Question: what are the two veins on a shrimp?
Answer: There are two “veins.” One is a white vein which is on the underside of the shrimp. It is white because a shrimp has clear blood. There is no real food safety reason to remove this one (I don't) but you may do so if it bothers you. The main “vein” is the one which runs along the top of the body.