Archive for December, 2008

Same player shoots again

Sunday, December 21st, 2008

Both the hatchingtank and the breedingtank have been cleaned.
The hatchingtank has been refilled with water from the main tank. The heat is on and now, we wait for a pregnant shrimp to show herself.

Day 13: total loss

Friday, December 19th, 2008

I have been looking in the tank for some time this morning, but I have not spotted any larvae.
I will wait for a second opinion tonight, but I fear batch 2 was a failure on day 13 .

Strange swimming

Thursday, December 18th, 2008

This morning I have spotted at least 2 larvae still alive.

One of them was swimming strangely with a bent body and small thrusts. It seems these larvae are larger and more developed to me, but the opinions once again, differ.

We have decided to give this survivor a chance though, we will not start on batch 3 untill either batch 2 is a total loss or growing out in fresh water…

25 ppt = lost

Wednesday, December 17th, 2008

The larvae that were transfered to 25 ppt are all dead.

In the 17 ppt tank we have seen about 3 or 4 surviving larvae. These larvae have developed a little further. They have been seen swimming horizontally, but we are not convinced they will survive tomorrow…. dreaded day 12….

Alive, but not so alive

Wednesday, December 17th, 2008

This morning’s check revealed some larvae still alive in both tanks. They do not appear healthy at all.

Tomorrow is day 12. The first batch was totall loss on day 12. From the looks of it, this batch could very well suffer the same fate.

They have been fed according to the new feedingschedule.

Lighting

Tuesday, December 16th, 2008

The opinions differ on this one. Is the lighting really a contributor to the larvae’s health? And if so: does the type of lamp matter?

The “other ones” both used a Fluorescent light, we were using a incandescent light.  At this moment both tanks are covered with the fluorescent light cap of the growout tank…

Don’t know if it helps, probably does not hurt.

Still alive

Tuesday, December 16th, 2008

This morning for the newly instituted “morning feed” larvae in both tanks were alive. They do not appear to be “kicking” however.

The larvae are less lively than on day 7, but this is to be expected after their brutal treatment.

There will be a second feeding tonight as 18:00 and again around 22:30.

learning… learning

Monday, December 15th, 2008

The surviving population of larvae was split in 2.

One group remains in the breedingtank, in which salinity has been reduced to 25 ppt. The other group has been transfered to the hatchingtank. There we have reduced the salinity to 17 ppt.

We have no hope that the larvae of this batch will survive, but we hope to be able to tell if we have larvae that prefer lower salinity.

In short: if they all die at the same time, this was all too much for them, if not, the batch that survives the longest sets the level of salinity for the third batch.

Salinity

Monday, December 15th, 2008

After consulting “The other ones” we decided that it is possible the salinity is at fault.

Mike Noren reports heavy losses on day 8 and 9 due to too low salinity. Our salinity has been at 2024, so it should not be considered too low.

Perhaps the french aquarist is right and we have another subspecies of shrimp. One that survives in more brackish water.

We have decided to split our population. One half will be transfered to the hatching tank and be given a salinity of 25 ppt and the other will get a refill of fresh water until we arrive at a salinity of 17 ppt.

Brainstorming possible suspects

Monday, December 15th, 2008

While brainstorming we have come up with the following possible suspects:

  1. Starvation
  2. Salinity to high
  3. Yeast poisoning
  4. Bad lighting

We will be looking at all these today to come up with a plan (to avoid the day 12 disaster)