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Crayfish, Crawdads, Ditch Bugs Reproduction


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

Crayfish; repro. ish concern
We took home a crayfish from my son's classroom several months ago and were surprised to find eggs hidden under her tail this morning. We really don't want babies (we thought we had a male) and didn't know if it is safe to remove the eggs. We don't want to hurt her, but I also don't want my kids to deal with her eating the babies or them eating each other. Please
<I would do nothing here. Likely these eggs are not fertile (were not fertilized); and will take care of themselves... Do just be vigilant re regular water changes, the use of iodide; as gone over on WWM.
Bob Fenner>

hello! I have questions about Cherax albidus's eggs        4/24/15
I have some question to ask you about Cherax Albidus's eggs.
Could you please tell me..
1. Why Cherax albidus's egg have fungus?
<Most likely: either not fertilised or water quality really bad.>
2. Could you tell me about methods for avoid fungus in Cherax albidus's eggs?
<Make sure they're fertilised. Honestly!
Crayfish are normally excellent mothers, and will clean and oxygenate their eggs. Check water quality, and make sure there's plenty of filtration and water circulation. While Methylene blue is widely used to keep fungus off fish eggs, this chemical may be toxic to crayfish, so use at your own risk. I wouldn't use it, and would instead focus on making sure the water quality was good.>
Thank you.
<Welcome. Neale.>

What does it mean when my reddish brown crayfish has white eggs     1/10/15
<Precisely what it appears to mean. Without a male crayfish, eggs will usually be infertile but some crayfish species are parthenogenic. Don't forget to use marine aquarium iodine (at half the dose) to this tank. Your female crayfish will need iodine after the process of making eggs and before she moults again. Lots of people don't know about the iodine, and their crayfish, sooner or later, wind up deformed or dead. Cheers, Neale.>

Crayfish; repro.     5/29/14
Hi there! I bought an electric blue crayfish about three months ago from the local pet store and "he" was really beat up missing several legs and one of his claws. Luckily, the crayfish grew everything back, moulted several times and a couple days ago I discovered "he" was a she because she is hiding a tail full of eggs.
I was absolutely delighted but now I am worried about her she won't eat and is constantly on guard.
<Is normal for this to happen. Don't worry about her. She will stay in the burrow, more or less hidden away until the baby crayfish have hatched.>
I have 2 loaches in the tank with her and they seem very interested in those eggs.
<Indeed. Part of their natural diet.>
I also noticed today that she was picking some of them off, will she eat the eggs?
<The unfertilised ones, yes. If stressed many animals will eat their eggs (even their young) to "recycle" the energy in another breeding attempt. In evolutionary terms this makes sense -- no point wasting time and nutrients on offspring with no chance for survival. So finding ways to minimise stress (isolating from tankmates for example) can be useful.>
I do not have a male crayfish so the eggs were quite a surprise, but then I read that they can hold sperm for 6-8 months and she was in a tank with other crayfish at the pet shop. Can crayfish produce infertile eggs without mating because she was kind of small when we got her?
<Possibly. Don't know for sure. Fertilised eggs will be speckled/dark, and very quickly show signs of developing embryos; unfertilised eggs go white very quickly.>
She is in a 55 gallon tank with the other 2 loaches should I separate her from this tank? I do not own another tank so I would have to go and purchase a small 10 gallon or perhaps buy a divider? How long does she usually carry the eggs before they hatch?
<Some, several weeks; maybe a month. Depends on the species.>
Thank you for your help in advance! -Heather
<Best of luck, Neale.>

Parthenogenesis?    6/11/13
Hi. I bought an electric blue crayfish from an aquatic pet store in town about a year ago. It was only about an inch and a half long when I got it, and has had no contact with other crayfish since. A few days ago my girlfriend notice what looked like a shrimp in our tank. After taking a long, close look, I noticed that there were baby crayfish crawling about. I looked online, and read about a marbled crayfish that can reproduce by means of parthenogenesis. I read some more, but couldn't find any record of an electric blue crayfish doing this. Is it possible mine has reproduced through such a means?
<It does sound likely. The Marbled Crayfish (or Marmorkrebs) is the most notoriously parthenogenetic crayfish and a species of Procambarus, while parthenogenesis has recently been reported among the commonly farmed and eaten Red Crayfish, Procambarus clarkii. Your pet is the Electric Blue Crayfish, Procambarus alleni, closely related to these
two known parthenogenetic species, so I wouldn't be at all surprised if you're seeing parthenogenesis in action.
Cheers, Neale.>
Re: Parthenogenesis?     6/11/13

Thank you very much for your timely and informative response.  I'm very excited to have such an interesting specimen. Cheers. Dave
<Most welcome! Cheers, Neale.>

crayfish molting during pregnancy?    1/30/13
Hi WWM Crew,
I have a pair of bright orange crayfishes (I'm not sure as to what species they belong to, please see pictures) and they were already mating  just a few seconds after I placed the male on the female's tank. After that, they were mating non-stop (like every 15 minutes?) so I searched the web to check if this was normal and found out that you had to separate them after mating because the male is just going to replace the old sperm plug and just repeat the cycle. Now after 1 week, the female molted! So my questions are:
1. is the sperm deposit affected by the female's molting process? do I need to re-introduce the male?
<Is... shed w/ skeleton, unless already used. I'd hold off on introducing the male. It may well eat the other>
2. when a male crayfish is in "form 2", he has to molt to be in "form 1".
Then if he molts again after that, will he go back to "form 2"?
<Usually will change back from "juvenile" in time, molts, w/ good conditions... see WWM re systems, nutrition of Crays>
Daddy Chong
<Welcome. Bob Fenner>

M, F

Re: crayfish molting during pregnancy?   1/31/13
Oh I see.. Just 1 quick follow-up question.. What species do my crayfishes belong?
<Don't know... would search Google images re. B>
Daddy Chong

Lobster/ Crayfish "in berry"? - 12/01/2012
Hi WWM crew - firstly, thank you for a great resource!
<And thank you for your kind words!>
I have learned so much but still have a few things I am puzzled about.
<Me too.>
I live in South Africa and in July I got a "lobster" as a pet. I think she is a Procambarus species?
<Quite possibly.  Maybe P. alleni.>
See the attached picture. We were told she is a female.
<Looks like it to me.>
I am not sure how old she was when we got her but she has moulted three times since we've had her and is now approximately 8cm long. She lives by herself in a tank about 25cm x 15cm.
<Bigger would be better, if it's reasonably possible for you.>

The temperature is kept at 24 degrees Celsius and we have a water filter.
So far all has been going well. We had been feeding her the Tetra Tabimin tablets but recently changed to the AquaPlus bottom feeder tablets as we were told they were the same thing but cheaper?
<I'm not familiar with the latter....  Do please consider feeding her some iodine-rich foods; frozen/thawed shrimp (the kind you would cook and eat yourself) with the shell still on, dried seaweed, etc., and/or dosing the tank with an Iodide supplement.  Although it's okay to use one designed for reef tanks, DO NOT use the amount recommended for a reef tank.  Just a drop or two per ten gallons per week of Kent's marine Iodide supplement is sufficient, for example.>
I am not sure if it's coincidence but a few days after we changed her food she started "itching" a lot - scratching all over but especially under her tail near her swimmerets. I thought it was because she was going to shed.
<Could be >
To my horror, I came home the following day to find her tank full of tiny little white "worms" floating in the water and stuck to the glass.
<Probably something (mostly) harmless just there as a result of "stuff" available in the tank for them to eat.>
After doing some reading it seems these were Planaria?
<Very possible.>
I cleaned the tank and all seems fine again.
<If they happen again, just step up your regular maintenance a bit.  A bigger tank will help in this.>
I am wondering if the new food caused this Planaria bloom?
<Any "overage" of nutrients available for them would allow for it.>
The next morning I awoke to find our lobster lying on her back, tailed clamped tightly shut.
Initially I thought she was dead but after yet more reading it seems she is laying eggs?
<Possible....  There is one known (almost) entirely parthenogenic Procambarus species, and others may also reproduce Parthenogenically, including possibly P. clarkii.  But it's also possible that the animal may have been moulting, or trying to, and having a hard time of it.>
It is two days later and she is still lying on her side/ back and seems very withdrawn (mostly in her cave).
<This is bad news....  Laying eggs should happen fairly quickly, usually right after a moult, and she should be up and about directly.  Lying on her side/back indicates trouble of some sort.  Do please be dosing with an Iodine/Iodide supplement to allow her to properly use available Calcium in the moulting process.>
She is eating though (we went back to the Tabimin).
<Very good that she's eating.  Try to get some shrimp or something similar into her as well, if she'll take it.>
I cannot see under her tail as it is tightly clamped shut. Today I also noticed a spider web-like substance on the pebbles in front of her cave?
What could this be?
<Could be, like the Planaria, just something opportunistically making use of available nutrients....  Maybe a bacteria, perhaps an algae....>
Thank you for your help and advice! Catherine Griffiths
<Best wishes to you and your Crayfish!  -Sabrina>

Lobster/ Crayfish "in berry"? - II - 12/18/2012
Thanks for your prompt reply Sabrina.
<Sorry for the delay on this one, Catherine.>
I had a gentle peek under her tail now and she is indeed carrying eggs under there!
Will definitely look for an iodine supplement though.
<Very good.  Best of luck with her!>
Thanks :) Catherine
<Wishing you and your inverts well,  -Sabrina>

Blue Crayfish with eggs      9/5/12
Hi, lately my electric blue stopped being as active and stopped eating.  At this point I hadn't discovered your site and since I have I have learned a lot about my pet.  She is in a 10 gallon tank with two "caves." She has burrowed in the gravel in one all the way to the glass bottom of the aquarium and established this one as her "home." When she retreated into the other one for 3 days and hardly moved while I was at work I became worried... thought I had a dead crayfish.  After spending the afternoon reading on your site what could be wrong with her I came across a post where someone's Cray was acting the same way and turned out it was producing eggs, sure enough, I went to look and she is "in berry."  She hasn't been in contact with any other crayfish since I bought her from a local pet store about 6-8 months ago and I am not sure if she was around any males there.
<Mmm, some species can/do "store sperm" in a packet>
 Is there any way to know if the eggs are fertile other than just waiting to see if they hatch?
<Mmm, yes; but mainly just waiting is advised, the best route to go>
 Most of them are black in color and a few are a whitish/orangish color. 
Just curious.  Thanks in advanced for your help! - Jacob
<Thank you for sharing. Bob Fenner>

marbled crayfish, in berry, then gone!     8/13/12
Hi there!
I have been searching your site, and I cannot find anything about a marbled crayfish that is in berry, then after a week or two, no more berries!!
<Happens... usually when infertile... dissolve, are eaten>
I have one marbled crayfish, 4 small swordfish, a small Pleco and a couple of snails in a 10 gallon tank. The Temp. in the tank remains around 82 degrees F.(i live in Phoenix, AZ) and until winter comes, it wont get any cooler.
<Mmm, this may be the issue here: Really need cooler water:
What could be the problem? How come the berries don't stay, and become baby crayfish? One day they are there, and Ill check another day, and they are gone!
Any info would be greatly appreciated!
Thanks a bunch!!
<Do peruse the above site for this animal's requirements. Bob Fenner>

<Cross> Breeding Different Genus' <Genera> Crayfish   3/20/12
Hi, first and foremost I would like to thank you guys for almost everything I've learned about crayfish. I've read and read but cannot find the answers anywhere (weeks of reading online).  I have a huge 6 feet long 150G tank housing random colorful platies and 2 different types of crayfish that are each about 3 inches long and live happily with plenty of food and hiding. 
With the right conditions, is it possible for a Cherax quadricarinatus female and Procambarus alleni male mate successfully (Or Cherax Quad female with Procambarus Clarkii male)? 
<Mmm, I don't think so... too different genetically, behaviorally>
Or likewise are there any examples or literature that point out what genus'/species would produce successful offspring when being bred?
<Don't know w/o doing a bit of visiting, computer-search bibliographic work. Do see here re: http://www.wetwebmedia.com/litsrchart.htm
Bob Fenner>

Pregnant Crayfish.... reading   9/21/10
I have a few questions about my pregnant crayfish. It would be just great if you could answer them.
<Will certainly try to help you>
My crayfish has been picking at her eggs and ripping at them. Is that normal?
<Mmm, it is normal for females to clean, aerate the egg mass>
Ever since she has been ripping at her eggs, the egg amount looks like it has been getting smaller. It looks like she only has 40 eggs now.
My crayfish hasn't been eating much since she has become pregnant. Do you know any reasons why she is not eating?
<There could be a few... chemical troubles in terms of water quality, stress, a lack of nutrition otherwise, a missing essential material (e.g. iodide...>
What is the average amount of eggs that hatch and the amount that actually survives?
<Highly variable>
My female has different color eggs, and I was wondering if that color affects the color of the baby
crayfish or its growth in the egg .
<Likely some are fertile, others are not>
The colors are like an orangey-yellow and like a few like darkish eggs. Which egg color will most likely hatch?
<The dark ones...>
Before she was pregnant she would always stay underwater. But now she has a pebble hill that goes above water and she always likes to lay on it. Is there a particular reason for that? Will my crayfish survive after the eggs hatch? I read on a website that said there is a possibility that pregnant crayfishes die after the eggs hatch and I just wanted to be sure about that.
Should I separate the eggs from the mom right after they hatch or wait a little? When the eggs hatch should I separate the other baby crayfishes from each other? If I do how much room would they need? When can I put all the crayfishes into one whole tank? I'm so sorry for all of the questions.
This is my first crayfish and the first time my crayfish is pregnant. It would be great if you could answer all the questions but if you can't answer all that is okay. Thank you for your help.
<... Answers to your questions and more are archived on our site. Read here: http://wetwebmedia.com/ca/volume_5/volume_5_3/crayfish_basics.htm
and the linked files at the bottom. Bob Fenner>

Pregnant Blue Crayfish - 8/10/10
I have / had a pregnant blue crayfish that over the weekend she picked all her eggs off. They are now just laying at the bottom of the tank. Any reason why?
<Difficult to say. Crayfish normally carry their eggs until the babies hatch and are fully mobile. Cannibalism typically follows from stress, e.g., overcrowding or poor water quality. There may be some variation among
species though. I assume this is Procambarus alleni; review the needs of this species and act accordingly.
Cheers, Neale.>
Re: Pregnant Blue Crayfish   8/10/10

I "assume" that since she picked off all the eggs that they won't hatch now. Is that correct?
<If they still look healthy, you could certainly try rearing them in a breeding net with an airstone nearby to keep them oxygenated. No promises, but you might get a few. But if they're opaque or fluffy with fungus, then no, they won't hatch. Cheers, Neale.>
Re: Pregnant Blue Crayfish
I'm not sure how far along she was when she began removing them over the weekend. They are just black and lay at the bottom of the tank. She, nor the other two crayfish in the tank pay any attention to them. I have the 3
in a 30 gal. tank but cleaned the tank not knowing she was pregnant until I put her back in and I guess from all the info I've gathered from you that is probably what stressed her and made her 10 days later start removing the eggs.
<They won't last long on the bottom of the tank. They do need to be agitated a bit to keep oxygen flowing across them. That's what she does with her swimmerets when she's carrying them. So as I say, if you want to have a stab at rearing them, put them in a breeding net, stick an airstone or at least the filter outflow current nearby, and see what happens. Not much more to add really. Good luck! Neale.>

Is there strength in numbers? Crayfish torture   4/11/10
Hi there.
I have about 25 crawdads in a 10 gallon tank but none of the crawdads will hurt the other crawdads. I know that the crawdads are supposed to fight others but they wont fight and they are standing on the rocks out of the water and 3 of them have eggs.
I have no idea what to do!!!!!!!!!!!!!
Please help me!
<Why do you want your crayfish to fight? As for coming out of the water, yes, they sometimes do that if the water is poor in oxygen. Your tank is rather overstocked and I imagine water quality is pretty dire, hence their behaviour. You would be wise to move them to a much bigger aquarium, and use this little tank for rearing the babies, should you want to. Do read here:
Cheers, Neale.>
Re: Is there strength in numbers? Crayfish... incomp., repro. sys., referral?   4/14/10

I didn't want my crawdads to fight it is just that they are suppose to but they didn't so I wanted to know what was wrong. And for the eggs why wont the females lay the eggs. The eggs are already fertilized over spring break but the crayfish wont come out I have no idea why. please tell me step by step on what to do for raising eggs starting from introducing the male and female to introducing the next generation. thank you.
<Females don't lay eggs. They carry the eggs around with them until they hatch, and that's when the miniature crayfish appear. In a tank with adults those baby crayfish have virtually no chance of surviving. So take a female
"in berry" (i.e., carrying eggs) and put her on her own in a 10+ gallon tank with a filter and lots of rocks and plastic plants. Eventually the babies will leave the eggs, scuttle under the rocks and plants, and you can remove the female back to her original quarters. The babies are notoriously cannibalistic, so you'll need to keep them well fed and segregate them as they mature, so the bigger ones don't attack the smaller ones. Make sure there are adequate caves to go round as well, otherwise the baby crayfish are very vulnerable when moulting. Cheers, Neale.>

Electric Blue Lobster, repro.   11/26/09
I have owned my electric blue lobster, Stella, for just over two years now.
When we purchased her from the pet store that I am currently employed at, she was in a large tank with two other males. Shortly after purchasing her, she laid some eggs and, after extensive research, we were able to set up four new tanks in order to give the babies adequate room to grow. I assume that she became impregnated by one of the males at the pet store.
We were successful in keeping about 100 of her babies alive, and when they became large enough we sold them back to the pet store. Since then, she has laid eggs several more times, even with no mate present. I understand that crayfish will sometimes lay eggs whether they have a mate or not. My question is: how long can a crayfish hold on to a sperm packet? I can't seem to find the answer anywhere! And also, if her eggs are infertile will they still be dark in color? She has been living alone for just over two years. Is there any possibility that these eggs are fertile?
Thanks for your time,
<Hello Sharon. Female crayfish can store sperm in the spermatic receptacle for several months. Biology books seem to suggest periods of up to 6-8 months, but there are reports of females producing offspring 18 months after mating. Various factors like water temperature probably come into play. So the short answer is that yes, females store sperm, and no, no-one really knows for how long! If the eggs are infertile, it should be apparent pretty quickly as they fail to change colour (as happens when the embryos develop). Hope this helps. Cheers, Neale.>

Cray fish Breeding tank 10/20/2009
Hi! Im a teenager fascinated by crawfish.
<Very interesting animals they are too...>
As of now i have a 10 gallon tank with 4 feeder gold fish and 1 Male Crayfish. He just recently molted, today actually. he has a hiding spot and gravel a small aerator for the water and a filter. i received him from the
wild and im deciding to breed him.
<Certainly possible.>
Im curious of what tanks i should get. 2 10 gallon tanks? one for the males and 1 for the female?
where would i put the babies?
<They stay with the mother until they're ready to fend for themselves, at which point placing them in another tank with lots of caves (they're cannibalistic) is an option.>
do i need to buy them a separator? im planning on donating some to a local PetSmart or pet-co and keeping a few in case some that im keeping dies. can you send me a link of anything for a breeding tank plan?
Thank you sorry if i have a few misspelled i checked like 3 times but i still may have some. :]
<One or two, but never mind! It's great you took the effort to spell check -- if only more of our correspondents would, it'd be a lot easier to read some of these messages. In any case, do read here:
Breeding "comes naturally" to crayfish, and all it really requires is that the male and female are kept together, but not so crowded one tries to eat the other. Sexing them is tricky, and you need to turn them upside down and look at the location of the genital openings. They're in different places on males and females. It's easiest to Google "sexing crayfish" and take a look at some of the photos. Anyway, males mate with females just after the time the females have moulted; the rest of the time, both sexes are pretty intolerant of one another. In a biggish sort of tank with two caves, the two should avoid each other most of the time, especially if well fed (sushi Nori, cooked vegetables, and the occasional unshelled prawn or frozen lancefish). After spawning, the female and male are separated. The female carries the eggs under her "tail" for a few weeks, and once the fully formed baby crayfish leave her, she needs to be removed or she'll eat them.
As they grow, they'll eat one another if hungry, especially when moulting.
It's worth making the point that breeding crayfish on a commercial scale requires a lot of space (and skill) and by and large hobbyists are lucky if they rear two or three of them. You might place a bunch of floating
breeding traps in a filtered 55 gallon tank, and put one to each trap, but that's the sort of effort required. Hope this helps, Neale.>

Crayfish, repro.
I had a quick question. My dad has a 120 gallon tank, and he had two crayfish awhile back. One blue and one red. They blue one died not long after he got it. So the red one ended up having a red baby. Now we have two red big ones. We had found another little red one a few weeks ago. Now today we have found a blue baby. I was wondering if the mother is red can her off spring be a different color?
<If the two colours you had were varieties of one species of Crayfish, a blue male and a red female, then yes, the mother could very well produce offspring of different colours. Just like a blonde human could give birth to a brunette baby! It's just down to the genes. On the other hand, if the two Crayfish were both females of different species, then the blue baby you've found may have been produced by the one that recently died, and was hiding somewhere in the tank. Crayfish produce offspring after mating, males mating with the females once for each clutch of eggs the female produces. So a singleton Crayfish may incubate eggs fertilised by a previous companion, but after that batch of eggs, she won't produce any more offspring. Hope this clears things up. Cheers, Neale.>

Breeding Trigger/Puffer food  9/21/09
Hello friends.
I have a 125 gallon predator tank with a Puffer and three Trigger fish.
Before I made the switch to saltwater, I started with freshwater like most folks do. During that stint, there was a time I had red and blue crayfish.
One day I had lots and lots of little crayfish running around eating each other. Long story short, I'm now on to saltwater and wondering if I can raise freshwater crayfish and feed the young to my saltwater chompers.
(using a separate 10 gallon freshwater aquarium of course).
Any input here would be great.
<Jason, yes you can use freshwater crayfish, but no, there's not much point. The cost/benefit ratio simply isn't there to make this a worthwhile endeavour. Sure, if you kept crayfish as pets anyway, and had some spare juveniles to get rid of, these herbivorous crustaceans would be a good choice as occasional snacks. You can gut-load them with plant material and algae wafers, and expect them to provide useful nutrition. So it's not like the situation with store-bought feeder fish, where there are absolutely no good reasons to ever use them whatsoever, short of deliberately wanting to make your fish sick. But as a staple, you'd need a pond, not a 10 gallon tank, to raise enough crayfish simply because of the numbers involved.
Let's say you used one crayfish a week, you'd need to breeding them on a fairly industrial scale simply to be able to supply 52 crayfish a year!
You'd also be increasing the chances your predatory fish would get hooked on live food, and thereby lose adaptability in terms of variation (squid, cockles, and other largely thiaminase-free seafoods).
There's also some anecdotal evidence that the use of live foods increases aggression, and that's the last thing you want with "big biters" like Triggers and Puffers. That's another good reason why Bob and other experienced aquarists stress so strongly that live feeder fish shouldn't be used for Lionfish, Morays and the like. The key issue is that fish like Triggers and Puffer patrol VAST areas of seabed picking off large
crustaceans, molluscs and cnidarians, and there's simply no way to mimic that in captivity. They eat a little, but often, while consuming a huge variety of prey, from chunks of coral through to hermit crabs. I'd sooner
concentrate on finding a healthy, varied seafood diet for my fish, and leave the 10 gallon tank for something more immediately useful, e.g., a quarantine tank or a refugium. This hobby is hard enough work as it is, and simplifying feeding down to the basics will make your life a lot easier.
Cheers, Neale.>

Freshwater blue lobsters, repro.  4/21/09
I accidentally came across a beading pair of blue lobsters.
<Hmm... they don't really form pairs: they mate, and then the male wanders off. Don't expect two adults to coexist in a small tank; these are territorial animals prone to fighting.>
I did not know they were male and female when I got them and I got them at different times.
I ended up with three "litters" of babies which I gave away. One day every Lobster in my tank just suddenly died and I don't know why.
<They all died at once? Most probably some kind of environmental change for the worse, e.g., the use of copper-based medication, or a sudden change in pH caused by a lack of buffering. Review the tank, in particular water chemistry, filtration, etc.>
After that a friend gave me two of the baby's back in hopes that I would get another breading pair. How do I know what their sexes are and will Lobsters bread with a sibling and is that recommended?
<It's never recommended to breed closely related individuals, whether human or animal. When you do so, the chances of mutations and deformities go up.
That said, as you probably know this is routinely done on breeding programmes where people want to "fix" a mutation or deformity into a lineage: this is how you create new "breeds" of cat, dog or whatever. In
other words, no, ideally you'd buy another crayfish to go with one you have, and so ensure the offspring have the best possible chance of good genes. But if you couldn't get another crayfish, it wouldn't be the end of the world, provided you didn't mind that any offspring could well be weaker or more prone to deformities than otherwise, and the fertility rate likely lower as well. Cheers, Neale.>

Red crayfish is pregnant. 4/19/09
I recently was cleaning my 55 gallon tank when I noticed that one of the crayfish had black eggs under its tail. I did some research && discovered she was pregnant.
<Lucky you!>
I bought a divider to separate her from the other fishes I have but when doing that one of the crayfish is trying to climb over the divider, I am assuming he is the father.
Is it ok 4 me to have separated her from him?
<Better than merely OK; it's a good idea!>
Also are those black eggs caring babies or not. && how far along can I tell she is. && how long is the process of her pregnancy going to be?
<Varies, but typically the eggs are carried for about a month. At which point they need to be removed from the parents and reared on things like algae wafers and softened vegetables. Can be cannibalistic, so keep an eye on them, separating out larger specimens from smaller ones, and provide lots and lots of hiding places for when they moult.>
P.s. @ one point she's was fighting with him to get out the little cave I have made. But he refuses && stays near.
Thank you so much 4 the help.
<Happy to help. And next time, be nice to us and send messages written with normal English rather than TXT speak. We do specifically ask for that at the "front door" of the site, and usually bounce back messages written in TXT speak. I was feeling nice, so answered your query, but next time won't be so forgiving! Cheers, Neale.>

Electric blue crayfish babies   3/23/09
Hello I had a few questions about electric blues I'd like to ask. I read through the Crayfish Reproduction FAQ and just wanted to make sure I'm doing the right thing. I just bought two of these guys which I believe both to be females (one of course is).One had eggs and now they look more like a white dot with a tiny bit of black on them. They seem to be growing there legs so I was wondering how much longer it will be until they leave there mom?
<Perhaps a few days>
She's had them so far for about 2 weeks. They are in a 20 gallon ph 8.0, Ammonia-0, Nitrite-0, Nitrate-5. I tried getting the ph down to 7.5
<I would leave this be>
when I was cycling it but it goes right back up. I have virtually no hardness to my water because of the water softener.
<Mmm, and use water from an outside spigot (that is not softened)... perhaps warm up with a bit of the inside/softened water>
So I feed the algae wafers, freeze dried krill, tropical flakes. I heard about the iodine but wont the carbon filter take that out?
<Yes... but not immediately likely... better to use on a punctuated basis, perhaps during water change outs (weekly), and put the carbon in the next day>
Should I just take the carbon out and just let my water changes clean the tank?
<Ah yes. Well done>
I don't want to kill the babies or the adults. Is there anything I'm missing to keep these guys healthy and the babies alive?
<Nothing "jumps out">
What should I do about the babies?
<Mmm... what do you want to do? Try rearing them?>
Can I just keep them in a little 2 gallon Betta tank I bought when they break from mom?
<Or move the adults... this would be better>
There of course is no Betta but I held on to the tank because it had a filter and bio wheel which I figured I could use it later. Or can they just hang out with the ladies?
<Mmm, not for long... likely to be consumed>
I guess they might eat them that way so I don't know. Please and thank you for any help you can give
ps I love your site I'm learning a lot from it!
<And contributing to it as well. Thank you for sharing your experiences, speculations with us Deanna. Bob Fenner>
Re: Electric blue crayfish babies 3/25/2009

I have a few more question for you about the baby's I've read that they can come in and out of water.
<Mmm, no... not until they are much larger>
So my question is if I get a little 5 gallon today and a rock or two for them to climb out a bit for air will this be ok? Or should I just get a air stone for them? I was just going to do a water change and put there moms water into the 5 gallon for now and throw a feeder guppy in to keep it cycled, will this even work? I got a not so good pic just for fun to show you. They are visibly moving now not much but a little its so cool.
<Very nice... I would keep the young in place, move the parents... You have read on WWM re? BobF>
Electric blue crayfish babies   3/23/09
<Perhaps a few days>
<I would leave this be>
<Ah yes. Well done>
<Nothing "jumps out">
What should I do about the babies?
ps I love your site I'm learning a lot from it!
Re: Electric blue crayfish babies 3/25/2009


Infertile crayfish eggs   1/28/09 Hello! I have learned from your site that female crayfish can lay infertile eggs. However, I cannot figure out WHY they do this. My female is the only crayfish I have and she has not shared a tank with any other crayfish for two and a half years. What would cause her to do this? Also, what will she do with the eggs, as they are most definitely infertile? Should I remove them? Thank for any help you can provide!! Sarah <Hello Sarah. Some animals will produce eggs periodically at a set rhythm, regardless of the availability of a mate. Humans are an example, the menstrual cycle having a periodicity of about a month. If I recall correctly, female crustaceans generally produce eggs at about the time they moult, and during a moult, a male will try to mate with them. They don't produce eggs with every moult, and in the case of coldwater species for example they only produce eggs when the weather warms up in spring. There is a scientific literature on this topic, particularly with regard to crayfish, because of the importance of some species as food. In any case, without a male present, the eggs will be infertile. Removal is up to you: she will eat any infertile eggs she finds, but obviously having a bunch of rotten eggs in the tank won't help water quality. Cheers, Neale.>

Crayfish eggs and oxygenation 1/12/2008 Hi, <Sue> We have one female crayfish, who is "in berry", and we have been observing her behavior in or third grade science class. We noticed that she rotates her eggs under her tail. After learning about basic needs, the students in the class inferred that she was moving freshwater around the eggs to supply the eggs with a fresh supply of oxygen. <This is so... as (tautologically) trying/resulting in removing detritus... that might well lead to fungusing> The students in the class wanted to know if there was a name for that process or the behavior that they observed in the female? <As far as I'm aware the process/pattern is simple termed "Berried egg manipulation, or cleaning"> We change the water in the basin twice a week, she is well fed with Elodea and fish food, has shelter, and is now in isolation. We have a video clip of the female crayfish rotating her eggs under her tail, and we wanted to describe what we were observing appropriately before posting it on the Internet. Thanks for your help, Sue <Mmm, maybe search the Net... with the species name: Procambarus clarkii and reproductive behavior. Bob Fenner>

Pregnant crayfish  9/10/07 I have a crayfish that has had eggs for at least a week. I noticed today that all the eggs are an off-white/cream color. Does this mean the eggs are not fertile, or will it take longer for them to darken? Thanks! <Only time can/will tell. Bob Fenner>

Breeding freshwater lobsters; using WWM...   6/10/07 I have a pair of fresh lobsters and one of them has eggs under her tail for the past 6 weeks. I'm looking for info on how best to care for the juveniles once they are born, feeding them etc. The two lobsters are approximately 5 inches and in a small breeding tank, approx 60litres. There are also tiger barbs in the tank at the moment. Any advice would be greatly appreciated. Also how long before they should start to hatch? <Please read here: http://www.wetwebmedia.com/ca/cav1i4/crayfish/crayfish.htm and the linked files below. Bob Fenner>

Female Blue Crayfish   5/13/07 I have read the info on your website but just want to make sure I understand our female.  She can still produce eggs but unless with a male will not be fertile? <Correct> Most of the eggs are dark but a few are white, I have no idea how long she has had them, she's been hiding we thought she was going to molt but apparently she had other things on her mind.  She was with 2 males and 1 other female until she killed them all 6-8 mths. ago, is it possible she's held onto it until now and became fertile? <Is possible that this female stored a "sperm packet" and auto-fertilized the eggs... The white ones "are" fungused, but the dark ones may be developing young> My children and I are just amazed by this whole thing as we had a red female for a year and a half and she never did this.  Oh one last thing I did move Blue as she was in a tank with semi-aggressive fish and we didn't want her or any possible babies to be hurt, will this cause her any problems? <Hopefully not... I would use this main tank as a/the source of all new water... to provide a safe, clean source... sans sanitizer from the tap/mains> Thank You! Amy S and Girls <My welcome to all. BobF>

Yabbies repro., fdg. young  - 05/02/07 In a group of yabbies (Cherax destructor) recently, I found a very small baby Yabby in all the left over debris from the adults. The baby is less then a cm long, I'm not quite sure how it ended up there, as there weren't any berried females or females with young in the tank the yabbies came from. <Nice find! The youngster at that size will have been around a while longer than anything in berry. Crayfish mothers carry the babies around under the tail for a while.> Anyway, since it managed to live through the long car ride home, I've separated it from the adults and placed it in a small container with about an inch of water. Firstly what on earth does it eat? Do they just scrounge up crumbs that the mother normally drops? Or do they need a special food? <They eat much the same thing as the parents, just smaller. These crayfish are omnivores, eating algae and plant material, as well as any dead animals they find. So I'd be providing pretty much anything, perhaps algae wafers of the type used to feed catfish, plus small crustaceans like krill periodically for the calcium.> Currently its sooo teeny and transparent, I've given it a tiny piece of steamed carrot (the adults all got a slice each) and a sinking goldfish crumble which should be soft enough for it to eat. It's so very small though, it's got the tiniest pincers and you can't even see the most of the tail. Is there anyway of estimating the age? And how often the baby will moult? <Sounds as if its a few weeks old. Crayfish moult most frequently when young, and one your size will moult every couple of days. Adults may only moult every few months, if that. They are comparatively easy to rear. The main problem is making sure the baby crayfish aren't eaten by other crayfish or large fish.> Thanks, Emma <Cheers, Neale>

Removing crayfish eggs  - 03/24/07 I recently swapped the large cichlids in my planted tank for  a community of various Anabantidae, and found left over feeder crayfish.   After watching them destroy my plants day after day, <What they do...> I decided to remove them from the aquarium and take them back to my LFS.  When I did, I found a female with lots of eggs.  I scraped them from her tail and returned them to the tank.  What is the likelihood of  the eggs hatching without the mother?   <Some... not likely if there are fishes there to eat them...> I am interested, because I am sure they will make a tasty meal for some of my fish once hatched. <Or vice versa in time... Bob Fenner>

Re: Removing crayfish eggs- 03/25/07 The eggs were dropped in the tank at night and are not visible anywhere in my tank at all.  Thanks for the info though.  They crayfish became a tasty treat for a porcupine puffer at my LFS. <Yikes... CRUNCH! Bob Fenner>

Unidentified Yabby 'bubble' 2nd email - photos attached.    02/17/07 I'm happy to report that our female Yabby was seen this morning happily attending to eggs under her tail. She is clearly very protective of them, backing away whenever she sees any of us peering at her. We are all very excited. <Neat> Is there anything extra we could be doing for her? <Mmm, you've read, re-read the postings, article on WWM? This is about the sum-total of all I know re> I clean the gravel and partial water changes once a week. There are two air filters in the tank and I clean one of those a week as well. I've been adding the iodine as suggested. They seem very happy and comfortable in their environment. <Good> Should we remove the male before they hatch? <Likely a good idea, yes> I'm going to get another tank in the next week or so and set it up so we can have it cycled before we need to move anyone. Any tips, as usual, will be very much appreciated. Kind regards Tascha Marshall Aus <See WWM... RMF>

Redclaw Lobster, repro.    12/29/06 Hi   <Hello there>   I have a male Redclaw called Redclaw and a female one named Gravy-Berry. <Likely Cherax quadricarinatus> I used to have 1 other male and 1 other female, 6-7 freshwater Yamato shrimps and some snails. As I <... I> went overseas some time ago, I had to give them away. but I found out Gravy-Berry had eggs so we decided to keep her and Redclaw, who was my favourite as he was always active and trying to snap at me when I went near. I dropped them off at my aunt's, in separate, smaller tanks.      when I got back and transferred them back to their original tank, I found that Gravy-Berry kept leaning to her side when she was near Redclaw. my father said that she was trying to ask him to fertilize her eggs. is that true? <Possibly> because I thought they were fertilized already. also,  ever since then they ate very very little. before I went overseas, the tank used to be choked with poo, but now it was more choked with food than poo. I hardly see poo at all. and Redclaw just slumps under the driftwood. he is no longer active.      what has happened and what can I do? <Clean the tank... slowly... vacuum a bit of the detritus out every few days, replace the water with some that you have aged, stored... Check the water quality, particularly for biomineral and alkaline content... Food/Nutrition?> is it because Redclaw wants his friends back? <... sigh... no> because he always had such a great time chasing them around, bullying them. I guess he cant bully the female in respect that she is pregnant. is that why he is bored? <...> and he doesn't seem to react to the female's tipping-overness. if the eggs aren't fertilized, what will happen? <Perhaps they'll decompose> because I've seen her dropping her eggs and eating them.    please help <Please read here: http://www.wetwebmedia.com/ca/cav1i4/crayfish/crayfish.htm and the linked files at the bottom. Bob Fenner> Rachel Kam Re: Redclaw Lobster  12/30/06 Thanks for the link, it is very helpful...maybe u <you> didn't get me right, as in, I thought the female had the eggs fertilized already, <Could be fertilized or no...> I mean why else would she lay a bunch of eggs, right? <No... lay them nonetheless... sometimes with or w/o a male or stored spermatozoa> That is because my other female had no eggs? <? Don't understand your implied causality here> And is there anyway to tell if the eggs are fertilized? <Mmm, yes... with a microscope, gauging development... or waiting to see if they hatch out> thanks. That's because i'm <I'm> a bit worried for my male lobster, he's really dull when he should be happy. So is my female! Please, please help! Rachel Kam <Please read where you were referred to, and the Net re the species. Bob Fenner>

Re: Redclaw Lobster. Repro.  12/31/06 Okay, thanks a lot! I'm so sorry for asking so many questions, but regarding the part which you didn't understand, I am wondering why some females lay eggs and some don't. I had two females, one which had eggs and one which didn't. My question is, why probes a female redclaw into laying eggs? Rachel Kam <There are environmental clues like temperature, light duration, water flow/depth... nutritional ones (w/o sufficient food eggs will not be produced or be healthy enough to hatch), chemical inputs (inadequate biomineral and alkalinity have been mentioned to you), and social/psychological mediators... the presence of males... as well as stress... many organisms have a "bail out" mechanism or two... for reproduction under adverse conditions... RMF> Re: Redclaw in Berry  4/2/07 Hello Bob,    <Rachel>   I would like to ask you a couple of questions to clarify some doubts:    <Okay>        Is it alright to separate the babies instead of the mother into a smaller temporary tank (approx 1footX15cmX20cm). I have two of these. How many of each baby should I place in the tank?   <Mmm... again, I would move the parent/s and leave the young in place rather than the opposite... IF you elect to move the young, do bring a good deal (as much as possible, practical, of the water they are in with them... And I would allow "nature to take its course" and leave all you do move to cohabitate (yes with some cannibalism) in the new setting>    When I scoop the babies out of the main tank, will using a small net hurt them?   <Possibly... better to use a large/r diameter siphon, or direct scoop... plastic, squared edged container>    The tank is getting dirty, is it better to wash it now or when the babies are released?   <After for sure... not much trouble currently, though it may look, smell unsanitary>    what does 'investigating in the culture of food stuffs' mean? Does it mean researching what food the babies eat? <Yes... Sorry for the confusion here>   Thank you for your replies to my previous query; they were very helpful! Also thank you for your trouble, it is very much appreciated. <Welcome my friend. Bob Fenner> Re: Redclaw in Berry   4/3/07 Sorry to trouble you again, Bob, but I would like to see your views about my suggested proposal of what to do. One thing to note is that in my tank, there is a large rock which makes the water in the tank brown after some time. My parent lobsters are not affected though, it should not be poisonous or anything. Just stating in case it might be of concern.    <All right>   #1: Transfer out male lobster before release of babies. <Good idea>   #2: When babies are finally released, transfer out female. <Yes>   #3: Place lots of material (I'm thinking of putting straw bits in for them to hide, is that all right?) <Should be, yes, if it is well dried, re-soaked to sink> for the juveniles to hide.   #4: After a couple of weeks, transfer them out and the parents in (I am planning to keep some while give others away; however I am afraid due to cannibalism rate I might only have a handful. In this case I'll return the parents when the juveniles are a month old)      However my temporary tank is extremely small as stated, will that have any effect for the adults if kept there for a month? <Do keep an eye on their behavior... potential aggression, water quality... may have to be separated somehow>      If my proposal seems wrong, please feel free to help me edit it. My female is small (approximately 6cm), thus her approximate number of juveniles (before release) is around 15.      Thank you for all your help! <Welcome Rachel. BobF>

Redclaw in Berry   4/4/07 Hello it is me again. Just to update you on my progress so far. I've separated the male into a tank only thrice his size. I've another of those tanks which I will be putting my female in soon. Babies are not released yet. Today I saw the mother lobster curling her tail towards herself and using her tiny claws to 'scratch the babies',. Probably cleaning herself. Babies are actively moving, however showing no signs of being released (It's almost a week since their eye spots and limbs appeared).      Also, as I find that PVC is a little hard to get in my area, I would like to ask you if some materials are safe for use:      1.) All kinds of plastic (If not please indicate which plastics are suitable)   2.) Rubber band   3.) Raffia string   4.) Any rock I pick up, so long as I wash it with tap water   5.)The net used to hold onions (onion mesh?)   6.) Any adhesive?   7.) Any other home materials I can use? <Mmm, am hesitant to endorse any of these... Likely a "clay flower pot", fired or not would be a good general suggestion here... Are almost all safe to use>   Thank you a whole bunch Bob, as today I found my male assaulting my female, just before I separated him. I also feel the advice was helpful as he had once devoured a 3cm lobster whole! Your fast replies are greatly appreciated!    <Yikes!>   PS: I have a huge driftwood (approximately 1-2 ft) in my tank now, will that suffice as hiding places for my now diminished bunch of un-released babies (approximately 8 left), or must I have more (like the straws?). <I would stick with/use the driftwood alone... much easier to clean, remove...> And I am puzzled how come there is one baby that is not red but white (but it has eyes. Not sure if it is moving). <Mmm, perhaps a melanistic/xanthistic, even an albino variety... does happen...> I am planning to buy a filter rock/netting during the weekend if the juveniles have hatched by then (as the numbers are small, they might die easily and it would be a waste to buy the filter rock for nothing) to use as hidey-holes. <Cheers, BobF>

Re: Redclaw in Berry  4/5/07 Dear Bob,    <Rachel>   Thank you for all your quick replies and all your help! My father lobster keeps trying to escape from his mini tank, but I suppose it should not be of concern as he is living alone in there (but it really is very small for a lobster his size.. about one-third of a gallon at best). Babies have not hatched yet (is that surprising? <Mmm, no> I was actually expecting it to be somewhen this week, but the week's almost over!). I guess I'll just do with the driftwood and not add anything other foreign objects like you suggested.   Thanks again! <Perhaps some sprigs of floating plant... BobF>

Re: Redclaw in Berry  4/6/07 Rachel here again! Hey Bob, regarding your last reply on adding floating plants, can they be fake plastic ones or must they be real ones? Babies still not out yet, when do you think they will come? Thanks again! <Either would be fine. I prefer the live. B>

Redclaw Juveniles  4/10/07 Hello Crew!    <There you are Rachel>   Today I noticed the first Redclaw juvenile leaving its mother. I named him Big Si. Big Si's a bit blur, His mother has eaten the Hikari Crab Cuisine pellets <Time to move...> and left crumbs for him, but he just doesn't see it. But I can tell he is hungry as he is clawing the poo-filled tank for crumbs. <Do you recall my stating you should be looking into foods for the young?> I just checked on him but he is nowhere in sight. He is either hiding or eaten up by his mother. I fed her half an hour ago and she is clawing for food again. I fed her again, and I suspect she has eaten Big Si in the half hour that I wasn't looking. I have researched and found that mothers only eat their young when enclosed in a small space, <And/or hungry> however my tank is a 15 gallon tank, with only one adult Redclaw (that's the mother).   I also have researched on juvenile foodstuffs, and I have decided to feed them brine shrimp and Hikari pellets. However can I feed them on brine shrimp alone? <For a while, yes> And are Hikari pellets fulfilling the high-protein diet they require? <Possibly>      Also, I am planning to transfer the juveniles out of their tank. How big must the diameter of the siphon be and how old must the juveniles be for safe transportation (as they are vulnerable when they are young)? <At least half an inch... but again, better to remove the female for now... leave the young present to grow. BobF>      Thank you, Rachel Kam

Re: Redclaw Juveniles, repro. & incomp.    4/12/07 Hello Bob, the female is keeping herself on top of the driftwood, out of the male's way, so I guess it is much calmer right now. <Mmm, tentative... dangerous possibly. Do keep your eyes on them> The babies are all right, today I bought some brine shrimp to feed them. Although it is frozen, my father has put it in the fridge. Is that all right, too? <Yes... just small amounts at a time...> I fed the brine shrimp to the parents as well, although they seemed to have very much ignored it.      When's a good time to reintroduce the little ones to the main tank? <... can't likely be done... These animals are cannibalistic... Unless there is a very large space, enough for all to have their distance... they will continue to consume each other> I am afraid as my male once ate up a 3cm juvenile. He's pretty rough, that guy. The female may have evaded him but the little ones...maybe I should not keep them in the main tank?      Thanks again, Bob! <Correct... I would trade them in at the fish store, gift them to interested friends... Bob Fenner>

Re: Redclaw Juveniles   4/15/07 Dear Bob,    <Rachel>   I must've missed one of the juveniles while transporting them out into the smaller tank as my brothers noticed one in the main tank last night. I couldn't find it so I left it there (probably will be eaten up by the big ones). I gave one of the juveniles to my friend, so now there are four left. It does not look as if they have molted yet, although I've read up and at this age they are supposed to molt almost every day.    <Can do>   My male just molted, he's now twice the size of my female (when I first got them my female was larger than he was). The female isn't bothering him at all, just keeping her distance at the top of the driftwood.    <Hiding... Queen of the hill... again, I urge your caution in observing, separating them>   The juveniles' tank is getting cloudy and murky due to uneaten brine shrimp and the Liquifry. <Need to change a good deal of the water out daily... possibly more often... with water from the main tank> Instead of siphoning out the stuff, I have decided to place them in another container (50% water from main tank where they were once in, 50% tap water <I would not use tap...> {this should be same as the water in their tank now, only not as murky, even though I did not take from their smaller tank at all}). Do you think I can do this? Meanwhile I clear the smaller tank and refill it with 50% main tank water, 50% tap water, re-transfer the juveniles back. I have not done this yet, but am planning to. Just asking your advice before I proceed.      Thank you, Bob!      PS. I've got a couple of decoration rocks and pebbles, although they do not have hidey-holes can I put them in after washing them? <Yes> Will it give the juveniles some coverage as they molt? <Hopefully yes> My friend has this rock she got from the sea, it has hidey-holes, can it be used after washing or will residue salt harm the juveniles? <Should be fine with your water change regimen> How can I wash the rocks thoroughly without using soap (which may not get washed off in the end as well). <Please read here: http://wetwebmedia.com/clnornart.htm and the linked files above. Bob Fenner>

Re: Redclaw Juveniles   4/16/07 Thank you Bob, one more thing to trouble you: I'm changing my main tank's water as it is getting brown again, and as I need to remove the male's shell (it's been in there for almost a week, he's not eating it). When I do this how do I clean my smaller tank if it is not advisable to add tap water? <Mmm,... as previously stated, it's a very good idea to use the "conditioned" water taken from the present/larger tank, to replace that removed to waste for the smaller> Thanks again! I cannot separate them as I have lack of space but will continue observing them carefully for any signs of aggression (the female has come down once, but went up again. So far did not see any aggression.). And the link you provided was very useful as well.    <To be clear... the behavior of the female, staying on top of the decor... is indicative of its fear... aggression by the larger male>   PS. Whenever I wash my main tank, I siphon out most of my water and add in tap water to the original level (about one-third). <A good technique in Singapore... I want to add for others reading here that the water in many other places in the world is too toxic to do this with impunity... that new water should be treated, stored, perhaps tested for residual sanitizer ahead of use. Bob Fenner>

Re: Redclaw Juveniles  4/18/07 Dear Bob,    <Rachel>   So I should not clean my main tank? When can I start adding non-conditioned water as there will be a day when I have to change the water in the main tank (getting dirty)...Or is there another way I can go about doing this?    <... I would change the water in your main display... with new... but use the conditioned/old water from it for making changes with your smaller system with the young... Is this clear? This is the third time this has been stated. Please do not write back with the same simple questions>   My female has finally come down, it seems the aggression has stopped, for now. The male does not look like he is bothering her, except the occasional shovel.      Yes, I agree. Singapore's tap water is cleaner. I got my lobsters from a reservoir, where the water in that reservoir (after going through further cleaning processes) goes into our tap. So it should be safe for the red claws.      Thanks!      PS. My juveniles appear quite hardy. I carried their tank around (as they are light they float around and often tip over with their bottom in the air). Also, before your advice to add "conditioned" water from the main tank, I did add fair amounts of tap water in (diluting their water). Through these entire week, I had to disturb the tank a couple of times as I took out two juveniles to give away. And yet, after all this, they are all alive and kicking. No cannibalism yet. <Ah, good. B>

Re: Redclaw Juveniles   4/19/07 Hello Bob!    <Rach!>   I am so sorry for the repeated questions as I was not exactly clear, but now I understand. Thanks!    <Ah, good>   One of my baby lobsters died yesterday afternoon, of unknown causes. The other two are still alive. Do you have any idea how the sudden death might have been caused? <Mmm, no... but do know that this is not uncommon... many invertebrates, fishes... are not "really ready" when they're young... do die off sometimes in high numbers...> Not due to cannibalism, as the other two are not interested in the dead body. I fed them Liquifry twice a day, so it cannot be hunger. I am not sure if it is the water quality, but probably not as the other two are not affected. I have removed the body. What should I do now?    <Keep on keeping on... I would switch to other foods now though...>   I heard news that a baby lobster that I gave my friend died. It had food, clear water and aeration. What could be the reasons?    <Developmental/genetic most likely... environmental, nutritional... many possibilities>   Really hope you can help!      PS. The parents are doing fine, they are having such an immense appetite. Only yesterday I realized. I fed them 10 pellets each, compared to the one pellet each when they were separated. I did not overfeed (I hope) as I added one by one, and as I could see they were clawing for more, I added in another bit, and so on. The shell has also been almost completely eaten (I think as I only found out their sudden appetite yesterday, the days before they might have had to eat the shell due to hunger [as the week before it was completely untouched]) <RMF>

URGENT: Redclaw Problems   4/27/07 Hello Bob,    <Rachel>   Not a very happy note! The female moulted in the morning, when I came back from breakfast, I saw white floss things floating around, an empty exo, and the female nowhere in sight. I think my male lobster ate her up! I'm feeling sick and sad, I should have removed her like you said but I had no extra tank.    <Ah, my young friend>   I found a juvenile in the tank (like my previous email stated my brother saw it and I thought it was eaten up, but apparently it was growing very well, now twice the size of the ones I keep in my smaller tank). No idea how come he managed to survive although I did not add in extra food. And I wonder how come the two other juveniles are still so small?    <Different circumstances... food availability mainly>   I'm very worried, now the whole main tank is cloudy (due to the white stuff floating around, also as I have not cleaned the tank for a long time now as you said I need the water for my juveniles). I really want to clean it now. I can't see what is going on inside (it's that bad), but I'm worried when I remove the driftwood to clean, the juvenile will hop off and get eaten by the bigger male. Also, If I clean the water will be drastically changed and I don't think the juvenile will like that. I can remove him to another tank (I'll try to persuade my mom to get a small temporary container) as placing him in the smaller tank will result in cannibalism (note that he is twice as big). However should I take the polluted, cloudy and brown water from the main tank with him? What should I do?    <I would clean the main tank, risk the short term predation>   Also would appreciate it if you could tell me how come he's grown twice the size of my other juveniles and factors affecting growth rate. I mean, by right my other juveniles should be bigger as they have received more attention. I'm afraid once I separate him from the main tank, his growth might be retarded like the other two in the smaller tank.    <Not likely>   Thanks, I hope you can reply as quick as possible as I have seriously no idea what to do now. <As you state... remove the driftwood temporarily and clean the larger system... BobF> Rachel Kam

Re: URGENT: Redclaw Problems 04/30/07 Hey Bob,      I cleaned up the main tank, still a little cloudy but much better. Transferred the larger juveniles (2cm)...2 of them in fact, into the smaller tank (afraid that big daddy Redclaw will eat them once they grow too big to hide in the crevices), while the other two smaller juveniles (one moulted, about 1.5cm while the other still 1cm...about the size when he was released) into a small plastic container. I tried adding in more food but they didn't eat the excess which just clouds the water after awhile. Now that I have 3 separate tanks, how do I clean the water for the juvenile tanks since they have no original 'main tank water'? Is tap water advisable?      Thanks a million for the quick reply! <Please read here: http://www.wetwebmedia.com/FWSubWebIndex/taptrtmnt.htm and the linked files above. RMF>

Freshwater Crayfish eggs  - 12/07/06 Hello Crew! My daughter brought Charlotte (freshwater crayfish) home from school in mid-October 2006.  At that time she had black eggs on her swimmerettes. The eggs have grown and changed to pinkish gray. While waiting for "birth" day, she molted.  What an incredible process to observe!  As per a suggestion somewhere in your site, we left the shell in there for her to eat. <Good> My questions are: Do you think that the eggs will still hatch or will she just eat them too? <They may well hatch... if the parent is hungry... some may be consumed> Should we remove the tail section? <?... no> Thanks for any suggestions that you may have. <You have read here: http://www.wetwebmedia.com/ca/cav1i4/crayfish/crayfish.htm and the linked files at the bottom? Bob Fenner> Red claw lobsters, ID and sexing    11/29/06 hello I'm from Singapore and I've caught 4 lobsters in a reservoir. one is definitely a red claw (it has a red claw), but the other 3 I'm not so sure. how can I find out what species are they? <Mmm, best to seek out in-print books on local livestock, or call folks in your water district (see your water bill re a contact number) here> are they just female red claws? how do I go abt sexing them? <The arrangement of the last pair of thoracic legs and the "pods" (overlapping body "plates"... posted on WWM, the Net> I know its something to do with gonopores, but I cant find them! Rachel Kam <These are not as easy to make out... but the legs and "pods" are indicative... take important roles in placement and maintenance of fertilized eggs. Bob Fenner>

Australian blue crayfish breeding question   9/16/06    Hi, I currently have a 125 gallon tank with 15 gold/blue/moonlight gouramis, 4 rainbows,1 big pleco, 3 Bala sharks, 2 tinfoil barbs, 1 four line catfish, 1 clown loach, 1 black ghost knife, 1 ornate Bichir and a 5 inch Australian blue crayfish. <Hope this last isn't hungry...> The Crayfish has been in the tank since i started about 6 months ago and have added the fish slowly over that time.   Other than the occasional disappearance of new fish <...> everything seems to be in harmony and has been for a few months.  The 5 inch female crayfish is in my 125 gallon tank and i have recently bought a 2 inch male aussy that is currently in my 38 gallon tank.  I have the hopes of one day having them breed. <Can be done>   I know these species get very large and I am assuming I have a large enough tank to give both enough space.  It also has lots of driftwood, ships, tubes, tunnels etc.  The 2 main threats to the small crayfish I imagine are the Bichir and the big crayfish. <Not the Bichir unless it's really much larger> Also just a note that the big crayfish is very well fed lettuce, carrots, peas, algae wafers, shrimp, bloodworms, brine shrimp) and any fish can come near her without much fear, she will just raise her claws and shoo them away.  She is very active but not overly threatening.  So my questions are as follows.  Will the small crayfish grow fast enough to get close to matching the other one in size? <I'd wait till they're closer... and introduce with a barrier twixt for a few weeks... and then release only when you can be present to "supervise", re-separate if necessary> how long might it take? <Likely a few months> If I relocate the Bichir will it be possible for the 2 to get along considering the amount of space and hiding places?  Any suggestions?  Also, last question for curiosity sake.  How long can an Australian blue crayfish live?     Thanks so much, Chad <Please read here: http://www.wetwebmedia.com/FWSubWebIndex/crayfishreprofaq.htm and the linked files above. Bob Fenner> Crayfish Gender Benders, No Breeding Here - 08/26/2006 Dear Sabrina, <Hi, Colin!> I feel like a complete idiot.... <Well, don't.  You're not.> Mavra is actually a male and Vladimir is also a male.   <Heeeheeeeee!  Well, ya win some, ya lose some.> Also Leonid turns out to be a girl.  Leonid is a Clarkii, would she be compatible with Vladimir, <Not for breeding.  Even if they could cross, please don't allow it.> though I might just give up on babies since I can't seem to tell the difference between male and female. <No worries, hon, you'll get there.  And some day the stars will line up for you and you'll have all the appropriate genders and space to make magic happen.> We now have Mavra in the 15 alone and Vladimir and Leonid in their own separate 10 gal. tanks.  They haven't climbed at all and seem happy. <Sounds beautiful.> Thanks again for all of the help  you've given me, <Glad, as always, to be of service to you and your inverts.> Colin <-Sabrina>

Procambarus clarkii Crayfish eggs concern/problem   8/21/06 Dear wet web media, <Colin> I have a slight "concern" about my freshwater Procambarus clarkii Crayfish. Her name is Beatrice, and we have just noticed she is carrying eggs. <Ahhh!> We have had her for about a month and she has never had contact with any of the males we own. As for the eggs, they have just appeared today. <Can produce these w/o a male present... won't be fertile> Is it possible that the eggs are infertile? <Yes> If they are, should we just let her hold on to them? <Yes, I would> This all happened pretty fast and we are excited to see if babies are produced. Crayfish owner, Colin <I worked with this species quite a bit years back... very interesting... and though originally form S.E. U.S., is established here in the wild in S. Ca.. Bob Fenner>

Crayfish Compatibility and Breeding - 08/08/2006 Hello again, <Hello!  Sorry about the delay....> Everything has been going perfectly, the ghost shrimp we got from the store are surviving with the crays, and Mavra has molted again after 17 days. <Awesome!> She is now as close to Vladimir as she will ever be. I think now would be a good chance to attempt to mate them, after giving Mavra a few days to develop her shell. My mother only has one concern, that there will be around 200 baby crayfish that will grow up to become 5+ inches. <Heeeeeeheeeeee!> If there would be triple digit babies, <NOT highly likely.> is there any way to keep the numbers maybe to the double digits? <They will probably limit themselves....  unless conditions are absolutely incredibly entirely perfect for them every step of the way.  And what to do with them?  Friends, family, fish stores, wholesalers!  Fun....> We plan to purchase a new tank, move her into it so she is alone, then after a while, introduce Vladimir, and see what they do. <Don't forget to dim the lights, put on some soft music....> We will keep a spatula handy if they start to fight. Afterwards if they do mate, we would put Vlad back in the 15 gal. tank, which would now be 100% his. I have read that it could be up to a week before the eggs appear and around 3 to 4 weeks for the eggs to develop. I have researched heavily and am trying to get as prepared as possible for this huge event. <How exciting for you!> Crayfish owner and possibly new stepfather,  -Colin <I hope to soon be congratulating you on crayfish babies!  All the best to you, Mavra, and Vladimir,  -Sabrina>

Crayfish mating process   8/6/06 Dear Wet web media crew, <Colin> I have 2 freshwater (Cambarus robustus, one male the other female) and I would like to mate them together, I have set up an extra tank, and had tried to put them in together. <Best to separate with a partition...> The male (Vladimir) is about the same size as the female (Mavra), and seems like he  is trying to mate with her, but she keeps running away from him, <Typical behavior... thank goodness you are/were observant> she had molted, but we gave her a few days to harden her shell. Is there anything I can do to spark a "love" note between them? Their tank is always between 74 and 78 degrees. Any tips on basic mating and breeding would help greatly, because I have read a lot of websites that explains what happens, but not how to get to that happening. Thanks, Colin <Mmm, please read here: http://www.wetwebmedia.com/ca/cav1i4/crayfish/crayfish.htm and the linked files below. Need much more information re your water chemistry, feeding... but you can educate yourself here. Bob Fenner> Crayfish Cambarus robustus Breeding Question, reading    6/28/06 Dear WWM crew, <Colin> I have sent a few emails hoping for a response but have failed to get one. =( <We respond to all (we receive), but do have ongoing issues with our webmail> I do hope you will reply to my email, as i really need your advice. I would like to mate my male Cambarus robustus with a female, but I am not sure about breeding, and google didn't help so much... <Do try Procambarus clarkii... much more common use, experimental model/animal... and nearly identical biology/husbandry> I also tried the forum but it would not allow me to register and gave me an error, so all I have is Email. <Will cc Zo here re WWF> When breeding do the 2 have to be the exact same for lack of a better word.. type. <? Yes to being the same species, no to being the same sex> My male was the only one of it's kind at the pet store and now they only have a kind that is completely different and a lot smaller. Is there any way to find a place that would sell s female robustus? and do you have any breeding tips? <See the above> I have read some websites that say the Male should visit the females tank for mating. <Need space to get together and apart...> Also if you have the time, I would like your opinion on the Crayfish Fry., along with some basic info on them. =D When separating them, would I need a new tank for every single one? That would take alot of tanks and cost alot of money. =O! Thanks for reading, (A.K.A. Colin) <Have you read here: http://www.wetwebmedia.com/ca/cav1i4/crayfish/crayfish.htm and the linked files below? Bob Fenner>


Blue lobsters Hi folks I'm new to this site so forgive me for any indiscretions. <No worries> A friend has asked me to find out.... his blue lobster has eggs on it should he leave it in the tank it shares with an Oscar and Piranha or should he put into another tank that it doesn't normally go in but it has other blue lobsters in? <The females will often give up on the eggs if she is disturbed at all so it is recommended that you leave her where she is.> Thanks for any help. Billy <Youre welcome. Ronni>

Crawfish Caviar I purchased a blue marron <crayfish> about 3 weeks ago. She (I'm assuming - I haven't really looked) She was out and about for the first week then, after her grand escape and recapture, has been in hiding until today. I had to see what was going on since the last one that went into hiding got stuck and died the cave (very smelly situation). Anyway when she finally came out I noticed many eggs attached under the swimmerettes (sort of dark in color) She soon went back into hiding and was very eager to do so. I never noticed any eggs when I got her. What happens now? time line wise. Does she need a male to fertilize the eggs? <Sure. Females usually "berry" from 1 to 3 weeks after mating. If she was with a male before you got her, then there is a chance you will see a hatch. If not, no chance> How long is the whole egg to crayfish process? <A lot of variables. Species, water temp etc.. The eggs will lighten if they are fertile> I haven't had any luck trying to find info. <Google "Crayfish". Tons of info out there. Don> Please help.    Thanks Shari

Crawdaddies  Hi, I need help!! I work at a Nature Center and received a donation (unwanted pet) of a mother craw fish with about 60 babies still clinging to her tail.  <You lucky Dawg, I love those little things, just added 4 to one of my sumps.>  They soon dropped off and began to grow. Mom thought they were tasty and started feasting on them.  <They are tasty.>  She now has a tank of her own. Well, the young one are growing, and range from 1/4 inch to 1 1/2 inches and are still light blue and soft (mom is gorgeous and deep red). The problem is now the babies are eating each other (and they get fed very well! Spoiled in fact) Will this stop when they are grown and have a hard shell? Is it territory? And what does one do with 30 or so young craw fish without 30 or so separate tanks?? Any help would be fantastic! Thank you, Michele  <I wish I had a better answer for you Michele, they are cannibalistic, which really becomes a problem when their shells are soft (young or molting). I would try putting them in as large of a tank as possible with as many nooks, crannies, hidey holes, and a sandy substrate to dig in, feed well, and hope for the best. As for what to do with them... In the words of Hank Sr. "Jambalaya, Crawfish Pie, and File Gumbo" throw in a 6pack of Abita Turbo Dog, some friends, and you've got a party.  http://www.foodnetwork.com/food/recipes/recipe/0,,FOOD_9936_4985,00.html  Or you could try to find homes for them, they make very entertaining pets. Best Regards, Gage> 

Blue lobster (crayfish) My blue lobster (about 6 inches) has repeatedly produced eggs she then carries on her feelers under her tail.  What I would like to know is how to breed her with a male so that these eggs will hatch.  How is the easiest way to distinguish between male and female lobsters? I know that the male has to hard feelers under his tail while the females are all soft....am I correct? And how do they mate?  I understand that it would not be wise to keep to lobsters in a tank together for an extended period of time, but I have plenty of tanks, and only want to get a male to mate with my female.  Please help!!  Thank you in advance. <This one was way beyond me so sorry for the delay I had to do some research. I found a wonderful sight online though great help. Take a look at this http://www.crayfishworld.com/breeding.htm. Good luck, MacL>  

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