Nematosomes can be observed circulating through the body cavity and tentacle lumen of adult anemones, occasionally coming to rest on the gastrodermis.
Once outside the body cavity, nematosomes can live from one to several days in dilute seawater, dependent upon the temperature at which they are housed.
The abundance of cnidocytes in nematosomes led to the early hypothesis that this tissue plays a role in immobilization of prey.
[2][8] Although the veracity of this hypothesis was challenged, recent evidence has confirmed that cniodcytes in nematosomes are capable of firing and immobilizing juvenile brine shrimp.
The presence of phagocytes in this tissue suggests nematosomes may play a role in clearing the gastrovascular cavity of foreign material and/or pathogens.