I had 2 goldfish and 1 died unexpectedly and now the remaining one has become lethargic and just just doesn't swim around the tank, as it did when it had a companion with it. Will it eventually die if I don't go and get another one soon ?

Hello Glenn I'm sorry to hear about your troubles, the best place to start is going to be having the water tested. Give us a call and we would be happy to help.

Or it could be nematodes (worms). Ick will show up on the body of the fish and looks like tiny white . Nematodes will live inside the fish and at night will protrude out of the anus. They will cause a fish to be lethargic. It could also be something else as . Parasites. I'm so sorry.

Im sorry for your loss and yes it will die soon but it sounds like it has ick. Check the tail for white dots. You need to treat your tank with ick cure today. It can be bought at any pet store or any walmart. Maybe to late but worth a try.