hi gold fish color changing weird

[BETTA999]

i had my gold fish for some time and i got it black an now half of him is gold and another thing it is having red bloches on the end of his tail now what it is

Edited January 9, 2022 by bettta999

[lefty o]

i know almost nothing of goldfish, but do know that some strains will change color as they mature.

[Colu]

When goldfish are young can have a brown or or  black colour as they get bigger the colour can  change quite dramatically I can see the red blotches in your picture if it a long fined variety it could have damage it high levels of ammonia can cause reddening of fins as well

Edited January 9, 2022 by Colu

[BETTA999]

thanks colu it is a veil tail

[PineSong]

A photo of your fish's tail where the red streaks are would be visible may help us tell whether the fins are red due to infection or coloration.

Lots of black goldfish turn orange as they mature.

Red streaks caused by infection may need to be treated with very clean water, aquarium salt added to the water, and/or antibiotics.

Have you tested your water to see what the ammonia or nitrite/nitrate levels are? Those might offer a clue if it is an infection.

[BETTA999]

pine song just water changed and its not part of his coloration i will treat him