Identification of carotenoids in the freshwater shellfish Unio douglasiae nipponensis, Anodonta lauta, Cipangopaludina chinensis laeta, and Semisulcospira libertina.

The biochemical properties of carotenoids from 2 species of freshwater bivalve, namely, Unio douglasiae nipponensis and Anodonta lauta, and 2 species of freshwater snail, namely, Cipangopaludina chinensis laeta and Semisulcospira libertina, were investigated. Diatoxanthin and fucoxanthin were identified as major carotenoids in both bivalves. In contrast, lutein and zeaxanthin were found to be the major carotenoids in C. chinensis laeta. In addition, a series of keto carotenoids was also identified in S. libertina.