Molluscs coral

Aragonite Green algae Molluscs Corals Pteropods" Bryozoans... 

A major biological sink for CO9 that is often overlooked is the calcium carbonate shells of corals, molluscs, and Crustacea. These invertebrate animals deposit CaCOa in the form of protective exoskeletons. In some invertebrates, such as the sderaetinians (hard corals) of tropical seas, photosynthetic dinoflagellates (kingdom Protoctista) known as zooxanthellae live within the ani-... 

Biogenic A. Calcareous B. Siliceous >30 >30 48 Foraminifera, coccoliths, calcareous algae, molluscs, bryozoa, and corals 14 Diatoms and radiolaria... 

While little biosynthetic information is available, it has been suggested [38] that 25 and 26 may be formed from AA (24) and EPA (14) via a cyclization mechanism (Scheme 3) similar to that which forms trans-cyclopropyl-containing diol 28 upon treatment of linoleic acid with performic acid [40]. An alternative biogenetic mechanism (Scheme 4), based upon that proposed for the structurally related red algal metabolites constanolactone A and B [41], would involve the formation and opening of an allylic epoxide intermediate created as a result of a 15-/ -LPO acting on either AA or EPA. Related compounds have been isolated from the coral Plexaura homomalla and the mollusc Aplysia kurodai (see below). 

Fig.1 Carbon skeleton of dolabellanes isolated from higher plants, liverworts, algae, molluscs, sponge (22), corals, fungi (mould) (ent-22) and neodolabellanes isolated from corals (23)...

Cone snails are found in tropical waters, often in the neighborhood of coral reefs. These molluscs produce a complex venom delivered through a specialized radular tooth that serves as a harpoon to immobilize their prey (Olivera et al., 1990 1991). Complete immobilisation of the prey takes only a few seconds (Terlau et al., 1996). The venom from a single cone snail can contain up to 200 different biologically-active components (review Shen et al., 2000). The primary structure of the naturally-occurring co-conopeptides derived from several species of Conus are... 

Some nudibranchs have adapted to feed on soft corals,270 273 ascidians,274 bryozoans,275 or on other molluscs rather than sponges. The mollusc Ovula ovum was reported to sequester the toxic sarcophytoxide (Structure 2.151) from Sarcophyton sp. and transform it into the less toxic terpene (Structure 2.152),276 but the deoxy metabolite was subsequently found in the soft coral.277... 

Bathydoris hodgsoni can be found in the deep waters of the Weddell Sea. This nudibranch elaborates the drimane sesquiterpene hodgsonal (Structure 7.78) and sequesters it in its mantle tissues.50 164The nudibranch Tritoniella belli collected from McMurdo Sound is the only documented example of an Antarctic mollusc sequestering defensive chemistry from its diet.44 Among the glyceride esters (Structures 7.79-7.81) isolated from this species, chimyl alcohol (Structure 7.79) can also be found in one of its prey items, the stoloniferan coral Clavularia frankliniana. Sequestration of these defensive chemicals is opportunistic, however, and other, still undescribed metabolites are more commonly associated with defense in this mollusc.49... 

Macromarines A Selective Account of the Potential of Marine Sponges, Molluscs, Soft Corals and Tunicates as a Source of Therapeutically Important Molecular Structures... 

The Cambrian explosion which occurred between 580 and 490 million years ago (MYA) provided the major marine invertebrate phyla including the sponges, molluscs and soft corals.22 The hypothetical ancestor of the modern invertebrate phyla, the Urmetazoa, is shown in Figure 6.3 and is attributed with the earliest production of secondary metabolites responsible for apoptosis mediation, control of morphogenesis, and immune and cell adhesion molecules. 

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