How to make dotted line for Bubble game?

I am making Bubble blast game and want to draw that animated looking dotted line that guide the ball
can any one tell me how to draw that line?

Try with the particular system in unity .In the particular editor set start speed to 18. In the Shape Tab, check SHAPE, choose EDGE and give it a 0.01 radius. Check the new particle controls in the release note of unity 5.4. From the site : We’re also rolling out a new trigger module, which allows you to modify particle properties inside a list of colliders. In its simplest form, you can destroy particles when they touch the colliders, but, by using a custom scripting callback, it’s now also possible to modify all particle properties. You can see this in action in the viscous volume effect below. Another keyword : raycasting.