虹管是一种生物构造，属于水生软件动物的一部分。下列三类水生软件动物：腹足纲、双壳纲和头足纲皆具有虹管。换言之，部分海生或淡水螺类、蛤蜊以及章鱼、鱿鱼等近似物种皆具有虹管。虹管属于管状结构，通常供液体流动（少数情形下供气体流动）。对软件动物而言，虹管中流动的液体可用于移动、进食、呼吸以及繁衍后代等多种用途。虹管同时也是软件动物的覆盖层，虹管所造成的液体流动则将液体导入（或排出）覆盖层上的孔洞。部分腹足纲生物具有单一虹管。双壳纲生物则具有成对的虹管。头足纲生物所具备之单一虹管或漏斗状构造则被称为漏斗管。

A siphon is an anatomical structure which is part of the body of aquatic molluscs in three classes: Gastropoda, Bivalvia and Cephalopoda (members of these classes include saltwater and freshwater snails, clams, octopus, squid and relatives).

Siphons in molluscs are tube-like structures in which water flows (or more rarely in which air flows). The water flow is used for one or more purposes such as locomotion, feeding, respiration, and reproduction. The siphon is part of the mantle of the mollusc, and the water flow is directed to (or from) the mantle cavity.