A 10-week feeding trial was conducted to investigate the beneficial effects of bile acids (BAs) on hepatic health status in tongue sole (Cynoglossus semilaevis). Three experimental diets were prepared with different levels of BA inclusion in the commercial basal diet: control group (CT: 0 mg/kg basal diet), low-level group (BA1: 300 mg/kg basal diet), and high-level group (900 mg/kg basal diet). At the end of the feeding trial, growth performance and survival rate were measured, as well as numerous physiological and biochemical parameters of the liver, including four hepatic function indices, five antioxidant indices, five lipid metabolism parameters, and three digestive enzyme activities. Moreover, the mRNA expression levels of three growth-related genes and three immune-related genes in the liver were assayed. Results showed that growth performance and survival were substantially improved in both low- and high-level BA inclusive groups. Further, the tested liver physiological and biochemical parameters combined with the quantitative real-time PCR results revealed enhanced antioxidant capacity, energy metabolism, digestive ability, and immune response. Finally, these findings provide a wider spectrum of the beneficial effects of dietary BAs on liver health in tongue sole.

In this study, we obtained the complete mitochondrial genome of Hypseleotris cyprinoides , which was 16520 bp in length. The mitogenome contained 37 genes, including the typical set of 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, and 2 Ribosomal RNA (rRNA) genes. A, C, G, and T distribution was 28.57%, 29.91%, 16.99%, and 24.53%, respectively. The length of the total protein-coding genes was 11441 bp, which accounts for 66.80% of the whole mitochondrial genome. The Maximum Likelihood (ML) phylogenetic analysis based on the concatenated nucleotide sequences of 13 PCGs showed that H.cyprinoides as a sister species to Hypseleotris klunzingeri was clustered in the family Hypseleotris. The discovery of the complete mitochondrial genome of H.cyprinoides would help to conduct in-depth research on Hypseleotris.

This study is aimed at evaluating the effectiveness of phytosterols as an alternative to cholesterol in practical diets of Pacific white shrimp Litopenaeus vannamei from the perspective of growth and nonspecific immunity. Five diets were formulated to contain different sterol sources and levels. Two diets were supplemented with 1 g/kg cholesterol (LC (low cholesterol)) or phytosterol (LP (low phytosterol)). Other three experimental diets were supplemented with 2 g/kg cholesterol (HC (high cholesterol)), 2 g/kg phytosterol (HP (high phytosterol)), or mixed sterol source (CP, 1   g / kg   cholesterol + 1   g / kg   phytosterol ), respectively. A total of 750 healthy and uniform-sized shrimp ( 0.52 ± 0.008   g ) were randomly distributed into 5 groups with 3 replicates and fed with the five experimental diets for 60 days. Results showed that the growth performance of shrimp was influenced by the sterol levels and supplementation with 2 g/kg sterol level facilitated the growth of shrimp. The inclusion of phytosterol has a cholesterol-lowering effect on shrimp, as evidenced by a reduction in hemolymph cholesterol and triglyceride contents in the HP group. Besides, supplementation with 2 g/kg phytosterol or mixed sterol sources had positive effects on the hemolymph superoxide dismutase, phenol oxidase, and lysozyme as well as hepatopancreas alkaline phosphatase activities, demonstrating that the nonspecific immunity and antioxidative capacity were improved. In conclusion, phytosterols could be an appropriate alternative to partially replace dietary cholesterol in shrimp feeds. This study preliminarily revealed the effects of different sterol sources and levels on the growth and nonspecific immunity of shrimp and provided a basis for further exploration of the mechanism of phytosterol.