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Discussion Starter · #1 ·
Hi, my name is Sean and I am 12 years old. I am doing a science fair project on shrimp genetics and my problem statement is: How does the color of adult shrimp affect the color of the baby shrimp. However due to limited time I cannot do the experiment how I wanted to (get a red and orange shrimp and try to crossbreed them) so instead I need to set up a probability experiment. I know that when the red and orange neocaridina heteropoda cross the babies will be brown or wild colored no matter what but if the red cherry shrimp is a double recessive and the pumpkin shrimp is a double recessive, why does the color go back to the wild color when they cross instead of being just red or orange?
How do the babies of the red and orange shrimp still contain the wild gene and how could I make this an experiment?
 

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Most of the colored shrimp you see are specifically bred to be the those colors. People take the reddest ones and breed them together. This isolates the color people want. If you take two different colors they will most likely revert to the wild color.

Here is an interesting chart for you
 

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Well, now you're somewhat getting into a bit of advanced genetics. As you mentioned, if you cross two species that have the wild gene, then you're not simply messing with two traits, for example we will use A and B. So you've got AaBb as the shrimp will be carrying that recessive trait no matter what their color or specs.

So to start the experience, I say branch out with more possible options. If you're going to limit it to just two, you're going to have a hard time explaining that wild trait. ;P
 

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Discussion Starter · #4 ·
So if rr represents the basic genotype of the red cherry shrimp and oo is the basic genotype of the orange variant, i am crossing rr with oo with the wiild genes mixed in too. What would you think is the more advanced genotype of red cherry shrimp with the wild gene.
rrw?
 

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Well, you're not really going to have a good option for using the punnet square on this one. As I don't know much about the species, I'm assuming as to what you say is correct in that crossing the Red and Oranges together will always produce brown.

For example purposes only, let's use this layout. RR = Red, rr = Orange, and WW = Brown, (Ww = nothing). Your punnet square would read
------RW-----rW---------------RW-----rW
RW|RrWW | RrWW---OR---Rw|RrWw | RrWw
rW|RrWW | rrWW---------rw|RrWw | rrWw

*The dashes are because this forum program doesn't like spaces.

However, if you want to simplify the experiment you might want to consider doing it over Crystal Reds/Blacks. Those fit very nicely in a punnet square. Since the wild type allele is dominant, it will always show itself when mixed between the two. Thus, it really doesn't matter what your genotypes are. It's a bit confusing to try and think about it even to me. XD
 

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If you really want to impress the people looking at your project, I'd suggest starting off with a hypothesis, like "Orange color is dominant over blue color". Next, come up with a way to test to see if it's true.

If you want to make your project into a something way beyond what the other people at the Science Fair are doing, run a Chi-Square test on your data. The reason why a Chi-Square test is useful is that it lets you estimate the probability that the results you have actually support your hypothesis, as opposed to the probability that your results are just some random fluke.

This is pretty hard reading, but it is a good overview of how it works: http://www.ncbi.nlm.nih.gov/books/NBK21907/. I needed help with it myself when I did my first science projects- my math teacher and a friend's engineer parent showed me how to do a Chi-Square test properly.

Good luck, don't be shy about asking others for help, and have fun!
 

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Well I tried to do that and them unfortunately the shrimp died when winter came along. They were next to a window. I think I only have about two weeks anyway..
Ah! You have learned more than most have already.:proud:
When it comes to experiments, a back up plan is critical.

Discuss this no matter what(if you had the option to redo the test etc).
We learn from making mistakes. And along the way, we makes lots of them.
Just try not to repeat them.

You might mention this, then see if you can find some data on shrimp that will support some hypothesis on color, then say "well I tried but....... Since I ran out of time, I used this data set". Not sure if that is okay or not with those grading. But it's certainly happened many times before to students.

A simple fish test that's fast: mating attempts with guppies.
Males with flashing colors vs plain old non colored males.

Another is O2 production in CO2 enriched water vs non enriched, you use a test tube to catch the O2 from Egeria densa etc.

You can also test the yeast fermentation tolerances by catching the CO2 produced inside test tubes and measuring the volume with various Yeast/water/sugar treatments.

Say you want to know what effect temperature has on yeast at say 20C, 30C, 40C and 50C(stick heaters can provide the different temps).
Then plot a graph of CO2 produced vs time for each temp.
Then postulate why you get a maximum at 30-40C and then less at 20C and 50C etc.

All these can be done in 1-2 days. The write up etc, may take a week etc.
Ask for help. Folks can help you.
 

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You're probably better off doing it the way mentioned in this thread. Doing it with live shrimp would probably take at least a month.
 
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