Tunicates, also known as urochordates, are members of the subphylum Tunicata or Urochordata, a group of underwater saclike filter feeders with incurrent and excurrent siphons that's classified within the phylum Chordata. While most tunicates live on the ocean floor and are commonly known as sea squirts and sea pork, others – such as salps, doliolids and pyrosomes – live above in the pelagic zone as adults. Most tunicates feed by filtering sea water through pharyngeal slits, but som… (More on Tunicates)