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Thread: M. Rosenbergii

  1. #1
    Moderator badflash's Avatar
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    M. Rosenbergii

    I tried a shot at raising these guys a couple of years ago. They were easy to keep, but I think in a recirculating system they need to be harvested when they are the size of a jumbo shrimp and not allowed to get sexually mature. Once they get over about 3" in body length the males become VERY aggressive and start killing each other.

    The basic process is to get some post larvals. You need to buy a thousand or so, as no one sell just a few for any reasonable price. You can get a thousand for $85 + shipping. These guys are only about 1/4" when you get them, but they grow fast. Be sure to provide loads of shells or small tubes for hides as they molt often and the others will eat them if they can.

    Here are a couple of little guys hiding under a submersible heater:


    A couple of weeks later they look like this:


    At a month:


    At around 2 months they looks something like this:


    The big males look like this at about 6 months. He's a little over 6" from nose to tail:


    I was raising mine in a kiddie pool using 2 400 watt water bed heaters to keep the water at 80F. I used a pond pre-filter and a home brew ball filter. It worked great. I wish I knew about aquaponics back then. I used bubble wrap for insulation.


    I'd recommend doing a 3 month cycle and then harvest. A 6' kiddie pool will support about a 1000 shrimp up to about 2", then you'll have mayhem, so just harvest them.

    They eat just about anything, but I used sinking catfish pellets. Keep the water really clean as bad water triggers aggression.
    The best fertilizer is the farmer's shadow

  2. #2
    Moderator jackalope's Avatar
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    Re: M. Rosenbergii

    Would something like these be good enough to use as food for Tilapia? It looks like at a month or two, they'd make a great live fish food. And $85.00 per thousand would probably give you some nice fresh meat for the Tilapia, as well as provide you with some breeders (If you were able to keep the aggressive ones separate). I don't know if there would be something else that would be cheaper, but if there was, that would be better. I'd only be interested in using them for food, not eating.
    I use the Linux Operating System ...... Free as in beer!
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  3. #3
    Moderator badflash's Avatar
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    Re: M. Rosenbergii

    Actually, the tilapia would provide nice fresh meat for the prawns. In 2 months they have some pretty wicked claws and can pluck small fish off as they pass by. Fingerlings appreciate very small crusteaceans, but once they get to be 2-3" they don't much go for live food. They become dominatly plant eaters.
    The best fertilizer is the farmer's shadow

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    Re: M. Rosenbergii

    "Would something like these be good enough to use as food for Tilapia?"

    Yes. In tilapia-prawn policulture one of the main advices given is to seed prawns first and a month later seed the tilapia fingerlings. Why? Because tilapia can eat the young prawn post-larvae. But I think that might be expensive. Might you think about using artemia salina instead (sea monkeys), this is cheaper!

  5. #5
    Moderator badflash's Avatar
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    Re: M. Rosenbergii

    Tilapia will eat anything, so live feed isn't really needed. When mine are tiny I feed them crushed flake food, which is quite inexpensive. As they grow I change them over to floating granules, and finaly to pellets. If you have access to duckweed, they can feed off that once they are 1/2", which just takes a few weeks.

    If you do feed brine shrimp, add a couple of tablespoons of sea salt per gallon. I don't advise this if you are growing plants, but in fry tanks it does a couple of things. This protects the fry against a lot of diseases, and the brine shrimp can live for days without making a mess.
    The best fertilizer is the farmer's shadow

  6. #6
    Moderator JCO's Avatar
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    Re: M. Rosenbergii

    jrmarchesini,

    Welcome aboard...glad to see you post. How about telling us a little about what you have going on. I remember speaking to you via emails and you were quite involved in AP
    JCO
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  7. #7
    Moderator jackalope's Avatar
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    Re: M. Rosenbergii

    I've changed my mind about these shrimp, I like the marbled crawdad (Marmorkrebs) ....... If they get too big, I can drop them in the blender (like I do with veggies and sprouts, blend it all together, and make my own flake food. I'm already doing that with lettuce/sprouts and soon will be adding duckweed, frogbit, and water lettuce. I bought some shrimp that the Goldies can't seem to get into their mouth, so the next time I grind up some duckweed, et al, I'll add the shrimp. I'm hoping they love it
    I use the Linux Operating System ...... Free as in beer!
    You're never too old to learn something
    Aquaponics - food'n'fish at your doorstep

    Helena, Montana - Home of the Northernmost Monument to the Confederacy

  8. #8
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    Re: M. Rosenbergii

    It was a blog I was following where a girl raises freshwater prawns (in her farm pond) that led me to the idea of aquaculture. The problem with the prawns is space. They need 1-1.5 square feet of bottom space each to not attack each other.
    Growing old is mandatory. Growing up is optional.

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    Re: M. Rosenbergii

    Can anyone here give me tips on how to acquire these? I've contacted a few aquaculture shops in FL and TX but they wanted a lot of $$ just to ship a small amount. Was curious what other people's experiences were. Even if someone has a few on their hands that they'd like to sell I'd be happy to get them. Preferably males.

    Thanks!!

  10. #10
    Moderator badflash's Avatar
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    Re: M. Rosenbergii

    These are really for pond culture. In an aquaponics setting you end up with 1 male and about 50 females out of 1000 juvies. I raised mine in a 6' diameter pool. They kill each other for sport and eat the loosers. Red Claw crayfish are a better bet.
    The best fertilizer is the farmer's shadow

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