- The kamongo was a fish that breathed air.
- What does that prove?
- Nothing. Except that the kamongo fish, which has lungs, exists today, right here in the Amazon. It hasn't changed in all these millions of years.

12 seconds sound clip from the Creature from the Black Lagoon (1954) movie soundboard.

You can hear this line at 00:40:41.472 in the Blu-ray version of the movie.

Quote context

[...]

- The unknown always seems unbelievable, Lucas.

- One accepts these things as legend and lets it go at that, but to actually believe that there exists something like a human being that can live underwater...

- This is no legend, as you'll soon see for yourself.

- What about the kamongo? Science hadn't heard about it until a few years ago. The kamongo lived way back in the Devonian age.

- Interesting that the fossil I found was out of the same period.

- The kamongo was a fish that breathed air.

- What does that prove?

- Nothing. Except that the kamongo fish, which has lungs, exists today, right here in the Amazon. It hasn't changed in all these millions of years.

- That doesn't prove the possibility of a gill-man.

- If the evolution of that species could reach a dead end way back then, and still survive, why couldn't another?

- Where is he?

- I was sure I had him in my finder.

- For a merman, he takes a fine picture.

[...]