''Nematostella'' is a genus of

sea anemone Sea anemones are a group of predation, predatory marine invertebrates of the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemones are classifi ...

s in the family

Edwardsiidae Edwardsiidae is a family of sea anemones. Edwardsiids have long thin bodies and live buried in sediments or in holes or crevices in rock. Genera The following genera are recognized within the family Edwardsiidae. * '' Drillactis'' Verrill, 1922 ...

. Of the three species in the genus, the best known is the

starlet sea anemone The starlet sea anemone (''Nematostella vectensis'') is a species of small sea anemone in the Family (biology), family Edwardsiidae native to the east coast of the United States, with introduced populations along the coast of southeast England an ...

(''N. vectensis''), which has been extensively studied as a

model organism A model organism (often shortened to model) is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workin ...

in fields such as genetics, evolution, and ecology. The defining morphological

apomorphy In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...

of ''Nematostella'' is the presence of

nematosome Nematosomes are multicellular motile bodies found in the gastrovascular cavity of the model sea anemone ''Nematostella vectensis'' starlet sea anemone. First described by Stephenson in 1935, nematosomes are the defining apomorphy (synapomorphy) of ...

s. Species:''Nematostella'' Stephenson, 1935.
''In'': Fautin, D. G. 2011. ''Hexacorallians of the World''. Accessed through: World Register of Marine Species (WoRMS). 2014. * ''

Nematostella nathorstii ''Nematostella'' is a genus of sea anemones in the family Edwardsiidae. Of the three species in the genus, the best known is the starlet sea anemone (''N. vectensis''), which has been extensively studied as a model organism in fields such as gene ...

'' (Carlgren, 1921) * ''

Nematostella polaris ''Nematostella'' is a genus of sea anemones in the family Edwardsiidae. Of the three species in the genus, the best known is the starlet sea anemone (''N. vectensis''), which has been extensively studied as a model organism in fields such as gene ...

'' (Carlgren, 1921) * ''

Nematostella vectensis The starlet sea anemone (''Nematostella vectensis'') is a species of small sea anemone in the family Edwardsiidae native to the east coast of the United States, with introduced populations along the coast of southeast England and the west coast ...

'' Stephenson, 1935 – starlet sea anemone

References

Edwardsiidae Hexacorallia genera {{Actiniaria-stub