hypural

hypural notch The crease formed when the caudal fin is bent or flexed.

尾下骨凹槽当尾被弯曲或弯曲时候，成摺痕。

hypural bones The fan-shaped series of bones (sometimes fused to one or two plate-like bones) to which the caudal fin rays are attached.

尾下骨尾成列硬骨(有时融合成一或二个板状硬骨)。