# CRS/CBS Breeding Problems: Effects of Fish Presence or Something More?



## MDT (Aug 8, 2014)

I often hear that many shrimps wont breed when there are fish present. However there is little discussion about this topic on the web and I was curious as to the thoughts and experiences of other breeders who have tried breeding shrimp with fish present, whether successful or not.

For the sake of discussion, let's exclude larger fish that naturally make a meal out of shrimps because I think that's a given.
I'm talking about small to really small fish here, like Celestial Pearls, Tetras, Rasboras, etc.
I know sometimes these guys might make a snack out of a shrimplet, but do they really cause the adults to breed less or not at all?

I'm having mixed experiences with this right now. I use to have PFR cherries and still have CRS/CBS.
With my cherries, they bred like crazy despite there being fish. I believe that's just because they are extremely easy to breed and care for.

But my CRS/CBS are difficult. I don't entirely know whether it's the fish or whether I am not meeting their conditions, but I'm just not able to breed them as well.
I only get a berried female once every month. I don't believe it's the tank parameters/condition, although my pH is a bit low (around 6.2). They also have a lot of shelter and hiding spots to feel comfortable. 

I guess this segue into whether or not I am providing ideal conditions for my CRS or whether the fish are causing them to breed less.

For clarity, here are my tank parameters:

pH 6.2
GH: 4
0 Nitrite
20ish ppm Nitrate
0 Ammonia
Temp: 22-24C

Tank is 1.5 years old, I do a water change once every 3 weeks, top off once a week. No CO2, some ferts during WC.


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## Bobsidd (Dec 28, 2012)

I've not had issues breeding CRS with any of the fish you listed in the tank. The babies very rarely survive, however. The only fish I've been able to keep and breed/rear young shrimp with is mosquito/brigitte rasbora. Cherries seem to have a better survival rate in fish inhabited tanks than CRS. I speculate that this is due to the relative lack of colour in Cherry babies. The red and white of the CRS babies must look like a target to a hungry fish. 

I've had very few berried shrimp over the winter too as breeding naturally slows down, but things are starting to pick up again in all my tanks. Interestingly, I had molts in all my shrimp tanks on the same day to mark the end of the winter slow-down. Not sure if it has something to do with moon phases, or something else, but all 10 shrimp tanks across two locations had males swimming around like mad looking for females on the same day after months of no berried shrimp.

Your parameters look fine. My advice would be, if you want to breed shrimp, keep shrimp only tanks. Otherwise, you risk hungry fish chewing into your profits. 

Good luck. 
Rob


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## MDT (Aug 8, 2014)

Hi Rob,

I appreciate your input. That's really interesting to hear about the winter months slowing them down actually, because I noticed a similar pattern in my RCS too. I have too few CRS to notice a pattern there but they have never really taken off with me, despite having them for nearly a year.

The problem is the females only produce maybe 8 eggs, once every month or so, and of those 8 eggs, I only ever get 2-3 that survive. Why do they produce so little eggs? Maybe I am not providing enough food for the babies? I don't know whether the fish are stressing them or if I am just not doing enough.

I just dont think the fish are eating them because my tank is very densely planted, on top my babies crawl all over the glass in plain view and the fish ignore them completely. I've only ever seen one cherry get eaten by a larger rasbora and that's cuz it was wriggling around like a worm in the water column. But who knows.

I think I am going to take your advice about a shrimp only tank though. Thanks so much for your insight.


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## SeaHorse_Fanatic (Apr 22, 2010)

The babies are so small when first born they almost inevitably will end up as fishy snacks. I do shrimp only tanks if I plan to have any babies survive.


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