I had to catch a pictus cat that I felt had outgrown my 55g tank. (I've since switched to smaller schooling fish... but **** I loved that fish) The only way I could catch him was to use a 2L ziploc food container (rectangular, almost clear) set down in the bottom of the tank, and I had to chase him into it with my hand, which I wrapped a scrap of old pillow case (thoroughly rinsed) so as to give some protection against his spines. I had to take all of the plants and decorations out of the tank, and it took me **** near 20 minutes, but I finally managed to corral him into the container and scoop it out before he could swim back out. (I actually caught him 3 times before that, but he kept getting out before I could get the container out of the water) A pictus cat's fins will not get caught in bed sheets/pillow covers, so if you make a small bag out of one, it would be great for catching them also. (used by large catfish owners because its easy on the fish and lets water out of it slowly so as to minimize stress)