" Blue " Cambarellus Shufeldtii CAJUN

badflash · Post by **badflash** » Fri Jan 19, 2007 3:56 pm

Lets just hope he stays this color when he reaches breeding age. The one in the lower left is that steel blue I don't care much for.

I'm looking forward to this weeks water change!

FISH WORLD ERIE · Post by **FISH WORLD ERIE** » Fri Jan 19, 2007 6:47 pm

These guys are tricky as far as their color goes. I have some that stay blue all the time and some that change their color. Might be a little while before we can keep them this color always.

zwergkrebszuechter · Post by **zwergkrebszuechter** » Sat Jan 20, 2007 3:57 am

Would someone please try to give their blue shufeldtii some better quality food with a sufficient amount of carotinoids? I got some blue shufeldtii, too, but mine turned brown, given correct food. Here is a link to an article that kind of supports my opinion that blue coloration in most crayfish is only caused by a lack of carotinoids, caused by the wrong food and an insufficient microfauna to feed on in the tank.

I had the same effect some years ago with Cambarellus chapalanus. These also turned normal colored after getting better food.

See this article:
http://www.ncbi.nlm.nih.gov/entrez/quer ... med_docsum

A genetically stable blue coloration such the one found in Procambarus alleni for example is not supposed to change to brown and back! Also there is either blue or not, no intermediate coloration is possible.

However blue dwarf crayfish would be great to have, but I am not at all sure, that they really are. I am afraid you are maybe just selecting for a trait that has no genetic background at all, but is an artifact, caused by improper diet.

badflash · Post by **badflash** » Sat Jan 20, 2007 6:52 am

zwergkrebszuechter, Can you suggest such a food that would be available in the US? I feed my crays a wide variety of food, some of which is for goldfish that is supposed to be loaded with carotinoids to give the fish good color.

I think what causes the color in these crays is different than in the other crayfish you describe. What ever the cause, selective breeding is producing a better color and a higher yield per hatch of the blue stain. This sure is not a single gene causing this or it would not express itself like this.

Would the crays be this prolific if they were lacking nutrition?

zwergkrebszuechter · Post by **zwergkrebszuechter** » Sat Jan 20, 2007 7:28 am

Well I had pretty much the same situation with Cambarellus chapalanus a while ago. There were some lighter and darker blue ones. But the color did not last, it changed back to brown, grey and all shade of color.
Similiar things are known from a wide variety of crayfish species, I know several dozens. Just look on aquabid for the occasional "blue morph" crayfish. Buy one and wait for it to turn back to normal brown color.
If it were a color mutation like in Procambarus alleni, it were a single gene.

I do not know what does make them blue, maybe it is also some (genetic?) problems with uptake of carotinoids, that will make them turn blue more easily than a crayfish without that problem. I also have heard of viruses causing blue coloration in amphipods, maybe it is something like that. I do not know.
All I do know that the color is not stable, as many of you wrote.

It does not need to have a negative effect on crayfish vitality. As long as there are no predators it probably have little effect.

You can try to feed foods with spirulina, daphnia, gammarus etc. And add more leaves to the tank. Maybe the water parameters also have some contribution, little is known. That article suggests it is the lack of carotinoids in food. It is the question wheather pigments for fish coloration are accessible for the crayfish metabolism. Usually these are synthetic astaxanthins etc, different from the spectrum found in natural food, like the above mentioned.

badflash · Post by **badflash** » Sat Jan 20, 2007 7:43 am

zwergkrebszuechter wrote:You can try to feed foods with spirulina, daphnia, gammarus etc. And add more leaves to the tank. Maybe the water parameters also have some contribution, little is known. That article suggests it is the lack of carotinoids in food. It is the question wheather pigments for fish coloration are accessible for the crayfish metabolism. Usually these are synthetic astaxanthins etc, different from the spectrum found in natural food, like the above mentioned.

I already feed my crays that sort of food, and the botom is covered with leaves. We'll see. If cutting out certain foods make a blue crayfish, then I won't feed them that. Be that none of the dwarfs I got from anyone else respond like this, so this is a selectible trait, not just something that happens now & then.

With my current batch the variability is between a nice near-electric blue and a steel-gray-blue. I see no brown or green in these.

FISH WORLD ERIE · Post by **FISH WORLD ERIE** » Sat Jan 20, 2007 9:14 am

My crays are also fed a diet high in Spirulina. I use the hbh brand. I feed a great variety of food also. They also receive color bits. The blue is stable on some of them and has not switched back. My hatches are getting better. Right now I have around 500 of them and I would say 80% of them show blue coloration. It does vary from cray to cray. Light to dark. I can isolate some in a tank and feed them a certain diet if you would like me to test your theory.

Right now all my cajuns are the blue gene variety. I pulled my originals from a batch of regular cajuns when I first had babies. I kept them seperared and bred both populations for a while. The blue group I pulled kept getting better coloration and the regular group just produced a few bluish ones every once in a while. I have since gotten rid of my regular cajuns and now only breed for the blue. The two populations received the same diet but never looked alike as the theory states. I believe with time we can fix the blue in them. The hatches from these are getting better and better. I do not belive the food would cause this. How many others are keeping the blue and still have the regular cajuns. Do you notice a difference or do they all look alike.

Jason,
FISH WORLD ERIE

Newjohn · Post by **Newjohn** » Sat Jan 20, 2007 12:07 pm

I also have both Color Forms.
The offspring from the Blues do look different from the Wild Colored Crays.
But, not all of the offspring from the Blues are all blue. there are a couple of Wild Colored Young.
I had to put all of the offspring in the same grow out tank. and you can see the difference.

These are the first Crays. that I received from Jason.
They did lose the intense Blue, after 1 week. So was the intense Blue caused by the stress of shippment ?

I will just wait and see
John

badflash · Post by **badflash** » Sat Jan 20, 2007 2:30 pm

What the heck, they are fun to breed anyway. I just pulled out 41 more babies with todays water change. All my females are expectant with two having hatchings on their bellies, so I expect I'll be able to keep harvesting this many just about weekly.

I'm in the process of converting my "pond" to a grow-out tank for them. I think I'm also going to invest in another 40 gallon breeder tank.

zwergkrebszuechter and Jason are likely correct that there is a food & mood component to their coloring. Figuring out what makes the best "blue food" should be interesting.

badflash · Post by **badflash** » Tue Feb 06, 2007 7:01 pm

Adult colors are a little more muted, but not bad. I'm thinking that plant protein vs. animal is better for th blue. Too early to tell..

Ths is one of my virgin (but not for long) F2 females.

Neonshrimp · Post by **Neonshrimp** » Tue Feb 06, 2007 10:21 pm

Beautiful

!

Thanks.

badflash · Post by **badflash** » Tue Mar 06, 2007 5:37 pm

Just an update. My babies hatched after my Thanksgiving disaster are now at breeding age:

One of the females has "pudd'n belly & would not pose but the larvals should be out & about shortly.

Here is one of the males just hang'n out:

For some reason these crays climb out of hiding and go up on the java moss to molt. Seem like this would NOT be a survival trait...

Newjohn · Post by **Newjohn** » Tue Mar 06, 2007 5:51 pm

Nice Photo's

They look to have alot of White coloration.

John

Neonshrimp · Post by **Neonshrimp** » Tue Mar 06, 2007 7:57 pm

Congratulations on the berried female and establishing the new colony

!

Seem like this would NOT be a survival trait...

Picking up bad habits incaptivity. Too much nurture, spoiled

badflash · Post by **badflash** » Wed Mar 07, 2007 6:30 am

Newjohn wrote:Nice Photo's

They look to have alot of White coloration.

John

Yes, this is what the "Ice Blues" look like when they grow up. They have blue markings and specles on a white background.

I have a few that turned out pure white with no blue. They are not albinos though. I have them spearated for a new color line.