Have you considered fresh water crayfish as a source of food post pole shift? In Australia we have Yabbies and Marron, they are scavengers and mud dwellers and the hardest part in raising them is keeping them from migrating to other dams. They can be raised in indoor tanks for long periods of time on minced meat and fish food (brine shrimp etc.). When we finally re-locate to our safe place we intend to have both crustaceans and fish with a system for protecting a small amount of breeders to begin farming again post pole shift.
Offered by Jan.
I have raised blue australian yabbies in my aquarium some years ago. They grow really fast, but when growing they tend to eat each other when smaller yabbies come into contact with stronger bigger yabbies (sort of fresh water crayfish). They practically ate everything I gave them, dinner leftovers, meat etc.
Offered by Michel.
If I remember my biology, crayfish lay eggs which they keep beneath their tails until hatched and big enough to avoid being eaten. Ever caught a mother crayfish with babies clutching the underside of her tail?
Offered by Roger.