Crayfish Coloration

[H. laoticus]

Hi there,

I've owned several of what I believe to be Cherax quadricarinatus over the years and I've never been able to give them the proper husbandry to maintain that beautiful bright blue coloration of theirs. I have read that it is quite normal for them to molt and lose that coloration, but I've also read it's possible to keep it. One problem is I haven't seen pictures of baby Cherax quadricarinatus, so I could just be wrong altogether.

Here's a picture of what all of the baby crayfish look like, around 2-3 inches and is the one I am currently keeping:
It has not molted in my care.
Notice how bright and vibrant the colors are.

Here is one I have kept that molted twice in my care and is about 2-3 inches as well.

I am curious to know why the colors are so different. They are both similar in size, but the ones I buy at my local pet store are extremely vibrant in color. The store only carries these sizes as well, so I don't know what they'd look like in the long run.
I'm just curious, because that second pic is a female that I bought which was very small and molted into the size of the one I just bought in the first picture. When it molted in my care, the colors were almost all lost. This leaves me to think it's my husbandry that is causing the color loss while the pet store is doing a great job.

I am wondering if the pet store has some secret magic water or food that is keeping that color.
I've asked them about their feeding and they said they'll eat anything--they also feed blood worms which I have not tried out.

Is it the water type/quality or is it the type of food or both?
I've been using tap water with a water conditioner--I may switch to distilled water to see the results.
I feed algae wafers, tropical fish flakes, the occasional cucumber slice, and I just bought shrimp pellets.

I have seen these crayfish which I believe to be the same kind grow to 6+ inches and still retain their bright blues.
For example, I believe this is the same species, but larger: http://www.youtube.com/watch?v=YXgf7fXXQWA

Maybe I'm just horribly mistaken about the species :?

 

[Elytra and Antenna]

The blue is caused by a virus but the ability for them to beat off the virus is affected by conditions. I haven't seen decent information on how to promote the virus and blue coloration but some species like P. alleni are better in captive conditions. The ones you buy at pet shops are farmed, not kept in aquaria.

 

[H. laoticus]

The blue is caused by a virus but the ability for them to beat off the virus is affected by conditions. I haven't seen decent information on how to promote the virus and blue coloration but some species like P. alleni are better in captive conditions. The ones you buy at pet shops are farmed, not kept in aquaria.

Hi, thanks for replying

I understand that they are farmed, but I have frequent visits to that pet store and the crayfish do grow larger in size. I'll buy a small one and come back several weeks later to see that the remaining have grown a bit. For some reason they are maintaining their colors and that's what's baffling me.

 

[Kruggar]

Awesome, when i was a kid we once caught a local crawfish at the local river, we put it in a tank with our turtle, and about a week later it was bright blue, stayed that way for what felt like forever... and then died? can't remember, a virus makes sense though... maybe the nastiest tap water helps?

 

[H. laoticus]

Awesome, when i was a kid we once caught a local crawfish at the local river, we put it in a tank with our turtle, and about a week later it was bright blue, stayed that way for what felt like forever... and then died? can't remember, a virus makes sense though... maybe the nastiest tap water helps?

wow, how were your water conditions and what was its color before? At this point I'm wondering what conditions would be best for the virus lol
So far I know that the pet store is really bad at keeping their fish because the aquariums are dirty and the fish have ich on them. They also don't use heaters, so that may be it too. I have a heater going and that speeds up my cray's growth and molting. I might take it out to see what happens because heat does help sick fish with some of their diseases.

 

[LeilaNami]

In the crayfish forums we frequent, they suggest that diet is the main cause of coloration. We feed a variety to ours including shrimp pellets, Hikari crab feed, fish, algae wafers, and some fresh fruits and veggies (like oranges and green beans, even garlic is okay). Our P. acutus acutus has maintained very bright blue chelae coloration. Our water is slightly acidic for the P. acutus acutus but a little basic for our P. clarkii that has a lot of blue and pink in her subadult coloration (she's about 5 inches now). We do not have a heater in either and the P. acutus acutus does not have light other than the room lighting while the P. clarkii tank has the light turned on for short periods. The temps are mid 70s.
Don't know if this will help you for your Cherax.

 

[Kruggar]

wow, how were your water conditions and what was its color before? At this point I'm wondering what conditions would be best for the virus lol
So far I know that the pet store is really bad at keeping their fish because the aquariums are dirty and the fish have ich on them. They also don't use heaters, so that may be it too. I have a heater going and that speeds up my cray's growth and molting. I might take it out to see what happens because heat does help sick fish with some of their diseases.

I don't really remember what conditions it was living in, our poor turtle got rather neglected, so the tank was probably dirty-turtle dirt! and it was brampton tap water... which is some of the grossest tap water I've tasted... lots of chlorine and fluoride... the tank was near a window so the turtle could bask, if memory serves... the crawfish ate some of our little feeder goldfish, at that point we were feeding the turtle pellets and dried shrimp... crawfish would've cleaned up

I just think it's amazing that you can get a brown crawfish from a river and make it electric blue... and buy an electric blue one for $50 bucks or whatever from petsmart! Has anyone ever seen one of these electric blue ones in the wild? I'll look into it I think...

 

[H. laoticus]

Thanks everyone for replying

Believe it or not, I actually received more replies here than on this other crayfish forum I've been seeking help from-- Rock on, Arachnoboards!

Update on my crayfish:
-My crayfish has darkened in color from a bright light blue to a deep dark blue. I don't know if it's a direct result from my husbandry or that it's ready to molt. It could be both, so I'll have to wait and see.
Here's a recent pic of it enjoying the Anacharis:

And here's something I found while searching the net, although it's not from a very credible source:
"By the way, if you have a blue crayfish, they will sometimes molt out of the color and revert to a common color. Leave the old blue exoskeleton in the tank and if they eat it, the blue can come back. The blue is not genetic but is caused by a harmless virus that gives its blue color to the crayfish. Some shrimp and other invertebrates may also turn blue if they eat the old exoskeleton from a blue cray." - Dan M.

Can anyone verify this? It wouldn't make sense in your case, Kruggar, because yours started off from a different color and then changed to blue even though it didn't eat any blue exos. I've also gone crayfish hunting around my area and have never seen any blue ones. They're either dark red or light brown.

It seems strange, but I'll keep it in consideration because the blue crays that have been in my care have never eaten their molts. This is most likely due to the high levels of calcium in the tap water in which the crays don't need to eat their exo for the calcium. I'll try to use all distilled water before it molts and hopefully it'll eat its molt.

 

[LeilaNami]

Thanks everyone for replying

Believe it or not, I actually received more replies here than on this other crayfish forum I've been seeking help from-- Rock on, Arachnoboards!

Update on my crayfish:
-My crayfish has darkened in color from a bright light blue to a deep dark blue. I don't know if it's a direct result from my husbandry or that it's ready to molt. It could be both, so I'll have to wait and see.
Here's a recent pic of it enjoying the Anacharis:

And here's something I found while searching the net, although it's not from a very credible source:
"By the way, if you have a blue crayfish, they will sometimes molt out of the color and revert to a common color. Leave the old blue exoskeleton in the tank and if they eat it, the blue can come back. The blue is not genetic but is caused by a harmless virus that gives its blue color to the crayfish. Some shrimp and other invertebrates may also turn blue if they eat the old exoskeleton from a blue cray." - Dan M.

Can anyone verify this? It wouldn't make sense in your case, Kruggar, because yours started off from a different color and then changed to blue even though it didn't eat any blue exos. I've also gone crayfish hunting around my area and have never seen any blue ones. They're either dark red or light brown.

It seems strange, but I'll keep it in consideration because the blue crays that have been in my care have never eaten their molts. This is most likely due to the high levels of calcium in the tap water in which the crays don't need to eat their exo for the calcium. I'll try to use all distilled water before it molts and hopefully it'll eat its molt.

If you use distilled, you'll be taking all other nutrients from the water your cray might need. How long have to kept the molt in with the cray before taking it out?

 

[H. laoticus]

If you use distilled, you'll be taking all other nutrients from the water your cray might need. How long have to kept the molt in with the cray before taking it out?

I've kept the molt in for over 24 hours and it doesn't eat it. It's probably because the tap water is already loaded with calcium, so it doesn't need any more of it to harden its new exo.
What would the crayfish need from the tap water compared to the water in its habitat?

 

[LeilaNami]

I've kept the molt in for over 24 hours and it doesn't eat it. It's probably because the tap water is already loaded with calcium, so it doesn't need any more of it to harden its new exo.
What would the crayfish need from the tap water compared to the water in its habitat?

Tap water contains minerals (other than Calcium) that the cray could use. Distilled water won't kill your cray but when water is distilled, all things are removed from the water, the good with the bad. If you wanted to reduce the amount of calcium, you could try a mixture of your tap with distilled (RO water) or try switching to spring water.

 

[H. laoticus]

Tap water contains minerals (other than Calcium) that the cray could use. Distilled water won't kill your cray but when water is distilled, all things are removed from the water, the good with the bad. If you wanted to reduce the amount of calcium, you could try a mixture of your tap with distilled (RO water) or try switching to spring water.

Do you know the specific minerals that the cray uses? What's the good in it?
Spring water sounds good, the tap water here tastes pretty nasty.

 

[bugmankeith]

Mabye they just get darker with age? Corn snakes for example are really bright when young, but their color tends to fade and is not as vibrant the older they get, but they still are the same color.

 

[LeilaNami]

Do you know the specific minerals that the cray uses? What's the good in it?
Spring water sounds good, the tap water here tastes pretty nasty.

I can't remember what or where I found that information. The only thing I can really say is that I know several people that keep salt water tanks and they use a product to add nutrients back into the RO water.

I dug around some and found a paper that specifically mentions depletion of sodium in crays exposed to distilled.
http://jeb.biologists.org/cgi/reprint/37/1/100.pdf

 

[Kruggar]

If it is a genetic thing, it would make sense that finding them in the wild is rare, as I'm sure that they would be seen much more, making life all around much harder. Do people breed them? It could be possible that two blue ones bred together would produce some blues too... if it is genetic...virus could make sense in my case though... it might take time for the virus to result in colouration.... just some food for thought....

 

[H. laoticus]

Update: Molt

Update on my crayfish: It has recently molted on the 2nd of October and has grown quite a bit in size.
I said in my last post that I would turn off the heater and I did. However, the crayfish stopped being active and stopped eating, so I assumed it was in premolt. I decided to plug the heater back in and sure enough it started molting within the hour.
Here are the pics of molting:

You can see the drastic color change after the molt. I'm glad to say that it hasn't stayed that color though; it's turned a darker blue again which is very nice to see.
I'm trying to get a pic of it in the open and hopefully capture its color, but my camera phone isn't getting the job done, so these are it for now
I was able to capture the molting on film, so I'll see if I can get it on here for you guys to see.

 

[H. laoticus]

Update

Hey guys,

Just a little update.
My crayfish just molted on 10-21-2010.
Notice the incredible color changes--she has orange on her!
I don't know if she'll keep the orange, but it sure looks cool.
As you can see, she's obliterated my plants.

Pics:
Crayfish next to molt--check out the color difference:

Nice clear shot of her:

Pics aren't that great, but this camera phone will be replaced soon enough

 

[H. laoticus]

Alright, everyone, update on my crayfish:

My crayfish has molted I think twice since I last posted, once on 11/23/10 and another time on 1/2/11. These are recent pics of it on 4/11/11:

Here are a couple of pics the day before her molt (4/18/11) when I noticed signs of premolt as the carapace was moving away from the abdomen.

You can see the white showing:

I awoke the next morning (4/19/11) finding this, her shed:

I was very pleased because she seems to get even more beautiful by each molt as she matures.

Awesome shot:

Old exo:

Her color is a little strange right now, but she will probably turn back to her usual color or something close to it. She will also eat her old exo in the days to come--kind of creepy when you think about it lol

 

[Travis K]

I used to keep these but the fish I had were too aggressive and eventually ate them after they molted in a not so protected area. I miss my fish tank.

one of them got even bluer another got darker, and yet another just stayed the same. Third strike and they were out, I quit buying them after the third one died post molt. LOL, I would provide them the perfect protected place to molt and they would eventually do it out in the open and get killed. Fish can not resist soft inverts.

 

[Texturedyeti66]

I have had a white albino crayfish i had it for 10 month and just now im see discoloration on its back and inside im guessing can anyone tell me if this is bad?