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Fresh water prawns

I saw a raft set up in China that grow Malaysian prawn underneath their deep water rafts. So I'm interested to know if anyone is growing Australian Red claw or Malaysian prawns in their system that way?

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Permalink Reply by Dr. George B. Brooks, Jr. on July 30, 2012 at 6:10pm

Hi. Some quick answers. Prawns are a low density species and very very agressive. However their ability to survive and grow depends a lot on food sources and space availability and there is a lot not known about how they respond to floating raft systems since each one is different. Inside of your growbed you have a 3 dimensional space filled with food growing on the roots (bacteria and other stuff) as well as dead roots and wasted feed (they are omnivorous). Lots of spaces to hide during molting (shedding their skin) which is when they are vulnerable to cannibalism, that is until they get big that is. In standard 2 dimensional pond culture if you are really really good you can get about 2,000 pounds per acre. At 10 prawns to a pound, thats about 2.1 square feet of space per animal. That gives you a good number to start with. I suspect with all of the extra food, varied diet and available 3 dimensional substrate provided by the roots you may be able to do better.

Males grow best but it is very difficult to tell the difference when they are small making all male culture difficult. Also it is not simply male vs female. There are a number of different male morphs that grow at different rates (orange claw vs blue claw for example) and the males can shift from one to another considering conditions in your grow tank.

Breeding is not easy. Though they readily mate and produce fertilized eggs, It takes very specialized brackish water (salty water about 15ppm) conditions to bring larvae to the stage where they can survive in your aquaponics. This is why there are so few breeders.

Just as a matter of interest, in the Dominican Republic the conditions for M. rosenbergii breeding may be found naturally. According to the FAO, the species was introduced there and may be established. http://www.fao.org/fishery/introsp/1314/en

There is also a couple of native Macrobrachium species you may wish to consider M. acanthurus and M. carcinus. M. carcinus has big meat filled claws that may add to their marketability. I've been wanting to try them for some time.

http://www.fao.org/docrep/field/003/ab490e/AB490E03.htm

I'm not an expert on shrimp transportation particularly shipping, at least not yet. I can tell you however my source which is Aquaculture of Texas. Craig Upstom has been breeding and shipping shrimp for years and may be able to address your question. http://www.aquacultureoftexas.com/

If the water is good for tilapia, it is good for prawns.

Hope this helps

Permalink Reply by Stuart Polkinghorne on July 31, 2012 at 12:14pm

Thanks Doc. I found some Red claw at a aquarium shop yesterday and the guy I get tilapia from has a few M. Rosenbergii in a small tank , not sure if he will sell me any though?

I also have a contact at the agro dept I can talk to, I'll ask if he knows who has some.