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To explore the morphological and phenotypic characteristics and differences among different populations of Larimichthys crocea, traditional morphological measurements were carried out on three wild populations from Zhoushan, Xiamen and Zhanjiang and two farmed populations from Ningde and Wenzhou. Seven morphological parameters of five L. crocea populations were compared and analyzed. The results of one-way ANOVA showed significant differences in trunk and caudal stalk among the five populations. The contribution rates of the first five principal components to the total difference among different populations were 29.984%, 18.462%, 17.234%, 12.167%, and 9.904%, respectively, and the cumulative contribution rates were 87.751%. Trunk can be used to distinguish different geographic populations best. The cluster analysis results showed that the distance between wild populations was the closest, while the distance between farmed populations was far. The step discriminant method established the classification discriminant function of 5 populations. The discriminant accuracy P1 was 78.3%-92.7%, the discriminant accuracy P2 was 76.4%-96.5%, and the comprehensive recognition rate was 99.3%. The discriminant accuracy of this method was high, and it could provide a reference for the differentiation of different populations of L. crocea. This study provided basic morphological data for identifying a large yellow croaker population, protecting germplasm resources, and breeding improved varieties.

Golden pompano (*Trachinotus ovatus*) is a marine fish of great commercial value. It was selected for a study on allometric growth using fermented soybean meal (SBM) as the primary protein source during an 8-week culture period. By comparing the gene expression levels of different individuals in the fermented soybean meal group, we discovered that 1026 genes exhibited significant changes in slow and fast-growth individuals. Among these genes, 358 showed high expression levels, while 668 showed low ones. Subsequently, we conducted go function annotation and KEGG pathway enrichment analysis on all the significantly differentially expressed genes. This analysis revealed that many of these genes were associated with oxidative phosphorylation, steroid biosynthesis, glyceride metabolism, alanine, aspartic acid, and glutamate metabolism. Identifying these differentially expressed genes is a foundation for unraveling the molecular mechanisms behind growth and development. Additionally, it provides valuable gene data for future studies on the cloning and expression of growth-related genes and offers insights for subsequent biological research.

To explore the external morphological differences of golden pompano in different geographical populations, eight quantitative traits of 210 samples from seven golden pompano populations were measured. Multivariate statistical methods, such as principal component analysis, discriminant analysis, cluster analysis, and One-way ANOVA, were used to compare morphological differences among the populations. Principal component analysis extracted the top five principal components with a cumulative contribution rate of 85.79%, of which the first three principal components could explain seven morphological features. The principal component scatter plot showed that the NH, CH, and LL populations had similar morphology. Using the stepwise discriminant method to establish the classification and discrimination functions of the seven populations, the discrimination accuracy of the DL population was 93.3% for P1 and 87.5% for P2, which was the highest, and the comprehensive discrimination rate was 71.4%. The clustering relationship diagram showed that the populations were divided into three branches, and the CH and NH populations were closest. In contrast, the DL and HF populations were farthest from the other populations. One-way ANOVA showed significant differences (P<0.05) among all traits of the populations, and the morphological differences between the HX and DL populations were the largest. The results of this study showed specific differences in the external morphology of golden pompano among different populations.