Oudemansiella raphanipes (OR) is a commercial mushroom which possesses high nutritional value and excellent and unique flavors. In this study, various agricultural wastes were utilized as substitute materials in the low‐cost and high‐yield production of mycelia biomass and polysaccharides by liquid fermentation. The sawdust, wheat bran, apple pomace, sugarcane, and corn particles were employed to cultivate OR, using the potato dextrose broth as control. Additionally, a preliminary characterization and in vitro antioxidant activities of partial purified OR polysaccharides were investigated. The substrate of sugarcane was suitable for mycelia growth of OR, with high yield of mycelia biomass and polysaccharides content. In vitro antioxidant activity assays demonstrated that OR polysaccharides could effectively scavenge 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) and 1,1‐diphenyl‐2‐picrylhydrazyl radicals. OR polysaccharides had configuration as revealed by Fourier transform infrared, and was mainly composed of fucose (Fuc), rhamnose (Rha), arabinose (Ara), galactose (Gal), glucose (Glc), xylose (Xyl), mannose (Man), ribose (Rib), and galacturonic acid (Gal‐UA), with mass percentages of 3.29%, 0.64%, 1.09%, 16.03%, 72.69%, 0.56%, 3.18%, 0.93%, and 1.59%, respectively. This study may offer support for decreasing the cost of OR polysaccharides production and dealing with these agricultural wastes.

The polysaccharide was extracted from Phascolosoma esculenta (PEP). Two purified polysaccharides (PEP‐1 and PEP‐2) were obtained by the column chromatography separation method. The molecular weights of PEP‐1 and PEP‐2 were 33.6 and 5.7 × 10³ kDa, respectively. PEP‐1 and PEP‐2 had the same monosaccharides composition, but their molar ratios varied. The in vitro antioxidant activity of the PEP, PEP‐1, and PEP‐2 were investigated by scavenging free radicals like 3‐ethylbenzoth‐iazoline‐6‐sulfonic acid (ABTS), •OH, and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH). Additionally, the in vivo antioxidant activity of PEP‐1 was examined using the Caenorhabditis elegans (C. elegans) organism. Results showed that PEP‐1 was much more effective than PEP and PEP‐2 at scavenging DPPH, •OH, and ABTS radicals. Additionally, PEP‐1 strengthened C. elegans' ability to endure oxidative stress. PEP‐1 possessed the in vivo antioxidant capacity, including the reactive oxygen species (ROS) content reducing, and protective effect on antioxidant enzyme activities in C. elegans. In summary, PEP, PEP‐1, and PEP‐2 might have the potential to develop as functional foods and clinical medications.

Microbial communities associated with fish mucosal tissues play important roles in host health and environmental adaptation. However, the effects of contrasting aquaculture conditions on the microorganisms of the large yellow croaker (Larimichthys crocea, L. crocea) remain poorly understood. In this study, 16S rRNA gene sequencing was used to compare the gut and gill microbiota of L. crocea cultured in a marine system and a saline–alkaline system, together with the corresponding surrounding water samples. The results showed that both host tissue type and rearing environment significantly influenced microbial community structure. Water samples generally exhibited higher alpha diversity than host-associated samples, whereas the gut and gill communities were clearly separated from the surrounding water microbial community. The intestine showed stronger culture system differentiation than the gill, suggesting greater niche selectivity, while the gill retained a closer association with the rearing water. Across multiple taxonomic levels, microbial composition differed markedly among water, gut, and gill samples, and the divergence between the marine culture and saline–alkaline culture system became more pronounced at finer taxonomic resolution. Differentially enriched taxa further revealed clear tissue- and habitat-associated microbial patterns. In addition, several dominant taxa were significantly correlated with environmental variables, especially salinity and nutrient-related factors, indicating that physicochemical heterogeneity contributed substantially to microbial community assembly. Overall, this study shows that host mucosal niche and rearing environment are associated with distinct gut and gill microbiota patterns in L. crocea and provides preliminary ecological information for future microbiome-informed aquaculture management, functional validation of candidate taxa, and the development of land-based culture systems for marine fish.

We investigate the early developmental characteristics of the skeletal system in Miichthys miiuy larvae using a double staining method on the whole larval skeletons (aged 130days). We systematically observed and described the morphological development of both the spinal vertebrae and appendicular skeleton. The results showed that there were 25 spinal vertebrae in M. miiuy, which consist of 12 abdominal vertebrae and 13 coccyges; The development of spinal vertebrae began at 12days after hatching (dah), with the emergence of ossified neural and haemal arches, where ossification appeared at 17 dah; and the appendicular skeletons were developed from the pectoral fins to ventral fins. The coracoid-scapula cartilage was clearly observable at three dah, and fin rays were clearly differentiated at 21dah. The cartilage of appendicular of the ventral fins was formed until 19dah, and the ventral fins were completely ossified at 21dah. Subsequently, the caudal, dorsal, and anal fins appeared at 10, 13, and 14dah, respectively. Additionally, the appendicular skeleton associated with the movement of M.miiuy was completely developed by 28dah. Finally we observed that there are four types of spinal vertebrae abnormalities during the early development of M.miiuy, which included spinal bulging, splitting of vertebrae, and supernumerary and bifurcated haemal and neural spines. Skeletal length and age (in days) were highly correlated (r²=0.942). There was a strong relationship between total length and skeletal length (r²=0.979) and between body length and skeletal length (r²=0.9779).

Phascolosoma esculenta ( P. esculenta ) is a benthic marine invertebrate endemic to China, and abrupt salinity shifts in aquaculture environment often cause mass mortality. In this study, individuals were divided into three salinity treatments: S20 (salinity 20), S10 (salinity 10), and S6 (salinity 6). Histological examination, enzyme activity assays, gut microbiota 16S rRNA sequencing, and transcriptome profiling were integrated to comprehensively evaluate intestinal responses to low‐salinity stress. After 30 days exposure, low‐salinity induced pronounced intestinal injury, including thinning of the mucosal layer (ML), villus collapse, and inflammatory cell infiltration. Malondialdehyde (MDA) concentrations showed a gradual elevation across groups (S20, S10, and S6), rising from 2.91 to 4.97 nmol/mg prot. Glutathione peroxidase (GSH‐PX) activity peaked at 37.23 U/mg prot in the S10, compared with 25.19 U/mg prot in the S20 and 29.36 U/mg prot in the S6, indicating activation of antioxidant defenses under moderate stress but exhaustion under severe stress. Acid phosphatase (ACP) activity declined from 4.32 U/mg prot (S20) to 3.99 U/mg prot (S10) and 3.02 U/mg prot (S6). Similarly, alkaline phosphatase (AKP) activity dropped from 1.33 U/mg prot (S20) to 1.03 U/mg prot (S6), reflecting suppressed immune function. Gut microbiota analysis showed significantly reduced Shannon diversity in the S6, with community composition shifting from Firmicutes/Bacteroidota toward Proteobacteria. Transcriptome analysis identified 125, 364, and 413 differentially expressed genes (DEGs) in the S10 vs. S20, S6 vs. S20, and S6 vs. S10 comparisons, respectively, which were primarily enriched in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways such as TNF signaling, RIG‐I‐like receptor signaling, and osteoclast differentiation. In summary, P. esculenta can maintain homeostasis by activating the antioxidant system under moderate low‐salinity stress. However, under severe low‐salinity conditions, it exhibits activated inflammatory responses, reprogrammed amino acid metabolism, and excessive activation of apoptosis, ultimately leading to severe damage to the intestinal barrier. This study elucidates the salinity tolerance mechanisms of this species from an omics perspective, providing important insights for its healthy aquaculture and selective breeding for salinity tolerance.