Losing spots in meth blue, gaining them back in clear water

Alrighty, so one of my goldfish, Mrs. T, loses her dark spots when she is exposed to meth blue, only to gain them back and hour later. Her dark spots are part of her mutation, and no other medication makes them disappear. She shows no signs of distress when exposed to blue. What could this be? Do I just have a color-changing goldfish? By the way, she's a Calico Fantail (the most beautiful one I've EVER seen, at that), and her dark spots are actually clusters of little brown dots. The dots never move, or change shape.

I'm just confused, honestly... I've looked everywhere, and no answer. The baths are a preventitive meausure, they get one every other month.

Tank Parameters (using API Master Test Kit):
pH: 7.4
Ammonia: 0.05ppm
Nitrite: 0ppm
Nitrate: 2.0 ppm (A little higher than I'd like)

Tank info:
Fairly heavily planted (aka Val and Sword kingdom) 40gal, home to Othello (slightly stunted Black Moor), Monty (Oranda), and Mrs. T (probably slightly stunted, of unkown past). I have a 40gal sponge filter and a 40gal HOB cansiter. I haven't done a water change in at least 4 months, but as you can see, the parameters are great! I would definitely water change if they were anything less, though. I hope to create a mostly self-sustaining tank, and my dreams are coming true!!! The water is literally crystal clear. I also have about 20 small ramshorns in there, so I am giving them most of the credit for such a sparking clean tank (oh, and my goldfish, for eating plant debris).

 

Bumping because I want answers

 

Sorry BananaBean ,
I read your post much earlier today.
Although I currently don’t have any goldfish I can say what I have seen with other species that may answer your question? I see only one question mark.
The answer to your question is.
Fish change colour.

I have seen adult tropical aquarium fish change colour in a few seconds. It is a communication system that all fish use.
For me to say any more than that requires me to contradict you.

 

Ok, well, I've just never heard of goldfish communicating in that way, but it's possible. And I would love to hear more, even if it does contradict me.

Btw, I did a water change, everything is at 0!

 

A couple of old snapshots of a rainbow cichlid.


And the same fish not long after with her fry.

The top picture is in the same tank about a week apart. Vertical strips are a stress signal or sign of stress sometimes.

One evening when completely sober I had this species flashing colour changes in around 20 seconds as the pair danced the spawning dance.

Just this week I had another species of dwarf cichlid with eggs in a coconut. She was very dark and trying to chase multiple fish away from her eggs. I removed her and the coconut. Before she was even in the net she had changed to a pale colour.

Quote
“She shows no signs of distress when exposed to blue.”
So my belief is your goldfish is stressed by being netted and moved around. That is I believe why it is changing colour.

If you believe your medication routine is doing more good than harm by all means continue. It is not a routine I am familiar with.

 

A couple of old snapshots of rainbow cichlids.
View attachment 851008
And the same fish not long after with her fry.View attachment 851009
The top picture is in the same tank about a week apart. Vertical strips are a stress signal or sign of stress sometimes.

One evening when completely sober I had this species flashing colour changes in around 20 seconds as the pair danced the spawning dance.

Just this week I had another species of dwarf cichlid had eggs in a coconut. She was very dark and trying to chase multiple fish away from her eggs. I removed her and the coconut. Before she was even in the net she had changed to a pale colour.

Quote
“She shows no signs of distress when exposed to blue.”
So my belief is your goldfish is stressed by being netted and moved around. That is I believe why it is changing colour.

If you believe your medication routine is doing more good than harm by all means continue. It is not a routine I am familiar with.

I don't personally net my fish. It just seems harsh on their slime coat, you know? I instead get a container I can scoop them up in, so they don't get hurt. I've been doing this routine for a year or so, and her color thing is consistant every time I put her in the blue.

An interesting thing was that when I put her in any other type medicated water, she didn't react. She also shows no signs of ditress in the blue, and swims around perfectly normally.

I'm not trying to be argumentative, really, I'm not. It's just really odd...

PS: The medicated water really seems to help! It's every other month, so not enough to hurt, but most of my goldfish are rescues with health issues, so it does help signifigantly.

 

My wife has said many times how handy it would be if fish could only talk.
It is up to us to guess what is going on.

For sure fish do some odd things.

 

My wife has said many times how handy it would be if fish could only talk.
It is up to us to guess what is going on.

For sure fish do some odd things.

Heck yes, that would be so useful. Then she could tell be what's going on!

 

here I go again nerding out... Apologies in advance

The words for it is , "Chromatophores and iridiophores"
chromatophores are in the dermis of the skin of fish, crustations, cephalopods, amphibians, reptiles, and that's "true color" only one color is found per chromatophore, and there's many chromatophore cells, the color changing from light to dark is the chromatophores either concentrating to the center of the cell or dispersing to the edges of the cells based on environment conditions.

Iridiophores contain guanine crystals that are highly reflective, like a fish scale for instance. these iridiophores will reflect the color of the outside environment much like a mirror this is "structural color" or modified color from light reflection and refraction.

I'd think the staining of the water with the methelyene blue, and it darkening, the Iridiophores are reflecting light differently number one, and the darkness of the water is causing the Chromatophores of the melanin cells to spread out instead of concentrate and lightening those spots, washing them out overall.

Substrate also has an affect, like white sand vs black rock, or brown soil and how a fish presents their colors either strongly or weakly as well as stained or clear water.

Like a camera, our eyes are quite similar. Color doesn't really exist, light and it's wavelengths exist and our perception of them creates colors and color intensities. color blind people aren't blind to color, they just see it all differently than the majority of people, it processes in their brain different than it does for the majority, but their perception of color is just as real as ours. Apples aren't red, the sky isn't blue and grass isn't green.

Anyways a lot like those arc sodium parking lot lights that make everything look creepy and washed out at night, they don't have remotely good CRI, and as a result the wavelengths of light are bright but poor quality, so our eyes perceives colors quite differently under that type of lighting condition.bright colors are dulled and grayed out, everything is drab and dreary, but it's the light, and our eyes and minds interpretation of the colors under that light, the colors didn't change at all, because colors don't exist, light and light wavelengths exist.