breeding crayfish

[BEVUP]

Ok didnt read all

but reminds me of my younger days when you would visit someones farm in the country ( talking Yabbies ) & there are other names, all there is is a pond for the cattle or sheep to feed so igues they are eating the odd dead one stuck in the mud & they are territorial

Oh i think their canibals as well

[canuckamuck]

I would love to know how they keep the yabbies from wandering away.

[wolfrunes]

@canuckamuck

My guess is your water temperature.. 11 to 15 degrees seems to be a littlr too low for them. It's like putting the whole lot into a harsh environment... Not all will die outright but only the fittest will be left standing in the end and will either manage to adapt or die off in the end too?

Just my humble opinion.. Have not any hands on experience yet.

[crayfish]

Canuckamuck>>> Hope everything is well with your crays and the problem has passed. If you have anymore deaths it is worth disecting the body and have a look inside, especially the stomach and gills. taking a close up picture and then enlarging it on a computer will allow you to see in fine detail. If the gills are red and swollen, or locked together then the problem is from the water or something in the water. If the stomach looks green then the problem is in food line, or a toxic intake. I posted a video on an earlier post about the anatomy of crayfish, worth looking at. It can also be found on youtube under "crayfish anatomy part 1, and crayfish anatomy part 2".

I would like to ask you something that even I think sounds stupid, but are you 100% sure that what you think are dead crays are maybe exoskeletons Did the dead crays you found have meat on them? The reason I ask this is that it is not easy to tell the difference between a dead cray and an exoskeleton. You can see an exoskeleton pic I posted a few days ago. It looks like a dead cray.

Just a stupid thought.

I wish you luck with the others and hope you have no more deaths.

[canuckamuck]

Hi Crayfish, I will have a look at the video. The crayfish seem quite happy these days, so no answer to my mystery. Very possible the cold weakened them too much Some the dead crays, found there way to BBQ, not me, my wife's family will eat anything. Anyhow, they were more than exoskeletons for sure.

Once again thanks for all your help, it is an interesting experiment so far.

[crayfish]

Hi. Inline with breeding crays I am setting up an aquaponics system with the big raceway tank. I have been studying the syatem for the last week and am fascinated by how it works. It really is very simple to construct and operate. Basically all that is happening is the waste ( excrement ) from the crays feeds plants and in turn the plants feed the crays. In order to make this work you first need to construct a bell syphon, I started building one yesterday and it is now running, I call it magic and everyone else calls it science. Here are the instructions for construction and operation. About 300 baht investment. syphon.pdf . I will post some pics of it working with the raceway tank on Monday. I am going to cut the outlet pipe from the raceway tank and split it in two, one pipe feeding the column filter, as it is doing now, and the other feeding the grow bed. I have read that food grows 4 times faster in this system than it does in the ground, plus it is 100% organic.

I have more or less completed phase one with the crays, which is the nursery. I am going to continue with phase two, which is growing them out to 100 grams.

This I can do around my house. I think I can handle about 600. I am not sure about phase three. I have the land and a large pond which is ideal for the final grow out but it is 3 kilometers from my house with no one to guard it. Phase three is where the most money is made, but as I have said in an early posting, I am not really in this for making big money, I am really enjoying it and maybe if it gets too big I may loose interest with the extra stress involved.It feels good just to keep it at a self sufficient level, and a small income.

The crays are all doing well. The new borns must be eating well as they are exerting a lot of energy swimming around the tank. The other females' eggs have yet to hatch out. Coming soon.

have a nice weekend

Crayfish

[weedywhaoo]

Crayfish,

Thank you for the pdf-file. I am eager to see the pictures of your set up on Monday. I hope it

works out good for you. What vegetables are you planning to grow?

[crayfish]

After a very busy weekend I managed to get together a simple aquaponic system up and running . I have cut the outlet pipe from the pump to the column filter and fitted a "T" section, added a vertical pipe which feeds the grow bed. I have also added a valve on this pipe and on the pipe running to the column filter.

This pic shows water flowing into the growbed. It takes 4 minutes to fill the bed and 40 seconds to empty.

This pic shows the bell syphon. One modification I will make is the diameter of the gravel guard, (the outer part). When constructing the syphon system it is important to have the bell pipe twice the diameter of the stand pipe. The gravel guard can be any size. The one I have made is too small as I can't get my hands in to remove any gravel that gets trapped inside, It is also difficult to remove the bell pipe. As you can see from the pic I have tied a piece of wire to the top of the bell pipe so I can easily remove it if necessary, haven't had to do so far. This system has been running continuosly since Saturday midday with no problems. If constructed correctly it is maintenance free and requires no motor or electricity as it has no moving parts apart from air and water. Really magic and great to watch.

This pic shows an overflow pipe. I added this incase there are any problems and the grow bed overflows. Without this an overflow would empty the fish tank and create problems with the pump.

This pic shows the two valves. The one on the feed pipe to the grow bed is fully open and the one on the pipe to the column filter is 90% open, so 90% of the water from the tank is reaching the column filter and has made no noticeable difference to the return flow.

This pic shows the water returning to the tank from the growbed. This is coming with good force and is supplying the tank water with a lot of oxygen as well as helping the water circulate around the tank.

This pic shows some plants I have planted. They seem to be doing well, they have been in there since Saturday afternoon. What I have put together here is just an experiment to see how it works. It is looking promising at the moment but I want to wait a week or so before I expand on it. I like the idea of growing vegetables such as cucumbers and marrow as they can be grown outside the growbed on straw with their roots in the water. Today I will buy some seeds and put them in some cotton wool and place them just above the full water level in the grow bed. The full water level is about 1 inch below the stones. This stops algae from forming and also keeps the water cool. I bought the stones from a garden center, they are light weight and do not get hot with the sun.

I really am excited with this. The crays feed the plants and the plants feed the crays, amazing.

I am getting some interesting reactions from the villagers, even when they look at the plants growing they say it is not possible to grow them without soil, I tell them just wait and see.

Finally a pic of one of the new borns Still have no idea how many there are but they are all doing well, no losses so far. They are living mainly on plankton and mosquito larvae. I am using one of the spare concrete columns and breeding mosquitoes. Before they leave the water I net them , dry them in the sun and feed to the baby crays, good protein.

[canuckamuck]

I am quite confident now that cold is the issue for my crays. The return of colder nights has resumed the death toll. I am down to three now. Water has been dipping to 10 degrees.

I also had a leaky drain in the neighboring tank, and I needed to move 200 Tabtim over to the raceway, so I could make a repair So the crays have now been evicted and relocated in a 1 meter concrete ring used for watering the garden. Who knows, they might like it better, if they survive the week that is.

Obviously I am now having doubts about the viability of breeding crayfish here. There is about 6 weeks where the water can be too cold for them. How to winter them will be the trick for me.

[ozzydom]

I am quite confident now that cold is the issue for my crays. The return of colder nights has resumed the death toll. I am down to three now. Water has been dipping to 10 degrees.

I also had a leaky drain in the neighboring tank, and I needed to move 200 Tabtim over to the raceway, so I could make a repair So the crays have now been evicted and relocated in a 1 meter concrete ring used for watering the garden. Who knows, they might like it better, if they survive the week that is.

Obviously I am now having doubts about the viability of breeding crayfish here. There is about 6 weeks where the water can be too cold for them. How to winter them will be the trick for me.

Maybe the scale of trying to breed the crays on a hobby basis is part of the problem,

If they were in a larger tank /pond the water temp daily variation is minimal and very slow to alter,its like a puddle freezing over in a frost whereas a pond normally doesnt.

[canuckamuck]

I am quite confident now that cold is the issue for my crays. The return of colder nights has resumed the death toll. I am down to three now. Water has been dipping to 10 degrees.

I also had a leaky drain in the neighboring tank, and I needed to move 200 Tabtim over to the raceway, so I could make a repair So the crays have now been evicted and relocated in a 1 meter concrete ring used for watering the garden. Who knows, they might like it better, if they survive the week that is.

Obviously I am now having doubts about the viability of breeding crayfish here. There is about 6 weeks where the water can be too cold for them. How to winter them will be the trick for me.

Maybe the scale of trying to breed the crays on a hobby basis is part of the problem,

If they were in a larger tank /pond the water temp daily variation is minimal and very slow to alter,its like a puddle freezing over in a frost whereas a pond normally doesnt.

Good thinking. It would be fairly easy for me to make a winter pond for crays. I think while there is still cold nights I should monitor the morning temperature difference between our pond and the tanks. 2 - 3 degrees would be enough. Thanks for that.

[weedywhaoo]

If your tank isn't too big, a heater could be used. I had a jacuzzi before in Pattaya andthe heater worked fine during the cold months. Something similar could be used.

Sent from my GT-I9300 using Thaivisa Connect Thailand mobile app

[teletiger]

I heat up an 800 litre concrete ring. It takes 2 x 400 watt heaters. Keeps the water to 24c minimum. Before the heaters it was dipping to 18/19c.

Regards.

[canman]

Possibly a simple solar heater using a small pump and black PVC pipe would be enough to get the water temp up during the day enough so that it would not dip to the 'kill' temp at night.

[crayfish]

Hi Canuckamuck>>> You're really not having much luck starting out on this venture. I have to agree with you that the problem is the cold.I have spent all morning searching websites for ideas. There are two issues to look at here, one, how to heat the water. Two, how to stop the heat escaping from the tank. There are several ways to heat the water. You can insert probes into the water that are heated with electricity, This would need to be controlled with thermostats that keep control over the temperature. I would imaging this setup would be expensive and consume a lot of electricity. Not a system I would choose.

Another way would be to run the water from the tank to the column filter through black plastic plumbing pipes which can be zizzagged to make a longer pipeline. You will be amazed how much heat can be generated during the day just from the sun. A bypass pipe and valve can be installed in line to divert the water directly to the column filter if the water gets too hot.

Solar power can be used simply by using mirrors to reflect sunlight to the water in the column filter.

Which ever method is used the heat needs to be kept in the water. The entire tank can be wrapped in roofing insulation material, it can be bought a any good building merchant and is called rockwool.It comes in rolls about 2 meters wide. The top of the tank needs to be covered at night to prevent heat rising. You can see how I have covered mine, on a cold night I just put a vinyl sheet over the top. Two days ago the morning air temperature was 15.7 and the water temperature in the big raceway tank was 21.5. Quite a big difference. I dont use a heater but I insulate the tank by covering it. Where I live the temperature doesn't drop as far as it does where you are.

I would have thought you have the same problem with the Taptim fish, they are native of a warm country!!!

I hope you find a solution to the problem and continue with the venture.

While the temperature is cold at the moment why not put them in a plastic bucket at night time and put it in your house.

Good luck

Crayfish

[crayfish]

Hi. Just a couple of pics showing another experiment I am doing. I constructed a framework from plastic plumbing pipes and tied a plastic mesh to it. Through the mesh I have put plants with their roots dangling in the water. Been there 2 days and are looking good. They have plenty of manure to consume.

Have a nice weekend

Crayfish

[canuckamuck]

Hi guys thanks again for the advice. If I am in a situation next year where I am wintering some crays, I will definitely be putting some of these ideas to use.

A tank dug in to the ground, with some form of solar heating for December January would likely be my plan. We are probably looking at about 6 - 10,000 liters so I doubt any electrical option would be considered.

As far as this particular round is concerned, we are down to 2 crays, the water was 10 again this morning. Perhaps I will give them a bucket in the house to live in at night for the next two weeks. If they survive they deserve to carry on. Must be some tough genes in those two.

[crayfish]

I had an unexpected surprise last night with one of the two females still holding eggs. I watched them in the afternoon and they were both still with eggs. This worried me somewhat as it has been about 9 weeks since they laid the eggs and they should have hatched by now. I decided to photograph the eggs to check what condition they were in, check if there was any sign of fungus. When I looked at them on the computer I was surprised to see that one female's eggs were in the stage of hatching.. This morning I could see they had all hatched out and clinging to their mother. The other female didn't come back out so I will check her today. I think the prolonged hatching is due to the cold weather. I am not going to separate them from their mother as I did with the first hatchings because they may attach themselves to the other female still with eggs, this may create problems.

The newborns in the small aquarium tank are growing well although at different stages. Some are the same size as they were born while others are three times the size. I suppose it is survival of the fittest, although I haven't seen and losses yet. They are eating plankton and crumbs I saved from the crayfish food I have made over the past 6 months.

I tried catching the Tilapia in the big raceway tankyesterday but gave up after a couple of hours. They are very fast swimmers and impossible to net. I need to make a trap. I want them out of the tank as there are two females and two male crays in there and I worry if the crays are with eggs that the Tilapia will eat the eggs. I am designing an aquaponic setup similar to this pic but will modify it. I want to use bell syphons instead of sloping growbeds as in the diagram. It is a simple setup and reasonably easy to construct, although I will use metal instead of wood for the framework. I'm not sure about putting the fish tank underground, good for controlling the temperature but not easy to drain. Will update as I go along with the project.

Canuckamuck>>> Happy to hear you haven't given up on the idea of breeding crays. What sex are the remaining two crays??? I have a randy male which you can have if you need a male.

[canuckamuck]

I have one of each at the moment. I will restock later, when it warms up. Currently I am fixing a tank so I can get the fish out of the pond. So no room for crays for a while anyhow.

[emiubon]

I had an unexpected surprise last night with one of the two females still holding eggs. I watched them in the afternoon and they were both still with eggs. This worried me somewhat as it has been about 9 weeks since they laid the eggs and they should have hatched by now. I decided to photograph the eggs to check what condition they were in, check if there was any sign of fungus. When I looked at them on the computer I was surprised to see that one female's eggs were in the stage of hatching.DSC05924.JPG. This morning I could see they had all hatched out and clinging to their mother. The other female didn't come back out so I will check her today. I think the prolonged hatching is due to the cold weather. I am not going to separate them from their mother as I did with the first hatchings because they may attach themselves to the other female still with eggs, this may create problems.

The newborns in the small aquarium tank are growing well although at different stages. Some are the same size as they were born while others are three times the size. I suppose it is survival of the fittest, although I haven't seen and losses yet. They are eating plankton and crumbs I saved from the crayfish food I have made over the past 6 months.

I tried catching the Tilapia in the big raceway tankyesterday but gave up after a couple of hours. They are very fast swimmers and impossible to net. I need to make a trap. I want them out of the tank as there are two females and two male crays in there and I worry if the crays are with eggs that the Tilapia will eat the eggs. I am designing an aquaponic setup similar to this picaquaponics.jpg but will modify it. I want to use bell syphons instead of sloping growbeds as in the diagram. It is a simple setup and reasonably easy to construct, although I will use metal instead of wood for the framework. I'm not sure about putting the fish tank underground, good for controlling the temperature but not easy to drain. Will update as I go along with the project.

Canuckamuck>>> Happy to hear you haven't given up on the idea of breeding crays. What sex are the remaining two crays??? I have a randy male which you can have if you need a male.

The Aquaponic setup look like the one thy have in Milwaukee, search for Aquaphonic Milwaukee in youtube there is a couple of documentary

[crayfish]

Try this one

http://issuu.com/msiles/docs/ponce-marhan__et_al._2005

[crayfish]

Hi Just an update on the crayfish situation. Everything is running very well. The small aquarium tank has about 150 craylings. The female I took out ,and the craylings are surviving on their own. They seem to grow at different rates, some are much the same size as when they were born while others are much bigger. I will put them in the small raceway tank in about 6 weeks. The big aquarium tank has two big females. The eggs have hatched out and there are up to 400 craylings in there. Again all of different sizes. All the craylings are eating a variety of food including mosquito larve, plankton, insects and food I have made which is vegetables and fish ground and pelletized. The two females I will put in the big raceway tank soon and leave the craylings on their own. The big raceway tank at the moment has two big females and two big males, ten smaller crays which I'm not sure how many are males or females, I never see them all at the same time. There are also 100 tilapia fish in there. They are growing fast and are contributing to the aquaponic system well. There doesn't seem to be any problems with keeping them with the crays. They have their own territory in the tank as do the crays.

Because everything is running well with the crays I have been concentrating my time and effort in aquaponics. First I set up the flood and drain system which works with a bell syphon. The plants were doing well but not as well as the plants I put in the raceway tank which is a continuous flow system. The problem with putting the plants in the raceway tank is that it restricts the flow of water in the tank, the roots get very long. Last weekend I constructed another continious flow system using plastic pipes.as you can see from the pics I have built a wood frame and put four 3 inch pipes side by side. I split the outlet pipe to the column filter and run the water from the tank to the pipes. The tank now has two filter systems, one with the plants and the other with the column filter. At nighttime I switch the pipe system off and use the column filter.

Here is a pic showing the overflow drain in the pipes. and a pic showing the plant pot on place with a layer of clay balls in the bottom..

This pic shows the valve setup. Each pipe has it's own valve to regulate the flow so they are all even.

This pic shows the underneath of the system with the overflow pipes running down to the 3 inch pipe taking the water back to the tank.

Except for the valves I have not glued anything together, there isn't a lot of pressure in the system and I may need to modify it later. One thing I wish I had done is used 4 inch piped instead of 3 inch. It would allow more room for the roots to grow and not block the water flow. This weekend I may build another floor of pipes above or below these pipes and connect them together. I have taken most of the plants from the raceway tank and put them in the pipe system. They have only been there two days but have not wilted and look O.K.

The investment for this set up is just over a thousand baht and well worth the investment when you think of the long term rewards.

[crayfish]

Hi. Breeding crayfish is a three phase operation. Phase one is producing eggs, hatching them and growing them to about 2 inches long. I started this venture 5 months ago and still have not completed phase one. I bought 2 males and 4 females at the start. All 4 females have produced offspring, a total of about 400. Here is a pic of ones that hatched out a month ago. They are about 1 inch long, there are 86 of these in one tank, along with about 100 tiny ones which hatched out last week. In about another month I will have completed phase one.

Phase two is growing these fingerlings into juviniles about 4 inches long, this can be done in tanks, but phase three is growing the 4 inch juviniles to full size which requires an earthen pond.They also need to be selected with only the males entering the final growout stage, otherwise they will mate and you would end up with thousands of crays, not easy to control and manage.

When I bought the first 6 breeding stock I was given 10 fingerlings free. They are now ready to reproduce and are living in the big raceway tank. I am deciding what to do with the first six breeders as I don't want them to reproduce again, I can either keep them and see how big they actually grow or as my wife suggested we can eat them. I've never eaten a crayfish but would like to, the problem is I am not sure I can kill them, these six I have watched grow and know them individually, but keeping crayfish as pets is not a good idea considering how fast they reproduce and how much land they require. Maybe I will have a taste this coming weekend, keep the wife happy.

To continue to phase three requires an earthen pond which I already have but needs a lot of work doing to it . First it needs to be emptied as it is full of catfish from the rice fields. It then needs to be lined with clay as it dries out in the hot season. A roof needs to be constructed to reduce evaporation and a wall put all around to keep the crays in and predators out. Then comes the marketing which requires a processing facility and packaging, plus transportation to the customer. I am 63 years old and not sure I want all that work. Maybe I will keep it on a selfsufficient level and eat a few and sell a few.

[crayfish]

Some pics missing from last posting

month old baby crays

[chaiyapoon]

I only know a bit about the signal crayfish problem in the Uk.

Many escaped from farming operations and now are listed as a pest that must be destroyed if caught.(can be eaten cannot be released)

They are in about 75% of Uk waterways rivers and lakes as they can walk long distances overland.Fishing clubs hate them are they take all

baits.They are burrowing into the banks and may cause collapse.They have virtually killed off the small resident uk crayfish population.This in

cold Uk waters.What damage may occur if these much larger non native species get into Thai waterways?

[Davidhurghada]

Hi, does anyone know about farming or keeping crays in brackish water 14 ppt

[namdocmai]

I have 2 male and 2 female crayfish, the red ones.

Last week i saw them laying on their sides in the sun and they didn't move at all for some minutes. I thought they were fighting and one killed the other one, it had the tail of the other one it's claw and i thought the other one was dead.

10 minutes later both were gone, hiding somewhere.

Do they mate this way? They are always hiding so i have no idea how many i have now.

[Evilbaz]

Thanks for an interesting thread.

I invested in a Queensland Redclaw project about 25 years ago.

Unfortunately, like most Qld "managed investment schemes" someone "managed the money" into their own account.

I did get to taste them - delicious - and a big overseas Asian market (particularly weddings - one per plate instead of one rock lobster (western crayfish) per table).

I'm sure the Thais will gobble them up but you need your growout pond in clear sight! (poachers).

Birds were a big problem.

[DerkMR]

I have 2 male and 2 female crayfish, the red ones.

Last week i saw them laying on their sides in the sun and they didn't move at all for some minutes. I thought they were fighting and one killed the other one, it had the tail of the other one it's claw and i thought the other one was dead.

10 minutes later both were gone, hiding somewhere.

Do they mate this way? They are always hiding so i have no idea how many i have now.

When mating the male holds the female and turns her upside down to place the sperm packet.

http://www.bluecrayfish.com/reproduction.htm

Bye,

Derk

[canuckamuck]

Hey what's with the porn? Some kid might see that.