massive death, night of day 8
massive death, night of day 8
The larvae had been doing very well. Only a couple of dead each day. The living were divided into two camps. One group hugging the back wall, and another group swimming in the middle. Hoff's book says that wall huggers are doomed, but they all had full bellies yesterday. Everything seemed to be OK. I fed them some finely powdered cyclopeeze and formula 1 several times throughout the day, there were tons of rots in there, and I fed them some bbs, but not a lot. Ammonia seems to be climbing slightly, so I thought it would be OK to introduce a sponge filter that has been running in my other tank's sump for a couple of weeks. It was kind of funny, when I put that in, I noticed that most of the larvae swimming near it stopped swimming, like they were resting. There was not a strong current near it, but a trickle of water coming out of the top.
Last evening everything looked good. The larvae were swimming around fat and happy.
It was Day 7, and many of the larvae were doing the tail curling thing that Joyce's book says is indicative of impending metamorphosis. Good! Some were getting some dark pigment, and I imagined seeing a tiny white band on top of their little heads.
This morning, half of them are dead. There are hardly any on the back wall. The ones swimming looked thin and fatigued. Feeding powdered food caused some activity, but not as much as I would like to see. I fed them bbs, but I am afraid it may be too big for their tired mouths to get around. I did a rotifer count on the tank water, and for the first time it is down less than 8 per ml. I am enriching some to add right now. I also added a little choramX to help detox the ammonia. I don't understand what happened. My previous batch from September had no losses at this time in the life cycle.
My guesses:
1. Joyce says metamorphosis can kill them all by itself, although my September hatch had no losses before or during metamorphosis.
2.Something wrong with the sponge filter
3. I didn't feed them enough last night.
4. The wall huggers were, as Hoff says, doomed, and this is their time to go.
Anyone else have a thought about this large die off?
Thanks in advance,
Kathy
