New black corys

[Rainbowqueen18]

Young black corys purchased...they have naked spikes protruding from back fun and dorsal fins ..is this a disease ??

 

[Essjay]

Could you post photos of the fish please so we can see what you are referring to.

 

[coriesinhawaii]

Without a picture it’s hard to say but from the description it sounds like a bacterial infection has caused the fins to wear away. With good water quality and diet they might grow back on their own without medication. You could add an immune booster like Voogle to help.