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Crayfish, Crawdads, Yabbies, Ditch Bugs Disease/Health 3

FAQs on Crayfish Disease: Crayfish Disease 1, Crayfish Health 2, Crayfish Health 4, Crayfish Health 5, Crayfish Health ,
FAQs on Crayfish Disease by Category: Diagnosis, Environmental, Nutritional, Trauma, Infectious, Parasitic, Social,

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,

Lobster trouble. Cray hlth.   6/27/12
Hey, I'm Jordan.  i am new to this but here i go.
I recently bought a lobster. I believe it is a blue cobalt lobster? Or an Australian red claw... It has red dots along its tail, cobalt in colour, at a small portion of its claw being red. I recently noticed worm like parasites on it. Its mostly on its underside, its joints and the cracks along it's shell. Its mostly in it's dents. The parasites have two feelers and move about a single spot. They are white in colour and about 1mm. I really need help and a solution to this problem. Im a newbie. Thanks for your help.
<Mmm, yes; we've had similar accounts. Do read here:
and the linked files above. Bob Fenner>

Blue, the blue lobster/crawfish    6/23/12
Hello, I just have a inquiry about behaviour. 2 weeks ago, I picked up what was titled a blue lobster.
<In the US at least, almost certainly the blue version of the standard crayfish species Procambarus clarkii, the species farmed and eaten across North America and elsewhere.>
Massive sale 85% off the regular price. He was about 1 inch long and later I noticed he was missing about 60% of his legs (rough guess).
<Like all members of the Decapoda, crayfish have ten legs, i.e., the two pincers and eight walking legs. There are other appendages to be sure, but these are specialised in other ways, such as the swimmerets on the abdomen.
So, if he has 60% of the original ten legs (including the pincers) he's down to just 4 legs (including the pincers). Does this help?>
Currently I am setting up his own tank that should be fully cycled end of this week ( I tend to cycle my tanks for at least 3 weeks before adding anything I want to keep, with a few fish I would other fish feed to betas or a fish I have yet to identify) Blue is currently sitting in a breeding basket with a house and a plant and a baby molly. This tank every thing is in the right range, pH is a little high for Blue (7.9) as this is my live bearing tank.  He just went through a molt.
<Good. Now, be aware the first moult is the easy one. It's the subsequent ones where things go wrong.>
He did not really get any bigger (most likely as he re-grew most of the missing limbs)
<Could well be.>
That being said. I was expecting him to hide in his house. He is not. He is wandering about following the baby molly out in the open. My question is, as this is generally abnormal behaviour after a molt, do I need to be worried?
<Nope, don't worry.>
Or is he just a strange little critter? He has been in the breeding box for 2 weeks now, could be he knows its safe?
<He doesn't "know" anything. But crayfish are opportunistic scavengers, and by their very nature explore their territories and try to either [a] eat or [b] swim away from anything else they bump into. It's a simple life!
Needless to say, both live plants and small fish are dinner items, sooner or later.>
Oh he does get lots of different foods, shrimp, blood worms, flakes, shrimp pellets, spinach, algae wafers, to name a few, and I add the reef iodine as well.
<Ah good. That's the key. Green foods, calcium and doses of iodine. Meaty foods are treats, once or twice a week, compared to the importance of greens and unshelled prey animals (krill for example).>
Thank you
<Most welcome, Neale.>

albino snow crayfish     6/19/12
I have a albino snow crayfish in a freshwater tank. I have had him sometime and he has molted a couple of times but hasn't for a while now. I changed the water and cleaned the tank like I usually do and added all the tank care chemicals I always use. But for some this time he is acting weird walking around with his tail curled under him. Won't eat the food he usually loves and doesn't stay in his usual hiding spot. Should I be concerned?
<I would be, yes. Do check the basics. Is the water temperature right for the species? The usual Snow Crayfish of the hobby is an artificial form of Procambarus clarkii, a species best kept at room temperature (around 18 C is ideal). Although not fussy about water chemistry, soft and acidic water is best avoided, so you're aiming for about 10+ degrees dH, pH 7-8. They are herbivores with a strong taste for carrion, so a diet based around algae wafers and green foods (cooked peas, blanched lettuce, spinach) will provide the main nutrients while occasional crushed snails, unshelled shrimps and whole lancefish (i.e., food with shells or bones in them) provide the extra protein and calcium they need to grow. All Crayfish benefit from additional iodine, which you can buy in marine aquarium shops for use in reef tanks. Add at one-half the dosage recommended and you should find your Crayfish is healthier and moults successfully. Last but not least, remember about their intolerance for many "medicines" such as copper and formalin. Many of these can be lethal to Crayfish, and copper can also be present in tap water, so remember to use a water conditioner that neutralises copper.>
Thank you!
<Cheers, Neale.>

blue lobster, injured    6/11/12
I have a blue lobster and have had him for about 2 months. Last night he escaped from his tank and fell about 15 feet
onto tile. We found him still alive this morning (not sure how long he was out of the tank) and put him back in his tank, but he isn't moving much and appears to have trouble moving his left side. He did eat an algae wafer we put into his tank, but still isn't moving much. Is he suffering, or will be able to recover from the fall? We aren't sure what to do.
<These animals can be very tough... even if the exoskeleton was cracked... given good care, food... it should recover and molt to having a full test in time. Read here re: http://www.wetwebmedia.com/FWSubWebIndex/crayfishdisfaq.htm
and the linked files above. Bob Fenner>
Re: blue lobster   6/12/12
Thank you for your reply. We'll see what we can do and hope he makes a full recovery!
<Ah yes, BobF>
Re: blue lobster   6/12/12

Yes, about 15 feet. He got out of my son's room and crawled into the hall and fell through the banister to the foyer below. It's a 2 story foyer and there's no carpet so he fell directly onto the tile. My husband found him on his back, but still alive.
<Yeeikes! And yay! B>

Red covering crayfish eyes... no useful data or rdg.      5/29/12
I have a freshwater dark blue crayfish (Rock), he is about 2.5 years old and has lived in his tank with 3 African Cichlids for about 1.5 of those years. His behaviour hasn't changed at all but he has something red covering both his eyes now. Im not sure he can see out of them anymore. One eye is completely covered and the other one is about 80% covered. There has been no changes to water as far as I am aware. Any ideas what this could be?
Thank you.
<Need information re water quality, foods/feeding... Does this Cray shed his exoskeleton regularly? Does it ingest the cast off to replace minerals lost? Do you treat the system w/ iodide-ate? Please read here:
and the linked files above. Bob Fenner>

Re: Health Concerns with Blue Crayfish    5/1/12
Hi again Bob,
Thanks for all your help in the past. Our blue Cray seems to be feeling better now. Water levels have been stable for about three or so weeks now.
She's stopped laying on her side and looking miserable. We think she may have just been in the process of laying her eggs when we saw her appearing so uncomfortable. Her eggs are still black and she's retained all of them on the underside of her tail. She's been eating every few days and is fairly active. We're assuming that the eggs are unfertilized, but we'd read that if they're unfertilized that crays will often drop them. She hasn't dropped any yet and is very protective of them, so we're not sure what that means.
Recently we started noticing that some of the eggs were turning a pinkish orange color and developing a fungus-looking cloud around them. She still has black eggs that appear unaffected by this, but it definitely is spreading, as now she has several large clumps of these orangish eggs coated in a soft white fuzz. Are we correcting in assuming that her eggs have fungus?
<Likely so>
If so, why hasn't she dropped her eggs by now, since they're likely infertile and diseased?
<Sometimes they become so sticky, they stay in place>
I've been researching fungal infections and treatments for invertebrates and some of them sound just plain scary! From what I've read Methylene Blue seems really messy, dyes everything, and can mess with the balance of the cycle - which is exactly what we don't want - and also seems to be best for dips. We're not sure if that's the right solution for her.
<No treatment at all>
 I've read that Malachite Green can be highly effective against fungus, but dangerous and deadly to invertebrates. Is this true?
 If so we certainly don't want to use it for our blue Cray, and that would also nix out SeaChem Paraguard as it contains Malachite Green. Interpet Anti-Fungus looked like it might be an option, but is hard to find in the USA and we want to start her on treatments right away.
The options that look the most promising are Esha2000, Mardel Maroxy for True Fungus (is there a difference between fungus and true fungus?),
<Yes; most of what people label "funguses" are actually bacteria... need microscopic examination to tell>
 Mardel Maracyn-Oxy (non-antibiotic), and Mardel Maracyn Powder or Tablets (antibiotic). From what I've read they all appear to be non-toxic and safe for invertebrates, and they all appear to treat fungus. Aside from that, I have no idea what the difference is between all those Mardel products, I don't know if we should be looking for an antibiotic or non-antibiotic treatment, and I have no idea which ones would be best or recommended. Any suggestions?
<Yes; to not treat period>
Also, now that the eggs have fungus, at what point will they fall off or will she drop them or pick them off?
<Will be shed w/ the next moult>
Will the anti-fungal treatments help this problem, or should we do something to scrape the eggs off of her? Is there a safe, non-traumatizing way to do this?
As always, thanks for your help!
P.S. I have also attached a few images of her with the fuzzy eggs.

Health Concerns with Blue Crayfish    4/20/12
Five weeks ago we purchased a blue crayfish from a local fish shop. We don't know how old she is, but she is about 4" long. She lives by herself in a 20 gallon tall aquarium with four artificial plants of varying size, a thick layer of artificial (blue and white) gravel - which we are hoping to switch out for natural stone gravel in the future, and a large piece of slate rock that is propped up by a smaller piece of slate to fashion a cave for her to hide in. Her tank also has a hanging submersible heater which keeps her water around 71-72°, a Top Fin filter system, and a pump with wall bubbler for aeration. We do not have any other fish or live plants or animals in the tank. Her diet consists of frozen peas, crab & lobster sinking pellets, algae rounds, and frozen bloodworms. Her water is about 3/4 RO water with 1/4 tap water.
<Why the RO? What aspect/s of your source/tap water are you trying to dilute?>

 We added the standard amount of tap water dechlorinator prescribed on the bottle and have switched out her filter's media cartridge twice since we've had her because the color on the gravel keeps flaking off and clouding the filter, which is why we want to replace the artificial gravel with natural stone gravel.
We are new to owning a blue crayfish and, because of a lack of research and understanding on our part, we did not know about the fishless cycling of a tank before introducing a fish into it. We had already purchased our blue crayfish. So we bought an API Fresh Water Master Liquid Test kit and have been testing the water for pH, ammonia, nitrite, and nitrate every other day. It took over four weeks for the tank to cycle. Not wanting to speed along the cycling process with any kind of BioBoost product, we used the prescribed dosage of SeaChem Prime to help detoxify the ammonia and nitrite while the ammonia spiked (up to about 1.0 for a week), and the nitrite spiked (up to about 5.0 for nearly two-and-a-half weeks).
<Both VERY toxic>

It was awful - our Cray hid in her cave the entire time, hardly ate, and spent her days and nights digging and rearranging her gravel beneath the rock. Every now and then she would come out to visit and stretch against the tank walls, but she wasn't being active outside the cave and she clearly wasn't happy about it, understandably. We think the only reason she made it through the cycle alive was because of the SeaChem Prime.
We are now at these levels: pH - 7.6, ammonia - 0, nitrite - 0, and nitrates - 10.
About a week or so ago I added a few drops of liquid iodide to her tank as well to help her in case she was molting.
I don't know if we should be adding iodide to help her molt, or calcium to strengthen her shell, as it kind of seems like crayfish need both. Do you have a recommendation of what to use and when?
<Yes... posted on our site. Read here: http://www.wetwebmedia.com/FWSubWebIndex/crayfishdisfaq.htm
and the linked files above>
Over the past few weeks we've noticed some odd discoloration on her. She was a nice bright blue when we got her. Now she has some red on the lower edges of her tail and bottom of her thorax. It's a gradual fade from blue to red, not patchy red blotches. We've also noticed that she now has visible dark brown lines on her abdomen, specifically in between the little segments of her tail when she curls it under her.
<I see this... troublesome... Perhaps a sort of chemical burn from the prior ammonia, nitrite exposure... Might be due to a nutritional deficiency>
We've read that crayfish discoloration can be caused by a number of factors including stress, dirty water, poor water conditions, and molting.
<Ah yes>
Because of the tank cycling we know that she's likely been stressed and dealing with poor water conditions for the past month. Luckily, they are back to normal now. Do you think that this could be the cause of her red and brown discoloration?
If so, how long do you think it will take for her coloration to return to normal?
<Next molt, two...>
Or could this be a sign she is due for a molt? We are not so worried about the red coloration, but the brown coloration between her tail segments concerns us.
Also, we were advised by a local fish store not to do any water changes while the tank was undergoing its first cycle.
<See WWM re... I would do such changes if NH3, NO2 exceeded 1.0 ppm, stop feeding.>
 However the water was getting dirty from food she was not eating when her appetite decreased, and when her ammonia and nitrite levels were at their peak we did a few 20% water changes with gravel vacuuming.
 But not much beyond that because we wanted to wait for her water conditions to level out before we started a pattern of bi-weekly of 25% water changes with gravel vacuum. So I suppose it is possible that her water could be fairly dirty (and it is when we stir up her gravel), although it looks pretty clear when it all settles, with the exception of the gravel color flaking off. But now that her tank has cycled we want to start changing her water and vacuuming her gravel more often. How often and how much can we clean her gravel without risking jump starting another cycle?
<Now, no worries>
She also has a large rust-colored spot on the top of her shell near her head. It appeared about three weeks ago and has not really shrank or changed any since then. It has grown some. It doesn't appear to bother her.
We thought it was caused by her slate cave. She relocates her gravel frequently, builds it up, then leaves herself no room to crawl out of the cave. When she tries to crawl out, since it is the highest point on her body, it scrapes against the top of the rock. We've been assuming that the scraping is what caused the rust-colored spot.
<Mmm, doubtful>
 We noticed it after she'd blocked herself in for the first time and was scrapping again the rock to try to get out of the cave. This happened just before the ammonia spike, about a week after we first got her. But then I recently learned of shell rot - and that it if often caused by poor water conditions and leftover food in the gravel - both of which were a problem for us, and became concerned that perhaps that is what the rust-mark is or that maybe that's what the brown on her tail is.
Do you think this is shell rot or just a scrapped shell from the rock?
<Stress overall>
How can we identify shell rot? Is there a treatment you'd suggest?
<Mmm, none>
 We've read that Melafix is a common treatment
<Is garbage... may alter nitrification>
(but isn't very effective) and that salt dips or adding a small amount of salt to her tank are the preferred treatment and are our best bet. We spoke to someone at the local fish shop who recommended that we just add a bit of salt to her tank and NOT vacuum her gravel, change her water, change her gravel, or give her a salt dip until she shows signs of improvement because if she's already sick the stress of these changes could do more harm than good.
Finally, she also has one little leg in the back with pinchers that are stuck open. There is a small red spot right in the joint and she picks at it and scratches at it. Do you have any idea what that might be?
<Again... the same causes>
Since her water has stabilized, she's started eating more (though less than she did at first - now she eats about every other day), but she remains fairly active, constantly moving her swimmerets, always rearranging her gravel, and occasionally coming out for a stretch or quick walk around the cave.
We are just, obviously, very concerned about the discoloration, possible shell rot, and any potential long-term damage from the water cycling. Since we are new crayfish owners we don't know if this is a sign of molting, a temporary repercussion of the poor water conditions during cycling, or if there is something more serious going on here (and if so, how to treat it).
What would you recommend we do?
<Read... I would have use Dr. Tim's One and Only or the Fritz or other bacteria "starter culture", but now it's too late>
The first two photos are her when we first got her. The second two are her
Any help you can provide us would be extremely welcome and appreciated.
Thank you!
<Do write back after reading if you have further questions, concerns. Bob Fenner>

Re: Health Concerns with Blue Crayfish    4/21/12
Hi Bob,
Thanks so much for your reply back. The RO water we are using is to dilute the high level of pH in our tap water (about an 8 normally). With the RO the tank water is around a 7.6.
<Mmm, for this species of Crayfish either is fine>
We have some new developments with our blue crayfish. Last night she was scratching under her tail a lot, but she came out for a few laps around the tank. As I mentioned in my prior email, her appetite has decreased, she's stayed mostly hidden in her cave for the past month, she's been rearranging her gravel endlessly, and we noticed black discoloration on her tail. We've attributed her odd change in coloration, lack of appetite, and hiding to the rough first cycle she survived though. She seemed to be feeling okay when we left for work this morning, and ate about half of an algae round.
<Ah good>
Tonight we came home from work and found her laying on her side in the cave with her tail curled up completely under her. She seemed very very uncomfortable and the situation looked grave. Then she started shifting and we noticed a whole lot of black under her tail. Upon further examination and lots of reading online, we've discovered she has tons of tiny little black eggs! All we can think is that she must have been pregnant when we got her, but we had no idea.
<Mmm, not pregnant... these eggs are not fertilized>
The more reading we did, the more others commented that their blue Crays hid all the time, dug the gravel a lot and lost their appetite before laying eggs...so it all kind of makes sense now.
Also, the black on her tail makes sense now too.
Now, of course, we have a whole new world of questions.
1. She looks SO uncomfortable. For the past several hours since we got home, her tail has been tightly curled up under her, holding the eggs. She lays on her side, then moves and tries to get comfortable, then shifts again, and keeps switching sides that she lays on, but she really doesn't move or walk much, just enough to try to flip sides and get comfortable.
She just looks extremely uncomfortable and keeps laying on her side. In all the other pictures we've seen online of other blue crayfish with eggs, they are all standing up and look almost normal. Is it normal for her to lay on her side and look so miserable while laying eggs? How long can we expect this to last?
<Not normal to lay on side... don't know how long the behavior will continue>
2. How long will these eggs stay with her under her tail?
<See/read where you were referred to... days to a week or so>
Will she drop them on the tank floor and let them hatch there, or will she hold onto them under her tail until they hatch? If so, how long until they hatch? Will she seem so miserable the whole time it takes them to hatch?
<They won't hatch... this is a dioecious species... takes two to tango>
3. Is there anything we can or should be doing for her right now? We're weary to do anything - change her water, vacuum the gravel, turn on her tank light, feed her, etc. - because we don't want to stress her out right now.
4. We read that most babies don't make it. I think the black color means they're fertilized, but again, we're so new to this that we really have no idea. It's all a complete shock to us since we were honestly convinced she was dying after that awful cycle and strange discoloration. What do we do with the babies? We can't keep them all (assuming any of them make it) because we only have a 20 gallon tank and simply don't have room for them all, but should we take them to the local fish shop to sell or remove them from her tank once they hatch?
<The stress from being put through cycling, the nitrogenous waste exposure prompted the egg production... close to death experience... Perhaps closer>
Again, any help or additional advice as to what we can do for her would be
appreciated. Thanks!
<Welcome. BobF>

Yabby's tail curl up, toxic water cond.s     3/14/12
Hi there,
Here I am asking for your help again. Missy (my female Yabby pet) has her tail curled up to her body in the last two days. She held it like that all the time, which is abnormal. Before she only did it when she needs to run or claim a rock. Is that a sign of sickness?
<Mmm, maybe... perhaps a dietary shortage, water quality or reproductive behavior>
She is the only one in the 2" tank. I change water change 25% every week.
Ph is at 8 and 2 drops of iodine every time I change water.
The tank however is going through a biological cycle with ammonia = 0.25,
nitrite = 5
<Even more so!>

and nitrate = 10. Tested last week. The reason I did not test this week is because through internet reading, it seems best for the tank to go through the cycle naturally, without adding any chemical liquid.
So if there is nothing I could do about it, there is no point to test the water. But the question is am I right? Should I buy the Stress Zyme to speed up the cycle?
<It won't do this... stop feeding for now and read here:
and the linked files above. Bob Fenner>
Thanks so much for your time and help.
Best regards,

I think my lobster is ill. Cray hlth. 2/12/12
Hi I have a blue lobster which I brought off a friend 5 months ago, she has been really active up2 now, but since yesterday she has been really lethargic, she shed her shell about 2 months ago, which I removed from the tank after a few hours, (I didn't realise I shud leave in there 4 her 2 eat) she hasn't eaten for 2 days now & is jus hiding under her bridge wiv her claws stickin out the side, which she has never done before, normally she is all tucked up, I am really worried she is dyin & don't no wot 2 do, please if u cud giv me some advice it wud b greatly appreciated, thanx Danielle.
<Hello Danielle. I do need some information here. How big is the aquarium?
What sort of biological filter are you using? How often do you do water changes? What foods do you provide? What is the temperature of the water?
And please, do try writing in English rather than text speak. We normally bounce back "gobbledygook" messages but you were so polite I didn't have the heart! Meantime, read here:
Cheers, Neale.>
Re: I think my lobster is ill 2/13/12
Hi, thank you for getting back to me, she does seem to be ok today, she's moving around the tank and looks a lot better, I think I was just worrying but want to make sure just in case I am doing anything wrong as its come to my attention that I don't actually know a lot about lobsters, so any information would be brilliant.
<Do read those links.>
I'm not sure what size the tank is but its 1 1/2 foot long, 1 foot tall and 1/2 foot wide if that helps.
<18 x 12 x 6 inches. About 5.6 US gallons. Quite small.>
The filter I use is a Fluval underwater 1, (I got it from my friend with the whole set-up she didn't really tell me anything else) The temp is in-between 24c & 25c and I feed her blood worm & dillies and I do a water change every couple of months. Thank you for your time.
<Do read, read, read. When you have specific questions, feel free to ask them. Cheers, Neale.>

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