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This study was aimed to investigate the effects of replacing dietary fish meal (FM) with defatted yellow mealworm (Tenebrio molitor) meal (DYM) on growth performance, intestinal health, serum immune, and antioxidant indexes of juvenile Chinese mitten crab (Eriocheir sinensis). Four hundred juvenile Chinese mitten crabs (4.94 ± 0.08 g) were randomly distributed into five groups in quadruplicate (20 crabs per tank), and each group was fed with diets that replaced FM with DYM at 0% (CON, containing 200 g/kg FM), 25% (DYM25), 50% (DYM50), 75% (DYM75), and 100% (DYM100) for 8 weeks, respectively. The results showed that the growth, serum immune and antioxidant indexes, digestive enzyme activities, intestinal histology, and microbiota composition of DYM25, DYM50, and DYM75 groups all reached the similar level as the CON group. While when 100% fishmeal was replaced, significantly decreased the final body weight (FBW), weight gain (WG), serum alkaline phosphatase (AKP), acid phosphatase (ACP), lysozyme (LZM), glutathione peroxidase (GSH‐Px), total antioxidant capacity (T‐AOC), and total superoxide dismutase (T‐SOD) activities, hepatopancreas protease activity, mid‐intestine folds height and number (P < 0.05), significantly increased the feed conversion ratio (FCR), serum malondialdehyde (MDA) content, and the abundance of intestinal harmful bacteria Shewanella (P < 0.05). Overall, these results suggest that 75% dietary FM (150 g/kg) can be effectively replaced by DYM without negative impact on the growth performance, intestinal health, serum immune, and antioxidant indexes of juvenile E. sinensis. [ABSTRACT FROM AUTHOR]

The widespread use of commercial feeds with high‐fat content in aquaculture may lead to oxidative stress and inflammation in fish during culture, which may cause changes in fish muscle texture. Therefore, mitigating oxidative stress and inflammation during fish farming holds paramount importance in improving fish muscle quality. In this study, we investigated the effect of different dietary levels of chlorogenic acid (CGA; 0, 100, 200, 400, 800, 1600 mg/kg diet, P1–P6) in commercial diets on the muscle of blackspotted croaker (Protonibea diacanthus) through an 8‐week feeding trial in open sea cages. The results showed that high dietary CGA levels (P5–P6) could significantly reduce muscle oxidative stress and inflammation (P < 0.05). Muscle toughness (hardness, chewiness, shear force, and gumminess) improved significantly as CGA levels increased (P < 0.05). It was also observed that the gap of muscle fiber was significantly reduced, while the muscle fiber density was significantly increased with the increase of CGA level (P < 0.05). Notably, dietary CGA also had a significant effect on collagen content in the muscle (P < 0.05), which may also be a crucial factor affecting muscle texture. Furthermore, it was found that the reduction of inflammation and increase of collagen deposition in muscle by dietary CGA may be related to the upregulation of transforming growth factor beta (TGF‐β) signaling pathway. Finally, it can be concluded that a dietary CGA supplementation of 1173.11 mg/kg is suggested for the aquaculture of P. diacanthus, based on the muscle texture quality. [ABSTRACT FROM AUTHOR]

This study was conducted to estimate dietary valine (Val) requirement for juvenile olive flounder (Paralichthys olivaceus). In a feeding trial, a total of 540 fish (initial body weight: 23.0 ± 0.2 g) were stocked into 18 tanks (210 L). Six experimental diets containing graded levels of Val (4, 8, 12, 16, 20, and 24 g/kg, dry matter basis) were fed to the fish in triplicate groups for 13 weeks. The lowest growth, feed utilization, and survival were observed in 4 g/kg Val group (P < 0.05). Dietary Val deficiency resulted in significant decreases (P < 0.05) in whole‐body protein and Val concentrations, hepatosomatic index, condition factor and plasma protein and cholesterol levels. Nonspecific immunity and antioxidant activities were significantly lower (P < 0.05) in 4 g/kg Val group than in other groups. Dietary Val deficiency upregulated the expression of proinflammatory cytokines and downregulated the expression of anti‐inflammatory cytokines and intestinal tight junction protein (occludin) (P < 0.05). Mucosal fold height and submucosa and muscularis thickness of fish intestine were significantly lower (P < 0.05) in fish fed 4 g/kg Val diet. Relatively lower lipid droplet in hepatic cell was observed in 4 g/kg Val group. Our findings suggested that dietary Val requirements for juvenile olive flounder would be 17.7–18.9 g Val/kg (35.4–37.8 g/kg on the basis of crude protein), estimated by quadratic regression analysis based on the weight gain, protein efficiency ratio, and protein retention efficiency. [ABSTRACT FROM AUTHOR]

Lepista sordida is a valuable edible mushroom rich in natural bioactive compounds. In the present study, a high-quality whole-genome of a domesticated strain of L. sordida was sequenced, revealing a 40.67 Mb genome in 13 contigs. Phylogenetic analysis revealed that L. sordida is evolutionarily closely related to edible mushroom Lyophyllum decastes and Hypsizygus marmoreus. Heat stress has a significant effect on the yield and quality of mushrooms, but the molecular basis for this is poorly understood in L. sordida. A label-free comparative proteomic analysis was performed under different heat stress conditions. The growth of L. sordida mycelia was inhibited, and nuclear apoptosis occurred under heat stress. Ca2+ and MAPK signaling pathways were found to be involved in heat stress signal transduction. It is hypothesized that the expression of various heat shock proteins plays a crucial role in the response to heat stress. In addition, the components of the ubiquitin-proteasome system and the thioredoxin system were upregulated, preventing the accumulation of misfolded proteins and possibly supporting the response to heat stress. In summary, these results provide a fundamental insight into the evolution and heat stress-responsive mechanisms in L. sordida and may facilitate the breeding of heat-tolerant strains for artificial cultivation. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of replacing inorganic trace minerals (ITM) with organic trace minerals (OTM) on growth performance, body composition, gut histomorphometry, digestive enzyme activity, apparent digestibility coefficients (ADC), and mineral balance in juvenile Nile tilapia, Oreochromis niloticus. Fish (n = 432; 2.5 ± 0.5 g) were randomly distributed into four groups with four replicates each (27 fish per replicate). A control diet (gross 15.2 MJ gross energy kg−1; 367.3 g crude protein kg−1) was elaborated to meet the dietary requirements of zinc (Zn), manganese (Mn), and copper (Cu) using ITM in the sulfate form (ITM100). From the control diet, three diets were elaborated using OTM to supply 100% (OTM100), 75% (OTM75), and 50% (OTM50) of Zn, Mn, and Cu ITM of the control diet, respectively, supplied in the glycinate form. Fish were hand‐fed six times daily for 8 weeks. Growth performance was not changed by dietary treatments. Fish fed on the diet OTM50 showed higher whole‐body and vertebrae ash contents and higher whole‐body calcium (Ca), Zn, and iron (Fe) retention than those fed on the control diet. The activity of digestive enzymes and the ADC of energy and nutrients, including Zn, Mn, and Cu, were similar in fish fed on diets OTM50 and ITM100. A reduction in Zn (−39.8%), Mn (−11.1%), and Cu (−14.0%) loss was observed in fish fed on the diet OTM50 than in fish fed diet ITM100. The dietary treatments did not affect the gut histomorphometry. In conclusion, the inclusion of OTM in Nile tilapia's diets represents a promising strategy to reduce 50% of ITM sources by utilizing Zn, Mn, and Cu OTM as glycinates without detrimental effects on growth performance, nutrient utilization, and gut function. These results additionally reinforce the environmental benefits of using OTM for precise mineral nutrition in aquaculture. [ABSTRACT FROM AUTHOR]