Congrats and thanks ficbot! Funny (very) short story.
Native french speakers would perhaps want to make remarks as for the use of french language (which seems quite good to me).
Just two minor remarks:
1) Usage of "tu" instead of "vous", as often typically do native english speakers (in english "you" is for all cases).
It is not likely that such a dialog in "singular" could happen in french, though it's a one-to-one dialog. "Pluriel de courtoisie" (vous) is rather a rule in such cases.
2) Concerning fishes, "échelles" is probably an erroneous translation of "scales". As far as I know, the word used in french is
écaille.