Did you ask the previous owner what foods he was feeding him but i agree night crawlers should work with the wiggling hopefully triggering a predatory response…
also, while im going to guess parameters are all good have you tested them anyway incase anything is off???
finally sometimes a stray electric current in the tank can also cause problems with scaless fish although probably less likely…
also, while im going to guess parameters are all good have you tested them anyway incase anything is off???
finally sometimes a stray electric current in the tank can also cause problems with scaless fish although probably less likely…