Amano Shrimps Breeding question

[coolraven]

Hi there.
My curiosity began when I have received a couple of Amanos. (9 females and 2 male, to be precisely). But, as I was raising them, I have noticed that all females are berried. So, having the time needed for trying to raise the zoes, I decided to give it a go.
First of all, I read all the information available on the internet, but it seems that I'm doing something wrong.
My experience goes like this: when the female was ready to give birth, I moved her to another tank, with same conditiones as the main tank(ph 7.0, temperature 76). After 2 days, I woke up in the morning and found few hundred of zoes floating in the tank. so I returned the female into the main tank, as she was not need anymore, and also moved the zoes to a smaller(8L) tank, with light on 24/7. Water conditions same as the main and breeding tank. As for hardware, a lamp for the so need light, and a small heater (I have to mention that this tank does not have any filter, so no aeration).
My problem until now is that, while I'm waiting for the minimum 4 days to be able to move them in brackish water (17ppm)or full strenght water(34ppm), half of my zoes are already dead. The plan is to try raising them at different salinities, to see which one suites them better.
Can anyone tell me what I'm doing wrong until now, or which could be the cause of my casulties.
I will also keep you updated with the future developments.

[Mustafa]

Why exactly are you waiting 4 days?

[coolraven]

Hi there,
In my attempt to recreate their natural "way", from the river to the sea, I considered it takes a time to get from fresh so salt water.
My action is also based on some breeding reports, which recommend to keep them in fresh water for minimum 3-4 days.

Best Regards

[Mustafa]

Just put the larvae in saltwater right away. "In nature" the adults are usually fairly close to the sea anyway (lower reaches of the river). I don't know if this species in particular does it, but Macrobrachium species, with similar larval requirements, migrate to estuaries before they release their larvae. Either way, in 3-4 days you can cover a ton of distance...I doubt any creeks that these shrimp occur in are even that long (especially if one considers the facts that Japan has a mountain range right smack in the center, and rivers can't cross mountain ranges, and no two east-west points in japan are more than 300 miles apart, actually much less). It would take most larvae only hours to get to the sea. Even a fairly slow flowing river, say about 3.5 miles per hour (walking speed), would cover a distance of 84 miles in a day and 336 miles in 4 days. In my experience most creeks and rivers actually flow faster than that.

[zapisto]

personnally i "dump" them in saltwater as soon as i remove the female (when most of the larvae spawn)

[coolraven]

I don't question the accuracy your reasoning (which I find logic), but the fact is that I have tried to throw them directly. In salt water all zoes were dead in 15 minutes, in brackish water in 2 hours. On the other hand, in fresh water during the third day I have had 50% casualties, and on fourth day all were dead. So I believe the truth (in my case at least) is somewhere in the middle.
Now having the problem solved (sort of) with the appropriate time of dumping in salt water, a new question rises. To keep them in brackish water, full strength sea water or to gradually increase the salinity from brackish to sea water? So, in order to do so, I will try all of the possibilities.
My objective is to go step by step, and try all the possibilities for each step, to see which one suites my baby shrimps best.
Any tips or suggestion is welcomed. I will also keep you updated.

Best regards

[coolraven]

A little advice to whom it may concern.
My experience so far showed there has to be synchronization with the female closing to give birth.
I have had 9 females berried, all during 2 weeks. So, at certain point, I couldn't tell the difference between the first one which got berried and the last one (they were hard to observe through the plants). All I could see was females carrying eggs.
When the first berried female was closing 4 weeks, I took the decision to move them all to the hatching (freshwater) tank. For the first females it was OK (they released the zoes normally), but for the last ones it was a little too early; so they dropped their eggs before the zoes were fully developed.
Conclusion: do not move the berried female too early in the hatching tank, as she might loose her "pregnancy"

Best regards