start them on the Otohime at the same size you start the fresh hatched Nauplii. I'd also start the cyclop eze as soon as they are big enough to eat it. The more and better nutrition you can give them, the better they will do. You also shouldn't switch any foods cold turkey, but overlap them. Also keeping green (nanochloropis) or brown (Isochryis)water in your rearing tank will provide nutrition to your rots and artemia throughout the day till they are consumed. It will also help maintain water quality via the phyto taking up ammonia.

 

[firebirdbandit]

Yes that has always worked well for me using phyto in the rearing tank.

 

[Bidadari]

Thanks for the advice. I was adding phyto until the day when there's no longer rotifers in the rearing tank, but never thought of adding it again after the babies started eating bbs.
Now I think it's a big possibility that the babies died due to brine shrimp shock. I did take out the sponge from the filter to clean it & changed more water than usual (20% instead of 10%), so that must be enough stress to cause the shock & I did lost 1 baby last night.
I hope they're all going to eat the cyclop. soon; in the mean time, I'll keep overlapping the gut loaded bbs & cyclop.
Otohime order is in
One more question for tonight, how many times a day do you feed postmetamorphosis babies?

 

[Baalz]

I wouldn't keep adding phyto after the rots are done.
Careful with those sponges too.. they get toxic easily.

I feed my post mets once early morning and once in the evening. Others do it quite a bit more. But this has worked for me and Iv'e been doing it for 6 years non stop.

 

[Bidadari]

That's what I've been doing so far, feeding those babies twice a day. I still notice that at least 1 hasn't shown any interest in cyclop. I guess I'll keep on trying. I can't wait to try Oto, but it won't get here until next week.

As far as sponges, yes they do get dirty pretty quick. I noticed lots of cyclop. get suck into it.