Hey everybody, I know this isn't a goldfish help forum, but I trust you guys a lot more to care for fish than searching google blindly.
My goldfish, Nigel is suddenly very listless. He still comes up to eat, but then just slowly scoots around the tank, instead of wildly swimming around like he did pretty much yesterday.
I'm thinking he might have parasites of some sort because his stomach looks a little flatter than usual, but I'm not sure. I would also get a picture of him but he's always been absolutely frightened by cameras.
His tankmate, Dea, is fine.. she's still chubby and swimming around.
I recently did a fairly large water change because I was away (my boyfriend was feeding them), so I'm not sure if it is stress related or not.
Nigel and Dea are both 2 years old in an 8 Gallon. I know it's small for goldfish that need 20+, and they've lived happily in it for 2 years so please don't just disregard this as an "overstocked" case. I've had 4 very happy goldfish that have lived around 8 years in a 15 Gallon before, which is also overstocked. I didn't plan on buying Nigel and Dea for the point of torturing them in an 8 Gallon. It was the only tank I had, in my apartment with barely enough electrical plugs for basic needs, and I only adopted them because my biology lab was going to just flush them after our shoaling experiments. Ideally I would put them in an aquarium pond, but that of course is out of the question.