Story
STO: Caninoids love to trade. They also have an acute sense for a good deal.
STS: Caninoids are tough traders. They will offer deals you cannot refuse.
Gameplay
When playing the Caninoids you will have some advantage with regards to trading. So you should pick your starting technology at level 2 accordingly. A good idea is something the other players do not have, or level 2 in Propulsion which will allow you to get into contact for trading quicker.