Fishes and their Symbolism
The fish as a symbolic creature represents abundance and wealth. Feng shui practitioners recommend having fishes and double fishes as good luck charms.
Yu, which means fish, phonetically matches the word for abundance, which might be a coincidence but is symbolic as well. It is very 
common to see objects representing fishes in many Chinese houses, most of the times in the kitchen but sometimes in the living rooms as well. Any suggestion of fishes even if it happens to be a design looking like fish scales is also considered to bring in wealth luck.
Fishes are an abundant source of nourishment and the staple diet of many oriental countries, especially those that line the ample shores and islands in
Fish is also seen as a symbol of fertility. Fishes are believed to be survivors and multiply in abundance. They exist in clusters and move as a team which makes them symbolize unity and marriage. A fish is believed to be a symbol of life renewal. They show strength of survival.
The Chinese believe that luck comes in pairs. They believe that a pair in any feature is a symbol of abundance; hence double fishes represent unity, marriage and abundance not only in food provisions but also in children and family and happiness in general. Having double fishes in the living room or the room in which the family gathers to eat is a great way of assuring abundance in all aspects and for all the family members.