What color am I?

[Newjohn]

I have also seen this, But it was with RCS.
I had a over crowed Tank and took several OK looking Shrimp to a LPS.
And within 2 hours the OK looking Shrimp colored up to be very nice looking .

John

[YuccaPatrol]

One thing we need to remember is that the color of many crayfish is not a permanent condition. Often, there is both a genetic element and an environmental element at work. Environmental conditions can induce crayfish to display different color patterns.

Many of us have seen this when we have move crayfish or shrimp from one tank to another or when we've changed something like substrate, lighting, etc.

As an example, the professor I work with did some research on a species of crayfish which displayed different colorations in two different lakes. Crayfish which were captured from lake #1 and moved to lake #2 took on the coloration of those originating in lake #2.

Here is the abstract from his paper

Color Morphs of the Crayfish Orconectes virilis
Robert W. Thacker, Brian A. Hazlett, Laura A. Esman, Craig P. Stafford, Troy Keller
American Midland Naturalist, Vol. 129, No. 1 (Jan., 1993), pp. 182-199
doi:10.2307/2426447

Abstract

Adult Orconectes virilis exhibit a variety of colors from yellow to blue to dark brown that are strongly correlated with habitat background color. We used field and laboratory experiments to examine both the proximate mechanisms and the possible functions of this color variation among populations of crayfish in northern Michigan. Field transfer experiments showed that adults can change color, brown morphs becoming blue and vice versa. Light penetration measurements at six field sites indicated relationships between differential wavelength penetration and the colors exhibited by crayfish in a habitat. Holding crayfish in water from different habitats induced color changes while feeding crayfish vegetation characteristic of different habitats did not produce significant color differences. Laboratory predation experiments, field enclosure experiments, and transfer mark-recapture experiments did not indicate any differential survival of morphs that matched or contrasted with the background.

As another example, my home population of C. diminutus live in aquaria which has a dark black substrate. These crayfish are generally dark variations of grey, brown, and rust colors. A group of these which were moved to a tank with a white sand substrate have taken on a translucent and very light tan coloration over the past few months.

This will continue to make it difficult for us trying to select for specific colors because it is not always easy to distinguish between the genetic component and the environmental one.

[ToddnBecka]

Many years ago I kept a couple of newts and a small crayfish in a 20 gallon tank with colored gravel. (I don't remember what color the gravel was, but it wasn't a natural color.) The small crayfish was always white, with no markings or pattern, probably because it couldn't adapt its color to blend with the substrate.

[badflash]

While some cajuns can shift colors, most can not. The abiliiity to shift is definitely genetic, while the color they shift too is environmentally affected. I think that makes it all the more interesting. The degree of color shift is also genetic. I've got several hundred to study so I can see the degree of diversiity. I'm sure you've seen it in the pictures I'm posting too.

The color of the ones I'm breeding never look anything like the "wild" ones. Having a cameleon cray is pretty neat.