Koi fishes and how an Hong Kong actor `lost' his fishes

Koi's are actually carps. Many instead of keeping real fishes purchase paintings of Koi's swimming. Most of the paintings usually have 9 Koi's swimming. (A few paintings have 8 fishes).
In Mandarin 9 sounds like `longevity' and in Cantonese 8 sounds like `prosper'.
The last illustration, is interesting because, it can also be applied to a swimming pool. Besides an uneven flow of water, it is equally inauspicious to have a swimming pool in the shape as mentioned in the illustration.