cowtail stingray
... that the tough skin of the cowtail stingray is used to polish wood?
... that the tough skin of the <b id="mwE2M"><a href="./Cowtail_stingray" id="mwE2Q" rel="mw:WikiLink" title="Cowtail stingray">cowtail stingray</a></b> <i id="mwE2U">(pictured)</i> is used to polish wood?