Marine molluscs

Studied considerably via 8 0 of foraminifera, biobotanical analyses, marine molluscs, and pollen assemblage. 

The middle Miocene climatic optimum at about 16 Ma is well established by the studies on shallow marine molluscs (Ogasawara, 1994). 

Based on the data on Neogene shallow marine molluscs of the Japanese Islands, the paleoclimate was reconstructed by Ogasawara (1994). After the middle Miocene climatic optimum at 16 Ma, a gradual cooling commenced at about 14—13 Ma. 

Ogasawara, K. (1994) Neogene paleogeography and marine climate of the Japanese Islands based on shallow-marine molluscs. Paleogeogr. Paleoclimatol. Paleoecol., 1 8, 335-351. 

Spencer DW, Bacon MP, Brewer PG (1981) Models of the distribution of " b in a section across the North Equatorial Atlantic Ocean. J Mar Res 39(1) 119-137 Staubwasser M, Henderson GM, Berkman PA, Hall BL (in press) Ba, Ra, Th and U in marine mollusc shells and the potential of Ra/Ba dating of Holocene marine carbonate shells. Geochim Cosmochim... 

Cimino, G. and Sodano, G. Biosynthesis of Secondary Metabolites in Marine Molluscs. 167, 77-116 (1993). 

The studies on the biosynthetic origin of secondary metabolites in marine molluscs are reviewed. Although the majority of natural products found in marine molluscs appears to have a dietary origin, de novo biosynthetic ability towards particular classes of compounds has been demonstrated. Marine molluscs are also able to modify metabolites sequestered from their specific prey. 

It is well established that the principal source of secondary metabolites in marine molluscs resides in the sometimes selective concentration of chemicals contained in their food. The chemical connection between molluscan predator and its algal or invertebrate diet has been confirmed as a result of many investigations of the chemistry of herbivorous [6] and carnivorous [3] molluscs and their dietary sources. However, the assumption often reported, as in a recent review [7], that marine molluscs invariably obtain their metabolites from dietary sources, should be regarded as an oversimplification. In fact, active biosynthesis of secondary metabolites has been ascertained in several cases, as documented here. 

Di Marzo V, Cimino G, Sodano G, Spinella A, Villani G, A novel prostaglandin metabolic pathway from a marine mollusc prostaglandin 1,15-lactones. 7th Internation Conf, on Prostaglandins and related compounds, 28 May-1 June 1990, Florence, Italy, p 13... 

Chitons are marine molluscs with shells consisting of movable plates. 

---