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Crayfish in IBC's (growing & breeding).

Discussion in 'Fish' started by Ringer, Jun 12, 2016.

  1. Ringer

    Ringer Active Member

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    image.jpg Hi,
    I been posting a bit about Redclaw crayfish in aquaponics . Just wanted to know about others having success or failures with these tastie little beasts or any other species. Also looking for any tricks , tips or opinions anyone has to offer. In the pic the big male was hatched in early May last year (late for Redclaw) and is the father of the juvenile and approx 150 brothers and sisters ,they are about 5 weeks old . I usually get 2x spawnings a year from each female and between 100 & 200 offspring per breeding (bigger crays have more eggs). All my crays are bred and raised in IBC's .
     
    Last edited: Jun 12, 2016
  2. Gratilla

    Gratilla Member

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    We discuss redclaw/crayfish/yabbies here from time to time.

    A search of the forum on these keys words should give you a few answers/pointers etc.
     
  3. Ringer

    Ringer Active Member

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    Appreciate that Gratilla , I understand how to and have searched the forum though.
    I've bred and raised redclaw in a personal and professional capacity since 1992. I know and understand industry best practice . Lately I've become more interested in looking for better techniques , innovative ideas and success stories from people involved predominantly in aquaponics rather than with "traditional" techniques. I'm not even sure if people think crayfish really have a place in aquaponics or if they're seen as just a novelty?
    Cheers
     
    Last edited: Jun 14, 2016
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  4. Luke84

    Luke84 New Member

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    If I get a feed of good redclaw every xmas then I'm happy.

    Moving into a place and setting up an IBC system to grow redclaw for 12 months and then harvest every xmas. Hoping to have it built by this xmas and ready to go for next. Ive got 20 redlcaw in a 4ft tank at home at the moment and I'm a little surprised I haven't got any females with berry's yet. As you may have seen from my previous threads my indoor tanks are still getting to 32 degrees. They have plenty of cover and hiding places but thought they would have bred by now. Might have to get out and catch some with berry's. Maybe to much light or over crowded.

    Any suggestions?

    White claw hatched last night and have separated them but they are for looking at not eating lol.
     
  5. Luke84

    Luke84 New Member

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    Hey Team.

    Just thought I would post as I have seen some interesting behaviour out of one of my female redclaw. Pretty sure she has eggs at the moment. Very pleased to see compared to a few days ago.

    So this particular female did a shed about a week ago. I know this because she has turned a nicer shade of blue and there was only 1 shell casting in the tank. The shell casting has since disappeared so assuming she or the other yabbies have eaten it.

    She has heavily altered behaviour. She has become a bit of a recluse, dopey and will not unfold her tail. She also has what appears to be the males sperm around her egg ducts. Every now and then she will roll over inside her hide and start pushing at the males sperm. Looks like she is trying to kick it off. It has been there for a few days now so I'm assuming it has had its worth and she is trying to get rid of it. I don't think there is a huge amount of eggs.

    She isn't the biggest of females. At a rough guess I would say 30-40 grams. My largest male is at 85 grams so I'm running off of that guestimate.

    Once she is showing her berrys I'm going to put her in a seperate tank so that she doesnt have to compete at all with the other yabbies. I'm going to then seperate her from the hatchlings into a well established tank that hopefully will have plenty of bits of crap for them to eat out of the substrate so that they can grow out a bit without having to provide to much of a special diet.

    Ive already put the adult white claw into a seperate tank and have been putting A flake of tropical fish food in every day to hopefully feed the hatchling whiteclaws. The way I see it it should be soft and small enough for them to chow down on.

    Any tips or tricks along the way would be much appreciated.

    "I'm not even sure if people think crayfish really have a place in aquaponics or if they're seen as just a novelty?"

    Dopnt worry Chief, They sure do have a place in my prospects.
     
  6. Ringer

    Ringer Active Member

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    Hi Luke
    20 per Metre is probably on the high side mate . For grow out I keep them at between 10 to 15 max "sub adult" crays per square metre . Crays breed after moulting so watch out for that and provide good cover for them when soft shelled.( I'll post a pic to show my shelters). Some crays are better breeders than others. Diet , genetics , water quality, day length even luna cycles can influence their spawning .Handling can turn them off breeding also.
    Good on ya for giving them a go Luke , I tried my first crays from my or any aquaponic system recently. I maintained the water clear and virtually additive free for 12 months ish so they had never been exposed to any earth or detritus nor any chemical fertilisers. By a mile they were the best tasting crays I've ever eaten , so without a doubt it was worth it.
    .
    As a tip, I suggest keeping brood stock seperatley and selectively breed for each season. In IBC's I stock 1x premium male from the previous seasons brood with 3 or 4 females that have been sourced from a new location and from different genetic stock . What's termed as "Hybid vigor" can drastically improve both growth rate and reproductive viability of your crays. Avoid buying all of your stock from one source at the same time and at the same size when you want to breed high quality crayfish. Inbreeding in traditional style large scale crayfish farms often goes virtually unchecked and the resulting offspring may suffer low growth rates and homaphrodite offspring amoung other issues.
     
  7. Luke84

    Luke84 New Member

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    Cheers Ringer.

    One of the things that has always been in the back of my mind is genetic diversity. I have sourced my redclaw currently from 3 different rivers and also a local shop. Hoping to kick goals in that department but I will certainly take your advice of keeping one male for breeding and giving him 3-4 females from different places. Good excuse to go camping anyway haha.

    Would you consider some sort of purge before harvest?

    I'm hoping to selectively breed some in tanks to achieve different colour strains. A local bloke has said its easily done (over time). These would not be for eating but more for display. Sort of like what Cherax park have been doing with their 'opals'.
     
  8. Paul Jones

    Paul Jones New Member

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    G'day Ringer just been reading up on this post and I'm also keen to have some fresh water crays in my system I have an Indy23 system down here in Victoria, it's about 2 months of age and coming along nicely. I have 100 silver perch and 100 Australian Bass and all going well. I was talking to a Worm Farmer bloke the other day and he reckons a great spot for a few crays in the system would be in DWC as they apparently would clean the roots and allow the uptake of nutrients to be more readily avaliable? What would your opinion be about that? Also are aware if the freshwater crays in Victoria are territorial?
    Cheers Paul
     
  9. Ringer

    Ringer Active Member

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    Hi Paul,
    Grab combo mate . Bass and yabbies , that's some of the best freshwater table fair Australia has to offer . Considering climate suitability Cherax Destructor would be your best option. I assume your temps would get too high for Marron and too low for Redclaw. Both Redclaw and yabbies will snip at and eat your roots if they can reach them . Freshwater shrimp especially the smaller species are a better option. They will clean algae from their tank including algae on plant material. If you decide to, the best way to introduce crays in to a system is source some disease free hatchery stock. If you go with yabbies get them as young as possible , the older the stock the more difficult it becomes to settle them successfully . I've seen mature pond stock unsuccessfully moved to tank environments and just never adjust , stop eating and simply die. To answer the last part of your question regarding territoriality the answer is yes , yabbies are the definition of territorial and aggression and not above canabalism in the wild . You can modify their behaviour in captivity though with the right type of environment , stocking density and feeding rate.

    Cheers
    Hope that helps
     
  10. Paul Jones

    Paul Jones New Member

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    Hey Ringer really appreciate that feedback mate I reckon based on what you've suggested I think I'll try shrimp in the DWC and fish tanks and see how they go and let you know. I'm also thinking of attaching a couple of IBC's off the side and run the system through them and put a few Cherax Destructor in them. Do they need little homes to stay in?
    Cheers Paul
     
  11. Luke84

    Luke84 New Member

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    Hello Paul. They would definitely benefit from having places to hide. I use pvc offcuts that are bundled together with zip ties. Kinda like a bundle of wood. I call it the yabbie chateau lol. When it comes time to clean the tank it's easy because I can pick it up in one piece. Pick it up carefully enough and the yabbies won't fall out so you can clean without having to dodge the yabbies.

    Having hides will hinder aggression and make them happier in general which is a good thing for destructor as they are a bit more territorial than redclaw.


    Sent from my iPad using Tapatalk
     
  12. Ringer

    Ringer Active Member

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    Hi Paul,
    Crays don't always require shelter mate , It's all dependant on the stocking density in any particular environment. There is an exception though, after moulting (shedding their shell to grow) a crays new bigger shell is soft , leving them vunerable predation from other crays.

    Almost everyone uses pipe as shelter , I don't .
    I'll try to be succinct ,
    Growers want to mimic the natural habitat of their crays by offering "pipe tunnels" as simulated hides . Makes sense right? Problem is real burrows and hides (rocks ,logs and leaf litter) only have one exit/entry hole and the crays will back in with their claws exposed in front for self protection. Pipes with two open ends aren't such an issue most of the time but when crays are soft shelled or holding eggs under their tail they can be blind sided from behind and fall victim to attach.
    Pipes also collect debris and crayfish are messy . They do work pretty well for the purpose intended but in high density tank environments they don't work very well. I have experimented for years and have found a much better way to do it. Rather than ramble on I'll upload some pics in the morning.
    Cheers
     
    Last edited: Mar 3, 2017
  13. Paul Jones

    Paul Jones New Member

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    Thanks Ringer and Luke. Be great to see your photos thanks Ringer. Wonder if plant pots would work well as they are only open one end hey?
    Also are you able suggest a reliable place I purchase a few crays from or shrimp or am I best to just go out and catch my own locals?
    Cheers Paul
     
  14. UndaToka

    UndaToka Member

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    a question popped into my head for you Ringer since you have experience and knowledge,..... can yabbies crossbreed ? like if i introduced a local creek yabbie to some redclaws would they interbreed or just try to eat each other??
     
  15. Ringer

    Ringer Active Member

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    It's an interesting question , I don't know your local species but the short answer is , yes it's possible for two different yabby (Cherax) types to interbreed and yes all yabbies will eat each other if the opportunity presents.

    Hybrid yabbies (Cherax albidus x C. rotundus) have been successfully interbred experimentally , an interesting anomaly they found was all offspring are male . This trait bred in to a hybrid of suitable adult size and growth rate for market would be a huge advantage in a comercial scale grow out operation.
    Ethicaly I feel experimental cross breeding is ok as long as there is a beneficial goal in mind . Importantly any hybrid stock must never be released or escape into the wild as they may outcompete and displace endemic species. Many of the 140 odd species of freshwater crays in Australia are very localised with small fragile populations that need to be preserved in the interest of genetic diversity. Who knows you may even have one of our amazing borrowing strains living in your backyard .
    Cheers
    Hope that helps.
     
    Last edited: Mar 5, 2017
  16. Ringer

    Ringer Active Member

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    Hi Paul,
    Here's the pics I promised , sorry they're a bit late.
    I've had my say regarding the short comings of traditional types of crayfish shelters usually used in aquaponics systems (bits of pipe for example). So I think it's only fair I try suggest a better option.
    Stay with me bud this will get a bit "blah blah blah".
    The secret to getting redclaw through the moult and breeding process and keeping juveniles alive is the right type of shelter . In their native habbitat Redclaw dont typically burrow but rather roam and shelter under logs , rocks and leaf litter as required .Knowing this I started trying to recreate the same in my tanks/ponds . After dozens of different trials over many years I've come up with these. The mesh size is perfect for craylings to move through if chased and water can still move in and around the shelter maintaining oxygen levels also eliminating debris accumulation. The most important benefit is crays with soft shells can Hide in the many tunnels created but also push through the folds if attacked. The forward facing spines on the crays heads stop them from moving forwards quickly through the tunnels so it slows any aggressors and instead of being trapped in a tube it allows threatened crays to flick there tail a shoot backwards in any direction out of or under the folds and away from danger. They really have made a huge diffence to the survival and growth rate of the crays in my system.

    I buy these bags in bales of 200 (way cheaper in bulk) from a supplier near the Brisbane fruit and veggie markets.
    . image.jpeg
    Each shelter requires :
    5x mesh bags
    3x lengths of aluminium wire (2.4mm tig welding wire)
    2x 50cm lengths of 25mm PVC pipe.
    image.jpeg
    Gather the bag length ways.
    image.jpeg
    Bend a small loop in one end of the wire then skewer the other end through each of the folds like a sewing needle.
    image.jpeg
    Continued next post...........
     
    Last edited: Mar 17, 2017
  17. Ringer

    Ringer Active Member

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    Fold the bags the same way along the opposite side and thread another wire though that side. Repeat the process and when all 5x bags are on bend another small loop on the pointed end of each wire to stop the bags sliding off.
    . image.jpeg
    Cut 2x lengths of 25mm PVC pipe the same as the width of your bags these will act as anchors to fold the hide to bottom. (ratcheting cutters make the job really easy , a very handy tool).
    image.jpeg
    Feed a length of wire through the pipe and secure it to the wire loops you bent at each cornered of the shelter. Once attached I fill each tube with washed gravel and then block the ends with a sponge plug to weigh it all down.
    image.jpeg
    They will darken with algae over time which is beneficial , these ones had been in the water a couple of minutes. The crays just flock to these shelters.
    image.jpeg
    Hope that helps.
    Cheers.
     
    Last edited: Mar 31, 2017
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  18. Paul Jones

    Paul Jones New Member

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    Hi Ringer,
    Wow mate that's fantastic and most imformative thank you very much for going into so much detail mate :thumbsup2:.
    Cheers Paul
     
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  19. David - WI

    David - WI Member

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    Well, I at least see why I failed now... that's really great info, thank you.
     

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