Octo corals

Maharaj D, Pascoe KO, Tinto WF (1999) Briarane Diterpenes from the Gorgonian Octo-coral Erythropodium caribaeorum from the Northern Caribbean. J Nat Prod 62 313... 

Sarcophyton species contain diterpenes up to 10% of their dry weight, and this large quantity of secondary metabolites plays an important role in the survival of Octo-corals with defensive, competitive, reproductive, and possibly pheromonal functions. Soft corals lacking physical defense thus seem to be protected from predation by the presence of diterpene toxins in their tissue. Nearly 25 species of this genus occurring in different seawaters have been examined chemically so far, and more than 80 cembranoid diterpenes have been isolated from the Sarcophyton genus since the 1970s. 

Several species of stalked, plantlike hydrozoans and octo-corals form small colonies in shallow intertidal waters. These organisms spend part of their lives as medusae and part as polyps. Like anemones, they gather food with their small tentacles. A less common but more conspicuous cnidarian along the shore is the jellyfish. Most jellyfish found in the intertidal zone are simply washed in, although the stalked jellyfish makes its home there. 

Coll, J.C., and P.W. Sammarco Terpenoid Toxins of Soft Corals (Cnidaria, Octo-corallia) Their Nature, Toxicity, and Ecological Significance. Toxicon Suppl. 3, 69 (1983). 

The atypical sterols of Hexacorallia are polyoxygenated sterols similar to those usually encountered among Octo-corallia, but published work almost exclusively concerns only the orders Antipatharia and Zoantharia. The black coral Antipathes subpinnata has yielded about 10 polyoxygenated sterols without polymethylated side chains, but their principal characteristic is the presence of a hydroxyl group on one or other of the angular methyls at C-18 or C-19 (Aiello, Fattorusso, and Menna, 1991,1992). Most of these steroids are toxic to the shrimp Artemia salina. Some structures are shown in Figure 20.67. 

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