Invertebrates
Animals that lack a backbone
Porifera
Placozoa
* 1 species (tricoplax adharens)
Cnidaria
Acoela
Ctenphora
* Have eight combs of cilia for movement and tentacles for hunting
Platyhelminthes
Ectoprocta
Syndermata
* 2900 species
Rotifers
*Microscopic organisms with complex organ systems in psuedocoeloms
acanthocephalans
Highly modified parasites of vertebrates
Brachiopods
Gastrotricha
Nemertea
Annelida
Mollusca
* 100,000 species
Loricifera
* 10 species
Priapulida
Onychophora
Tardigrada
Arthropoda
* 1,000,000 species
Nematoda
Hemichordata
Chordata
* 57,000 species