How many types of freshwater eel tail catfish are there?

[jjohnwm]

The dorsal on the OP picture is way back by the tail; the D dogofwar fish has a dorsal right up near the head. Don't think they are the same.

 

[dogofwar]

Nope - different fish

 

[blackbullhead]

The fish in OP's picture is part of the family Trichomycteriae (which includes the dreaded candirus). Can't narrow it down much beyond that, but looks like Trichomycterus or Ituglanis.