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Depth of yabby tanks

Discussion in 'Equipment' started by yabbie, Dec 19, 2010.

  1. yabbie

    yabbie New Member

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    Well week off so home and wandering around looking at my spaces etc. Worked out where the main fish tanks are going, grow beds etc but working out what to do with yabbys.

    I was or am thinking about say using the bottom 300mm of IBC conatiners as yabby tanks. Then using a steel frame, stacking them vertically. Centre mount a pipe say 250 mm high. Pump into the top one and when it fills up, water flows into the pipe and down into the next tank thus in 15 minutes or so, all tanks are full and then any water added to the top tank, will cause a cascade effect. Take on tank out and it simply will overflow from the one above to the one below. Put it back in and it simply fills up and away we go. Each one will be covered say with a plasic eg crate material or simalar.

    Is there a prefered depth for yabby's?


    Also I have worked out a feeder for the fish tank but looking for ideas to keep a bit of feed up to the yabbys. I work in the mines and whilst I have a caretaker here that can keep an eye on things, just wanting to cover all bases. Ideas anyone?
     
  2. bobbyd

    bobbyd Member

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    Yabbies aren't fussy with water depth,
    They go into shallow water because its warmer and deeper water because preditors that walk on the shore cant get them (Ibis,Igrets)
    Give them hideing places,food and o2 they will be happy as.
    The biggest problem with the ******s is they are prolific breeders!!
     
  3. RupertofOZ

    RupertofOZ New Member

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    The biggest problem with the ******s is they are homicidal genocidal murderers!!
     
  4. toraman

    toraman Member

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    LOL, Cherax destructor is such a tough official name for them. A friend had quite a few in his aquarium all living happy together, one the females was in berry too - the big male fussing over the female, they looked so caring. Then....... they all went all loopy eating and ripping each other apart limb from limb over a few days. :24locos: I'd love to keep them one day, if I can provide the conditions whereby they can behave themselves, heard it helps to provide them lots of PVC pipe from them to hid in.
     
  5. Yabbies4me

    Yabbies4me Administrator Staff Member

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    If you want to just lump them all in the one tank with a heap of hiding spaces, especially for the small ones, they will breed continously and you'll always have some yabbies to eat, but there will be a lot of cannibalism and they'll grow slowly.

    Ideally though, you need four separate tanks. One for the blokes, one for the shielas, one for the prego sheilas/sprogs (fish tank is best for this one), and one for the juveniles.

    Put some of the blokes and some of the sheilas in the prego sheila/sprog tank at a rate of about 1:3 (lucky ******s) until most/all of the shielas are berried up, then remove the blokes back to the bloke tank.

    Once hatched, the sprogs will stay attached to the mother, they will occassionally get off for a wander, but will return to her. Once they stop returning to her, remove her back to the shiela only tank.

    When the young'ens get to about 10mm long transfer them to the juvenile tank. When the juveniles are big enough, sex them and seperate them into the bloke or sheila tanks.

    They grow much faster when sexes are separated and there will be much less fighting and cannibalism.

    40mm PVC cut to about 10 inch lengths.
    .
     
  6. bigdaddy

    bigdaddy Super Moderator

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    Hi yabbies,

    What's the ideal temp range for them?

    Roughly how long do they take to grow?

    Cheers.
     
  7. Yabbies4me

    Yabbies4me Administrator Staff Member

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    I've had them breeding in temps from 14º to 30º, but mid 20's seems to be the ideal.

    I was on the phone once to a marine biologist because I was having problems with some of my yabbs. It was the middle of winter and he was lecturing me on the fact that they won't breed below 20º... at the same time I was standing in front of one of my tanks looking at hundreds of newly hatched young and a dozen berried females... the water temp was 14º... :confused:

    In my tanks they were growing to edible size in just over 12 months, a lot quicker than their supposed growth rate in nature, but I was keeping the sexes seperated. After the first year their growth rate slows dramatically, to the point where growing them on isn't really justified, especially for commercial growers, but for the backyard bloke time may not be a concern.

    They like a pH around 7.5 or 8.0, my tanks were always kept up around there, they may not grow as quickly in AP systems where the pH is in the 6.0's

    Cheers, Yabbies.
    .
     
    Simon M likes this.
  8. ratfink

    ratfink New Member

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    hello...you can breed yabbies in most temps..if the tank is at a stable temp most of the time, all you need to do is just slowerly add more daylight and at the same time slowerly increase the water temp.. ever watched them doing the deed?. male is always on top.

    good source of food for your fish aswell..in a hatching tank, place some chicken wire about 2 inches off the bottom. when she drops the bundles, take her out and gather up the babies...trout and most other fish loves them big time..
     
  9. Yabbies4me

    Yabbies4me Administrator Staff Member

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    Yabby Handling 101:

    Yabby Handling 101:

    Tip: When sexing yabbies it's advisable to pick them up by the blunt end... not the sharp end!!! :genius:

    Norm's got some yabbies in his ST and he was having probs with them fighting and ripping each other claws and legs off, so I decided to sex them for him and separate the boys and girls.

    He's got short lengths of 40mm PVC for hides and I could see the blunt end of a yabby sticking out one end, so I covered that end with my fingers and quickly scooped the pipe out of the ST in the other direction... theory: the force of the water rushing into the pipe as you scoop it out keeps the yabby in the pipe, plus yabbies swim backwards.

    It was all going good... except I didn't count on there being two yabbies in the one short pipe... the second one facing the opposite way, ie: sharp end towards my fingers that were covering the end of the pipe.

    Here endeth the lesson.
    .
     

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  10. bobbyd

    bobbyd Member

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    Contary to popular believe yabbies arnt cannibals and I have netted berried females in winter, water was 8 degrees, evidently in colder water it just takes longer for the eggs to mature/hatch
     
    Last edited: Mar 9, 2011
  11. RupertofOZ

    RupertofOZ New Member

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    You must have a strange breed of yabbies down there in Vic...

    Mine regularly eat one another...
     
  12. SolTun

    SolTun Member

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    Last edited: Mar 10, 2011
  13. Yabbies4me

    Yabbies4me Administrator Staff Member

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    Yep!...

    On the weekend I was given 8 yabbies to put into my single blue barrel system. I brought them home in a 20Ltr mayonaise drum, I salted the water to remove parasites and left them overnight in the drum with an airstone in the water. When I went to put them in the blue barrel system in the morning... there was only 7.5 yabbies!... one had shed his shell overnight and his mates had helped themselves to a meal.
    .
     
  14. Yabbies4me

    Yabbies4me Administrator Staff Member

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    I have no reason to doubt others experience with yabbies, especially from different regions, but my experience was different to the above...

    A few years back I used to breed yabbies and because of the size the tanks they weren't heated. I only ever saw two berried females in water colder than 14º (my tanks could get down to 11º or 12º in winter), on both occassions the eggs were on the females so long they went mouldy (there's a big word for it, but I can't remember it)... and they shed the eggs.

    Cheers, Yabbies.
    .
     
  15. Benno

    Benno Member

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    Probably you were both talking about different species of "yabbies".
     
  16. Khriz

    Khriz New Member

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    How do we tell or know which yabbies are male or female? Any photo reference on this? Thanks...:24locos:
     
  17. Yabbies4me

    Yabbies4me Administrator Staff Member

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    Hey Khriz.

    Where the third set of legs join the body the females have two round openings, one on each side, they just look like a small round dot.

    The males "bits" are at the base of the last set of legs.

    Cheers, Yabbies.
    .
     
  18. SolTun

    SolTun Member

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  19. bobbyd

    bobbyd Member

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    Too true Rupert, I have had plenty eat each other aswell but I dont think canabilisim is a natural thing for them, I cant image their species surviveing, but other species do eat each other after mating.
    Evidently they are attacted to the chemical excretted during moulting, hense the hiding place requirements.
    Good water and plenty of suitable food and they will live happerly at high densities.
    The extensive style yabbie farmers (multiple dam system) I have visited dont provide the above.
    I dont know if the berried females I have caught in winter ever hatch their eggs, I wouldnt think so.
     
  20. REDCLAW PIRATE

    REDCLAW PIRATE New Member

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