The CBC recently posted a photo essay based on a report released by the Census of Marine Life. The census says that 17,650 species live below 200m of water where sunlight can't reach them. Of those species, 5,600 have been recently discovered.
The Census of Marine Life is a ten year exploration of the diverse creatures inhabiting the earth's marine waters. The Census team is comprised of scientists from 80 different countries and is sponsored by groups such as the UN Environment Programme and the Intergovernmental Oceanographic Commission of the U.N.