siphon

In zoology, a siphon is a tubular organ found in various animals, particularly mollusks and arthropods, used for drawing in or ejecting fluids. For instance, in bivalve mollusks like Spisula, siphons are tentacle-fringed structures that form posterior inhalant and exhalant orifices, allowing water to enter and exit the mantle cavity for respiration and feeding. Some bivalves, like predatory ones, can even evert their siphons to capture prey. In cephalopods, a siphon (also called a funnel) is a flexible tube through which water is forcibly ejected from the mantle cavity, enabling jet propulsion for movement. Siphonophores, which are colonial marine hydrozoans, also utilize specialized zooids for functions like locomotion.12345