(32) Others, although likely not able to be placed into a living cnidarian group, may be stem cnidarians, or even stem anthozoans
. The discovery of better preserved fronds in the Cambrian that closely resemble some of the Ediacaran fossils would seem to support this interpretation.
The stable substrate provided by rocky habitats support communities of algae, sponges, hydrocorals, encrusting non-scleractinian anthozoans
and scleractinians (as ranked in this study) similar to those of coral reefs.
These three groups are the Scyphozoans, the medusas or jellyfish; the Hydrozoans, which include the Hydras and the fire corals; and the Anthozoans
whose most familiar members are the sea anemones and the corals.
Predation on zooplankton by the benthic anthozoans
Alcyonium siderium (Alcyonacea) and Metridium senile (Actinaria) in the New England subtidal.
Investigations of other invertebrate population structures, including anthozoans
. have demonstrated a broad range of genotypic diversity, from populations that are almost completely dominated by single clones (Black and Johnson 1979; Mladenov and Emson 1990) to those with no evidence of asexual reproduction (Hunt and Ayre 1989).
The multifunctional muscle cell in anthozoans
is called an epitheliomuscular cell.
The ability of anthozoans
to display discriminatory tissue reactions to foreign grafts has been demonstrated by many workers (Jokiel & Bigger, 1994; Rinkevich et al., 1994; Perma et al., 2005).
Similarly, studies conducted in the Gulf of Alaska and Irish Sea show that most motile organisms are less severely affected by chronic and experimental trawling than are anthozoans
, sponges, bryozoans, hydroids, tubicolous polychaetes, and barnacles (Freese et al., 1999; Bradshaw et al., 2002).
The rocky substrata are enriched with sessile fauna such as oysters, barnacles, and numerous species of anthozoans
. In particular.
Opalia funiculata.--The scalloped wentletrap is a gastropod that parasitizes large anthozoans
(Morris et al.
(1988)(for polychaetes), Agudo (1987)(for anthozoans
A similar strategy is found in the septal retractors or pennatulid anthozoans
(Satterlie and Case, 1978, 1980).