White squiggly string on dorsal fin of Glofish Tetra

I am new to this forum and this is my first mystery. I have tried googling and finding information but can't find anything that looks like what my fish has. I have a 15 gallon tank with 3 glofish tetras and a mystery snail. Ph is 6.2 temp is about 75. Two of the tetras are about 1 yr old and the one I am nervous about is about 6 months. He is eating fine and isn't displaying any different behaviour but about a week ago I noticed this white squiggly string coming out his dorsal fin. I thought he swam through poop and it got stuck. But now there is a squiggly thing coming out his tail fin (not poop) too and the top one is still there. I did a 30% water change 2 days ago and no difference. I attached a pic. Is this a worm or parasite? Should I be concerned or try to get it off?

Welcome to TFF

Anchor worms, maybe? @Colin_T , have a look, please

Slaphppy7 said:

Welcome to TFF

Anchor worms, maybe? @Colin_T , have a look, please

Anchor Worms in Freshwater Fish

Anchor worms in fish can be an itchy problem. By properly quarantining new arrivals, you can easily reduce them on your fish.

www.thesprucepets.com

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Thanks so much. These pics might be better.

post pictures of the fish under normal white light

Hopefully these are better. He is fast so it is hard to get a good shot.

Thank you so much for taking a look. I am a bit nervous for him and don't want him to infect my other little guys.

can you turn the normal white light on the tank when you photograph the fish?

Colin_T said:

can you turn the normal white light on the tank when you photograph the fish?

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That actually is the normal light. The tank has a black background so it makes the fish glow. I can try and put my flash on the camera. So sorry!

I'd remove it with tweezers. I had something similar on some tetra imported from Thailand a few months back, they were slightly different than the standard anchor worms I'm used to. After removing them all I had no further issues.

One more try

Think it is Dermosporidia