Zoanthus sociatus

Several species have been shown to not modify S-320 or MAA concentration in response to UVR, such as the zoanthid Zoanthus sociatus, in response to increased levels of UVR [101], the octocoral Clavularia sp. over a depth gradient [51], the coral Montastraea annularis on transplantation from 24 m to 12 m over 21 days [102] and the temperate anemone Anthopleura elegantissima in UVR-exposed versus UVR-shielded experiments [53]. Data such as these have been used to suggest that MAAs are not directly photoprotective but are rather a byproduct of other chemical reactions and that photoprotection is a secondary function. An alternative explanation is that, at least for all of the above studies that involve coelenterates, the MAAs are derived from diet and therefore rather than MAA concentration being dependent on the intensity of UVR is dependent on the concentration of MAAs in the food source. 

Kelecom, A. Studies of Brazilian Marine Invertebrates. VIII. Zoanthosterol, a New Sterol from the Zoanthid Zoanthus sociatus (Hexacorallia, Zoanthidae). Bull. Soc. Chim. Belg. 90, 971 (1981). 

The sea anemone Aiptasia pulchdla and the zoantharian Zoanthus sociatus. 

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