Effects of dissolved oxygen, starvation, temperature, and salinity on the locomotive ability of juvenile Chinese shrimp Fenneropenaeus chinensis

Effect of oxygen supplement on post-mortem metabolic profile of shrimp during cold storage

Shrimp, renowned for its exceptional nutritional value, holds a pivotal position within the realm of aquatic products. The supplementation of extra oxygen to shrimp throughout the entire supply chain has found application within the commercial seafood market. In this study, a dual-platform metabolic analysis, coupled with multivariate data analysis, was employed to discern the impact of supplementary oxygen. Furthermore, this approach facilitated the construction of the post-mortem metabolic profile of shrimp during cold storage. A noticeable decrease of alcohols, ketones and carbohydrates which are related to the energy metabolism in shrimp has been found during cold storage, compared to the fresh shrimp. The degradation of nutritional amino acids was alleviated in shrimp after 4 h of extra oxygen supplement. Furthermore, a higher concentration of identified fatty acids, integral to lipid metabolism and functioning as flavor compounds was observed in shrimp subsequent to oxygen supplementation. Therefore, the additional oxygen supplementation exerted influence on multiple metabolic pathways, including nitrogen metabolism, amino acid and peptide metabolism, nucleotide metabolism, carbohydrate metabolism, and lipid metabolism. This study has constructed a comprehensive post-mortem metabolic profile of shrimp during cold storage, thereby establishing a theoretical foundation for the utilization of oxygen supplements in the preservation of seafood.

New Insight on Vitality Differences for the Penaeid Shrimp, Fenneropenaeus chinensis, in Low Salinity Environment Through Transcriptomics

Excessive rainfall changes salinity in shrimp farming ponds in short period and exerts low salinity stress on the outdoor breeding shrimp under global warming. Fenneropenaeus chinensis can have different performance on vitality in low salinity environments. To reveal mechanisms of vitality difference in shrimp living in low saline environments. This study based on the normal and moribund F. chinensis in 10 ppt salinity environment using high-throughput sequencing identifies 1,429 differentially expressed genes (DEGs), 586 of which are upregulated, while 843 of which are downregulated in the normal group (FCN10) as compared to the moribund group (FCM10). Meanwhile, another transcriptomic analysis is conducted on the normal and moribund shrimp from 25 ppt (FCN25 vs. FCM25) salinity environment as the control, in which 1,311 DEGs (upregulated: 327 genes, downregulated: 984 genes) are identified. In this study, intersective pathways, GO (Gene Ontology) categories and DEGs from the two groups of comparative transcriptome are investigated. The two intersective pathways (Metabolism of xenobiotics by cytochrome P450, Pentose, and glucuronate interconversions) significantly enriched by DEGs are related to detoxification. In these two pathways, there is one vitality regulation-related gene (VRRG), the Dhdh (dihydrodiol dehydrogenase), which is upregulated in both the groups of FCN10 and FCN25 as compared to the groups of FCM10 and FCM25, respectively. Similarly, in the 25 top intersective GO categories, four VRRGs are revealed. Three of them are upregulated (Itgbl, kielin/chordin-like protein, Slc2a8, solute carrier family 2, facilitated glucose transporter member 8-like protein and Cyp3a30, cytochrome P450 3A30-like protein); one of them is downregulated (Slc6a9, sodium-dependent nutrient amino acid transporter 1-like protein isoform X2). These GO categories are related to transmembrane transporter activity of substance, enzyme inhibitor activity, monooxygenase activity. RT-qPCR analysis further verifies the VRRGs. The study gives new insight into understanding the vitality differences for F. chinensis, in low salinity environment. The pathways and DEGs in response to low salinity stress in modulating the vitality of F. chinensis that could serve as tools in future genetic studies and molecular breeding.