I've read recently it was less than 15% of hobby fish were still cyanide caught. That said cyanide poisonsing works pretty quickly, w/in th efirst monh or so and usually the fish in question don't eat and get emaciated. If you had your fish for more than a few weeks i doubt they were cyanide caught. I guess it still could happen
I believe its still only used in one locale
Bill- I take it you did Mass spect or GC to show that infact the livers of your fish in question has cyanide metabolites