small pointed structure serving as a skeletal element in various marine and freshwater invertebrates e.g. sponges and corals
例句
用作名词(n.)
Magnetic flux tubes that tilted away from the vertical can focus and guide the rising material up into the solar atmosphere to form a spicule.被垂直掀动的磁流管可能聚集并引导物质上升进入大气层内形成针状体。
