Traditional morphometric analysis of Large Yellow Croaker (Larimichthys crocea) relies heavily on manual dissection, which is time-consuming, labor-intensive, and prone to subjectivity. To address these limitations, we propose an automated quantitative approach based on deep-learning–driven instance segmentation. A dataset comprising 160 X-ray images of L. crocea was established, encompassing five anatomical categories: whole fish, air bladder, spine, eyes, and otoliths. Building upon the baseline YOLOv11-Seg model, we integrated a lightweight Convolutional Block Attention Module (CBAM) to construct an improved YOLOv11-CBAM network, thereby enhancing segmentation accuracy for complex backgrounds and fine-grained targets. Experimental results demonstrated that the modified model achieved superior performance in both mAP50 and mAP50–95 compared with the baseline, with particularly notable improvements in the segmentation of small-scale structures such as the air bladder and spine. By introducing coin-based calibration, pixel counts were converted into absolute areas and relative proportions. The measured area ratios of the air bladder, otoliths, eyes, and spine were 7.72%, 0.59%, 2.20%, and 8.48%, respectively, with standard deviations remaining within acceptable ranges, thus validating the robustness of the proposed method. Collectively, this study establishes a standardized, efficient, and non-destructive workflow for X-ray image-based morphometric analysis, providing practical applications for aquaculture management, germplasm conservation, and fundamental biological research.

The large yellow croaker (Larimichthys crocea) is an important economic fish in China. However, intensive farming practices, such as high stocking densities, suboptimal water quality, and imbalanced nutrition, have led to a decline in muscle quality. Muscle elasticity is a key texture property influencing muscle quality. Herein, transcriptomic and metabolomic analyses were performed on four groups: male high muscle elasticity (MEHM), female high muscle elasticity (MEHF), male low muscle elasticity (MELM), and female low muscle elasticity (MELF), to explore the molecular regulation underlying muscle elasticity in the large yellow croaker. Transcriptomics identified 2594 differentially expressed genes (DEGs) across the four groups, while metabolomics revealed 969 differentially expressed metabolites (DEMs). Association analysis indicated that the valine, leucine, and isoleucine biosynthesis pathways were significantly enriched between the MELF and MEHF groups; 2-Oxoisovalerate and L-Valine were DEMs; and the gene encoding L-threonine ammonia-lyase was a DEG. In the MELM and MEHM groups, pathways such as arginine biosynthesis; arginine and proline metabolism; and valine, leucine, and isoleucine degradation were significantly enriched. 4-guanidinobutanoate, L-aspartate, N-acetylornithine, and L-leucine were among the DEMs, while the DEGs included glul, gls, srm, hmgcs, and aacs. These findings provide insights into the molecular mechanisms controlling muscle elasticity, representing a theoretical foundation to breed high-quality large yellow croakers.

Silver pomfret (Pampus argenteus) is an economically valuable marine species with growing potential for large-scale aquaculture in China. In recent years, significant progress has been achieved in artificial breeding, nutritional research, and disease management; however, the industry’s development remains constrained by technological and operational challenges. This review provides an overview of the biological characteristics of P. argenteus and systematically summarizes the research progress and technological applications in artificial breeding, nutritional physiology, disease management, and aquaculture systems. It also analyzes the key constraints hindering the development of its aquaculture industry. Based on current research progress and industry needs, five strategic measures are proposed to accelerate industry development: (1) establishing a comprehensive germplasm repository; (2) breeding high-performance new varieties; (3) developing species-specific compound feeds; (4) enhancing disease prevention and biosecurity systems; and (5) standardizing operational protocols for different aquaculture systems. The implementation of these measures will provide a theoretical reference and technical support for the high-quality development of the P. argenteus aquaculture industry in China.

The large yellow croaker (Larimichthys crocea) is an economically important marine fish in China, whose growth rate in aquaculture has yet to meet the industry’s demands. Understanding the mechanism underlying inter-individual growth differences will create a favorable condition for selective breeding. In combined transcriptome and metabolome analyses, this study collected muscle tissues from four groups of croakers categorized based on sex and growth rate: fast-growing males, slow-growing males, fast-growing females, and slow-growing females. We identified 2344 differentially expressed genes (DEGs) and 198 differentially expressed metabolites (DEMs). Three genes, bpgm, mstnb, and mylpfb, played a crucial role in the growth regulation of large yellow croaker. The pathway enrichment analysis showed that “Aminoacyl-tRNA biosynthesis”, “Alanine, aspartate and glutamate metabolism”, “Inositol phosphate metabolism” and “Retrograde endocannabinoid signaling” pathways were involved in growth regulation. This study provides new clues for future research on the molecular mechanisms of growth regulation in large yellow croaker and builds a theoretical basis for improving the growth quality of this species.

The large yellow croaker (LYC, Larimichthys crocea) is highly regarded for its delicious taste and unique flavor. The gut microbiota has the ability to affect the host muscle performance and elasticity by regulating nutrient metabolism. The purpose of this study is to establish the relationship between muscle quality and intestinal flora in order to provide reference for the improvement of the muscle elasticity of LYC. In this study, the intestinal contents of high muscle elasticity males (IEHM), females (IEHF), and low muscle elasticity males (IELM) and females (IELF) were collected and subjected to metagenomic and metabolomic analyses. Metagenomic sequencing results showed that the intestinal flora structures of LYCs with different muscle elasticities were significantly different. The abundance of Streptophyta in the IELM (24.63%) and IELF (29.68%) groups was significantly higher than that in the IEHM and IEHF groups. The abundance of Vibrio scophthalmi (66.66%) in the IEHF group was the highest. Based on metabolomic analysis by liquid chromatograph-mass spectrometry, 107 differentially abundant metabolites were identified between the IEHM and IELM groups, and 100 differentially abundant metabolites were identified between the IEHF and IELF groups. Based on these metabolites, a large number of enriched metabolic pathways related to muscle elasticity were identified. Significant differences in the intestinal metabolism between groups with different muscle elasticities were identified. Moreover, the model of the relationship between the intestinal flora and metabolites was constructed, and the molecular mechanism of intestinal flora regulation of the nutrient metabolism was further revealed. The results help to understand the molecular mechanism of different muscle elasticities of LYC and provide an important reference for the study of the mechanism of the effects of LYC intestinal symbiotic bacteria on muscle development, and the development and application of probiotics in LYC.

Macrobrachium nipponense, a commercially popular crustacean species within the Chinese context, is recognized for its exceptional nutritional composition and palatability. There are significant differences in growth between male and female M. nipponense. Herein, transcriptomics was used to determine the hepatopancreas transcriptome differences between sex-related size differences in M. nipponense. We identified 974 differentially expressed genes (DEGs) between the SHE (female) and BHE (male) groups, which were validated using RT-qPCR. The genes encoding matrix metalloproteinase-9 (MM9), Ribosome-binding protein 1 (RBP1), Aly/REF export factor 2, and hematological and neurological expressed 1 (HN1) may play a role in modulating the sex-related size differences observed in M. nipponense. Clusters of orthologous groups and gene ontology functional analysis demonstrated that the DEGs for sex-related size in M.nipponense were associated with various biological functions. The Kyoto Encyclopedia of Genes and Genomes pathways analysis demonstrated that upregulated DEGs were mainly enriched in lysine biosynthesis, tryptophan metabolism, and lysine degradation pathways, whereas the downregulated DEGs were mainly enriched in ascorbate and aldarate metabolism, retinol metabolism, and drug metabolism-cytochrome P450 pathways. The results indicated the molecular mechanism underlying the sex-related size differences and identified key genes. This data will be invaluable to support explanations of individual differences between male and female prawns.