She doesn't look good I'm afraid, poor thing...
Can you take a longer video please, of the whole tank, including holding still while focusing on the other fish so we can get a good look at the them, and the tank as a whole? And give us as much info about the tank set up/water parameters, recent changes etc. Answers to the above questions, plus how long you've had these fish, and anything else you think may help. Remember that we haven't all seen and memorised any of your previous threads, can't see the tank or fish or run tests ourselves, so we're relying on you to try to puzzle out what might have happened. Figuring out fish illness/deaths is really hard at the best of times, since we're not vets and many things can be the cause, so the more info you give us, the better the chances that someone can figure out what happened and hopefully prevent any further losses.
Copy pasting this template and answering as many questions as you can is a good start.
Tank size:
tank age:
pH:
ammonia:
nitrite:
nitrate:
kH:
gH:
tank temp:
Fish Symptoms (include full description including lesion, color, location, fish behavior):
Volume and Frequency of water changes:
Chemical Additives or Media in your tank:
Tank inhabitants:
Recent additions to your tank (living or decoration):
Exposure to chemicals:
