Can you explain this goldfish behavior?

Wife has four Black Moors, 2-3 inches, in a 50 gallon tank.

One of the larger ones was laying on the bottom at one end of the tank looked as if it were dying. Water tested OK but the fish laid there all day so we moved into a 10 gallon isolation.

Twenty-four hours later the isolated fish is swimming around in a healthy manner and all three of the others are laying on the bottom at the same spot at one end of the big tank most of the time. They do sporadically move around normally.

What are your thoughts?

There has got to be something wrong with the water.

Sounds like some contaminant in the water. Goldfish will go to the surface to gulp air, so it’s not an oxygenation problem. Time for a water change and cleaning.

Could it be a temperature problem?

Do a water change and check the temps in both tanks.

Occupy Fish Tank, get some pepper spray.

Done and rechecked.

After the one large fish was moved to another tank the second largest fish is still spending most of its time in the corner. I mean really stuffing itself into the corner and insisting upon staying there until probed to move and moves normally, then returns.

How much water did you change, and are any of the fish behaving normally?

I would check your water temp…do you have anyother fish in the tank besides the black moors?

Check the ammonia levels, not just the PH.

Maybe they were laying little fish eggs…

None of these black moors is named Othello, I trust?

Goldfish spawning is done on the run, so to speak. It involves a lot of chasing and bumping.

Doesn’t it always?

Live bearers, like gambasia and guppies have a sort of hit and run thing.
Lake Tanganyika cichlids do a love of chocolate and flower buying.
Janeslogin, how are the moors?

I wondered about this. I thought they chased each other near floating stuff rather than laying quiet on the bottom but I don’t know this much about black moors.

Here is the complete history: the largest of the two big ones was observed on the bottom appearing near death on 27th. It was moved to another tank and started immediately behaving as it had been doing for a couple of years.

Six parameters were checked, five chemical and temperature and all were normal. 30% of the water was changed pulling temperature down about two degrees to 67oF or so.

Soon the other fish in the tank were huddled in the bottom corner where from which the first fish was removed. The largest stayed in the corner for most of the next 24 hours. The two smaller fish were sometimes somewhat active.

This morning they were all doing their typical floating around up and down back and fourth as our black moors have always done.

So, thanks everyone. Do you know of a link to a forum specifically for black moors?

I’d believe a goldfish forum or aquarium forum would suit your needs.
The above poster is right about the ammonia levels.
How long are these guys, and is the tank filtered?
Goldfish are much more messy than tropicals. I’d filter the hell out of it and have some plants to clean up the water.
And keep lots of water on hand for water changes.

All good advice.

For water changes I’d recommend keeping a pair of 5 gallon buckets around. One filled with water to sit for a few days so the chlorine and ammonia can evaporate, and an empty one to remove 5 gallons of water before you pour the new water in. Don’t stack the full one in the empty one unless you put something in the bottom one so that they don’t fit together tightly, otherwise you won’t be able to seperate them.

Yes, good filtering is important, even for goldfish. Good aeration helps keep ammonia levels down and is healthier for the fish. Be careful about overfeeding them. Don’t give them any more food than they’ll finish every last bit of. Feed them more times a day instead of giving them a lot at once.

Also don’t put a baby in a high chair with a sippy cup in reach of the tank.

Even? Especially for goldfish: goldfish produce a lot more poop than other fish. I had really good luck by doing ammonia cycling before adding fish to tanks and the resultant biofilter helped keep the mess down quite a bit.

I meant that in regard to goldfish’s ability to gulp air to survive in poorly oxygenated water. But high ammonia levels are bad for any fish.