hypurals In fish larvae, flattened bones along the ventral side of the urostyle. Those on the dorsal side are called epurals. From these bones the caudal fin rays arise.

• 尾下骨(仔鱼)在仔鱼中，平的硬骨沿著尾杆骨的腹侧边。在背部侧边上的称为尾上骨。从这些硬骨尾鳍鳍条出现。