My tank has been set up a couple of years and i have been through many different types of fish. i currently have a couple cherry barbs, some neon tetras, and a red fish that i forgot the name of. just recently one lone cherry barb started growing pale and got this big patch of black and white scales. then it only occasionally it would use its fins to swim. finally it would lay down randomly on a plant or rock and sit there for a long time. it is still doing this now and for some reason out of no where it turned a very bright red. all the other fish are acting normal. oh and earlier it looked as if it was protecting something. possibly eggs? can anyone tell me what might be going on?