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Crayfish, Crawdads, Yabbies, Ditch Bugs Disease/Health 4

FAQs on Crayfish Disease: Crayfish Disease 1, Crayfish Health 2, Crayfish Health 3, Crayfish Health 5, Crayfish Health ,
FAQs on Crayfish Disease by Category: Diagnosis, Environmental, Nutritional, Trauma, Infectious, Parasitic, Social,
Treatments

Related Articles: Forget Crawfish Pie, Let's Make a Crawfish Tank! By Gage Harford, Invertebrates for Freshwater Aquariums by Neale Monks, Freshwater Shrimp, Crayfish, "Lobsters", Prawns Freshwater to Brackish Crabs

Related FAQs: Crayfish 1, Crayfish 2, Crayfish ID, Crayfish Behavior, Crayfish Compatibility, Crayfish Selection, Crayfish Systems, Crayfish Feeding, Crayfish Reproduction, Freshwater Invertebrates/Use in Aquariums, Freshwater Crustaceans for the Aquarium, FW Crustaceans 2, Fresh to Brackish Water Crabs, Hermit Crabs,

crawfish; hlth.        8/9/15
my crawfish died yesterday right before it died its claws had both fallen off no other appendages did though i was wondering if you would know what happened to her we caught her out of a river about three weeks ago and she's been living in the tank fine until now like she had food and a hiding place a water filter and such there were no other animals in it though so
wondering if you know what happened thanks gabe
<Help us to help you, Gabe. Some facts would help. The key thing is this:
how did you supply her with iodine? That's the #1 reason Crayfish "fall apart" in fish tanks after a while. Without iodine they can't moult, and obviously as they get bigger with each moult, they'll need ever more iodine each time. So there comes a point where there's no enough, they start to moult but fail, and either die or end up deformed. If the latter, they can sometimes moult back into normality, if they get enough iodine. Which brings us to the how. Marine aquarium shops sell potions for iodine that you add to the water. Half the dose on the packaging is fine. This is cheap and convenient. You can also supply iodine-rich foods (seaweed for example, as in Sushi Nori) but this isn't as convenient or cheap. Meantime do have a peruse here:
http://www.wetwebmedia.com/fwsubwebindex/crayfishdisfaq.htm
Follow the links at the top to various FAQs and detailed articles. Cheers, Neale.>

Please help with my yabbie      5/29/15
Hi
<Howdy>
I have a blue yabbie 'pepper' that I've had for about 7 months now and he's very much loved. He's been looked after and has been doing very well. 21l tank plus filter plus an air rock with water changes every 2-3 weeks as it's needed.
<Umm; what re water quality, feeding... Iodide/ate use?>

I just came home today to find him lying on his back with his tail curled up dead. I've had him since he was little and I have no idea why this has happened when he's been so well? There are no markings on him anywhere.
What's happened and what can I do to prevent it.
<Highly likely a simple nutritional deficiency at work here; or a water quality/environmental one...>

Please I would really appreciate your help
<Have you read here?
http://wetwebmedia.com/CrayDisDiagF.htm
and the linked files above? Bob Fenner>

Crayfish; hlth., infectious; no pic          5/22/15
Hello
My name is luck
I would like know crayfish marron or Cherax Tenuimanus have Aphanomyces astaci or not????
Tq
<Judging by? Looks, behavior? Have you read the wiki coverage:
http://en.wikipedia.org/wiki/Crayfish_plague
Bob Fenner>

Lobster claws dried up and are stiff; moulting beh.      4/2/15
So I had to move my lobsters by hand and I thought he was dead after 20 minutes even though I kept him soaked and moist but he was just limp and thank God he started moving again after I thought he died then I put him in a very small cup only big enough for his body but his pincers stuck out so later when I finally threw him I'm the tank at last I notice he is always
curled up and still he is alive as his legs move and his mouth is moving his tail is still able to uncurl but he doesn't and I've noticed his claws are just limp normally he would raise them but he doesn't do anything with them then I got him out and noticed they were hard as rock I don't know if it was because of being out of water too long and being dried up I don't
want to force them open as that might break em so will they overtime just go back to normal or should I break em off because I know they will grow back but just will be smaller I don't want to break em off so what should I do should I wait for him to molt
<Never force a moult of a crustacean, however distressing it seems. If the animal can complete its moult, it will; forcing a joint to snap is not only stressful but, if the joint isn't properly formed, can lead to serious (fatal) injury. Now, nine times out of ten, improper moults come down to lack of iodine. What's the iodine source you've been offering? If the answer is "huh? iodine?" then that's your problem. You can buy iodine drops for marine aquaria inexpensively, and either use at full dose (for marine tanks) or half dose (for freshwater) and your crustacean pets will moult normally. Indeed, some problems they have now will be healed after one or more successful moults. Buy beyond this, there's nothing you can actual do for your crustacean beyond the obvious: optimise water quality, check water chemistry is correct, and minimise stress. Cheers, Neale.>

ghost lobster questions; sans data        3/19/15
i have a ghost lobster that is around 4 inches in length. His head is turning brown. Seems healthy, eating great, active and night as usual. So see no change in behavior. Just want to make sure there is nothing to worry about. Was wondering if they may change color some when getting ready to molt.
<Mmm; might be "nothing"; but the color change could be evidence of something off with water quality (which you give no indication of) or nutrition (ditto). READ on WWM re Crayfish Systems and Feeding. Do you need help using the search tool, indices? Bob Fenner>

 

Crayfish - change in behavior after change of aquarium and molt     12/4/14
Dear WWM Crew, My husband and I live in Japan and about a month ago we bought a couple of crayfish,
<Oh! I kept these as a youth there as well (Dad was a lifer in the Nav)>
which are very common in pet shops here. By Googling and checking pictures we believe we have Procambarus clarkii but we might be mistaken,
<This one species of Cray has been transplanted by humans most everywhere>
they were not very specific in the shop. We got a white one and an orange one. I have read your articles and FAQ but we are still wondering about a change in behavior in one of our crayfish. They told us since they were roughly the same size they could live in the same aquarium,
<Mmm... until one molts and the other is hungry... DO keep your eye on them, DO provide a one-way in only (like a blind piece of PVC... pipe and cap) and KEEP them fed (daily)>

and in the shop they were kept in the same box. So we set up a 60L tank with plenty of hiding places and few plants that we were told they enjoy eating, plus filter and heater set to 23°C (there is no such thing as central heating in Japan and our rooms can get very cold during winter)
<S/b fine for these animals>
. We bought them the specialized pellets they sell for this type of crayfish and started our adventure. After few days they seemed to be doing good, <well> and showed distinct personalities, the white one despite being the one who got most easily scared by our presence would stay in the open while eating, while the orange one would come to the glass and show his bravery whenever we approached, but would carry away his pellets and feed only while hiding inside a cave. Perhaps a week after we got them I caught them by chance in the middle of a fierce fight and in the next couple of days the white guy started “mysteriously” loosing <losing> limbs. So we decided to separate them, at least for the time being as clearly the white guy was no match in his state. The decision was even more pressured as white guy molted and we knew he would be too soft and could get killed.
<Too likely so>
We transferred orange fellow to a smaller tank with similar setting.
<Good>
This was three weeks ago. White guy has since molted again,
<... some deficiency at play here... What is the hardness of the water? Do you measure pH... ? What water source are you using? Are you administering iodine (ide-ate actually)?>
his legs growing very fast and himself growing quite a lot. We are surprised by such fast molting and hope it is normal.
<Not normal, nor healthy>
I have more or less come to understand his routine, he stops feeding for a while, he molts and after a couple of day she has finished eating his exoskeleton and is back to his normal antics, eating his pellets as usual. Orange guy on the other hand, has us very worried now. For the first two weeks he behaved as he had in the big tank, playful and showing himself when we approached, but hiding to eat and sleep. On Monday evening we discovered he had molted when we returned from a weekend trip. It's been 4 days since we found him and he has eaten only about half of his exoskeleton and has refused any extra food we tried to give him, he stays in his cave and rarely comes out all. Is this behavior part of his normal routine after molt?
<Again; something is off, missing here... see the terms above in the archives on Crays on WWM>
Just as he has behaved different from white guy, he acts different in this case too? How long should we wait for him get back to normal? We are worried he needs something else,
<Yes>
which we are missing from his small tank compared to the fellow in the big tank. He has less space and hiding places, fewer plants, which he barely eats anyway as opposed to white who constantly nibbles on them, and different rocks at the bottom. Everything else we have tried to keep exactly the same. Any advice or recommendation would be very helpful. I attach a picture of how we found him four days ago after we came back, in case it helps identify him and if something is wrong. We have since cleaned all the uneaten food that you see in the picture, and changed25% of his water. Thank you very much, Camilla
<The I2 will likely work wonders... Can be purchased for aquarium use... Check your water quality otherwise. Perhaps your water is "too soft", lacks Ca, Mg salts, carbonate. Bob Fenner>

do Louisiana crawfish hibernate in captivity      11/17/14
My daughter rescued a crawfish from a crawfish boil last May - about 6 months ago. We keep Isabelle (the crawfish) in a 10 gallon tank, filter, gravel, half full and a hiding place.
<Neat! I "did this" also... with likely the same species, Procambarus clarkii; as a college student studying this animal's substrate preference behavior>
We feed her mostly the pellets and occasionally some veggies. She seemed to be doing okay. Had some eggs, but lost them.
<Not fertile if solitary>

She molted a month ago and seemed fine. Last week she was on her side. We flipped her over. Today she's seems virtually dead. Hardly moving.
<Mmm; very common... usually an issue of nutritional deficiency, particularly a bit of iodine/ide... or usable iron... Search, read on WWM re... or write back if you can't/don't figure out how to use our indices or
search tool>
At one point I thought she was dead, but in a shallow bowl of water (to observe her) the water kept circulating so she is clearly still breathing.
It is November - is she beginning some sort of hibernation?
<Mmm; not likely if indoors... i.e. kept where warm>
Could this be nutritional?
<Yes; almost assuredly>

We didn't know to keep the exoskeleton in the tank, so she lost out on that. I'm wondering if I need to be in emergency-doctor mode or hospice nurse mode. Help!
<Can be rescued likely by application (to the water) of the above... there are commercial prep.s for aquarium use... or one can assemble DIY>
Thanks for your site, it's really the only place to find good info about keeping crawfish as pets (though I wish I hadn't overlooked the part about leaving the exoskeleton in the tank!)
Thank you,
Pamela Berg,
Northbrook, IL
<Please do write back if any of this is incomplete. Bob Fenner>
do Louisiana crawfish hibernate in captivity
     11/17/14
My daughter rescued a crawfish from a crawfish boil last May - about 6 months ago. We keep Isabelle (the crawfish) in a 10 gallon tank, filter, gravel, half full and a hiding place. We feed her mostly the pellets and
occasionally some veggies. She seemed to be doing okay. Had some eggs, but lost them. She molted a month ago and seemed fine. Last week she was on her side. We flipped her over. Today she's seems virtually dead. Hardly moving. At one point I thought she was dead, but in a shallow bowl of water (to observe her) the water kept circulating so she is clearly still breathing. It is November - is she beginning some sort of hibernation?
<Nope. Just to be clear: only warm blooded animals, specifically mammals rather than birds can hibernate. For sure some cold blooded animals become torpid but they don't actively lower their temperature or metabolic rate -- they are simply forced into a situation where ambient coldness makes their metabolic rate slow down. So, if you're talking about crayfish, they'll be as active as ambient water temperature allows, and indoors, that's pretty
much optimal all year around so far as North American crayfish species go.
Put another way, unless the tank is frigid-cold then it's very unlikely a cold blooded crayfish would be deliberately slowing down in the same way as a hibernating dormouse.>
Could this be nutritional?
<Immeasurably more likely.>
We didn't know to keep the exoskeleton in the tank, so she lost out on that. I'm wondering if I need to be in emergency-doctor mode or hospice nurse mode. Help!
<Optimise water quality and chemistry as per normal, but also use iodine drops (sold for marine tanks, used at about 50% the quoted dose). Iodine is the "wonder drug" for many crustaceans because it's lacking in their diet
when given generic aquarium foods. Providing iodine prevents all sorts of problems, and in some cases, can undo damage. Crustaceans, like molluscs, tend to exist in a binary state under aquarium conditions -- they're either
thriving or dying, with not much in between. Do start reading perhaps here:
http://www.wetwebmedia.com/fwsubwebindex/crayfishdisfaq.htm
Links to various articles and FAQs at top.>
Thanks for your site, it's really the only place to find good info about keeping crawfish as pets (though I wish I hadn't overlooked the part about leaving the exoskeleton in the tank!)
Thank you,
Pamela
<Glad to help. Cheers, Neale.>
Re: do Louisiana crawfish hibernate in captivity
     11/17/14
Thank you so much. I'm off to the aquarium shop to get marine iodide (iodine?) and better food (and a new filter). Didn't realize how much all we loved this little girl until we thought we lost her.
<Ahh; a good life lesson. BobF>
Re: do Louisiana crawfish hibernate in captivity
     11/18/14
Hi Bob,
We changed her water and added the .25tsp of marine iodine (it said 2 tsp per 50 gallon and our tank is 10 gallon). The person at the local aquarium shop said the calcium in our hard water is probably good for her too
<Yes it is>
-- and she did almost instantly perk up.
<Ah yes; the I2... miraculous in appearance eh?>
Last night she was crawling all over, trying to escape -- very uncharacteristic of her, though I've read on your site how they can be real escape artists, so we were very hopeful, almost giddy with excitement. We thought it was a real miracle -- my husband called her Lazarus.
<Ooh, a fave character in the R. A. Heinlein books he shows up in>
This morning she was on her back and motionless, though after I flipped her I can see she's not dead. She is not eating -- even last night as her little alien gill-like belly button of a mouth was going bonkers, she would
not eat any of the food we put in the tank -- bottom crawler pebbles, lettuce, algae tabs, a frozen pea. I thought about putting a few small fish in there to stimulate her and maybe she'll eat them. Or get some fresh plants?
<These would help... and just a drop more iodide-ate every other day>
Thanks for your help-- and any more advice you might have.
Pamela Berg
<Reading (on WWM, elsewhere re Crayfish) and patience. Bob Fenner>
Re: do Louisiana crawfish hibernate in captivity      11/18/14

Bob,
Thanks for all your advice. I made a small donation to your wonderful website/organization.
Pam
<Ah; thank you. B>

Blue Crayfish lying on side and not eating    2/8/14
Dear WetWebMedia
<David,>
I have searched for days all over your website and others but find a few possibilities on what the "problem" might be. Could you assist?
<Possibly, but crustaceans tend to exist in a binary state so far as healthcare goes: they're either fine or dying. That's because we have virtually no understanding of how to use medicines to help them. The one exception here is Iodine, which can be a "silver bullet" in some situations, specifically prevention of moulting-related problems. Other than that, about all you can do is optimise the environment and hope the crustacean pulls through under its own steam. Many do.>
I am from the UK and I have had a Blue Crayfish for around six months now.
"His" name is Baldrick (he says hello).
<Hello.>
Lately Baldrick has been lying down, intentionally, not falling or getting pushed over by anything on his side which is what prompted my search.
<I see.>
A bit of history: He was extremely active as a "baby". He would jet around the water, dig, wreck and climb the plastic plants. All sorts.
<Sounds normal so far.>
As he got bigger he did less but I figured that was natural. He hasn't shed for quite some time - I think two-three months now whereby before it was monthly.
<Again, not unusual; as crayfish age, moulting becomes less frequent, and eventually may stop altogether if the crayfish is very old.>
I always left the shells in there as he seemed to like eating them.
<Correct analysis; recycling the calcium. Not essential you do this (old moults are a way for crustaceans to get rid of heavy metal poisons like copper, for example) but crayfish should certainly have some source of calcium available to them, whether a moult or something like a unshelled prawn to eat instead.>
He would go through his normal cleaning cycles but lately, the last few days I've noticed he is almost constantly cleaning himself, almost violently (before it would be the occasional big clean and maybe just a little rub here and there). He is almost always jamming his back legs where the swimmerets are. I thought there might be a problem or eggs (some how) but it looks normal under there.
<He may be having a problem moulting; do you use Iodine?>

Today he was really having a go around his eyes and opened his face (like something out of predator) up for a "full" clean - I'd never seen that before. Lately he quite often will tuck his tail underneath himself and scuttle around as if he is about to be eaten, then lay down on his side and not move for a little while. I thought he was dead until I tested him by dropping a bit of food in there. He jumped up in his usual way and scoffed the food instantly. However, the last two days he's barely eaten. He responds to fresh food as always - but only eats maybe one pellet. He brings other pellets to his mouth, tries them and then drops them which is very out of character for him. I have food two days old just sitting on the bottom of the tank - he is completely disinterested. When you think it's all doom and gloom and he is about to die, he will untuck his tail for around 10 minutes and wander around without any problems - however the feeding hasn't rectified.
<If you don't use Iodine, do so; you can inexpensively buy Iodine supplements for marine aquaria, and dosing at one-half the amount quoted on the bottle will be ample. Iodine is essential for proper and regular moulting, but unless we offer crayfish Iodine-rich foods (primarily seaweed like Sushi Nori as well as certain seafoods) they often are starved of Iodine. Without the Iodine the moulting process sometimes "jams", and crayfish can find themselves in all sorts of trouble. Using Iodine is a quick, cheap fix (and preventative) to these problems.>
He is alone in a large tank. I have changed about 40% of the water and cleaned the glass - no effect.
Thanks in advance
Yours
David
<Hope this helps, Neale.>

Some Help- Crayfish; the usual lack of data     12/7/13
Hi,
My name is Christa and I have a crayfish that is  slate colored and lives in a 20 gallon with water ranging between 78-82 degrees.
<... what species is this? This temp. is too high for non-tropical>

 I have notice his right eye turning color after his molt about a month ago and now his eye has some huge white ball formation over it. I do not know what it is or if he will die from it.
I would like some help on this,
Thanks
<Hopefully not die; but need information... re the set up, water quality, and nutrition. Most Cray species kept by hobbyists need hard, alkaline water, and regular iodide-ate additions to the water... Read here:
http://www.wetwebmedia.com/CrayDis4.htm
and the linked files above. Bob Fenner>
Re: Some Help- further blather sans reading    12/8/13

I really have no idea what species he is. He's about 4 inches long. He's been living in my tank with that temp for half a year already with no problems. But if it's best to put him in colder water, then I can move him to a small tank. It would be best right?
<Assuming you didn't pay a (very) premium price for one of the Australian species (Cherax spp.), then you have one of the standard issue US species, usually Procambarus clarkii or else (usually less commonly) Procambarus alleni. As you'd expect for species native to the southeastern United States, they are both room temperature species. Survival for about half a
year before things go wrong is actually very common -- and my guess would be that a moult is long overdue, but lack of iodine in the diet has prevented this from happening. As Bob suggests, get some marine aquarium iodine drops (not expensive) and use at 50% the dose recommended on the packaging (so it's even less expensive). Beyond that, a mixed diet
including Sushi Nori (rich in iodine) and occasional unshelled shrimp and krill (rich in calcium) will be useful, alongside a predominantly greens-based diet (algae wafers, cooked peas, softened vegetables).
Basically crayfish are easy to keep for a few months... the real art is keeping them across several years! Cheers, Neale.>
Re: Some Help-    12/9/13

I have moved my little guy to my 10 gal tank. The little bit of water is room temp. And I do throw in algae wafers and shrimp pellets. Thanks for the help!
<...I2? Read where you've been referred. B>

Crawfish dying within 24 hours   4/10/13
<Hi Eric, Rick here>
I live near a store that regularly offers live crayfish for sale.
<I know you don't live near me, crayfish are a rampant invasive species in Arizona and are therefore restricted by Game and Fish!>
With my young daughters prompting, I've tried twice to pick a lively one out of the box and place it into a well established aquarium.
The test strips all read okay and I had a submersible filter in for filtration and supplement air.
Both specimens died within a 24 hour time period.
After researching care for these guys, I can't seem to find a reason for them not to be making it.
If there was something wrong with the tank, I would think they'd at least make it longer than a day.
Any ideas would be helpful.
<The only thing that comes to mind for me at the moment is that perhaps they weren't properly acclimated to the tank. What procedure did you use to make the transfer from plastic bag to tank?>
Thanks,
Eric
<Rick>
Re: Crawfish dying within 24 hours 4/9/13– 04/10/13

Hey Rick,
Thanks for the quick response.
Honestly, I took them out of the bag and placed them into the tank.
Keeping in mind these guys were sitting in a crowded box with no water at the store, I figured the sooner I got them into the water the better.
<Hmm. I'm not sure what you can do here because every acclimation process always assume the fish starts in water. Could there have been a large temperature difference between the bag and the tank water?>
The second time I tried, the crawdad lived over 24 hours in the tank and was very active and feisty. Next day, he was gone.
<It certainly sounds like stress of some kind.>
I wonder if what they've been through to get to market is just so traumatic,
they don't have much of a chance past a certain point.
<Possibly. You might try easing them into water. Empty your tank and form the substrate so there is a hill. Put enough water so there is a pond on one side of  the tank and dry land on the other side. Place the crawdads on the dry land part and let them enter the water on their own. Once they are in the water regularly, add a half gallon at a time until the tank is at the desired level. Also, take a look at this website I stumbled across.
http://lifestyle.iloveindia.com/lounge/crayfish-care-13248.html   It has some ideas on how to transfer, but again, it assumes the fish starts in water.  It might be that being out of water at the store is the root cause.
Their gills must be moist to work properly in air. Actually, as I proofread and think about this some more, I wonder how long the fish has been completely out of water. Could be the gills are already dried and damaged before you bought the crayfish.  - Rick>

Sudden Death of Procambarus clarkii     3/25/13
<... we have a limited amount of space w/ this webmail prog.. Ask that people in turn only send a few hundred Kbytes... yours is about 8 meg.s...>
Dear WWM team,
<Cath>
About a week ago I purchased two Procambarus clarkii (I think that is what they are - see attached cell phone photo - excuse the blurriness) from a local supplier from which I had purchased my two Cherax quadricarinatus (Lucille and Luigi) who are absolutely thriving (see other attached photos).
<Very nice>
I have had Lucille for nearly a year now and Luigi for about 4 months.
Luigi and Lucille are kept separate to each other and separate to the two new lobsters. I was devastated when less than a week later, both my new babies were dead.
<Mmm>
I admit that I was probably a bit hasty and did not prepare the tank properly for them but all seemed well for the first few days. I cleaned the tank thoroughly prior to bringing them home - the day before purchase. I have a sponge filter to keep the water clean, use a dechlorinator that removes chloramines and chlorines and the temperature is kept at about 24 degrees Celsius by means of a heater (not really necessary in our climate!).
The white lobster (Pepper) was fractionally smaller than the red one (Chili) (+/- 4 to 5cm) but this did not seem to cause any major issues.
The tank had plenty of little hiding spaces for them to retreat to. Pepper was the first to die. "He" was fine at feeding time (using the Tabimin Bottom Feeder tablets) and then the next morning I awoke to find him lying dead on the tank floor. I quickly removed him and put it down to the fact that he was smaller and maybe had gotten bullied by Chili or that perhaps the shock of moving was too much for him. This was two days after purchase. I had a good look at him and did not see any lesions or obvious abnormalities.
About three days later, I went to feed Chili. I dropped the Tabimin piece in the tank and waited. "He" did not appear as usual. At first I thought he had escaped (irrational as the tank has a lid) but eventually found him burrowed down in the gravel under one of the ornaments. I must mention that when I brought him home I noticed that one of his pincers was missing a "prong" and that one of his legs was also "amputated". This didn't really bother me as I know that they are capable of regeneration. He also had one or two tiny brown/black spots on his shell and one or two on his legs.
<As you state; should be of no consequence>
Basically my question is - do you think that this was simply a case of being too hasty and not preparing adequately?
<Could be these co-mortalities are coincidental; but better to further consider whether there is something amiss here; perhaps w/ the system, water quality>
 Or could the broken pincer and brown spots mean something? I had a good look at Chili's corpse and nothing seemed untoward (I work at a veterinary pathology lab - was contemplating performing an autopsy!).
<If you think it might prove fruitful... better some base knowledge and a mass spec. sampling of a few tissues methinks>
My Cherax lobsters are absolutely thriving so that is why I am puzzled as to why the other two died so suddenly. I also want to make sure that they didn't have anything that could be passed on to my other two.
Kind regards,
CATHERINE
<Is there an ornament present in this system? Some source of metal (the Cherax may have become habituated)... I'd be running a pad of Polyfilter in the water/filter flow path to look for color... and have you read here:
http://www.wetwebmedia.com/CrayDis4.htm
and the linked files above for insight/s. Bob Fenner>

Chili and Pep
Lucky Luce & Luigi

Unexplained crayfish death    3/25/13
I have had an electric blue Cray for about 2 years. She was in a 20 gal tank with a fancy guppy (fish seems perfectly fine). She was VERY outgoing and active.
<Good signs of health>
She molted about a month ago and seemed in great health. I fed her on Friday before leaving town for the weekend and upon returning, I found her on her back in the middle of the tank. We cleaned her tank regularly and never had any problems with her at all! The tank readings were all within normal parameters (tank is cycled).
<Need values... >
 I attached some pictures because the only thing that was truly odd, is that she looked pale compared to her usually bright blue color and her tail seems very pink.
<Yes; likely calcium/magnesium deficiency or imbalance>
 Please help. I loved my Cray and at least want to know what went wrong.
Thanks.
Carolina Zakes
<Did you supplement I2? Please read here:
http://www.wetwebmedia.com/CrayDis4.htm
and the linked files above. As you'll find, the above two issues are quite common in Cray losses. Bob Fenner>

Blue Lobster, hlth.  3/8/13
Hello!
 I have read over the site many times about blue crawfish/ lobster which ever they are called. I have had my blue for about 4 months now :) 3 nights ago she had this white fuzz around her tail, almost like her tail had busted open and meat was coming out. I turned the light off to prevent any more stress. I went to bed with the notion that I would have a dead baby in the morning. Lucky for me I woke up to all the white fuzz gone and a tail full of dingle berries! I am super excited. Since I saw she has berries, I have not had the light on in the tank. The only light that is seen in the tank is natural light from my from windows (they have sheer curtains over them, so the do not let in a ton of light. Am I able to have the light on with out stressing out my blue or should I just leave it off till the babies come?
<If the crayfish is alone, then likely yes, you can have the aquarium light on. If there's some other crayfish or fish with it, turning the light on may spur tankmates into aggressive or foraging behaviours that might irritate the crayfish. Add some floating plants if you can to provide shade; cheap aquarium pondweed (as sold for Goldfish) is fine, and provides a useful source of food, too. Alternatively, a good solid cave (like a flowerpot) will provide just the sort of home she wants.>
That is if they are fertile.
<Won't be without a male.>
I had black moor and a telescope goldfish in the 10 gal tank with my blue till I saw the eggs, then I moved the fish to the 55 gal (they were going to be moved here anyways) so they would not try to eat the eggs.
<Wise; Goldfish don't belong in 10 gallon tanks, and it's not really good to keep them in 20 gallon tanks either. Your 55 gallon system is a far, FAR better home.>
I miss being able to see my craw all light up. Can I turn the light on or should I leave it off? Before this I would have the light on from about 12 pm-10 pm Thank so much!
Meghan
<You should be fine turning the lights on. But turn the room lights on first, so that the animal gets used to the light before switching on aquarium light. Cheers, Neale.>

blue crayfish acting strange     3/7/13
Hello-
<Hi Ann>
I have a blue crayfish in my classroom aquarium that has been acting strange for a couple of weeks.  I have had the crayfish for about 6 months.
 It is in a 30 gallon aquarium with some rosy barbs and neon tetras.
<Surprising that these species all get along here; temperamentally and water-quality wise>

 She ( I think it is a she) has a log to hide in, but has not been staying in the log for the past couple of weeks, instead choosing to walk around and sometimes lay on her side.
<Laying on side... could be reproductive behavior, evidence of nutritional deficiency... or nothing>
Also  for  the past couple of weeks she has been curling her tail under her body when she walks around.  When she uncurls her tail she is picking at her stomach with her little back feet.
<How long have you had this animal?>
 Sometime she puts the tip of her tail down on the floor of the aquarium and raises the back half of her body and feet off of the floor.  My students are convinced that she is pregnant and that she is going to have babies any day now.
<Mmm, can you see eggs?>
 I am not so sure because she is the only crayfish in the tank, and I do not believe that they are asexual. 
<Are dioecious, from the Gk. meaning "two houses", boys and girls...>
I have tested the water and it is ok, but I did a partial water change anyway.  I would definitely be interested in any insight that you may be able to offer.
Sincerely,
Mrs. D
<Mmm, well, IF the one was in the presence of a male before your acquiring it, there might be a packet of sperm that was transferred... But females will/do "go through the motions" often w/o actually producing eggs, and of course, viable young. I would have you review what we have archived:
http://www.wetwebmedia.com/FWSubWebIndex/crayfishbehfaq.htm
and the linked files above. Are you providing Iodide/ate? Is there sufficient alkalinity here? Has this specimen molted in recent times? Bob Fenner>

Crayfish claws fell off    2/21/13
Hello!
<Hello,>
I obtained a crayfish last year after finding it left alone in a cooler at a craw fish boil, and all the others had been cooked.
<Yikes!>
I was at one again recently, and I nabbed another, making sure it was female after plenty of research to make sure my first one was female, and learning what to look for. I didn't have a completely proper holding tank, since I'd like to try and keep in one tank, with possibly a divider to keep them separated, so I placed the new one in a smaller little tub with low water and some rocks and a cup to give it somewhere to hide. It's been in the corners and I've hoped that it'll be okay in it's temporary new home before I can obtain a new, larger tank for the two. But today I noticed that both claws have fallen off, and I'm worried that it could be too stressed and might need better living quarters than what it has, but my other crayfish may be too big for my holding tank, and I don't want to chance a bad confrontation between them that leaves me with still only one crayfish. What should I do to help my new crayfish feel comfortable and safe, that won't leave her dead? My current tank is a ten gallon,  and according to paper testing strips has decent water, though the nitrites are a little high. I had trouble cleaning my tank last time, and I must not have cleaned it properly. Would my new Cray be better off in my tank than in it's holding tank?
<Crayfish are indeed best kept singly unless the aquarium is very spacious (realistically, 55+ gallons) in which case large groups seem to be relatively stable compared to twos or threes. A divider can work for smaller tanks (egg crate cut to size works well for this) but still, keep an eye on them because there's always a risk one will climb over the divider during the night. Fighting crayfish will commonly pull off one another's legs or claws, even cannibalizing their companions! In any case, do have a read here:
http://www.wetwebmedia.com/ca/volume_5/volume_5_3/crayfish_basics.htm
http://www.wetwebmedia.com/ca/volume_1/cav1i4/crayfish/crayfish.htm
Crayfish are tough animals and heal well given good conditions. If they lose their claws, they can still feed and will grow the claws back in stages with each moult. A key problem with moulting is the lack of iodine common in captivity; you can either use marine aquarium iodine supplements at 50% the dosage stated on the bottle (a cheap and easy solution) or else ensure their diet is rich in iodine through the use of seaweed foods like Nori and marine invertebrates like mussels (this approach is fiddly and not worth it unless you really do know what you're doing). Have a read here:
http://www.wetwebmedia.com/CrayDis4.htm
Plus the linked files on crayfish health and disease listed at top. Cheers, Neale.>

Red Crayfish with Milky White Eyes?   2/3/13
Hello, I came across your website and noticed there was a lot of information but I could not seem to find information about my particular problem. I have a red crayfish in a 75 gallon tank with about 18 cichlids. Today, his eyes I noticed turned milky white.
<May simply be pre-moulting if this really did appear out of nowhere. But physical damage can cause the eyes to cloud over too; cichlids in particular "go for the eyes" when attacking (as do many fish, which is why eye spots on the tail as decoys are so very commonly seen among fish). Physical damage to the eye won't get better, but it will be removed and replaced with healthy tissue once the crayfish moults. Regardless, isolate the crayfish in its own aquarium for 2-3 weeks. Put a flowerpot in there for a cave, but otherwise leave the tank nice and clean. As ever, dose with iodine supplement (as sold for marine aquaria) at 50% dosage to ensure a proper moult.>
It is a community tank of Central American cichlids and African cichlids.
<Not a recommended mix, but can work if you choose species carefully.>
I have read info on the type of water parameters you need for these guys, and realized it is not perfect for him...The temp is 78, the pH is about 7.6, the KH is about 6-7 drops (Think that is in the 100-125ppm range) Ammonia, Nitrites are zero. Nitrates are about 40 (I know this is considered high, I am going to do a large water change) I have an Emperor 400 filter, two powerheads for water circulation and two airstones hooked up to an air pump.  I try and feed him a sinking algae wafer once a day, also sometimes at night instead of during the day but I often times have a problem with another fish getting to it first and taking it.
<A good clue he doesn't belong here.>
Or, if the crayfish does get it, I have a Jack Dempsey cichlid come in and steal it from him occasionally, right out of his little claws.
<Yes.>
I did read today on your website that I need to add iodine into that tank. Could you tell me why this is exactly?
<You're looking for products such as Salifert Natural Iodine, Kent Marine Iodide, Seachem Reef Iodide, etc. Typically inexpensive products, $5-10 a bottle. Dose at half the stated amount on the bottle, so very economical.>
The marine iodine I read increases algae growth, which I do not actually want.
<In a cichlid aquarium without live plants you will battling algae anyway thanks to the high nitrates, so iodine won't make any perceptible difference.>
He has not increased in size in over 4-6 months, thus, he has not gone through a molt yet.
<Again, a good sign he doesn't belong.>
This also I know is a bad thing. Is it the water parameters mostly being off? Aggression from fish maybe attacking him? Stress? Not enough food? No iodine?
<Some combination of these. Crayfish are best kept alone, and contrary to what many beginners suppose, they aren't suitable "critters" for tanks filled with aggressive cichlids. Because crayfish are so easy and cheap to care for properly, there's really no excuse to keep them in community tanks. A 10-gallon tank, a basic filter and a flowerpot are all you need for a singleton!>
Could you provide me with information as to why his eyes changed color like that? Is he actually blind now? (It kind of seems like it, because he does not raise up his claws when a fish is nearby, like he can't even tell they are there?)
<His vision may be blocked, yes; crustacean eyes are compound eyes, but unlike our eyes, they have the exoskeleton over the top of them. So when the exoskeleton gets damaged, it clouds over -- there's no eyelids that can be opened up like our eyes. They're basically looking through a window all the time, but on your crayfish, the window is opaque.>
Thanks for your help, I hope I can hear back from you soon, as I consider his health a real concern. I understand I might need to give him away to someone who can provide better water conditions…
<Much information here:
http://www.wetwebmedia.com/ca/volume_5/volume_5_3/crayfish_basics.htm
http://www.wetwebmedia.com/ca/volume_1/cav1i4/crayfish/crayfish.htm
http://www.wetwebmedia.com/fwsubwebindex/crayfishdisfaq.htm
http://www.wetwebmedia.com/fwsubwebindex/crayfishsysfaqs.htm
No real art to keeping crayfish properly if you understand the basics. Cheers, Neale.>
Re: Red Crayfish with Milky White Eyes?    2/4/13

Thanks for all the info. I noticed something interesting the other day when I went downstairs. He actually dug himself a deep hole in the gravel, and literally blocked off the two entrances into where he is with gravel, as if he intentionally was planning to protect himself from intruders. This leads me to believe that he is planning for a molt soon. Should I leave him be there?
<Ideally, yes.>
Or should I disturb where he is and take him out into a freshly set up 10 gallon tank (This other tank hasn't been cycled yet, but I tested for the usual things and all is well, nitrates are really low and no ammonia/nitrites. Temp and pH is the same as my main tank)
<Put him in whichever tank has the mature filter. Moving a crayfish at or immediately after moulting isn't a great idea though. If you must, drive it into a plastic container, lift it out with some water, then release it into the new tank. Don't try to carry the crayfish with your fingers or lift it out of the water with a net.>
I kinda feel like he will be safe where he is. Does the molt happen overnight?
<Pretty much.>
If so do you think the fish will smell his exoskeleton and go in and eat it than possibly attack him when he is vulnerable?
<Does happen, hence crustaceans going into burrows at this time.>
If he is in the process of molting, will it be safe to take him out and move him into a new tank during this process? Thanks again for the info.
I'll go see if my local fish seller has the marine iodine I need soon.
David
<Cheers, Neale.>

Red Growth On Eyes (Cherax Destructor) (photos attached)  2/1/13
To the Crew
<Em>
I think my pet yabby (Cherax destructor) is suffering from some sort of parasitic infection.
<Mmm, looks more like a deficiency syndrome of some sort; that or an over-abundance of something that is "burning" this animal>
 For quite some time he’s had some brown diatoms on his exoskeleton, I didn’t think anything of it because I was having an issue with the algae at the time,
<... are you treating the water w/ some sort of chemical/s?>
but he seems to have some sort of bright red growth on his eyes. It’s definitely impairing his sight, because things like camera flashes which used to greatly disturb him no longer have any effect. He seems to be eating less, but I don’t know if it’s because of a loss of appetite or because he’s having trouble finding the food before the fish hoover it away. He seems to be less mobile, spending much time with his tail curled, but when he does move the movement seems natural.  He doesn’t seem to groom as often as he used to. He has strange ring like growths on his claws and the tips of his legs seem off colour, but this may be algae. I don’t know the exact water hardness but there is coral rubble and seashells in the water so it should be reasonably hard and alkaline.
<... need to know, have adequate biomineral content (Ca, Mg... and alkalinity) as well as periodic administration of Iodide-ate. Have you searched, read on WWM re?>
I live in Australia so crayfish plague shouldn’t be possible, but I can’t find any other diseases known to affect yabbies.
He’s in a 175 litre aquarium, with a sand substrate, an Eheim pickup 2012, an aqua one wet and dry filter, and a Jager heater that keeps it at 26 degrees Celsius. There are also several Darwin red nose shrimp, 9 black banded Rainbowfish, three salmon red Rainbowfish and one bristle nosed catfish in the aquarium with him. The tank has been set up and cycled for around 9 months, and I haven’t had any issues until now. He has a shelter from the light made from Mopani wood arranged as a cave. He’s 20cm long with his claws and tail fully extended, and I suspect him to be quite old. He’s moulted once while I’ve had him, because of his size I didn’t think much of it.
I’ve had him for over a year now and I’ve grown very attached to him. I’m going on a trip overseas in two days and will be leaving him with a house sitter, and I have no idea what I can do for him! I’d hate to lose him and I feel that I need to do something for him, as he seems to be near blind and unhappy. I have obtained an iodine supplement and will start dosing right away, and I’ll leave a note instructing the house sitters to dose him while I’m gone, but they have no experience with aquariums of their own and I don’t want to ask too much of them.
Kind regards, and thank you in advanced.
EM
P.S. I'm very sorry to have emailed this twice, but I took some photos and forgot to attach them, I've attached them now and I hope they'll help you. Thank you for your patience.
<Read here: http://www.wetwebmedia.com/FWSubWebIndex/crayfishdisfaq.htm
and the linked files above. Bob Fenner> 

 

Red Growth On Eyes (Cherax Destructor)   2/3/13
To the Crew
<Em>
I think my pet yabby (Cherax destructor) is suffering from some sort of parasitic infection.  For quite some time he’s had some brown diatoms on his exoskeleton, I didn’t think anything of it because I was having an issue with the algae at the time, but he seems to have some sort of bright red growth on his eyes.
<I wrote you re this issue a day or two back... Have you read where you were referred?>
 It’s definitely impairing his sight, because things like camera flashes which used to greatly disturb him no longer have any effect. He seems to be eating less, but I don’t know if it’s because of a loss of appetite or because he’s having trouble finding the food before the fish hoover it away. He seems to be less mobile, spending much time with his tail curled, but when he does move the movement seems natural.  He doesn’t seem to groom as often as he used to. He has strange ring like growths on his claws and the tips of his legs seem off colour, but this may be algae. I don’t know the exact water hardness but there is coral rubble and seashells in the water so it should be reasonably hard and alkaline.
<Need to have water test kits, or others test for you>
I live in Australia so crayfish plague shouldn’t be possible, but I can’t find any other diseases known to affect yabbies.
He’s in a 175 litre aquarium, with a sand substrate, an Eheim pickup 2012, an aqua one wet and dry filter, and a Jager heater that keeps it at 26 degrees Celsius. There are also several Darwin red nose shrimp, 9 black banded Rainbowfish, three salmon red Rainbowfish and one bristle nosed catfish in the aquarium with him. The tank has been set up and cycled for around 9 months, and I haven’t had any issues until now. He has a shelter from the light made from Mopani wood arranged as a cave. He’s 20cm long with his claws and tail fully extended, and I suspect him to be quite old. He’s moulted once while I’ve had him, because of his size I didn’t think much of it.
<This is very little moulting behavior... likely indicative of more than just age... Likely a water quality and/or nutrition imbalance issue>
I’ve had him for over a year now and I’ve grown very attached to him. I’m going on a trip overseas in two days and will be leaving him with a house sitter, and I have no idea what I can do for him! I’d hate to lose him and I feel that I need to do something for him, as he seems to be near blind and unhappy. I have obtained an iodine supplement and will start dosing right away, and I’ll leave a note instructing the house sitters to dose him while I’m gone, but they have no experience with aquariums of their own and I don’t want to ask too much of them.
Kind regards, and thank you in advanced.
-EM
<Just in case our previous email was lost, please read here: http://www.wetwebmedia.com/ca/volume_5/volume_5_3/crayfish_basics.htm
and the linked files at the bottom. Bob Fenner>

Iodine for Florida Blues   1/29/13
Hello. Sorry for bothering you people with so many questions regarding my Florida Electric Blue Crayfish! But they are my boys, and I want them to live in the best possible condition! An update: Orion, the egg carrier who lost a claw due to aggression from the large alpha Boris, now I know the reason for the aggression. Boris, a few days later, was also carrying eggs, the same day I found that Godfather was hiding so much in his tower because he, too, was carrying a large batch of eggs!! So I will have my hands (and tanks) full in about 2 to 3 weeks, when I find the hatchlings. I am already preparing a good environment for the hatchlings, hoping to grow at least a few young crayfish from the 3 batches of eggs. I'm glad that the three Crays lay eggs approximately the same time, so the hatchlings should be ok, if they're the same size and have a lot of hiding places, to avoid too much cannibalism which I know is unavoidable.
<Indeed.>
My first question: When I place my hatchlings in their temporary home, what is the best material for the bottom of the aquarium?
<Best: nothing at all but bare glass. Easiest to clean, and the silt and detritus is the stuff that promotes fungus on eggs and bacterial infections on very young livestock. If plain glass doesn't suit, then something easy to clean would be fine. A very thin (1-2 mm) bed of soft silica ("pool filter") sand for example or very fine pea gravel.>
I don't trust the sources I have read from. One said that soil/peat moss, preferably from a local pond, with some dead leaves is the best for hatchlings. I think this is a terrible suggestion, mixing outside materials into an aquarium of hatchlings. Another suggestion was leaving the bottom of the aquarium empty till the young Cray are about an inch in size. Is this appropriate, having nothing for the little guys to walk around and dig in?
<Is fine.>
Another said aquarium sand. This seems more believable, but with the frequent water changes required, I'm unsure of how the sand could be kept clean of uneaten food and Cray feces.
<If very thin, as stated above, there won't be any anaerobic decay (you need a few cm for that to happen). In any case, faeces tend to sit on top of sand, rather than sink into the gaps between gravel particles.>
Would the coral/gravel mix I use in both of my crayfish tanks be find for the hatchlings as long as they have a lot of plants and hideouts?
<Yes.>
My second question is the use of Iodine. I went to four different LFS and none of them had any idea or knew about any form of iodine/iodate salt for use in aquariums. All of them sent me to the pharmacy to pick up Iodine Tincture BP 2.5% (25ml bottle) with a mix of Iodine 25mg/ml and Potassium Iodide 25mg/ml, with non medical ingredients of Ethyl Alcohol and Purified Water.
<Doesn't sound safe.>
Without thinking much about it, I put 3 tiny drops in some water from the aquarium and mixed it into my 10 gallon, and 5 diluted drops into my 20 gallon. Only now am I in fear that my Crays, Zebra Danios, Yoyo Botias, and two young Gyrinocheilus Aymonieri in terrible toxic danger!! Two hours have passed since the iodine drops, all the creatures are acting normal, no red gills or panicked stress, Crays are fine too. Is it possible that they will all survive my ignorant toxication of the aquariums? Please help me, I am afraid of what I will find in the morning, whether there will still be life in my tanks!
<Iodine is readily removed by carbon, so you could always choose that. In any case, if the animals are fine a few days later, they're probably haven't been harmed.>
If anything happens to my beloved aquarium friends, I will have some visits to the four LFS to do, and some strangling and beatings to hand out to those "fish experts" and myself for being stupid enough to buy and add the pharmacy Iodine to my Aquariums.
<You're looking for products such as Salifert Natural Iodine, Kent Marine Iodide, Seachem Reef Iodide, etc. Typically inexpensive products, $5-10 a bottle, and you can use them at half the dose stated on the bottle.>
Thank you, as always, to your time and support, and priceless help and advice!!
Much appreciated. ~Sylvia
<Glad to help, Neale.>

Crayfish pincher claws too long and crooked after molt   1/28/13
> Hi,
> We are new crayfish owners, only about 2 months.  Our Cray has just gone through his second molt and it seems to not be going well.  He finally emerged from his hiding place and there was shell everywhere.
<... should be left in place for ingestion, reincorporation...>
 Immediately we noticed that both of his pincher arms were unbelievably long and all bent the wrong way.  The poor thing is unable to move.  He falls over and cannot right himself.  He also will not eat.  He also seems to have little white feathers coming out from where his tail meets his body. 
<Mmm>
> After reading your web site I gathered that some iodine will probably help the situation.
<Yes>
 We have a 10 gallon tank  a with waterfall filter.
> Is this normal?
<Not normal, but quite common... symptomatic of deficiency syndrome... lack of necessary biomineral et al. Read here re:
http://www.wetwebmedia.com/FWSubWebIndex/crayfishdisfaq.htm
and the linked files above>
  Will he shed these enormous appendages or will he eventually gain enough strength to move them? 
<Only given better conditions... I2, Ca, Mg...>
> Thank you so much for any advice you can throw our way!  We're really worried about our little guy!>
> I've attached a photo so you can see him.
> Jen
<Enjoy the reading, learning, empowerment... Bob Fenner> 

 

Black Spots on Crayfish  1/1/13
Dear WetWeb Media Crew,
My 3-year-old crayfish has two black spots just above his eyes, on his carapace. I wouldn't be worried about except one of my other crayfish died two months ago and that crayfish, who had the same marks, died molting. Are these marks shell rot and something I should be worried about? They are pink in the center and almost look a bit raw, but are rimmed by black and don't look like any images of shell rot I've seen before. I am attaching a few images of my crayfish, Slippy. Hopefully you can help me figure out if something is wrong. Thank you. (Ignore the white spots in the water, that's the light reflecting.)
<This crayfish doesn't seem to be damaged or suffering, so I'd not worry overmuch. But do review two key aspects: diet and water chemistry. So far as diet goes, make sure you are providing both calcium (e.g., whole krill) and iodine (e.g., Sushi Nori or marine aquarium iodine drops at 50% stated dosage). For water chemistry, make sure the pH is above 7 otherwise the shell will tend to erode over time. Since crayfish moult less the older they get, older specimens show this type of shell erosion worse than young specimens. Do review the page linked below, and follow the links at the top to useful articles:
http://www.wetwebmedia.com/fwsubwebindex/crayfishdisfaq.htm
Cheers, Neale.>
<<Excellent concise direct response Neale. Well done as usual. BobF>>

Re: Black Spots on Crayfish    1/3/12
Thank you so much for clearing this up for me, I wasn't sure and I haven't seen it anywhere else online. I'll have to go by some Nori for the little
guy.
<Most welcome. Iodine drops will likely work out cheaper, more effective in the long term. But Sushi Nori can work if used regularly. Cheers, Neale.> 
Re Black Spots on Crayfish  1/18/13

My crayfish just shed, and he has these huge bulges in his shell and where they are on his shed there are these holes where I can see straight into the shell. The holes were white, but it didn't look like shell rot though I was worried it was. How can I help fix this? I'm really worried because of these lumps.
<Not much you can do at this point! If it can sort itself out, it will.
Ideally, allow the crayfish to consume its moult and then hope for the best.>
I've attached pictures below:
<I see.>
Any helps or tips on what to do would really be appreciated. I meant to feed the little guy some Nori but for a week and a half he only wanted to eat his food pellets. Thank you so much.
<You can buy crayfish and crab specific foods (e.g. Sera Crabs Natural) and these should go a long way to ensuring a balanced diet. Seafood generally is good: unshelled shrimp, mussels, etc. Using an iodine supplement (sold for marine tanks) at 50% dosage seems to work wonders at ensuring good, regular moults. Cheers, Neale.>

Black Spots on Crayfish - 1/25/13
Hi WetWeb,
I found my crayfish on her side this morning, only moving her swimmerets and occasionally a leg. It doesn't look as though she's about to shed, and her limbs are all kind of rigid. Is there anything I can do to help her?
I've checked, and she doesn't appear to have any worms or soft spots in her shell. Her eyes are still clear. I don't have a pump, but I do regular water changes, and what she swims in I drink. What can I do?
Thanks for any help.
<Can you tell me what source of iodine you are using? And at what dose?
This is a key thing with crayfish care. By the time problems develop, there's almost nothing you can do, though adding another dose of iodine may help. Certainly don't try pulling at the moult or anything like that. Do also check water quality; without a pump, how is this aquarium filtered? No matter how pure the water you add, it does need filtering unless you're
changing 50% of the water every day. Cheers, Neale.> 

White Lobster/Red Spots   12/27/12
Hello, I have a white lobster (crawfish) I have had him for about 3 months.
I had him in my African Cichlid tank since bought him.  I noticed he has gotten red spots on him. Like the ends of his claws eye guards and the bumps on his shell.  I thought it may have been because the pH in the cichlid tank is at 8.0 so I thought it was to high for him.  I moved him to my fry tank and he hasn't changed. He has not molted yet since I have had him.  I tried to rub the red off but it's not coming off.  Have you ever heard of this?  I can send you a picture to better explain if you want. 
Thanks, John
<Hello John. This does sound like the shell is eroding, i.e., losing minerals. These can be because the water is too soft but also because moulting has been delayed, typically a problem caused by insufficient iodine in the diet. Let's review. Crayfish need moderately to very hard water with a high degree of alkalinity, so first of all check the carbonate hardness, which should not be less than, say, 7 degrees KH (general hardness, degrees dH, is less important but should be fairly high as well, preferably 10 degrees dH). Now, what sources of calcium are you providing?
Things like whole fish with bones in (e.g., lancefish) and unshelled invertebrates (e.g., krill) are good. And how are you ensuring iodine levels are sufficiently high? What iodine supplements are you using? Marine aquarium iodine drops at 50% the quoted dose work well. Cheers, Neale.>
Re: White Lobster/Red Spots 12/27/12

Thank you for your fast response and providing me some insight to getting him healthy again.  I'm heading to the pet store today and get some iodine drops and a hardness tester.  All I have been feeding him is shrimp pellets and algae wafers I didn't even think about his calcium needs.  Thank you for your response.  John
<Most welcome. Do read these articles while you're on the site:
http://www.wetwebmedia.com/ca/volume_1/cav1i4/crayfish/crayfish.htm
http://www.wetwebmedia.com/ca/volume_5/volume_5_3/crayfish_basics.htm
Cheers, Neale.>

Blue Lobster/ Hammers Cobalt Blue Lobster
Blue Crayfish, Playing Dead? - 10/15/2012

Hello,
<Hi!  Sabrina here tonight.>
We just recently purchased a blue lobster and he has been moving around the tank fine the last few days since we bought him. Now we are having a problem with him ending up on his back.
<Not good....>
With him going belly up does that mean he is dead or playing dead or what?
<Well, they don't really "play dead"....  My best guess is that he's trying to moult and having trouble.  Yikes!>
I have been searching for answers to find out what is going on with it and an coming up empty handed. Please help me come up with an answer. He isn't moving as much as he first was and the tank has been up and running for at least 6 months with out problems and it is chemical free water.
<"Chemical free" isn't really telling much.  I mean, after all, water is a chemical compound, right?  The important things you need to know about your water is the readings from your tank for Ammonia, Nitrite, Nitrate, and pH.  Ammonia and Nitrite must always be ZERO, Nitrate as low as possible (preferably below 20ppm).  pH will depend upon your critters and their
specific needs, though most freshwater pets are more interested in having a very, very stable pH rather than a precise one.>
What is the best way to care for the little guy?
<All freshwater and marine invertebrates need iodine to help them use calcium to build their new exoskeletons and moult.  Lacking iodine or calcium can spell certain death for shrimp and crayfish.  Most tapwater in most places in the US has "enough" calcium for it not to be a worry, but iodine is another matter.  You will probably need to supplement Iodide in
the tank water.  I believe there are (finally!) some freshwater supplements available, but failing that, you can use a reef Iodide supplement - just DO NOT use the full saltwater dosage as printed on the label!  Less than a tenth of the amount suggested will be more than sufficient.  For example, I use (and recommend) Kent marine Iodide at a dosage of just one or two drops per ten gallons each week in freshwater tanks containing invertebrates. 
It's not a lot, but it makes all the difference in the world.  Hopefully it's not too late for your lobster/crayfish buddy.>
Thanks for the help!
Stumped on the care for him
<You might also find some fun and useful information in our articles and FAQs on freshwater invertebrates: 
http://wetwebmedia.com/FWSubWebIndex/fwlvstkind2.htm Scroll toward the bottom and you'll find lots of links for information about various inverts.
 Best wishes to you and your crayfish!  -Sabrina>

blue crayfish stuck in shell    9/18/12
Good afternoon,
I bought a blue "lobster" from the pet store back in May, and this is the first time he molted. I noticed his old tail is still stuck over the new one. I'm not sure how long it's been like that since he molted while I was sleeping. Do I just leave him and eventually he'll get it off on his own?
Will this cause damage to his tail?
Thank you,
Jessica
<Do you provide supplemental iodine supplement (actually iodate/iodide) in the form of marine aquarium iodine drops? Failed/improper moults are a VERY common symptom, result of not providing iodine. In a normal moult the entire moult should come off and usually the crayfish turns right round and eats it, recycling the calcium therein. If the moult doesn't detach completely, that's bad, and tends to imply a problem with moulting (ecdysis, do read online re:). There's no fix, and if the crayfish will recover, it will under its own steam. But do acquire, use iodine supplement (or at least an iodine-rich food, e.g., seaweed, sushi Nori). Cheers,
Neale.>
Re: blue crayfish stuck in shell    9/18/12

<Just in case Neale is out for the day (he's in the UK), am responding as this appears to warrant prompt response>
So don't try to pull it off? Just let him do it?
<Don't pull, let this animal "do it">
Will the iodine effect the
other fish (a Pleco and dwarf gourami)?
<Will not affect negatively>
And is the iodine with the saltwater stuff?
<It is>
 Last time I asked for it the employee gave me a strange look and told me I don't need it.
<Search WWM re Crayfish and Iodide-ate... they DO need it, along w/ adequate alkalinity and alkaline earth presence. Bob Fenner>
Re: blue crayfish stuck in shell    9/18/12

So don't try to pull it off?
<Not a good idea.>
Just let him do it?
<If he can, he will.>
Will the iodine effect the other fish (a Pleco and dwarf gourami)?
<Well, since you shouldn't keep crayfish with tropical fish this is normally not an issue. But no, the iodine supplement is safe if used as instructed. You only need about half the dose quoted on the bottle.>
And is the iodine with the saltwater stuff?
<Correct. Do note that while we're throwing around the term "iodine" here, speaking of the element, we actually mean iodide or iodate salts, so NOT the iodine solution (tincture) used to clean cuts and sold in drugstores.
If memory serves, it's potassium iodide that's normally provided to invertebrates like crayfish.>
Last time I asked for it the employee gave me a strange look and told me I don't need it.
<The world is full of contradictions. Do you research, reading and then come to your own conclusions. There's an ample literature re: ecdysis of crustaceans and the key role played by iodide/iodate. Cheers, Neale.>

Crayfish with loose shell and white fuzz at joints 7/10/12
Hello. I'm looking for some help with my clarkii crayfish, Claudia. About a week ago her shell seemed to come loose at the join between the base of the body and the tail. Just today I noticed that she is developing some strange looking white fuzz around the joints where her legs meet her body, and she has some green fuzz that looks like algae around the base of her antennae.
Please see the attached picture).
<I see all this in your excellent photo>
I've had her since January 1 of this year. She lives in a 15 gallon tank with 7 tetras who she completely ignores. I perform frequent water changes, 4 gallons every 5-7 days.
<Good>
 In mid-February she hatched a ton of eggs (all the babies are gone now) and soon after molted twice within a few weeks (and has grown about an inch in length, to her current 6 inches from claw to tail). She hasn't molted since then.
<This is telling>
 I keep seashells and cuttlefish bone in the tank for calcium.
<Need to test for same>
She eats Aquatic Shrimp Crab & Lobster food sticks, algae pellets, and frequently munches on the aquarium plants.
<Ah yes>
 The tank stays at a consistent 74-76 degrees, and the pH is around 7.0. These conditions have been fairly consistent since I added her to the tank, although the pH has gone up a bit, from 6.6 the last time
<You want this in the low 7's for the Procambarus and Tetras>

 I checked it in April. Before Claudia I kept a male white crayfish in the same tank - he was adult sized when I got him, and he lived for about a year.
Is there anything to be done for the poor girl?
<Yes... the items mentioned and the use of iodide-ate... Please read here:
http://www.wetwebmedia.com/FWSubWebIndex/crayfishdisfaq.htm
and the linked files above>
Any advice you can give would be greatly appreciated, thank you.
Jefferson Powers
<Welcome. Bob Fenner>

Irregular spots growing on crayfish     7/4/12
Hello there! I have had a blue crayfish with a small guppy for about a year now. He has a 20 gallon tank with sand substrate, a filter and 2 hiding spots. He eats algae wafers and on occasion, blood worms. His water temp is at about 70-73 F. He is very playful, barely ever hides and actually seems to crave interaction. He has molted at least 5 times since I've had him, but last time (about 3 weeks ago), he came out with a small, bright red spot on his head. Over time, the bright red has turned into orange/brown splotches. She has two more tiny dots like that on her tail. I did some research, and it said this might happen during molting.
<Mmm, yes; quite common... do leave the old molts in place (they're reincorporate)... And one needs to be aware of the alkaline earth, alkalinity needs.... and use/dose a modicum of iodide-ate occasionally. All revealed by your reading here:
http://www.wetwebmedia.com/FWSubWebIndex/crayfishdisfaq.htm
and the linked files above>
He has not molted again since, but I have noticed that there are more, small spots and it looks like they are growing right at the junction of the head plate and his back. The blue color in that ridge is darker than the rest of his body and the spots are growing over the dark blue. His appetite and behavior do not seem to have changed, but this has never happened to him before. I love my Cray and he's always been in optimal health! Please help. What can I do?! Is this shell rot?? I attached a picture of the spots.
Carolina
<The reading... water quality, nutrition. Bob Fenner>
Irregular spots growing on crayfish. Neale's go      7/4/12

Hello there! I have had a blue crayfish with a small guppy for about a year now. He has a 20 gallon tank with sand substrate, a filter and 2 hiding spots. He eats algae wafers and on occasion, blood worms. His water temp is at about 70-73 F. He is very playful, barely ever hides and actually seems to crave interaction. He has molted at least 5 times since I've had him, but last time (about 3 weeks ago), he came out with a small, bright red spot on his head. Over time, the bright red has turned into orange/brown splotches. She has two more tiny dots like that on her tail. I did some research, and it said this might happen during molting. He has not molted again since, but I have noticed that there are more, small spots and it looks like they are growing right at the junction of the head plate and his back. The blue color in that ridge is darker than the rest of his body and the spots are growing over the dark blue. His appetite and behavior do not seem to have changed, but this has never happened to him before. I love my Cray and he's always been in optimal health! Please help. What can I do?!
Is this shell rot?? I attached a picture of the spots.
<Do have a read here first, the Disease section, and check your environmental conditions with the ones you're providing.
http://www.wetwebmedia.com/ca/volume_5/volume_5_3/crayfish_basics.htm
Understanding of crayfish disease (indeed, of crustacean healthcare generally) is minimal, so prevention is the main way forward. Do check water chemistry (hard water is better) and that you provide calcium in the diet (squished snails, unshelled shrimps/krill and small whole fish such as lancefish -- not feeder fish though!). Do also ensure you're providing regular iodine, in the form of marine aquarium supplement (at 50% dosage) with each water change. There are specific crayfish foods with added iodine, and these are worth using too. There are a few more-or-less harmless parasites that infect crayfish and cause damage to their shells, but given sufficient calcium and iodine, crayfish can moult successfully and effectively minimise this damage. Once crayfish reach a certain age (around 2 years for the common Procambarus clarkii) they moult infrequently, if at all, and very old specimens will naturally have tatty shells, encrusted with algae and suchlike, but their shells are still strong and firm, unless the crayfish is kept in soft, acidic water that dissolves away the shell. Cheers, Neale.>

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