  This is an entry for the Gallery of Fluid Motion of the 62st Annual Meeting
of the APS-DFD (fluid dynamics videos). This video shows the formation of
sharps cusps in the interface of a viscoelastic liquid with air considering a
selective withdrawal device. We found that a wide variety of shapes can be
observed, similar to those appearing in the rear of air bubbles ascending in
non-Newtonian liquids.
