Nearly all the Gammarus I had in the 10 gal tank have died. They seem to have disappeared rather quickly. I have no idea what happened to them. The ones in the 3 gal tank are doing better, but they're not multiplying. I put 3 from the 10 gal tank into another 10 gal tank. It's the one I put the Azteca in. I haven't seen any sign of them either lately.