The fish are at the stage where they need to move onto bigger things to eat whilst they will still eat plankton , blood worms and brine shrimp I am going to introduce them to cooked yabby meat. I have caught about twenty large yabbies from my largest dam and I am going to prepare them the same as I would to eat myself . Once I have the tail meet I will freeze it , this allows me to store them for a long time and enables me to cut them into fine strips the correct size for the fish.If you would like to grow yabbies for yourself to eat and you have a dam and yabbies are present  then you can  feed the yabbies this will give you more and bigger yabbies, yabbies like legumes so peas beans Lucerne, all of these are legumes and there  are other things they will readily eat, however stay away from meat It  could mess up the water if it goes uneaten . if you wish to go further into growing your own yabbies on a bigger scale then please  leave your number in Coments  and I will be glad to help as much as I can.