Backyard Aquaponics
A place to discuss aquaponics

Any chance these could be incorporated into a AQ system instead of say yabbies?

I would have to keep them away from the fish but i think i could manage that

Are you talking marine or freshwater ? Not aware of any freshwater crabs that are big enough to be worth the effort.

Freshwater (Im thinking of the ones in fish tanks at chinese restaurants) They might not be fresh water now i think of it lol

Some marine species can be grown quite successfully in a brackish system (3-5 ppt salt). Marine shrimp for example can be grown at 3ppt as long as they are slowly conditioned to it as post-larval. Don't know about any species of crabs or lobster. You would probably need to get them young and I am unaware of any breeding facilities for those species. Freshwater prawns are very tasty, but they are also territorial and don't take well to decent stocking densities.

Pretty sure you're talking about the big King Crabs - they're definitely marine.

http://www.nativefish.asn.au/spiny.html
Don't know if anyone has tried these.or if you could get any to try.
But would be impressive .

Think they're extremely slow growing... like years...

Blue crabs can grow out in a year but are extremly cannibalistic. This guy grows them out for soft crabs in individual enclosures that are pipe to a main water system. I bet there are a lot of people wish for this system with the ongoing BP spill and fishery closures.
http://www.youtube.com/watch?v=3KtzOhVfV6g.
There is also more info here:
http://www.thefishsite.com/fishnews/801 ... ater-ponds
You may need to do some research to get the little crablets as the larval stages have to be in salt water and is a fairly complicated operation. I was planning on just saving the by catch from shrimping.

I've seen some websites mentioning freshwater farming of blue crabs in ponds in the American Southeast. It looks like they don't do much besides put crabs in, but on the other hand the stocking densities might be quite low.