of carotenoids reached the maximum inР juvenile. Besides, the expressions of related genes (ABCA1, βCMOOX, and SR-BI) were upregulated at different larvalР stages, especially βCMOOX gene, which participated in the biosynthesis of carotenoids. The levels of βCMOOXР increased rapidly from D-shaped larva to shell stage about 38. 2~43. 3 folds, which suggested that βCMOOX might beР involved in the synthesis of mytiloxanthin during the shell stage. The results provided data support for elucidation of theР metabolism pathway of carotenoids in shellfish.Р Keywords:Mytilus coruscus, larval stages, carotenoids, dietary microalgae, high performance liquid chromatographyР coupled with mass spectrometry(HPLC⁃MS)