AUTHOR=Sun Yu , Guo Kefan , Yu Xiaobo , Li Yanhong , Yao Weizhi , Wu Zhengli 

TITLE=Molecular and biochemical effects on metabolism and immunity of Hyriopsis cumingii fed with four different microalgae

JOURNAL=Frontiers in Marine Science

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2022.970781

DOI=10.3389/fmars.2022.970781

ISSN=2296-7745

ABSTRACT=<p><italic>Hyriopsis cumingii</italic> has attracted attention because of its pearl production performance and water purification capacity. Realizing sustainable industrialized culture of <italic>H. cumingii</italic> or applying it to bivalve biomanipulation for controlling water eutrophication needs urgent studies about the selection of suitable algae and the effects of different microalgae on mussel physiology. To contrast molecular and biochemical effects of high-quality microalgal diets (<italic>Chlorella vulgaris</italic>, <italic>Navicula pelliculosa</italic>, and <italic>Cyclotella</italic> sp.) with toxic <italic>Microcystis aeruginosa</italic> on metabolism and immune physiology of <italic>H. cumingii</italic>, levels of related enzymes and genes were analyzed during the 28-day exposure period. Results showed that the <italic>Cyclotella</italic> sp. diet could significantly (<italic>p</italic> &lt; 0.05) maintain higher levels of metabolic enzymes (glutamic oxaloacetate transaminase (GOT), glutamic pyruvate transaminase (GPT), pyruvate kinase (PK), and hexokinase (HK)) and genes (CPT1 and LDLR). <italic>C. vulgaris</italic> and <italic>N. pelliculosa</italic> treatments significantly (<italic>p</italic> &lt; 0.05) reduced activities of these metabolic parameters. The <italic>M. aeruginosa</italic> treatment significantly (<italic>p</italic> &lt; 0.05) enhanced levels of immune enzymes (alkaline phosphatase (AKP), superoxide dismutase (SOD), and catalase (CAT)) and genes (HcIL-17 and IAP) on day 1 or 7, and there was a significant (<italic>p</italic> &lt; 0.05) reduction on day 28. Results suggested that <italic>Cyclotella</italic> sp. was the suitable algae for <italic>H. cumingii</italic>, followed by <italic>C. vulgaris</italic> and <italic>N. pelliculosa</italic>, and toxic algae caused metabolic disorders, immune injury, and poor physiological status. The study has practical significance in the sustainable cultivation of <italic>H. cumingii</italic> and provides a theoretical basis for bivalve biomanipulation in eutrophic water.</p>