Crayfish (Shell Rot!!!)

[26pets]

I've had crayfish for about 2yrs now. I've bread my crays and everything. Now all of a sudden I have a case of shell rot in my tank . I have it on 2 of my female marbles..... What should I do? And how can I treat it?
Side Note: This is my display tank.... So I have allot of crays in the tank.... My Blue breeding pair is in the tank.... Should I be worried.... Allot of blues are in there.....

 

[Lupin]

What do you generally feed them? What are your pH, GH and KH? Do you leave their old shells in their tank for them to eat? You could supplement them with calcium by adding calcium carbonate in your tank.

 

[black_sun]

Shell rot is caused by a lot of things. Generally, it's because something is wonky in the water that's allowed for the infection to take hold in an existing injury. Too much food and debris trapped in the water or substrate for a prolonged period of time will do it. Along with weird pH levels and the like. Over-crowded tanks and stress are also know causes (well, there's debate on whether it's causes or just contributing factors). Check everything in your tank to make sure nothing is spiking or being out of the norm.

A side note, Marbles are bred to be highly non-aggressive. Having them with another species of crayfish may be detrimental to their health. But that's an observational call for you to make.

Anyway...

For minor injuries, you can use Melafix. However, more than likely it will not do anything (and may not even slow down the process). And one should keep in mind that Melafix is entirely organic and can act as food source for certain types of bacteria. This leading to a bacteria boom in the tank. So, personally, I would recommend not using Melafix for anything and finding alternative treatments to any issues you may have. But that's a call for you to make. That aside, you can use the following treatment for Shell Rot:

"1.) Grab a set of scales and measure out 35 grams of salt.
2.) If you don't have micro scales a good teaspoon is around 4.7grams, so 7 nice teaspoons will do.
3.) I don't mind what salt you use, personally I prefer pool salt.
4.) Throw that in 250ml of boiling water and stir in until dissolved.
5.) Then take 750ml of water from your crayfish's tank put it in a 4 litre ice cream container or something similar with high sides.
6.) Add the dissolved salt solution to it and stir again.
7.) Drop an air stone to keep the water nice an aerated.
8.) Set up an alarm clock/timer to 10 minutes.
9.) Drop your crayfish in and make sure it can not escape.
10.) Go do some maintenance on the tank.
11.) Come back and remove your crayfish when the alarm goes off.
12.) Repeat every 3 days as needed until next moult or lesions are "bleached out".


Please note, nothing will CURE shell rot. What you are doing is slowing down the process so that it doesn't reach the layers of shell underneath the infected one, so that when the crayfish molts it will be free of the infection.

 

[Yabbadoo]

>>>snip<<<
That aside, you can use the following treatment for Shell Rot:

"1.) Grab a set of scales and measure out 35 grams of salt.
2.) If you don't have micro scales a good teaspoon is around 4.7grams, so 7 nice teaspoons will do.
3.) I don't mind what salt you use, personally I prefer pool salt.
4.) Throw that in 250ml of boiling water and stir in until dissolved.
5.) Then take 750ml of water from your crayfish's tank put it in a 4 litre ice cream container or something similar with high sides.
6.) Add the dissolved salt solution to it and stir again.
7.) Drop an air stone to keep the water nice an aerated.
8.) Set up an alarm clock/timer to 10 minutes.
9.) Drop your crayfish in and make sure it can not escape.
10.) Go do some maintenance on the tank.
11.) Come back and remove your crayfish when the alarm goes off.
12.) Repeat every 3 days as needed until next moult or lesions are "bleached out".

>>>snip<<<

Salt baths are great for cleaning up crays. I did 3 of mine yesterday.
Big Daddy now looks like he's been waxed & polished !!! Heaps of those white nemos came off aswell as all the slime. Never tried it for shell rot however.

I use 10 grams of salt per liter. Leave in highly airated bucket etc... for 30 mins. Take them out and put in another bucket, Freshwater / Salt Free, for 5 mins as a rince. Return to tank.

 

[26pets]

Everything seems normal in the tank besides a little Nitrate Spike <20. I did a water change last night. Alittle more than a 50% water change. Can shell rot spread to other crays?

 

[26pets]

A side note, Marbles are bred to be highly non-aggressive. Having them with another species of crayfish may be detrimental to their health. But that's an observational call for you to make.

I've noticed that when I breed marbles I have none fight. But when I breed blues I get some that like to be the tough guys. But the way I breed my blues now and days there hasnt been any issues. My display tank no one bothers each other. My big guy "Larry" He has only 1 claw. Hes never molted since Ive had him. Idk why? I think because hes scared of the other guys. But the thing is hes the biggest guy. And hes the scaredest. He'll get a female into mating and here comes gary. Takes the girl from him...... Poor Larry....

 

[Yabbadoo]

Everything seems normal in the tank besides a little Nitrate Spike <20. I did a water change last night. Alittle more than a 50% water change. Can shell rot spread to other crays?

If your other crays are healthy it shouldn't. The problem starts when they get an injury. Usually from aggression. If one of your healthy stock drops a claw or limb the bacteria may take hold at the injury site.

If it's not shell rot, it could be shell staining??? Iron level to high???
Acidic water causes alot of shell probs. Keep PH around 7.5.

 

[26pets]

1- Marble has a dark brown spot under her tail. After doing the water change and adding salt to the tank. The spot lighted up. Hopefully it will go away.

2- Marble looks like she has a bite on her tail end? She molted somewhere between last night and today. Shes still soft. But I couldnt find her shell?

 

[black_sun]

I've noticed that when I breed marbles I have none fight. But when I breed blues I get some that like to be the tough guys. But the way I breed my blues now and days there hasnt been any issues. My display tank no one bothers each other. My big guy "Larry" He has only 1 claw. Hes never molted since Ive had him. Idk why? I think because hes scared of the other guys. But the thing is hes the biggest guy. And hes the scaredest. He'll get a female into mating and here comes gary. Takes the girl from him...... Poor Larry....

Yea, Marbles have been bred to be handled (primarily as bait), so they have extremely docile temperaments and don't really fight or defend themselves (don't defend aggressively rather, they still tail-flick to escape) to any great extent. Where as blues (P. alleni, most commonly seen "blue" cray - but I don't know if that's what you have) are one of the most aggressive NA species and actively fight. But with proper housing arrangements can be toned down quite a bit (but this might be a likely cause the the Marble's injuries, a nip or bite from a blue).

That aside, the larger the crayfish the farther the time between molts will be. You can try and speed up the process by warming up your tank a few degrees. Usually the increased temperature will trigger a molt (but if he's not comfortable molting with tankmates, like he doesn't have a cave or something to hide in, he'll try to hold off on it for as long as possible). But if he's currently breeding, you won't want to trigger a molt. He's in Form I (again, if is the common blue. If it's a Cherax quad, this doesn't apply), and when he molts he'll go into Form II and not be able to mate until the next molt. ...but he'll get the beginnings of his claw back though! And maybe he can chase Gary away from the girls, hehe

 

[black_sun]

1- Marble has a dark brown spot under her tail. After doing the water change and adding salt to the tank. The spot lighted up. Hopefully it will go away.

2- Marble looks like she has a bite on her tail end? She molted somewhere between last night and today. Shes still soft. But I couldnt find her shell?

1- Keep an eye on her. Prophylactic treatment and treatment for the lightened spot would be recommended. Just as a precaution.

2- Not removing an infected shell isn't a great thing, but it isn't horrible either. If the new shell wasn't breached by the infection and the cray doesn't have new/open injuries, the infection isn't going to take hold. The shell removal is really more a "better safe than sorry" thing.

Then again, this is all assuming it is, in fact, shell rot. But Yabbadoo, raises a great point. pH and metals in the water can cause a lot of issues. Iron, for example, will stain and/or tinge the shell a rusty red color (and eventually kill the crayfish if the levels get too high).