# keeping CRS with CBS in one tank?



## johnny313 (Apr 15, 2011)

I see pictures of people keeping Crystal reds and Crystal blacks in the same tank. wouldnt that screw up the colors? or can you keep them together?


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## GeToChKn (Apr 15, 2011)

I think if a red and black mix, they will produce mostly black babies and those babies crossed back with a black will give black and with a red will give red and the odd time you get a choco brown.


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## johnny313 (Apr 15, 2011)

Check out this post in SnS... they kinda look like Crystal Brown shrimp then.. correct?

http://www.plantedtank.net/forums/swap-n-shop/150698-fs-crs-cbs-shrimp-packs-new.html


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## HolyAngel (Oct 18, 2010)

yeah you can get mostly black shrimplets, or the black will start to turn brownish starting from the bottom of the shrimps as you cross them more and more over generations. I have a couple that are half red and half black currently, like a two toned shrimp. depending on the light it'll look red or black or both.


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## johnny313 (Apr 15, 2011)

so I guess the best thing to do is keep them separate. my CRS had black / brown babies. 
not great quality though.


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## GeToChKn (Apr 15, 2011)

Some people like the browns, including myself. Some of them look neat if the brown is solid, plus its a nice way to get some gene variety in your gene pool since the reds have all come from 1 pair of reds, breeding a bit of black in gets some fresh genes in their. If you are breeding high quality to sell, you may want to separate them.


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## blacksheep998 (Jan 16, 2011)

If you cross a CRS and a CBS not carrying the recessive red trait, then all offspring should be black, but will be carrying the red trait. The F2 generation will be about 1/4 red, and 2/3 of the black shrimp will still be carrying the red trait.

The interesting thing is that thanks to the Hardy–Weinberg principle, the ratio of red to black genes in the population won't change without a selection pressure. http://en.wikipedia.org/wiki/Hardy–Weinberg_principle

I've got a mixed tank, and started out with 20 red and 10 black, so a 2:1 ratio. After about a year I moved them into a new tank and kept count of how many and what colors went into the new tank. I ended up with about 70 black and 150 red. Basically spot on the original ratio.

Also, my shrimp came from a population that had been mixed reds and blacks for about 5 years. And out of 200+ shrimp in my group there's only 3 browns. As near as I can tell, the brown shrimp are ones carrying one copy of the red trait and should be black, but for whatever reason are partially expressing the normally recessive gene.

They don't seem to pass this on to their offspring though. Their offspring will be red or black, no more likely to be brown than any other shrimplet. I haven't seen any loss in color quality from the mixing. Even the brown shrimp have good solid colors.


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## theemptythrone (Sep 5, 2011)

Conversations where you guts start talking genetics get me all excited, Idk why


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## Geniusdudekiran (Dec 6, 2010)

Let's do some Punnet squares! I'm doing this in honors bio right now! And have a test on it on Thursday!


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## Geniusdudekiran (Dec 6, 2010)

theemptythrone said:


> Conversations where you *guts* start talking genetics get me all excited, Idk why


Yes, we are guts j/k


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## hammor (Dec 2, 2014)

Any updates on the experiment?


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