This looks like a sole? It was almost completely transparent. The photo is in focus, but it's still hard to see any detail.
Caught in a trawl.
Tonguefishes are a family, Cynoglossidae, of flatfishes. They are distinguished by the presence of a long hook on the snout overhanging the mouth, and the absence of pectoral fins. Their eyes are both on the left side of their body, which also lacks a pelvic fin.