Why did my small common goldfish turn a mottled black color?

Question

This happened over the course of a week.

Answer 1

A fish turning TO black isn't always a good sign. The coloration indicates that it's been exposed to some type of irritant or rough handling (think of this as being similar to a bruise or rash developing).

Assuming you haven't been abusing your fish, and there aren't others in the tank bullying it and pushing it into the decor, I would first suspect your water quality. Goldfish produce a good amount of wastes, including ammonia, which is toxic to them. The ammonia is converted by bacteria to nitrite (which is also toxic) before being converted to nitrate, which they tolerate better. If you've only had the fish for a few months, or it's in a small container (especially if it's unfiltered), this may be your problem. Goldfish shouldn't be in less than a 10 gallon tank as babies, and may need 10-20 gallons per fish as adults. Common goldfish can get up to 18 inches, and the volume is needed to dilute their wastes. You can take a water sample to your pet store for testing to see if this is your problem.

Also, if you've used aquarium salt or medication in the tank, these may have caused the problem if too high of a dose was used. When doing water changes, you should only replace the amount of medication/salt removed in the replacement water, not the entire dose, unless specifically directed to do so by the instructions.

A last thing to look for would be the presence of parasites on the fish. This may be causing him to scrape against objects in the tank hurting himself in an attempt to try and remove them, or their damage to the skin may be the source of the color change. If this is the problem, use of a good antiparasitic medication would be in order.

Answer 2

Your Moore which by employing the way is the only real black goldfish is raised in runs. regrettably they are additionally mixed breeds with others. high quality breeders will basically breed blacks with blacks, despite the fact that if moores are available lots of colorations, yours grow to be only a mix and not something carried out by employing you nutrients or different will replace him back. he would be gold/orange to any extent further. Sorry. on occasion it rather is the way it si.

Answer 3

Sounds odd, but going by um, science, I would say a change in environment? Maybe you use different water then what it normally has, food change, any number of things could have been the cause.

Answer 4

that is a sign it was trying to recover by ammonia poisoning -- how large is the tank? Or, sometimes blue goldfish change colors...

Answer 5

OMG! What did you feed that poor thing?

Answer 6

hahahaha

Answer 7

flush it