my observations with breeding Amanos

[brbarkey]

I have some interesting observations about breeding amanos. I have two separate tanks with amanos in them. One is at school and the other is at my home. The group at my home always has eggs. The group at school never has eggs. The water chemistry at my home is a pH 7-7.1 and gh of 15-18. The water chemistry at my school is a little different because it comes from RO Water, which i rebuild to a gh of 8 and the ph always fluctuates from 7 to 8...my controller sux but that’s a different story.

My first question is why is there a difference between the two tanks...I would like to get the shrimp at my school to have eggs but I dont want the same hardness...Do you think its the swing in pH that causes the lack of eggs? What’s everybody elses water chemistry like when their amano's have eggs?

My other observations are from my breeding of the amanos. I have used the methods by this article
http://mikes-machine.mine.nu/breeding_yamato.htm

I have successfully breed amanos twice using this method both times yielded 5 amanos each. Both times major losses occurred when I moved the larvae from fresh water to salt water... I think they were getting caught in the air stone bubbles or something. The first time the larvae disappeared, i thought died, but in 3 weeks i found 5 amanos in the salt water tank...i moved them to a freshwater tank where they are doing fine. The next attempt the larvae disappeared and i thought they died as well...I didn’t really check until three months had passed and I found 5 amanos in salt water thriving. They were small but all healthy. I left them in there for another month or so to see if they would live and they did. I moved them to a fresh water tank and they are fine as well.

The water chemistry in the breeding tank is unknown because i never tested it. However i did test the specific gravity and I always kept it around 1.018.

I just thought it was weird that the adults could live in salt water

The next step is to get mover yield from the amanos...

[Mustafa]

Interesting observations. Thanks for the report!

As to why the females in one of your tanks are not carrying eggs...the constant PH fluctuation would definitely be a reason. I guess C. japonica are pretty tough because many other shrimp species would just die after a while if the PH fluctuates too much. You want to keep their environment as stable as possible. Once that is given they should produce eggs just fine provided that you feed them enough.

[chlorophyll]

I just had my first successful Amano metamorphs. My experience is much closer to what the original poster in this thread described than to the Mike's Machine write up, in that it's kind of like the less you do, the better chance of success. I didn't lose my larvae and discover PL's later, but my care was pretty minimal. I don't have the total yield count yet, but it looks to be more than 10-20 coming out of a 2L container, and I hadn't put many larvae in there in the first place.

Water was somewhere in the 26-31 ppt salinity range, temperature at 26-27 C. Moderate aeration with a fine bubble airstone. Unsure if this was necessary, but I introduced rotifers and had them culturing right there in the larval container. About every 4 or 5 days or so, I scooped out about a fifth of the water and fed the culture with some clean water and some greenwater (I had Nannochloropsis and Tetraselmis, but possibly any saltwater greenwater would do). This fed the rotifers and refreshed the water a bit (basically, I was taking care of the rotifer culture, not the larvae themselves). Algae and other matter would clump up and settle on the floor, but I didn't really bother stirring it up or even cleaning it up. Some of the larvae seemed to like the stuff and they kind of hung around in it. I'm really not sure if they were eating any rotifers (probably were) or if they were just eating that junk on the bottom. But in about 3 weeks PL's started showing up. They are only about 4 mm.

The old japanese scientific article (Hayashi & Hamano, 1984) that Mike Noren mentioned on his site said that supplemental feeding of a rice bran food helped the larval rearing, and that rotifers and chlorella (greenwater) were insufficient for completion. But from my case, supplemental feeding may be unnecessary, and just aid to foul the water and create more maintenance. Perhaps to yield hundreds, it may be necessary though. My low larval density probably allowed for low maintenance.

[Mustafa]

Congrats! The more info is provided from different attempts at breeding these shrimp, the better.

[badflash]

Now that I finally have a female, along with about 14 males I see a sudden change in behavior, sort of like in high school when a pretty girl shows up on the playground.

Even though she is showing no signs of eggs behind her head, 6-8 males are with her constantly. They aren't doing anything, but anywhere she goes, they go. Anyone else notice this?

[badflash]

Got any details on cullturing salt water rotifers? Where do you get a start? I can do green water, no problem.

[Mustafa]

Here is one source:

http://www.aquaculturestore.com/swinverts.html

[chlorophyll]

Wow, there's some interesting inverts at that source too.

Here are mine:
http://www.advancedaquarist.com/issues/ ... reeder.htm
Very good article on culturing them

http://www.lfscultures.com/cultures.html
For wet live cultures. A small culture should be enough. I've only bought copepods from them, but with the order they send a little instruction sheet on copepod and rotifer culture. You may be able to request the sheet my email.
They also accept paypal payments at their email address, even though it doesn't say so on their site.

http://www.florida-aqua-farms.com - click on the "live cultures" category
For dry resting cysts, which I used. Remember to specify "S".
If you order a small vile, you may be surprised how few eggs are in there. But you can get a good use out of it... just DON'T follow the intructions on the package and use the entire vile as starter. Cut the rubber top open and shake a few specks into your starter culture water and you'll have a decent starter group of live ones in 5 days.


Now, I'm not sure how old these new PL's are. I checked my records and I put a small batch of new larvae in the container on 9/26/05 and another new batch on 10/28. PL's appeared on 11/12. So they PLed in about 47 days, or in just 15 days. When I put the second batch in though, I was pretty sure the first batch had died off... you see, when I put the first batch in, I had also been raising another species of larvae in that same container... when the last of that species died (and those DID die unfortunately, around 10/20/05), the small container appeared bare of ANY larvae. But maybe this is another case of thinking japonica larvae were gone only to notice them when they were larger. I do know these are new PL's though... I have several larvae that look just like the PL's but are clearly still larvae by behavior.
Anyway, I definitely have to try to do this again from scratch.

[Jan]

I would like to report my breeding of C. japonica. I have group of thirty adults in aquarium designated only for them. I rear this species without any problem approximately one year. I try to breeding C. japonica approximately four months. Mortality is about 95% during larval stage now , but it is improving. When females have eggs I transfer ones to special tank inserted in normal tank. The special tank is similar rear tank, but it has grid as a bottom. Normal tank is without any equipment as plant, wood, substrate and so on except of aeration. Released eggs fall through grid on the bottom of normal tank. Reason is the females (and male also) feed their eggs in aquarium. I siphonate released eggs (with debris and feces) in regular intervals (every two days approximately) and I transfer them to the special jars. Very huge aeration is here for egg move in water (it is like a hatchery of brine shrimp, but without any salt!!!). Every two or three days I siphonate laevae from these jars by means of light attraction. I transfer larvae to directly to full salt water without any problems. I tried various ways and combination of salinity, food as yeast, live freshwater algae, dried freshwater algae, special food for marine zooplancton and invertebrates as corals and so on, photoperiod, temperature, water change, type of salt, aeration, density of animals, but without any prominent success. I just now use 34 ppm salinity, 24 °C, 200 individulas/ four litres (one tank), rate light and dark 12 : 12 hours, no aeration!! I feed them the way I scrape every day part of walls and bottom of tank and disperse scraped materials in water. I do not add other food during all development. I change 1/3 of water volume every three days. Water is realtively visually clear, but very huge density of microorganism is here (i see it only when I light tank by torch at night (rotifers?infusorian?). The biggest mortality is usually about seventh day of development. Reason is maybe to depletion some microelement or other nutrient thet larvae carry from eggs (mothers). I do not know. Metamorphosis and posthatch development is not problem for animals. I just now prepare special tanks for larvae with biological filtration and powerful lights for bigger algae development. I will try it again and again i reach at least 50% mortality. It is my object!!!

I would like to ask you about your opinion. The famous web sites about breeding C. japonica recommend permanent light without any dark. If you light off, larvae die. Is it cause low oxigen concentration during night? They often feed larvae by live algae (green water). Are algae possigle to exhaust oxigen under critical concentration for larvae?

Jan

[badflash]

My experience is with algae, and not breeding of C. japonica, but I can tell you that when the lights go out the algae calls upon its stored sugar reserves and burns oxygen. Algae also effects the pH to an extreme. I have measured pH >11.0 in dense algae cultures. The pH swings and oxygen problems may be killing the shrimp. In ocean watter they is a huge volume to buffer this effect and the fry would be able to move to areas of better water conditions.

[chlorophyll]

I know that when doing M. rosenbergii larvae, turning off aeration is a complete detriment. C. japonica may not need as much, but I would think you'd be hard-pressed to sustain any high density of larvae with no aeration, unless maybe under continuous lighting. If turning off the light, it would definitely be advisable to have a source of aeration. I always try to have some aeration, and I give the larvae lights off for about 8 hours a night.

As for my batch that I reported on earlier, all that I expected seem to have PL'ed. So I came out with about 16-20 from my 2 L culture. Recently I even left them unattended for 10 days when I went on a trip (at the time they were all still late-stage larvae) and everything turned out all right. Just today I decided to investigate on their progress... at first it looked barron, but when I slowly lifted the (white ceramic) air stone out of the water they all popped and jumped off the air stone. One was noticably larger than the others.

It's really convenient, what the original poster of this thread noted. Under favorable (possibly aged) conditions, not much attention is necessary, and when they become PL they also need not be removed from the salt water ASAP.

[brbarkey]

Does anybody know if the Shrimp eggs will hatch in slightly brackish water? I havent tried breeding them in a year but I always have females carrying eggs. Will the mom live in brackish water?[/quote]

[badflash]

From what I've read it takes full sea water ,not just brackish water for the Amano Fry. Full salt kills the adults from reports I've read, at least moving them from fresh to salt does. Maybe if they haven't made it back to fresh water they can deal with it better.

[chlorophyll]

My biggest peeve with these is getting a good hatch. Seems as if the female will eat her eggs or babies because I usually don't get a huge batch to move over to salt water. Either that or the babies just don't survive long in freshwater (but people have always said they last in FW for at least 5 days..).

I never did try to use brackish water to hold the berried female because that Mike Noren article said it won't work. But maybe it would. A gradual increase is always better though... instead of just plopping them into saline water. Even with the babies, people have said taking them from fresh straight to full strength seawater is ok... but I'm pretty sure it hurts them and there's better success going by steps like 0ppt >> 10 ppt >> 20 ppt >> 30, over the course of a day or at least, the course of an hour.

Oh, there was one time when I got a great hatch. The female was at a point where she was releasing a few at a time, as they tend to do. But then, I removed the airstone and put her in a dark place. About an hour or two later she had released a huge number (virtually her whole brood). For some reason I never tried it again though to see if it did it again. I guess I didn't think it would, and I've been too lazy to be on task with it.

[badflash]

I would not try the backish thing. Think about how these animals are in nature. They live in the freshwater streams that dump into the ocean. The babies hatch and get swept to the sea. The transition from fresh to salt would be pretty abrupt and would not involve the adult.

There may be varieties that fry need backish rather than sea water as there are reports on this, or your salinity might be a bit off. As to the hatch, it would seem that giving them a quiet dark place would be good. She may be stressed and not doing a good job. I plan to move any pregnant females to their own tank with little else in it once the eggs are on their swimmerlets.