Yu Wang

Frozen mysid shrimp is the primary feed for farmed medicinal seahorses, yet no standardized storage duration exists, and whether storage-related feed changes affect the lipid-based medicinal quality of seahorses remains unknown. This study used targeted lipidomics to compare 98 lipid species across six lipid classes in three farmed seahorse species—Hippocampus erectus, H. abdominalis, and H. trimaculatus—fed mysid shrimp frozen for either 2 or 10 months. Prolonged storage did not cause a uniform decline in lipid quality; instead, each species exhibited a distinct response pattern. H. erectus showed compensatory increases in fatty acids, whereas phospholipids predominantly decreased; H. abdominalis exhibited broad attenuation across multiple lipid classes; and H. trimaculatus displayed an intermediate, class-dependent pattern. Notably, oxidized sterol derivatives declined consistently across all three species despite divergent fatty acid and phospholipid responses, suggesting that oxidized sterol derivatives may serve as candidate cross-species indicators of storage-related feed changes, although validation is required. Acylcarnitine profiles remained stable in H. erectus but decreased in the other two species, suggesting possible differences in lipid utilization among species. These preliminary results suggest that frozen-storage guidelines may need to be evaluated on a species-specific basis in future studies, with sterol monitoring as a candidate indicator for further evaluation.

Frozen mysid shrimp is the core feed for commercial seahorse aquaculture, yet quality deterioration caused by long-term cold storage severely constrains the survival and reproductive performance of seahorses. By integrating targeted metabolomics, physicochemical spoilage indicators, and 16S rRNA high-throughput sequencing, this study multidimensionally analyzed the stage-specific mechanisms of nutritional degradation and microecological deterioration of mysid feed at −20 °C under fresh (0 months), short-term frozen (2 months), and long-term frozen (10 months) conditions. The results demonstrate that short-term storage (2 months) effectively suppresses microbial-induced spoilage of mysids; however, freeze–thaw stress triggers cellular lysis, leading to a significant depletion of key water-soluble feeding-attractant amino acids, notably glycine and aspartate. In contrast, long-term frozen storage (10 months) induces severe lipid peroxidation and a massive accumulation of total volatile basic nitrogen (TVB-N). Microbiome analysis confirmed that the fundamental trigger for feed deterioration during the late storage stage is the explosive community succession of psychrotrophic specific spoilage organisms (SSOs), with Shewanella, Photobacterium, and Pseudoalteromonas emerging as the absolute dominant taxa. The highly active extracellular lipases and proteases secreted by these microbial communities extensively degrade the structural lipids of the feed, ultimately resulting in a paradoxical rebound in free fatty acid content during long-term storage. In summary, our research comprehensively details how freezing compromises diet quality through specific biological and chemical pathways. This establishes essential scientific groundwork aimed at refining commercial preservation techniques, executing precise dietary enrichments, and ultimately securing long-term viability across the captive Hippocampus breeding sector.

Marine biofouling by sessile invertebrates such as Diadumene lineata poses a persistent threat to marine infrastructure, and antifouling agents are critical for mitigating this issue, yet their molecular mechanisms of action on fouling cnidarians remain poorly understood. In this study, acute toxicity tests and 24 h attachment inhibition assays were conducted, followed by transcriptomic sequencing of pedal disc tissue from D. lineata exposed to N-oleyl-1,3-propanediamine. The 96 h-LC₅₀ of the agent was determined to be 38.66 mg/L, and exposure to 70 mg/L agent achieved complete 24 h attachment inhibition. Transcriptomic analysis identified extensive transcriptional perturbations across four core physiological systems: metabolic reprogramming via activated PPAR signaling, immune dysregulation characterized by impaired antigen processing and DAMP-mediated inflammation, disrupted post-transcriptional regulation and proteostasis, and compromised axon regeneration with decoupled damage sensing and repair. Collectively, these interconnected disruptions synergistically impaired the structural integrity, energy supply, and stress adaptation capacity of pedal disc cells, ultimately leading to adhesion inhibition in D. lineata. This study clarifies the multi-pathway toxic mechanism of antifouling agents in fouling sea anemones, providing a foundational molecular framework for future research.

To address knowledge gaps in urban wetlands’ role in sustaining avian diversity along migration corridors, this study systematically surveyed three Yancheng wetland parks with a distinct habitat gradient. Monthly surveys were conducted from January to December 2024 using fixed-width line transects and point counts, with three 300 m transects set in each park and all birds within 50 m of the transect line recorded, and Shannon–Wiener, Simpson, Pielou’s Evenness, and Margalef Richness indices were employed for quantitative analysis. A total of 83 bird species across 16 orders and 41 families were documented, including the National Class I Protected and Endangered Oriental Stork and three Class II nationally protected species (Black-winged Kite, Crested Goshawk, Common Kestrel). Fengyi Lake Park, with 71 species, served as a critical migratory waterbird hub. Yandu Wetland Park sustained community stability through high habitat heterogeneity, supporting specialized breeders, and Dongfang Wetland Park, with 34 urban adaptor-dominated species, provided key autumn pulsed resources for frugivores and granivores. This study identifies habitat heterogeneity as the primary driver of avian community differentiation and highlights that the ecological functions of urban wetlands are contingent on multi-habitat complementarity. We, therefore, advocate for prioritizing the construction of heterogeneous habitat structures in urban wetland planning, enhancing functional complementarity and connectivity among distinct wetland types, and preserving the continuity of migratory bird habitat corridors along the East Asian-Australasian Flyway. These findings furnish robust scientific evidence and actionable guidance for regional green space planning and biodiversity conservation.

In this study, we added Bacillus licheniformis to the diet of hybrid sturgeon (Acipenser baerii ♀ Acipenser schrenkii ♂) to determine its effects on growth performance, blood physical and chemical indices and intestinal microflora composition. One hundred and sixty adult hybrid sturgeon were selected and fed with four types of diets (equal nitrogen and fat levels) that were respectively supplemented with 0.00% (control group), 0.10% (Group B), 0.20% (Group C) and 0.40% (Group D) B. licheniformis for 120 days. Results showed that the fish in group C had the highest final body weight, weight gain rate and specific growth rate (p < 0.05). The feed coefficients, crude protein and crude fat of group B, group C and group D were significantly lower than that of group A (p < 0.05). And the crude protein (CP) and crude fat (EE) in groups B, C and D were significantly higher than the control group (p < 0.05). The serum TC and TG, ALP, ALT, AST and GLU contents in the B. licheniformis-added groups were also significantly higher than those of the control group (p < 0.05). In addition, Cetobacterium was the dominant bacterial taxon in each group. With increasing the content of B. licheniformis in the diet, the Cetobacterium content decreased and the Plesiomonas content increased correspondingly. Adding B. licheniformis to the diet greatly decreased the abundance of Streptococcus, Candidatus Competibacter and Lactococcus. Our results indicated that appropriately adding (0.20%) B. licheniformis could increase growth, reduce the feed coefficient and increase the diversity of the intestinal microbiota of hybrid sturgeon.