From Sakae Sushi

Yu sheng (Lo-hei)… A must have dish during Chinese New Year in Singapore~

It usually consists of strips of raw fish (most commonly salmon), mixed with shredded vegetables and a variety of sauces and condiments, among other ingredients. Yusheng literally means “raw fish” but since “fish (鱼)” is commonly conflated with its homophone “abundance (余)”, Yúshēng (鱼生) is interpreted as a homophone for Yúshēng (余升) meaning an increase in abundance. Therefore, yusheng is considered a symbol of abundance, prosperity and vigor.

http://en.wikipedia.org/wiki/Yusheng