sea squirts

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Tunicates

Tunicates are marine filter-feeders with a unique, sac-like body structure. 

In their respiration and feeding they take in water through an incurrent (or inhalant) siphon and expel the filtered water through an excurrent (or exhalant) siphon.

Most adult tunicates are sessile and attached to rocks or similarly suitable surfaces on the ocean floor; others such as salps, doliolids and pyrosomes swim in the pelagic zone as adults.

Various species are commonly known as sea squirts, sea pork or sea tulips.

Tunicates contain a host of potentially useful chemical compounds, including:

  • Didemnins, effective against various types of cancer, as antivirals and immunosuppressants
  • Aplidine, effective against various types of cancer
  • Trabectedin, effective against various types of cancer

Various Ascidiacea species are consumed as food around the world. In Japan and Korea, the sea pineapple (Halocynthia roretzi) is the main species eaten

The use of tunicates as a source of biofuel is being researched. The cellulose body wall can be broken down and converted into ethanol and other parts of the animal are protein-rich and can be converted into fish feed.

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