RCS clear coloring - stress/water quality induced?

[wendamus]

I've had my RCS for a few weeks now, and they were doing really well in my 10 gallon fry tank. However, I had to empty that to install dividers, and the RCS moved to my 40 gallon tank. It's well established, heavily planted, and stays stable at no ammonia, no nitrites, and ~20 nitrates right before my twice weekly water changes.

They seemed to be doing well for a while, they've been in there about 1.5 weeks, but now about half of them have lost all their color.

The tank is slightly overstocked with juvenile guppies and a ~5 inch pleco. I've broken up algae wafers and scattered them around the tank every night since the shrimp arrived so the pleco can't guard them all at once, so I don't think they're hungry.

There are 18 RCS, all around 2 months old, I think they've just about all shed their skin in the last few weeks, I thought that was pretty normal.

I had a little nitrate spike, got almost up to 40, but I've done daily 15% water changes for 3 days, and they're not coloring back up, and the nitrates are back down to their standard 20.

Is it stress from competing with the pleco? None of the guppies are big enough to threaten them, nor do they seem to mind each other.

I can't figure out how to get my nitrates lower than 20 with this many guppies growing up, I've got a ton of hornwort, java moss, watersprite and anacharis. Is there anything else anyone can think of?

My 10 gallon will be cycled and back to normal soon, and I can move them back in there, but I'm definitely bummed they can't make it in the bigger tank, I figured they'd really like all the plants.

 

[luckydud13]

I don't think they would change their color. My cherries have yet to get alot of color. ALSO, if your substrate is light, they will lighten. If it is dark, then they will darken.

 

[msjinkzd]

I too am curious about the substrate differences.

 

[SchizotypalVamp]

Are you sure the lighter ones aren't males?

 

[wendamus]

I'm pretty sure some of them are male, but in some cases they're completely clear, and at one time they all had more coloring, even when they were younger.

Here's a link to a few pictures, one taken a week ago just as they'd moved into this tank, and a couple from today, one with a clear shrimp and another with a bright red one. The substrate is bright blue rock with organic substrate underneath for the plants.

http://www.wendamus.com/guppies/shrimp/

Please forgive the pics, it turns out it's hard to get the camera to focus on something completely clear.

 

[chazsgirl]

I have alot of light ones in my tank,(bare bottom) but there is this 1 that is blood red! not sure about that, also the yellows are vibrant and cherry babies are all pretty reds, but there are lots that just have like a few red stripes like u have pictured.
you could make some snail jello with color enhancing food(i have just started doing that), my shrimp live for the snail jello!

 

[Danimal62]

That aquarium is stress inducing for Cherry Shrimp. The random colors of the substrate and the predators (and perceived predators). Cherry Shrimp coloration is affected by many things, here are a few:

1.) Genetics – a cherry shrimp can only be as red as their genetics allow. Your shrimp are nice looking, but odds are they will never be the FULL DEEP DARK RED.

2.) Environment – It is well documented that Cherry Shrimp get darker in an aquarium with dark substrate. The reason for this is quite simple really, and explains why these shrimp never survive in the wild! When the shrimp are on dark substrates they naturally darken to blend in. In the wild, a darkened Neocaridina heteropoda is a deep brown/gray, but the Cherry Shrimp just turns bright red (so they stand out and would get eaten quickly).

3.) Stress – A stressed out Cherry Shrimp will grow pale. Changing aquariums is on stress that is on these shrimp now, predators is another stressor. The pleco is a big fish (shrimp naturally don’t like them) and a competitor for food. The guppies are predators and will eat any shrimp they can get in their mouth.

So, overall, there is a lot working against these shrimp to reach their full potential red!

 

[wendamus]

Ok, that's what I was afraid of, but I was hoping they'd find some peace with all the plants, java moss, driftwood, etc. I'm glad it wasn't the nitrates because it's even harder to keep the nitrates lower in the smaller tanks, I've got a constant oversupply of guppies.

Because the moving is also stressful, I'll let 'em hang out in this tank another week or so 'til I'm done cycling a couple of tanks and then figure out which one will be for fry/inverts only.