Is it normal for a Moore Fancy Goldfish to change color?

Question

from black to white then gold? i read up that they only change with age( live up to 20 years) but the fish that i have now is only about a year and a half.... any ideas? one of my fish just died today, from an unknown cause, could the death of the fish and the color of another be linked?

Answer 1

I haven't heard of black to white to gold, but I have heard of black to gold to white. They can change color with age, but it's not unusual of goldfish to undergo several color changes due to genetics while they're young. This link documents a change from black to gold: http://thegab.org/Articles/ColorChange.html

Did your fish show any unusual behavior before it died? My initial thoughts on this would be that if the two were kept in a smaller tank, as they grew, the ammonia they produced (and therefore the nitrite and nitrate as well) increased as well. Even though two goldfish might be fine in a smaller tank while young, the same tank may not support both as they got larger. Did either show symptoms of swimming at the top of the tank and "gasping" at the surface, or sitting at the tank without much activity? See these other symptoms: http://freshaquarium.about.com/cs/disease/p/ammoniapoison.htm , http://freshaquarium.about.com/cs/disease/p/nitritepoison.htm

Another possibility would be the heat of summer - goldfish prefer cooler temperatures (under 75o, and ideally under 70o), so if the water was too warm, there may not have been enough dissolved oxygen for them.

Answer 2

Hi v-v, I'm sorry to hear of your loss. I don't think it has anything to do with the colour change on your Moor however. Black is the most unstable pigment so it's often the case that Black Moors end up anything but the colour their name suggests! This is quite normal & absolutely nothing to worry about, also it can happen at any time during the lifetime of the fish, or sometimes the colours never change it's totally unpredictable but generally they get lighter with age.

Regarding the fish you lost today perhaps it would be an idea to post details, did it display any strange behaviour/appearance or have you altered/added/removed anything in your tank recently? Alternatively feel free to email me about this, I may be able to suggest something.