The Aplacophora are a very interesting group of exclusively marine molluscs. These worm-like creature were once considered to be holothurians (sea cucumbers) but they were later identified as molluscs from their mantle and primitive radula (two key features of molluscs). Most have been found in very deep waters (as in 5km+ deep). Most of the discovered species live their life buried in the mud feeding on detritus and microscopic organisms in the mud. Some prey on cnidarians. Most are tiny (as in a few mm in length) but some tip the tapes in excess of 30cm long. All have no internal or external shell, though they do have calcareous spicules in their mantle. So far ~300 species have been documented. In the Mollusc Diversity Playing Cards the 2 of Spades is the large Aplacaphoran, Neomenia yamamotoi.
