"Fishing License" joke

Banta was carrying a large fish in a bucket of water away from a lake, which was well known for its excellent fishing when a Fishery officer stopped him.
The officer says, "Do you have a fishing license?"
Banta replies, "Don't need a license, this is my pet fish."
"Pet fish?" the officer asked.
Banta answers, "Yes, every night I take my fish down to the lake and let him swim around for a while, then I whistle and he jumps up on shore and I put him in his bucket and we go back home."
"That's a bunch of baloney, fish can't do that."
Banta looks at the officer and says, "You want me to show you?"
Very curious now, the officer says, "O.K. I've got to see this"
Banta pours the fish into the lake then stands there waiting.
After a few minutes, the officer turns to Banta and says, "Well?"
"Well, What?" Banta says.
The Officer asks, "Are you going to call your fish back?"
"Fish! What fish?" Banta responds.