*4.5. 1O2 Quenching Activity of Carotenoids*

Quenching activity of 1O2 was measured according to the method described in the literature [26]. 1O2 quenching activities (IC50 values) of pectenolone and astaxanthin were 7.9 and 6.5 ΐM, respectively.

## **5. Conclusions**

Carotenoids originating from phytoplankton are accumulated in the sea angels, *C. limacina* and *P. doliiformis*, through eating the herbivorous sea snail, *L. helicina*, in the food chain. In sea angels, dietary carotenoids were oxidatively metabolized, as shown in Figure 3. Sea angels mainly accumulate carotenoids in their gonads. Carotenoids in the gonads of sea angels might protect against oxidative stress and enhance reproduction. Furthermore, carotenoids in sea angels can then be found in salmon through the food chain. 
