breeding crayfish

[ozzydom]

Hi Norman,

as far as I remember from breeding crayfish and shrimps as pets the young ones need animal proteins to grow, so no way to get them starting with your mostly vegetarian homemade food.

But there is a good option at least up to some quantity and this is called "Moina". It's a genus of aquatic plankton and being sold in pet shops which have a good variety of fish. In Udon Thani I know only one but normally you can ask for breeders of siamese fighting fish (pla kat) and they should have some in culture.

All they need for good reproduction is a lot of sunlight to have a lot of phytoplankton to feed on. Usually they are bred in the concrete rings used for the large water pipes available at builders shops for THB 150.-, just take some cement and fill the bottom so that it's a closed container and fill it with water. Some liters taken from a public lake will help growing the plankton faster. When it's nice green you can add some Moina and the quantity will explode within 1 or 2 weeks.

Bye,

Derk

As Derk states, juvenille crayfish require plankton ,as in phytoplankton and micro organisms as their food source, lakes and river water have resident supplies which can be boosted simply by adding phosphate in the form of 16-20-0 fertilizer.

A few buckets of river or lake water added to your system plus the addition of phosphate fertilizer and your food source will take care of itself.

The water requirements for redclaw are it seems almost the same as we use in our Nile Tilapia farming,apart from redclaws needing more aeration and constant slow water movement.

As we can tell by Normans posts, he is having a ball with his hobby and thanks to him for passing on his experiences .

But the difference between a hobby and a commercial enterprise is a very large and expensive leap.

The high capitol expenditure and operating costs of a commercial operation for a non existent market(at this stage) with an unknown cost or market value makes it a risky venture.

Having said that, redclaws have the benefit of the grower being able to breed their own stock ,hence cutting out hatchery costs.with them really having to be grown on as monoculture (single sex) ponds ,they would be fairly labour intensive.

A fairly low bio-mass per pond and an up to 12 months grow period with high running costs and a to be established market makes it a gamble ,which if I had the pond area spare I would be tempted to punt on.

Keep up the good work Norman.

[David48]

OD ... how do you think the White Shrimp and the Crayfish Norman mentions cohabitate ... ?

[ozzydom]

OD ... how do you think the White Shrimp and the Crayfish Norman mentions cohabitate ... ?

Pretty sure they would not .

[DerkMR]

Having said that, redclaws have the benefit of the grower being able to breed their own stock ,hence cutting out hatchery costs.with them really having to be grown on as monoculture (single sex) ponds ,they would be fairly labour intensive.

Well, I think you just have to figure out at what age you should separate them.

That would be the time to empty the juveniles pond and sort them out into two or more growing ponds.

With the males growing bigger you have the choice to let them grow while selling the females.

Today I upgraded my fishtanks to 65 but I still have some place where I could put two 200 l crayfish tanks

The redclaws sound pretty interesting...

Bye,

Derk

[crayfish]

Hi. An update after a busy weekend with the redclaws. Last week I purchaced a plastic food container. I first checked to find out which plastic is suitable for the job.Be careful putting plastic in a tank, there are many plastics that give out chemicals that will kill the crays. I googled using " safe plastics for food. There are code numbers specifying the type of plastic.As you can see from the pic I cut square holes all around and cut a large hole in the lid. These openings I siliconed mesh ( used for guarding against mosquitoes ) over them. The siliconed mesh on the lid did not stick so I imagine it is a different kind of plastic, hopefull not a dangerous one, only the container had the code number showing it was safe, the female has been in there for 2 days and is doing well. By fitting the lid with a hole in it prevents the female from climbing out. The container is in the large glass tank and has one female with eggs in it. I put together some plastic plumbing fittings and constructed legs for the container to sit on, by doing this I have not utilized floor space in the tank The other female with eggs is now in the small glass tank. I have taken the 10 juveniles from the small glass tank and they are now in the raceway tank which I have had running for the last week to get some kind of ecosystem up and running. The juviniles like their new tank. The tank is a perfect design for crayfish I have regulated the current so the surface water is flowing freely and the ground current is flowing slowly. The ground current fluctuates in different parts of the tank and the crays have each found their favourite spot to reside.

DERK ... Thanks for the info on aquatic plankton, I have tried all the pet shops in town and cant find any. I have taken water from the village reserviour and added it to the tank. Hopefully that will work. I need to get this together properly before the eggs hatch, new borns need plankton for sure.

OZZYDOM.... Thanks for your contributions on this thread. You mention adding Phosphate 16-20-0 to the water. Can you give me what amounts to add per litre?? This project started of as a hobby and in some ways it still is, but I can now see it becoming a business enterprise. I have nearly finished phase one of the project, " The nursery", that is growing eggs to a two inch redclaw. Up to now I have reared the breeding stock and produced eggs. It really is a matter of being in front all the time. When these eggs hatch I will have about 1000 cratlets on my hands. They can stay in their tanks with their mothers and then into a raceway tank ( a big one). I have already invested 25,000 in the project and will need to invest maybe another 15,000 to finish setting up the nursery. Not a lot of money for so much fun and excitement. I think the nursery is the hardest part, phase two is growing them our to sellable size. The investment for that I have yet to calculate. The most important thing to consider is available land. The nursery has taken all the available land around my house. Phase 2 requires at least 1000 square meters of land, depending on how many you want to grow up to 90 gram. 1000 sq mtrs will accommodate about 4000 - 5000 crays. Phase 3 will need an earthen pond of a similar size to grow out 2000 to full size. I have the land already so the investment is ready made. Phase 2 and 3 require some kind of covering to protect from the sun and rain. I would not consider taking on this project if I did not have the land available.

A pic of an exoskeleton This is from one of the juviniles in the raceflow tank. It moulted on Saturday night. It looks like a dead cray but it is not. I like to see them moult, it shows me they are growing well.

Two pics showing one of the juviniles before I moved them to the raceway tank.

The two females with eggs have not eaten for a few days. This I understand is normal. If they eat a lot they may be forced to moult, if that happens they will loose the attachment to the eggs. I have read that they can go up to two weeks without eating. They are spending all their time in their hidyholes and not excerting any energy so no real need for a lot of food.

Have to go, work calls

Regards

Norman

Edited December 27, 2013 by Lite Beer

[crayfish]

Hi Work finished and back again. Forgot to mention before about moving a female with eggs attached to another tank. When a cray is feeling threatened they fan the end of their tail and whip it under their tail. This creates a powerful thrust and they zoom backwards very fast. They can do this horizontically an vertically. They always do this if you try to catch them with a hand held net, the small nets sold at aquarium shops for catching fish in a tank. This I needed to avoid as the female would break the attachment with the eggs. What I did was I waited for them to go into a plumbing pipe, then put a hand over both ends of the pipe and lifted them out. They must have been disorientated when they went in the pipe in one tank and came out in another tank without realizing they had been moved.

DAVID48 .... You ask if redclaws and white shrimp could cohabit. I would imagine you would be presented with a few problems. I know for sure that redclaws are non aggresive towards each other but not sure if they would be aggresive towards another species. You are sure to have problems if they were to breed in the same environment. Do they have the same tollerance to water conditions, PH levels. temperature levels, salinity levels. Can they transfer diseases to each other. Can they eat the same level of protein???? I know nothing about white shrimp but these are some of the things I would be asking. I don't really see the benefit of keeping them together.

Best way to find out is put a few together and see what happens. Good luck

[ozzydom]

Norman,the initial dose I use works out to be 10 grams per cub metre of water.

Interestingly ,I called into the Udon fisheries dept today to glean some info for DB and the subject of red claws came up.

It seems that somebody in the Phen district (between Udon and Nong Khai) imported some redclaw from Oz and is having a bacterial problem, evidentally they were advised to administer formalin to the pond and wanted to get details of supply of the chemical.

Fisheries are going to try and find out who and where for me.

[ozzydom]

.

Edited November 25, 2013 by ozzydom

[DerkMR]

DERK ... Thanks for the info on aquatic plankton, I have tried all the pet shops in town and cant find any. I have taken water from the village reserviour and added it to the tank. Hopefully that will work. I need to get this together properly before the eggs hatch, new borns need plankton for sure.

Where are you located?

Here n Udon we also have only one pet shop having Moina.

My first batch which I tried to breed collapsed so today I bought the second batch, unfortunately the setup is now very fresh as I had to clean up the collapsed devices (I use cement mixing containers - like 150 l each). So most probable is that I have to start artificial feeding which you can do with yeast.

Bye,

Derk

[DILLIGAD]

Very interesting topic, Norman. (Especially over a few Leo's now and again) !!!! 555

Sent from my iPhone using Thaivisa Connect Thailand mobile app

[crayfish]

I noticed yesterday afternoon that one of the two females ( without eggs ) in the big glass tank had her tail tucked up under her ( most unusual ) I watched her on and off for a couple of hours and she was still in the same place with her tail still tucked up. At first I thought something was wrong with her. As I continued observing her I noticed that the big male was paying her a lot of attention and tapping her with his claw.This went on for another hour or so until the male gave up and went on his way. Shortly after this she straightened her tail and was happily walking around the tank, with no further interference from the male. From this behaviour I conclude that the male wanted to mate with her but she was either not in the mood or she was not ready to lay eggs. I have been trying to figure out what actually triggers of the mating process. When the male mated with the two females with eggs, he knew a day in advance he was going to mate as he had prepared the caves for the females by clearing all the small stones out. For a female to mate she needs to be sure that she is not going to moult while she is carrying eggs or she will loose them. The behaviour I observed yesterday was maybe just the male feeling randy and wanting to get his legs over. I get like that myself once in a while, but I haven't tried tapping my wife on her head with my claws, don't think that would help.

I have seveal videos of the crays but at the moment can't upload them. I have asked Thaivisa admin if they can allow me to upload, haven't heard back yet. If not I will upload them on youtube and put a link to this thread.

Everything is running well with the crays. After moving them all about last weekend they have all settled into their new environments well.

The raceway tank is perfect for crays, they like the slow running water. I am about to build another one but about 4 times the size, this will be for the new borns.

Bye for now

Norman

Edited December 27, 2013 by Lite Beer

[crayfish]

I noticed yesterday afternoon that one of the two females ( without eggs ) in the big glass tank had her tail tucked up under her ( most unusual ) I watched her on and off for a couple of hours and she was still in the same place with her tail still tucked up. At first I thought something was wrong with her. As I continued observing her I noticed that the big male was paying her a lot of attention and tapping her with his claw.This went on for another hour or so until the male gave up and went on his way. Shortly after this she straightened her tail and was happily walking around the tank, with no further interference from the male. From this behaviour I conclude that the male wanted to mate with her but she was either not in the mood or she was not ready to lay eggs. I have been trying to figure out what actually triggers of the mating process. When the male mated with the two females with eggs, he knew a day in advance he was going to mate as he had prepared the caves for the females by clearing all the small stones out. For a female to mate she needs to be sure that she is not going to moult while she is carrying eggs or she will loose them. The behaviour I observed yesterday was maybe just the male feeling randy and wanting to get his legs over. I get like that myself once in a while, but I haven't tried tapping my wife on her head with my claws, don't think that would help.

I have seveal videos of the crays but at the moment can't upload them. I have asked Thaivisa admin if they can allow me to upload, haven't heard back yet. If not I will upload them on youtube and put a link to this thread.

Everything is running well with the crays. After moving them all about last weekend they have all settled into their new environments well.

The raceway tank is perfect for crays, they like the slow running water. I am about to build another one but about 4 times the size, this will be for the new borns.

Bye for now

Norman

Edited December 27, 2013 by Lite Beer

[crayfish]

ozzydom..... I would like to know the bacterial problem with the redclaws you mentioned. If the guy imported the reds from Australia he must have an import license, translated to English, and a health check on the reds from the Australian goverment fisheries department before they will export them. To get hold of formalin in Thailand is not easy. It was easily available a few years ago but was widely used to preserve fruit by injecting it into the fruit body. The problem is that formalin is carcegenic ( promotes cancer). It is a preservative that works by killing bacteria, but the dosage needs to be controlled.

[Farma]

I spotted crays on sale at the Khon Kaen walking street market behind the bus station last Saturday night. The sign said Khon Kaen crayfish farm and gave a phone number. Might be worth chasing it up if you live nearby.

[ozzydom]

ozzydom..... I would like to know the bacterial problem with the redclaws you mentioned. If the guy imported the reds from Australia he must have an import license, translated to English, and a health check on the reds from the Australian goverment fisheries department before they will export them. To get hold of formalin in Thailand is not easy. It was easily available a few years ago but was widely used to preserve fruit by injecting it into the fruit body. The problem is that formalin is carcegenic ( promotes cancer). It is a preservative that works by killing bacteria, but the dosage needs to be controlled.

When/if fisheries get back to me ,I will try to contact the people in question and find out more.They are evidentally not far from Udon.

A guy in our village has gallons of formalin,he pumps it into cadavers to preserve them until time for cremation.

[David48]

Just a wee heads up about transporting Prawns ... thus, I presume the same with the OP's subject.

There are a few Farms here that supply the live export trade of Prawns to the Japanese market.

The process involves, from my understanding in packing them in sawdust and chilling them and then airfreighting them to Japan.

[teletiger]

Just a wee heads up about transporting Prawns ... thus, I presume the same with the OP's subject.

There are a few Farms here that supply the live export trade of Prawns to the Japanese market.

The process involves, from my understanding in packing them in sawdust and chilling them and then airfreighting them to Japan.

I presume they wouldn't be 280 Baht per kilo......

Regards.

[ozzydom]

Just a wee heads up about transporting Prawns ... thus, I presume the same with the OP's subject.

There are a few Farms here that supply the live export trade of Prawns to the Japanese market.

The process involves, from my understanding in packing them in sawdust and chilling them and then airfreighting them to Japan.

We started sending live crays by air from Tasmania to Japan 40 odd years ago, their temperature was very slowly lowered to about 4degrees celsius then packed in styrene boxes with damp chilled wood chips and off to the airport.

At 4 degrees the crays virtually go into hibernation and use very little oxygen.

[DerkMR]

I have been trying to figure out what actually triggers of the mating process.

Very easy - when the females exuviate they are ready to mate.

That's also why they need caves as freshly exuviated they are endangered by far more predators as with the toughened exosceleton.

Bye,

Derk

[David48]

Just a wee heads up about transporting Prawns ... thus, I presume the same with the OP's subject.

There are a few Farms here that supply the live export trade of Prawns to the Japanese market.

The process involves, from my understanding in packing them in sawdust and chilling them and then airfreighting them to Japan.

We started sending live crays by air from Tasmania to Japan 40 odd years ago, their temperature was very slowly lowered to about 4degrees celsius then packed in styrene boxes with damp chilled wood chips and off to the airport.

At 4 degrees the crays virtually go into hibernation and use very little oxygen.

OD ... yes, that's the general process as I understand it.

teletiger ... mate, I have no idea of the landed price in Japan ... but I'm sure it's more then a Thai's minimum wage.

From this article http://australian-food.com/rocky-point-prawn-farm-434.html, they export 500kgs to Japan on an annual basis.

[crayfish]

http://www.youtube.com/watch?v=G03dH5Fisdw&feature=youtu.be

Just trying out the youtube connection with a short video

Edited December 27, 2013 by Lite Beer

[crayfish]

http://www.youtube.com/watch?v=39xT5xzNu3s

A website worth a look for info on vortex filters

[David48]

http://www.youtube.com/watch?v=39xT5xzNu3s

A website worth a look for info on vortex filters

Well worth a look at this one ...

[crayfish]

^{Another vid}

^{/http://www.youtube.com/watch?v=JegjvRrLnpw&feature=youtu.be}

[canuckamuck]

I think I will be ordering some of these crayfish next week, some breeding pairs. Thanks for the thread it got me into something new.

[crayfish]

When you purchace breeding stock, try to get males and females from different bloodlines:not related, as the offspring will be smaller. If you get the chance ,select your own crays, pick the largest males and females. Good luck. If I can help you in any way please feel free to ask.

I encountered a small problem this weekend. The plastic food container in the big glass tank is the problem. I let the burried female out ( she was happy to get out and is now tucked away in her hidy hole with the big male guarding her, he's happy too). The mesh I used is too small, it allowed a steady current through but the mesh got blocked with debri in the tank. When I took the tank out I found that the silicone had not adhered to the plastic and was very easily taken off.Have to rethink on this one. I want her seperate from the other crays in the tank when the eggs hatch. I have started building another raceway tank and may put the other crays in the tank in there and let the burried female have the tank to herself with her offspring. The other crays in the tank are 2 females, yet to breed, and two males, the smaller one yet to breed.There is no immediate rush for this as it will be about 3 or 4 weeks before the eggs hatch. The other burried female in the small glass tank seems to be well, she stays in her hidyhole and rarely comes out, this is normal behaviour when they are with eggs. The ten juviniles in the raceway tank have made themselves at home, each with it's own territory

When I started this thread I mentioned that I purchaced 10 small red crays before realizing they were not what I wanted. They are living in a circular concrete tank with an aireator. I really don't know what to do with them. They have grown well and are about 4 inches long. That I think is about as big as they will grow. I need to do something before they breed. Maybe I will satisfy my wife's appitite and let her mix them with some somtam.

All for now.

Norman

[crayfish]

FAO Fisheries & Aquaculture Thailand

www.fao.org/fi/website/...xml=nalo_​thailand.xml〈=en

If you have nothing better to do for the next hour or so, have a read about laws on aquaculture,Thailand

[DerkMR]

When I started this thread I mentioned that I purchaced 10 small red crays before realizing they were not what I wanted. They are living in a circular concrete tank with an aireator. I really don't know what to do with them. They have grown well and are about 4 inches long. That I think is about as big as they will grow.

Locate a pet shop with aquariums and offer them - the usual size they have in stock is like 6 - 8 cm but Thais like big animals ;-)

Bye,

Derk

[crayfish]

http://www.youtube.com/watch?v=9VAvx_-t9YI

Last night the third female mated and is with eggs, she is the smallest female of the four. Made a video

[crayfish]

• http://www.fao.org/fishery/legalframework/nalo_thailand/en

Downloaded wrong yesterday. Here is the thai laws on aquaculture in thailand.