Jerome,
I don't recall having seen one before either, but it may have a different purpose.
While it is located at the bottom of the strainer basket where a drain would be, I can't think of why it would have a drain there (and none of the ones I've seen had a drain there), so, maybe it is for an intake from a chlorination unit?
That strainer basket is under negative pressure, so it would be sucking in whatever was being fed into that tube.
Looks like the red coupling/connector end is broken, which may be why the two pieces are separated.
(I rotated the photo so 'up' is 'up'. Either that or Von has an uncanny ability to stand horizontally from the side of vertical surfaces.

)