The riddle says like this:
We have 5 houses of five different colors and in each of them lives a person of a different nationality.
Each of the owners drinks a different drink, smokes a different brand of cigarettes and has a different pet.
We have the following keys:
The British lives in the red house.
The Swede has a dog.
The Dane takes tea.
The green house is to the left of the white house.
the owner of the Green House drinks coffee.
The person who smokes Pall Mall has a bird.
The owner of the yellow house smokes Dunhill.
The one who lives in the center house drinks milk.
The Norwegian lives in the first house.
The person who smokes Brends lives next to the one who has a cat.
The person who has a horse lives next to the one who smokes Dunhill.
The one who smokes Bluemasters drinks beer.
The German smokes prince.
The Norwegian lives next to the blue house.
The one who smokes Brends has a neighbor who drinks water.
And finally the question:
Who is the owner of the fishy?