A. All those white spots are due to the infamous “Ichthyophthirius multifiliis” or better known as “Ich”. This is one of the most common fish parasites and or diseases encountered in the hobby, and if dealt with sooner rather than later, it is easily curable.

A fish recently bought with little research, being fed the wrong diet can be a culprit as-well. Not all fish will accept freeze dried staple such as flake food, and such species would require a more specialized diet.

 Another obvious reason could be that the fish are suffering from a sickness of some sort. Like all animals, including humans, when fish get sick they lose their appetite, and in some sicknesses such as the dreaded BLOAT, or Dropsy, the fish will altogether cease eating and if not dealt with sooner will eventually die.