[5] Sun anemones are marine organisms that are distributed in shallow areas of the sea floor, typically at depths from 1–10 m.[6] This species is epibenthic.

is zooxanthellae that has been investigated to establish complex relationships with sun anemones, even to the extent of coordinating cell cycles with hosts.

[8] Another endosymbiont is the Clibanarius tricolor, or the blue-legged hermit crab, which has been recorded to live in symbiosis in the Caribbean and Indo-Pacific Regions.

[11] In a further study, Periclimenes yucatanicus, or spotted cleaner shrimp, were additionally observed in symbiosis with S. helianthus in the Florida Bay.

[12] Like many other sea anemones, S. helianthus excretes a variety of toxins that can serve different purposes such as prey capture, protection and defense against predators.

Basulto et al. concludes that Sticholysin II functions in exclusive roles within the anemone's physiology, including predation and digestion.

[16] Kem et al. reports a study where a newly found variant of actiniid neurotoxin, namely Sh 1, was extracted from S. helianthus and yielded genetic similarity to toxin II of Heteractic paumotensis., another species in family Stichodactylidae.

[18][19] It has been further developed into an “investigational drug”, known as Dalazatide, in which it targets the disease-causing cells corresponding to ailments including type 1 diabetes, lupus erythematosus and multiple sclerosis [20] The aforementioned cytolysins, St I and St II, have also shown pharmacological potential in studies with guinea pig models, with direct implications on neural and cardiac activity.