i think my duster died

i woke up this morning to find that the end of my feather duster's tube was covered in slimy stuff. kind of like when a fish dies and you dont get to it quickly enough and it pretty much disappears into a slimy mess. i only have 1 fish and the remains didnt look like my fish, since he is white and orange and the slimy stuff had some stuff that looked blueish like it was from my duster. i removed the slime. i didnt remove the tube however. should i?? last time i checked (and not today) it was stuck to the inside of a rock. do you think he died, or is this normal?? it doesnt seem normal, its never done this before. tia.
 
Top