Color morph or caused by diet? Not sure

I caught this Procambarus clarkii earlier this year and he was a normal colored crayfish with maybe a bit more black then usual. He molted a couple of weeks ago and turned this outrageous color of blue/purple. Someone said it might be dietary but it's been eating the same food as the rest of my crayfish and they haven't changed color. They eat leftover fish food,dried krill and algae wafers. He also lost his claws so I had to put him by himself so he wouldn't get eaten.

Edited by davidjh2, 02 November 2011 - 06:36 PM.

That is strange from a normal to a blue. Will be interested in theories on this.

Usil

I've seen this many times in Cambarus dubius I have collected. When collected they often appear almost black (if they have not recently molted), but after one molt are normally navy blue, in my area at least. I've seen a number of blue clarkii. This color is probably stable and not a result of diet.

Rick

Edited by rick, 03 November 2011 - 09:33 AM.

This breeder (link: http://www.bluecrayf....php?f=20&t=584 ) selected for the blue coloration in their dwarf cajun crayfish. They mention it, here, let me find the quote,

The color is a genetic trait, but it is induced by food and living conditions. Feeding mostly veggie based foods seems to bring out the blue, but not all of the crays exhibit this. Not even ones bred from blue parents. Each brood produces one or two with strong blue, but even that seems to be limited. I suspect part of my proble[m] was snails. The crays would grab them and eat them. The meat would kill the color.

Here is a range of colors any give blue may cycle through:
http://i25.photobuck...ys/cajblue3.jpg
http://i25.photobuck...ays/blueboy.jpg
http://i25.photobuck...ays/biggirl.jpg
http://i25.photobuck...ays/iceblue.jpg
http://i25.photobuck...s/newblumom.jpg
http://i25.photobuck...crays/hangn.jpg
http://i25.photobuck.../babybelly1.jpg

Question: Redgoalie asked, "So, only the mottled ones go into the blue phases, right? So the striped will always stay somewhere in the brownish range, correct?"
Answer: Badflash replied, "I can't say for sure that the striped phase can go blue, but I know all the ones I've seen that are blue are mottled, not striped. These were bred for many many generations selecting the bluest looking males and the darkest females."

Link: http://www.bluecrayf....php?f=20&t=584

Edit: I'm sure you already knew about that person, though, now that I look at it, because you started a topic on that very same forum. Oh well, I am unable to delete this post, so... *shrugs* Maybe the algae wafers (low meat diet) brought out his inherent blue coloration. It's not like he's been eating snails, with his front claws missing.

Edited by EricaWieser, 03 November 2011 - 11:35 AM.

From what I've read color changes in crayfish is the same as albinism in humans. It's very rare and it's genetic. Most crayfish that aren't the standard color for their species would not live very long since standing out is not a very good survival trait when you're that low on the food chain. This applies to a true color morph not one brought about by diet and/or lighting. I've had other crayfish turn blue but never quite so vivid a color and what color they had generally faded over time. I know now that the color changes were due to their diet so I try and vary it now the same way you do for fish. I don't think the color change was due to environment or diet since nothing has really changed in the tank in quite some time an I've had more then a few crayfish in the tank over the course of the last 2 years or so with no color changes. The one possible change in diet would have been the switch I made to feeding my fish mostly Cichlid sticks. They tend to sink and my crayfish love them. He's not eating them now so if his color doesn't fade between now and his next molt and his his color doesn't fade after the molt then that should mean it is a true color morph and if that's the case I may just try and breed him with to produce that color