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This study was conducted to evaluate the influence of dietary lysophospholipids combined with 1% dietary fish oil reduction on the growth performance and hepatic lipid metabolism of largemouth bass (Micropterus salmoides). Five isonitrogenous feeds were prepared with lysophospholipids at 0% (fish oil group, FO), 0.05% (L-0.05), 0.1% (L-0.1), 0.15% (L-0.15) and 0.2% (L-0.2), respectively. The dietary lipid was 11% in the FO diet and 10% in the other diets. Largemouth bass were fed for 68 d (initial body weight = 6.04 ± 0.01 g) with 4 replicates per group and 30 fish per replicate. The results showed that the fish fed diet containing 0.1% lysophospholipids had higher digestive enzyme activity and obtained better growth performance compared to the fish fed FO diet (P < 0.05). The feed conversion rate in the L-0.1 group was significantly lower than that in the other groups. Serum total protein and triglyceride contents in L-0.1 group were significantly higher than those in other groups (P < 0.05) and the contents of total cholesterol and low-density lipoprotein cholesterol in L-0.1 group were significantly lower than those in FO group (P < 0.05). The activity and genes expression of hepatic glucolipid metabolizing enzymes in L-0.15 group were significantly increased compared to those in FO group (P < 0.05). Reducing 1% fish oil along with 0.1% lysophospholipids added to the feed could improve the digestion and absorption of nutrients, enhance the activity of liver glycolipid metabolizing enzymes, and thus effectively promote the growth of largemouth bass.

The Emeishan large igneous province (LIP) was emplaced on the western Yangtze plate during the Permian and its formation is primarily attributed to a mantle plume. Recent research has shown that material from this plume modified the melts in the Palaeotethys subduction zone. However, it remains poorly understood whether, in turn, the subduction of Palaeotethys affected the formation of the Emeishan LIP. We report here geochronological, petrological, geochemical and isotopic studies of a gabbroic intrusion located in Jiangwei, in the Dali area of the Emeishan LIP. The gabbro has a weighted mean SHRIMP U–Pb age of c. 262 Ma. The key geochemical features include: depletion in Nb, Ta and Ti; enrichment in Th, U and Sr; low light to heavy rare earth element ratios; 87Sr/86Sr(t) values of c. 0.707; and ε Nd(t) values of c.−0.21. We conducted pMELTS thermodynamic modelling and batch-melting calculations to evaluate the origin and evolution of the gabbro based on real components of low-Ti picrites and xenoliths from the Yangtze lithosphere. Our results show that 3% melting of a hydrated spinel peridotite source from the Yangtze lithosphere can produce magma equivalent to the gabbroic intrusion. Integrating this conclusion with the tectonic background of the western Yangtze plate and the volcano-stratigraphic record of the Emeishan LIP, we infer that the early-stage magmatism of the Emeishan LIP was triggered by Palaeotethys back-arc extension with fluid modification from the subducting slab. Supplementary material: Tables S1–S7 are available at https://doi.org/10.6084/m9.figshare.c.5433267 [ABSTRACT FROM AUTHOR]