These factors would provide an advantage over red swamp crawfish young that hatched at the same time. Recent research suggests that whichever species successfully produces large numbers of babies first during autumn months will predominate in the pond for the rest of the season. Much information is lacking, however, regarding interactions of these two species. These two species are often similar in appearance, especially at a young age. They can be easily identified, however, by experienced persons.
Despite efforts to exclude white river crawfish from many farms, both species will thrive under routine culture practices, and they often coexist in production ponds. No evidence exists of natural hybrids between these two species. Several books provide an excellent overview of the anatomy and biology of these and other crawfish species.
Both species, however, possess a number of traits that are usually associated with animals that live in warm waters. These species are short-lived 2 years or less , have high juvenile survival and can alternate between reproductively active and inactive forms.
Moreover, P. These crawfishes have life cycles that are well-adapted to farm production strategies Figure 1. Mature animals mate in open water where sperm is stored in a special receptacle, after which the female retreats to a burrow to eventually spawn.
Females carrying eggs or hatchlings are highly susceptible to predators, because they cannot use their normal tail-flipping escape response.
Crawfish of all ages and sizes, whether mature or immature and male or female, will dig or retreat to burrows to survive periods of dewatering. Crawfish ponds are usually drained during the summer months to allow for planting and growth of vegetation.
Prior to draining, some mature crawfish burrow near the waterline. As the water level drops, additional crawfish burrows appear lower on the levee and are sometimes found on the pond bottom; however, the burrows on the pond floor often contain a high percentage of non-reproductive crawfish, such as males and immature juveniles.
Ovarian egg development in mature females is temperature dependent, usually beginning prior to burrowing and reaching completion within the burrow.
Developing eggs within the ovary become rounded, increase in size, and change from a light color to dark as they mature. At maturity, the large black eggs are shed from between the walking legs, are fertilised externally and are then attached to the swimmerets on the underside of the tail with an adhesive substance called glair.
Although crawfish can survive in high humidity within the burrow, some standing water is necessary for successful reproduction. The number of eggs laid varies with female size and condition, but large red swamp or white river crawfish females can have more than eggs. The hatching period depends on temperature and usually takes about 3 weeks. Hatchlings instinctively remain with the female for several weeks after their second molt although they are no longer attached. It is critical that the female and her young leave the burrow within a reasonable time because little food is available in burrows.
When conditions force the crawfish to remain in the burrow, increased mortality can occur. Pond flooding or heavy rainfall is usually necessary to encourage female crawfish to emerge from their burrows. Females emerge with their young or sometimes with eggs attached to their tails Figure 3 , and advanced hatchlings are quickly separated from their mother as she moves about in the open water. Because reproduction is somewhat synchronised in pond-reared crawfish, ponds are routinely flooded in autumn to coincide with the main period of reproduction.
White river crawfish are autumn and winter spawners, but red swamp craw fish reproduction may occur at any time. Extended reproduction and differential growth typically result in a population of mixed sizes in most ponds.
As with all crustaceans, a crawfish must molt or shed its hard exoskeleton to increase in size. Frequent molting and rapid growth occur in production ponds when conditions are suitable. Growth rate is affected by a number of variables, including water temperature, population density, oxygen levels, food quality and quantity, and to a lesser extent by genetic influences.
We had worked with her on Monday so we have a pretty good indicator when the eggs were laid. Today, Thursday, we came to school to find another mama putting eggs under her tail. Pretty fascinating We have them in tubs so the kids can see them and work with them. We move them to a separate basin to feed them except for elodea in their containers. I have separated the mothers.
How often should I feed them? Will the babies be okay in the basins as long as I put in homes and things for them to hide under??? The sad part is we will probably be out of school before any of them hatch. They should be fed every day, but you will always need to searched for any food they have hidden during the weekly water changes and cleaning. We have a blue crayfish and we are getting ready to move, we have planned on rehomeing things out of our 30 Gallon tank. It is a big move..
A good rule of thumb is that a crayfish will try to eat anything that it shares a tank with — be it plant or animal. I hope this helps. We have three freshwaters and I wanted to confirm that this is indeed true — I hand feed them all! Hey my blue crawfish had no then mate and all of a sudden it had a sack of eggs weeks pasted and it buried the eggs after that the eggs turn pink?
And the crawfish died what do I do with the pink eggs? This is especially true since they were discarded by the female. However, on the off chance that some might still hatch, the only thing to do in this situation is to keep the aquarium water clean, and watch and wait.
When I bought my blue crawfish, it was alone in a tank with a lot of tropical fish. Months had past since I had him and all of a sudden my blue crawfish had a black sack of eggs. The tank I had my crawfish was a 15 gallon, with two neon tetras. So my crawfish ended up burying the eggs after a while the eggs stated to turn pink, my crawfish ended up dying a few weeks later, but the pink eggs are still there what should I do?
I have a really ill crayfish she is beautiful but has been itching like mad the last week and running around the tank like she is trying to climb out. Is there any medication I can add?
It sounds more like there is a problem with your water. Have you tested your water parameters lately? I would experimentally do several large water changes over the next few days to see if that helps, and I would definitely get your water tested. I would also search your tank to see if there is anything rotting in there. And crayfish are also known to hoard food, so during the next water change, search to see if there are any hidden stashes of food.
You need to add ornaments and caves for them to hide in. Soo hi I find this page very helpful since just yesterday I decided to raise one when my father caught one! I have a few questions to ask too: If I place some live worms with the crayfish will the crayfish go for it??? I only have a small circle container with one crayfish in it, plus the rocks so it can breath. Any advice?? You definitely need something much larger to keep it in.
I would recommend any type of non-toxic container until you find a more suitable home for your crayfish. They actually prefer vegetables and maybe consider the worms as more of a weekly treat. Crayfish can actually survive fully submerged in water, but you should add an air stone, or sponge filter if you can afford it.
So thanks for the advice! Is this okay for the crayfish, since I had read that leaving shells in the same place as a crayfish can be bad for it. Also, since the shell sticks out of the water, the crayfish fully submerges from the water when it chooses to climb on top of the shell. Is that bad? And if i wash the live worm with water, will that wash off the pesticides and insecticides? Thanks so much for you time and patience!
But keep up with the vegetables. Just make sure to remove any uneaten vegetables after 24 hours or it will start to rot. Where did you hear that? The concern comes from collecting them outside in an area that may have been recently sprayed. So thanks! I apologize for waking you up early again at12 am! I feel a little better now. Every night I hear the scratching sounds of the crayfish at night. And my father uses minnow fish I believe for his bait, and yesterday one of his died, so I tried feeding my crayfish that and he gobbled it all up!
Is it alright if I feed him one most days of the week? Because the whole container becomes foggy and dirty. After a few weeks of observation, I notice my crayfish do a funny thing.
You know those leg things on the bottom of her large tail? As much as it amuses me watching her do that, I would love to know if you know why. We are deep in crawfish boil country, and our female red North American crayfish was a rescue 3 weeks ago from a big annual crawfish boil we always attend. Our sons 8 and 11 wanted to keep her, so she remained on the table while we ate, then went home in a tupperware container.
That was 3 weeks ago. Very cool. I had no idea a seasonal foodstuff could be such a good pet. Do you know what it means when our crawfish approaches and waves all of her maxilla, or when she seems to do a little dance involving all of her legs?
Sometimes she does both at once. What is this? The water is changed every day we use water conditioning drops. Is this too often? Is this enough space? If she still needs to molt at full size, do they still molt? Would it be unhealthy to let her run around on the floor for a few minutes during water changes?
Thanks so much for hosting this site and sharing your knowledge. But you do see it in nearly all species of crayfish though only very rarely in the dwarf crayfish for some reason. As for your aquarium for your crayfish, it is definitely too small at this point. For a crayfish that large you should probably have around a gallon tank, and it should be filtered.
I like to use sponge filters since they are both cheap and excellent aerators. When transitioning from air to water, they should be placed in water no higher than their head for a few hours a bucket works for this. After that, they can be added back to the aquarium, but they should be held upside down to allow any air bubbles trapped in their gills to become dislodged. Hi Robert! As a follow-up, our crayfish has been doing well.
She had eggs, but gradually they all fell off. My question is: Research tells me she should completely molt during a hr period. This crawfish has been molting for 4 days. Does she need outside help to free it? Or should we leave her alone? Sometimes crayfish have a rough molt, but you should definitely leave her alone.
You might want to try adding some iodine to the water in the future. It helps with the molts, and you can get marine iodine to add — though you should only add it at about half the recommend strength.
There will be a next time; she was a fantastically interesting and engaging pet. She died overnight. Thank you so, so much for your advice and help. This board has been amazing. Have learned so much. Keeping a crawfish was a great experience. I have an electric blue with eggs that started out brown, but turned orange within a week or so. They will have been there for one month tomorrow.
Is this normal? You can safely remove them at this point if she drops them. Otherwise just wait until she does, or she eats them. The eggs tend to die one by one, so it takes a while before they start to fall off.
They usually start falling off one at a time. We just acquired a crayfish…not sure what breed. We have a small gallon tank, no filter yet and there is just a little bit of water…I assume for ease of transport. My question is how much water should I put in the tank and how often does it need to be cleaned, what kind of water tap? Can I feed it corn until I get other food? I am really clueless how to keep this little guy. You can fill the tank up to almost to the rim with no problem. As for the filter, the cheapest choice is usually a sponge filter and pump, which you can normally get for around 15 dollars.
It requires very little maintenance, and lasts for a very long time. All you have to do is squeeze it to clean it during weekly water changes. The water can be tap water, but it should always be treated to remove any chlorine. You can buy bottles of water conditioner from any fish or pet store in your area. The crayfish may eat corn, but you should stick to lightly boiled vegetables like zucchini, cucumbers, broccoli, and romaine lettuce.
You can also pick up shrimp or invertebrate pellets from a fish store, and just offer vegetables as an occasional treat.
This is usually the easier option, and shrimp pellets are very cheap. The one we have is a plastic reptile tank. Also, is putting gravel down a good idea? Thanks again. Please help whoever knows. I work at a pet store and one of the blue lobsters has something going on with it. Is she pregnant? Or was she pregnant and the babies are dead? Is she sick? I have no idea. Also, if they are babies. Should I isolate her from the other? Need all the suggestions I could get.
Thank all!!!! It sounds like the eggs have turned, but otherwise the female still sounds alright. If by some chance they have hatched by now sorry about the delay in response, I was on vacation , then they should be isolated as soon as possible. We have had a crayfish now pregnant for over 3 months! What is happening and when will they hatch?
Nothing seems wrong and the female looks happy enough…. What colour are the eggs? Usually a crayfish only carries the eggs for about a month or so. Healthy eggs should be a purplish black colour almost. That is correct, nice almost blackish colour and all looks healthy. What species of crayfish is it? Hi robert, I have a white crawfish which molted approx 1 wk after purchase expected , but, it then molted again within 2 wks!
How large is your crayfish? It may just be that your crayfish is getting a lot of food and has very good conditions. Crayfish molt to grow their body, and if they have an excellent food source, they may grow quicker. Just make sure to leave the discarded exoskeleton in the tank for the crayfish to consume. He appears to be young. Is in 37gal tank with a red and a blue female. The 2 females have molted only once, and we can see the growth. However cannot see much of growth in male even after 2 molts.
They were all almost same size when purchases. Purchased white male and blue female 1st; male use to move around bottom of tank. Then purchased red female. Since then, male usually hangs out on plant n away from bottom of tank even though there are many hiding spots. It always sucks losing a crayfish.
Hi my son got a crayfish from his teacher just before the end of school. It lasted till the end of July. I think it died because it was out of water for a long period of time and also got hurt.
It had escaped during the night and my son found it in the morning when he was about to feed it underneath the china in the dining room. It was the second time it escaped but the first time from a 5 gln tank and it had grown.
We quickly placed it back in the 15 gln tank and watched it during the day. During the afternoon, we noticed it went close to the hanging filter and started its way up the wall. I think it has a damaged claw because it took off its left claw. It stood around around after that just looking as if was sitting on its curled tail but we saw movement so thought it was sleeping. The next day, it was in the same position but not moving, my wife went to check on it by reaching for it but did not move and was stiff.
Not sure if I should get another one for my son. It was not his fault it died, it just escaped and fell four feet to the ground then crawled under the china with a bad claw. The first thing to do is to cover your aquarium with a fish tank cover since they will always try to escape.
One thing to be aware of though is that when you put the crayfish back in, you need to put it in upside down so any bubbles can be purged from their gills. I personally would always recommend these pets, though they are somewhat shortlived. I have a 90g pond with 10goldfish. I have noticed crayfish in the pond that have a blue color.
I have one that got in there, not sure how as it was covered with a net. We thought maybe a owl dropped one and it fell in the pond. These do fine with my goldfish and the frost crayfish was in there for 2years. Any help is appreciated. Crayfish are known to travel long distances over land, and if you have any streams or ponds nearby, they may be coming from those.
So we separate her quickly into 10 gallon fish tank. The mom still alive and we put it back to big fish tank while the babies left here in 10 gallon fish tank. The babies separately hiding into gravel. I smashed moms food and feed it into babies. Am I doing it right?
And one thing, is my guppies safe from that mother crayfish? Just keep on top of the water changes, and continue to offer them easily consumable foods, and the babies should be good. You will eventually start to face some cannibalism among the babies though, so depending on how many you want to keep, you might want to start separating them into other tanks.
And as for the guppies, in my experience nearly every species of crayfish will attempt to eat the fish they share an aquarium with.
Eventually it will likely start to pick off some of your fish. So I just got crayfish the other day from the river down the road. The thing is one is female one is male I figured that two males would be more territorial. The male was aggressive but then the female molted and is now much bigger than the male. Will she want revenge and eat him after he molted? How large is your tank?
As long as you provide numerous caves and other places to hide, it should be alright. A crayfish is smart enough to know to hide when its molting, but if you have a very small tank, it may be discovered. It can take a crayfish a while to adjust to its new habitat. However, just to be on the safe side, I would check your water quality, and try offering it a few different foods types, like maybe shrimp pellets, or some frozen food like brine shrimp or blood worms.
Hey, I got a few questions this time. I just cleaned my community tank and was a bit surprised to find 5 baby crays in it! I knew I had a male and a female, but I thought she had killed and eaten him during one of his molts.
Most of the babies seem to be in colors of blue too. Is this odd? The babies are several different sizes ranging from just under and inch to over 1. The rest are all back in the community tank. Will they all be okay in there? I do throw more plants in occasionally between cleanings and I grow water lettice in my outdoor pond to bring in.
All occupants seem to enjoy eating that. Will it be too crowded for the babies to stay? I know the crays have been getting some of those too. Should I be getting more minnows? Am I providing enough food? Unfortunately, it sounds like that tank is really overstocked and with fish that have really different needs. Goldfish prefer cold water, and depending on the species of catfish, most of the other fish like tropical temperatures in their tank.
Also, turtles produce incredible amounts of waste, and it would be hard to keep that size of tank clean just for the turtle unless you have one of the smaller musk turtles, which are great pets by the way. But just keep in mind the crayfish will always be trying to eat the fish as they grow, and the fish will try to eat the crayfish during molts. My tank has been like this for years, water quality is really good and all inhabitants get along well.
We got him newly hatched from a nest in the backyard. He may have eaten some of the babies, but that was hardly unexpected. You are correct about the goldfish preferring colder water, but they started out as tiny feeders for sheldon and they got big before he got around to eating them.
I did ate all but 2 goldfish out and put them in the outdoor pond. Both sets of goldfish seem to be doing well enough and everything else is a warmer water fish so I keep the tank at about 76 degrees. With double filtration and a full ecosystem setup I rarely even get algae growth in my tank and only pull it apart to clean it 2 times a year. The fish clean up after the turtle, the crays and catfish clean up after them and the plants do the rest. I was just giving a suggestion though for the future.
So seeing as how I am not having water quality problems, and nobody seems to be eating anyone not intended to be eaten, will 6 crays be ok in that tank? I have friends and even a local pet store interested in taking them once they are 1. Any idea if they will stay blue? Also worried that dad will breed with his daughters once they get past the inch size.
Will they do that? I would try to rehome at least a few of them if possible. And crayfish turning blue is a mystery as far as I know. It seems once they turn blue, they will remain that way as long as they remain in the same conditions.
Hi Robert. Thanks for this awesome site. Until recently I had 2 blue crayfish. Anyway, the problem I have is one has gone missing and the other has eggs under her tail! What do you recommend I do? And the hatchlings themselves become cannibalistic as they age, so that will reduce the numbers even further. After they hatch and are free swimming, the mother should then be removed too. The good news is there is generally a lot of demand for blue crayfish You can sell them on local fish forums, trade them for credit at fish stores and if that fails, you can usually give them away.
And as for the male, in my experience they tend to disappear when the female becomes egg laden. But take that advice with a grain of salt, and it may have been eaten during a molt or pulled a houdini on you. I feel your pain with the pleco too. When I first starting keeping crayfish, I lost a lot of fish trying to find tankmates for them.
I even had a friend who lost an adult arowana to a crayfish. I have no idea how that happened. I eventually went with crayfish only tanks, as it seems to be the least trouble that way. Robert, Thanks for replying. Unfortunately we found the missing male crayfish earlier this evening after my dog was sniffing around underneath the tv cabinet. There he was behind some wires on his back. Poor thing has passed away, although I currently have him half submerged in a bowl of warmish water.
Ah well, at least the female is still around. I might keep a couple back but will see how it goes. The eggs usually hatch after around a month, and then your tank will be swarming with little hatchlings. Also Know, can crayfish regrow limbs? Yes they grow back , It may seem cruel but clipping off the "thumb" portion of the claw will make them much safer to keep with fish, they grow back also during moults.
Development of sensory processes during limb regeneration in adult crayfish. During the regeneration of a limb, new sensory neurons develop within the limb, and their axons must then grow into the ganglionic root to make the appropriate connections for the new limb to become functional. Asked by: Timoteo Mossner asked in category: General Last Updated: 13th March, How long does it take for a crayfish to regenerate?
Crayfish , and other crustaceans, have the capacity to regenerate antennae Harrison et al. Do crayfish feel pain? The researchers' previous work also found that hermit crabs and prawns exhibited similar pain-avoidance behaviors indicative of sentience and feeling. Like lobsters, crabs, and crayfish, other marine animals feel pain.
In fact, fish are similar to dogs and cats in their experience of pain and pleasure. Do crayfish pincers grow back? Yes it will.
When the crayfish molts next A small claw will come back, then as he continues to molt it will grow back to normal size. How many times do crayfish molt? Crayfish molt because they must shed their hard exoskeletons and grow new, larger ones as their size increases. In the classroom they are used by biology teachers to demonstrate evolution and cloning in a current, real-world environment.
Some aquarium hobbyists now use the marbled crayfish as a self-replicating source of feeders for carnivorous fishes of all sizes. Sport fishermen are raising colonies for use as bait, particularly for saltwater fishing, and it is even rumored that this species is being farmed by the Chinese government for use as a source of cheap food for humans!
They grow very quickly to adulthood, usually around 3 to 5 inches 8 to 12 cm , at which point they can start to reproduce. From the time a baby hatches, it takes about 5 to 7 months for the crayfish to have babies of its own. Each of these female crayfish is capable of holding to eggs each time, with incubation periods between 22 and 42 days.
The younger adults have a smaller number of babies, with brood size increasing as they age. Apparently the mothers do not eat their young as most crayfish do, and they can occupy the same aquarium together with very little cannibalism.
Still, the young ones sometimes overtake a sibling in a power play. Like other crayfish species, they grow by molting, or literally crawling out of their shell.
Being efficient creatures, they will eat their discarded exoskeleton. There are now videos online showing the various stages of a marbled crayfish being berried see the Resources section at the end of this article. An Internet search on the marbled crayfish will turn up a number of articles from the British press that feature frantic horror stories about this animal taking over ecosystems in Europe.
While the marbled crayfish was discovered in Germany, it is considered an American animal. Hysterical, sensational hype found in British articles—in scientific journals and the tabloid press—also claim that this species carries a virus or fungal plague that can kill crayfish species exclusive to European rivers and lakes. However, biologists in the United States tend to downplay these stories, as no outbreak has actually been recorded in Europe or elsewhere.
To date, marbled crayfish are legal to keep in the U. The diet of the marbled crayfish is mainly vegetarian, and it will eat most live plants found in aquariums, particularly Anacharis and Cabomba.
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