what determines when shrimp gets pregnant?

Cajunspice · Post by **Cajunspice** » Sun Apr 17, 2005 6:30 pm

I have cherry red shrimps that laid their eggs for a week. When will they be pregnant again and does the pH or anything else affect it? My pH is 7 and temperature at 82 with a kH of 4.

Post by **Mustafa** » Sun Apr 17, 2005 6:46 pm

Good question. Although I can't possibly know all the factors that contribute to the development of eggs in the females' ovaries, I know from experience that the amount of food plays a role. As long as the shrimp are well fed they reproduce pretty regularly. If they are starving or sick the ovaries just don't produce any eggs.

Mustafa

chlorophyll · Post by **chlorophyll** » Mon Apr 18, 2005 1:26 am

I'm honestly not in the greatest habit of monitoring water chemistry parameters. But I can say from personal experience this species of shrimp can have ridiculously fast reproduction rate.

I set up a tank outside my home, very heavily planted, a few rocks, short period of direct sunlight int he morning, indirect sun for the rest of the day, so daytime T is probably around 80-86 F; nighttime 70-79 F.
Added 4 small guppies, 3 berried female N.d. sinensis, 2 males. Sparce flake feedings ever 2-3 days, for the fish primarily. In just 3-4 weeks not only were there babies already 5-6 mm long, but I happened to spot 2 of the females with some more eggs. One could have been carrying the eggs she had when I put her in, but the other one's eggs were a new batch. I was surprised.

Another poster (edinjapan, I think) in another thread also recommends this outdoor method (climate/weather permitting) for fast propogation of shrimp that require no or little larval rearing. Something about combination of the warm water, high vegetation, ample cover, day/night schedule, and sunlight that makes conditions very appealing for spawning.

edinjapan · Post by **edinjapan** » Mon Apr 18, 2005 7:21 am

chlorophyll wrote:I'm honestly not in the greatest habit of monitoring water chemistry parameters. But I can say from personal experience this species of shrimp can have ridiculously fast reproduction rate.

I set up a tank outside my home, very heavily planted, a few rocks, short period of direct sunlight int he morning, indirect sun for the rest of the day, so daytime T is probably around 80-86 F; nighttime 70-79 F.
Added 4 small guppies, 3 berried female N.d. sinensis, 2 males. Sparce flake feedings ever 2-3 days, for the fish primarily. In just 3-4 weeks not only were there babies already 5-6 mm long, but I happened to spot 2 of the females with some more eggs. One could have been carrying the eggs she had when I put her in, but the other one's eggs were a new batch. I was surprised.

Another poster (edinjapan, I think) in another thread also recommends this outdoor method (climate/weather permitting) for fast propogation of shrimp that require no or little larval rearing. Something about combination of the warm water, high vegetation, ample cover, day/night schedule, and sunlight that makes conditions very appealing for spawning.

YUP!! That's how I do it. The abundance of food seems to trigger replacement of the shrimp's exoskeleton and the next day is when the males are assured of the best possible chance to successfully mate with the female. Females can reproduce at other times but, the most successful time is after a moult.

Post by **Mustafa** » Mon Apr 18, 2005 7:34 am

edinjapan wrote:Females can reproduce at other times but, the most successful time is after a moult.

Actually, Ed, females can accept sperm packages *only* after molting. There is plenty of literature about this. If you think you saw a female carrying eggs without molting, then you must have just missed the molting...it happens.

With the all the species I am keeping, including freshwater and saltwater shrimp, the females carry eggs only after molting...never seen females carry eggs in between. So my observations clearly confirm the literature.

Take care,
Mustafa

Cajunspice · Post by **Cajunspice** » Mon Apr 18, 2005 10:24 am

i remember reading from a thread mustafa said his shrimps gets pregnant right after laying one batch of eggs by feeding daily. So feeding promotes molting therefore promotes breeding?

too bad the weather in my area won't allow me to set up an outdoor tank.

GunmetalBlue · Post by **GunmetalBlue** » Mon Apr 18, 2005 12:16 pm

> "With the all the species I am keeping, including freshwater and saltwater shrimp, the females carry eggs only after molting...never seen females carry eggs in between."

My humble observations confirm this, though I refer to the grass/ghost shrimp. The day after molting, the shrimp seems especially ravenous for food, then eggs seem to appear about 2-3 days after molting. And as most of you already know, it helps with replenishment to leave the molted shell in the tank. I feed them daily, and they seem to molt, then carry eggs about once a month.

> "too bad the weather in my area won't allow me to set up an outdoor tank."

Chlor and Ed are lucky to have conditions for a more ideal propagation, but I'm sure you'll do fine, Canjun, perhaps need a bit more patience, that's all.

Gm Blue

edinjapan · Post by **edinjapan** » Mon Apr 18, 2005 6:36 pm

Mustafa wrote:
edinjapan wrote:Females can reproduce at other times but, the most successful time is after a moult.
Actually, Ed, females can accept sperm packages *only* after molting. There is plenty of literature about this. If you think you saw a female carrying eggs without molting, then you must have just missed the molting...it happens. With the all the species I am keeping, including freshwater and saltwater shrimp, the females carry eggs only after molting...never seen females carry eggs in between. So my observations clearly confirm the literature.

Take care,
Mustafa

I haven't been very observant as regards my shrimp. I remember an article in FAMA concerning the banded cleaner shrimp, they form pairs and fight all others for territory. Seems the key to forming a pair is to have the males approach the female after she'd moulted. The first male to successfully mate with the female was accepted as her mate. Obviously they all follow suit...

fugly · Post by **fugly** » Tue Apr 19, 2005 2:29 pm

Mustafa wrote:
edinjapan wrote:Females can reproduce at other times but, the most successful time is after a moult.
Actually, Ed, females can accept sperm packages *only* after molting. There is plenty of literature about this. If you think you saw a female carrying eggs without molting, then you must have just missed the molting...it happens. With the all the species I am keeping, including freshwater and saltwater shrimp, the females carry eggs only after molting...never seen females carry eggs in between. So my observations clearly confirm the literature.

Take care,
Mustafa

can you provide links supporting this? i've seen my female amanos carrying eggs w/o finding any exoskeletons in the tank. the tank only has java moss, so unless i'm blind... i have some pretty special shrimp.

Post by **Mustafa** » Tue Apr 19, 2005 2:42 pm

fugly wrote: can you provide links supporting this? i've seen my female amanos carrying eggs w/o finding any exoskeletons in the tank. the tank only has java moss, so unless i'm blind... i have some pretty special shrimp.

Yes I can (once I find the time). The fact that you can't find shed exoskeletons does not mean that the females did not shed. It does not logically follow. Those exoskeletons get eaten *very* quickly in many tanks. So, you don't have to be blind not to see them.