Phylum Gastrotricha (Hairy Backs)

Wikipedia Entry

Approximate Number of Species: 450

Largest:  Urodasys mirabilis at a length of  0.157 inches (4 mm)

Smallest:  Chatonotida sp. at a length of  0.0027 inches (0.07 mm)

References:

Brusca RC & Brusca GJ (2003) Invertebrates (Sinauer Associates, Inc., Publishers, Sunderland, MA) 2nd Ed.

Renaud-Mornant J (1986) Gastrotricha. Stygofauna Mundi: A Faunistic, Distributional, and Ecological Synthesis of the World Fauna Inhabiting Subterranean Waters (Including Marine Interstia), ed Botosaneanu L (E.J. Brill, Leiden), pp 86-109.

A. Clausen, personal communication