The ponyfish genus Aurigequula is a relatively poorly studied group within the Leiognathidae, with its diversity and phylogenetic relationships in the West Pacific remaining unclear. This study reports the first confirmed record of Aurigequula striata from Chinese waters, based on two specimens obtained from a fish market in Sanya, Hainan Island. Newly collected specimens of A. fasciata from the same region are also provided, which enabled detailed morphological and genomic analysis. The morphological descriptions are supplemented by detailed photographic documentation of fresh and preserved specimens, addressing the historical scarcity of reliable visual references for these species. Furthermore, we present the first complete mitochondrial genomes for both A. striata (16,629 bp) and A. fasciata (16,537 bp). Our phylogenomic analysis, based on 13 protein-coding genes, strongly supports the monophyly of the subfamilies Gazzinae and Leiognathinae. Within Leiognathinae, however, the analysis suggests paraphyly of Aurigequula , with A. fasciata forming a clade with Leiognathus equula to the exclusion of A. striata . This result conflicts with the current morphology-based generic diagnosis, which relies on consistent differences in the length of the second dorsal-fin spine and body coloration patterns. This study significantly expands the genomic resources for the understudied genus Aurigequula but also highlights the limitations of relying solely on mitochondrial data for resolving generic-level relationships. A more robust phylogenetic framework for Leiognathidae, capable of reconciling molecular and morphological evidence, will require the integration of multiple independent nuclear loci.

Monitoring the freshness of Salmo salar within cold chain logistics is paramount for ensuring food safety. However, conventional physicochemical and microbiological assays are impeded by inherent limitations, including destructiveness and significant time latency, rendering them inadequate for the real-time, non-invasive inspection demands of modern industry. Here, we present a novel detection framework synergizing hyperspectral imaging (400–1000 nm) with the Transformer deep learning architecture. Through a rigorous comparative analysis of twelve preprocessing protocols and four feature wavelength selection algorithms (Lasso, Genetic Algorithm, Successive Projections Algorithm, and Random Frog), prediction models for Total Volatile Basic Nitrogen (TVB-N) and Total Viable Count (TVC) were established. Furthermore, the capacity of the Transformer to capture long-range spectral dependencies was systematically investigated. Experimental results demonstrate that the model integrating Savitzky-Golay (SG) smoothing with the Transformer yielded optimal performance across the full spectrum, achieving determination coefficients (R²) of 0.9716 and 0.9721 for the Prediction Sets of TVB-N and TVC, respectively. Following the extraction of 30 characteristic wavelengths via the Successive Projections Algorithm (SPA), the streamlined model retained exceptional predictive precision (R² ≥ 0.95) while enhancing computational efficiency by a factor of approximately six. This study validates the superiority of attention-mechanism-based deep learning algorithms in hyperspectral data analysis. These findings provide a theoretical foundation and technical underpinning for the development of cost-effective, high-efficiency portable multispectral sensors, thereby facilitating the intelligent transformation of the aquatic product supply chain.

Neobythites nanhaiensis sp. nov ., a new cusk eel species from the South China Sea, is described based on 14 specimens collected at a depth of 400 m near Nan’an Reef. This species is readily distinguished from all congeners by the unique presence of two (rarely three) distinct black ocelli on the mid-flank, a trait absent in all other Neobythites species. It further lacks stripes, fin ocelli, or dark fin margins. The meristic features include dorsal-fin rays 107 (90–115), anal-fin rays 93 (80–94), pectoral-fin rays 25 (21–27), total vertebrae 62 (58–64), and 9–11 developed gill rakers. The complete mitochondrial genome (17,287 bp) was sequenced, exhibiting the typical vertebrate structure with an A+T bias of 55.1%. Phylogenetic analyses based on both the COI gene and the complete mitogenome robustly supported N. nanhaiensis sp. nov . as a distinct monophyletic lineage, sister to N. marginatus in the mitogenome phylogeny. This integrative taxonomic approach, combining morphology, meristics, otolith morphology, and mitogenomic data, confirms the establishment of this new species, which lies outside any existing species group within the genus due to its unique flank ocelli.

In this study, the complete mitochondrial genome of the Taiwan tai Argyrops bleekeri was determined for the first time by next-generation sequencing. The circular mtDNA molecule was 16,646 bp in size and the overall base composition was A (27.77%), C (28.95%), G (16.60%), and T (26.68%), with a slight bias toward A + T. The complete mitogenome encoded 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and a control region. Phylogenetic analysis based on the 13 PCGs of the Sparidae family revealed that Argyrops appears to be most closely related to Pagrus and Parargyrops, but further research is needed.

The complete mitochondrial genome of Acheilognathus imberbis Günther, 1868, a small freshwater fish inhabiting tributaries of the Yangtze and Yellow River systems, was sequenced and characterized. The circular mitogenome spans 16 576 base pairs, containing 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and a non-coding control region. Nucleotide composition analysis revealed an AT-rich genome (A + T = 58.93%) with distinct guanine deficiency (15.88% G content), consistent with a typical vertebrate mitogenome bias. To resolve debated phylogenetic relationships within Acheilognathinae, we performed phylogenetic analysis using concatenated sequences of 13 PCGs from 37 representative species. Results confirmed the monophyly of Acheilognathinae, which diverged into two primary clades: Acheilognathus and the Tanakia – Rhodeus complex. Notably, the monophyletic status of Rhodeus received limited nodal support, suggesting potential taxonomic revisions. Pairwise genetic distances (Tamura–Nei model) ranged from 0.0071 to 0.2600 across the subfamily. Through homology analysis, some Acheilognathinae fishes are clustered together, and the genetic distance is much less than 0.0406, suggesting re-evaluation of their classification criteria. Positive selection analysis based on the ND2 gene using site models revealed no statistically significant codon positions under positive selection. This mitogenomic resource advances molecular systematics and evolutionary studies in Acheilognathinae fishes.