Black spots on betta?

[Ivory142]

Got these black spots showing up on my betta fish.  he had one on his head, I went ahead and threw some aquarium salt in there and waited, it seemed to go away.    Then I noticed these.  You can see them on the other side of his body, but I thought I would just show this side.  It also looks like a black line is forming on his underside where the beginning of the bottom fin is.  You can see it there.   

I did a water change today after having salt in there for a week.  Then I tested the parameters (listed below).   I changed the filter cartridge, it was time to do it.  

P.S.  - He isn't acting lethargic or not eating.

Does anyone have an idea of what is going on?

 

•  
• pH - between 7.2 to 7.6
• Nitrates - 0
• Hardness - not sure
• Nitrite - -0
• Ammonia - 0
• KH/Buffer
• Water Temperature  usually 78-80

The second picture is what he looked like when I first got him.  Just wanted to show his head.

Edited July 15, 2023 by Ivory142

[TheSwissAquarist]

@Colu

If I remember correctly, betta colors do change as they mature, and looking at his head it seems that the colors between these ‘dark spots’ and the head scales are matching.  Just to demonstrate the possibility: 
The darkness also seems confined to where the scales are, however he may also be losing scales. 

[Ivory142]

I can still see the scales.  I had to take a video and then do a screen capture, so the image quality isn't great.  Bettas are always moving.  Thank you for the reply, because I've been worried about this.  I usually don't get blue fish, but this one just appealed to me.

[TheSwissAquarist]

On 7/15/2023 at 6:39 PM, Ivory142 said:

I usually don't get blue fish, but this one just appealed to me.

These days I can’t walk past a cool betta without thinking about squeezing it in one of my tanks. 

[Colu]

If it's just change to the colour of the scales that can be  natural colour change as bettas age it not uncommon for them to change colour if its raised black spots then something else could be going on its difficult to tell of your picture if the black spots are raised @Ivory142