Copper nanoparticles (CuNPs) have been widely used in various industrial and commercial applications, which become a potential threat to aquatic organisms. Nevertheless, their potential toxicity to the epididymis and sperm remains little known. In this study, we evaluated the effect of CuNPs and copper ions (CuSO₄) on the spermatozoa viability, epididymal structure, antioxidant enzyme activity, and inflammatory cytokines in cauda epididymis of the Chinese soft-shelled turtle. Results showed that the spermatozoa viability of Chinese soft-shelled turtles decreased significantly with an increase in CuNPs or Cu ions concentrations. The epithelial cells of the epididymal duct of the Chinese soft-shelled turtles with the treatment of 5 mg kg⁻¹ CuNPs were slightly swollen, and the connective tissue between the epididymal ducts was loose. The epithelial structure of the epididymal tube was severely damaged with an increase in Cu ion concentrations. Compared to the control, the antioxidative enzymes activities and the expression of IL-1β, TNF-α, and IL-6 mRNA in the epididymis significantly increased with the treatment of CuNPs or CuSO₄. The present study revealed that Cu ions exert more harmful effect on the epididymis and spermatozoa viability of Chinese soft-shelled turtles than copper nanoparticles.

The assertive growth of photovoltaics (PV) will occupy a lot of land resources. There is also a needed land resource to expand the culturing area of Eriocheir sinensis. The aquavoltaic systems offer a potential solution to integrate PV power and E. sinensis culturing. In this study, we cultured E. sinensis in an area of PV panels (PV group) and an area with no PV panels (control group), respectively. The results showed that the weight gain rate, body length, body width, and meat yield of male crabs in the PV group significantly increases. In addition, the moisture of muscles, hepatopancreas, and testes in the PV group has significantly increased, and the total lipids of the hepatopancreas and muscles in the PV group were significantly decreased. Moreover, the PV panels affected the content of eight amino acids in different tissues, including Met, Arg, Cys, Pro, Gly, Leu, Tyr, and His. In addition, several saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA) had been significantly influenced by the PV panels. ∑MUFA, docosahexaenoic acid (DHA), ∑n-3 PUFA, ∑n-6 PUFA, and n-3/n-6 PUFA ratio (p < 0.05) in the PV group had significantly decreased. The results of tissue color showed that the L* value of ovaries was significantly higher than in the control group, and a* and b* values of hepatopancreas were significantly lower. In conclusion, PV panels could promote growth performance and amino acid nutrition of crabs. However, the PV panels had a few negative influences on the fatty acid composition and tissue color.

Food deprivation is a common stress in crustaceans that can affect their behavior and physiology. In this study, a video recording analysis system was used to compare the predation rate and behavior of the Chinese mitten crab, Eriocheir sinensis, foraging on the freshwater snail, Bellamya quadrata, under different degrees of food deprivation. The activities of lactate dehydrogenase, α-amylase, pepsin, and lipase in the hepatopancreas of crabs were determined after food deprivation for 0, 3, 9, and 15 days. The results showed that the predation and encounter rates of E. sinensis increased and then decreased with an increase in food deprivation time. The proportion of stationary time of E. sinensis initially decreased and then increased, whereas the proportion of searching and handling time increased initially and then decreased. There was a significant difference in the probability of capture upon encountering; however, food deprivation did not significantly affect the probability of consumption upon capture. Under food deprivation, the proportion of E. sinensis crushing tactics after nine-day food deprivation was significantly lower than that in the first nine days. Lactate dehydrogenase activity in the E. sinensis hepatopancreas after food deprivation was significantly higher than that in those not subjected to food deprivation, and the activities of α-amylase and pepsin in the hepatopancreas were consistent with the predation rate trend, showing an initial increase followed by a decrease. In conclusion, different degrees of food deprivation significantly affected the predation cycle of E. sinensis on B. quadrata. These results lay a solid foundation for further studies on the foraging behavioral ecology of E. sinensis and provide important information for improving E. sinensis production.

Lipopolysaccharide (LPS), a major cell wall component of Gram-negative bacteria, is considered to lead to some disease development in commercial crustaceans. However, mantis shrimps Oratosquilla oratoria (Crustacea: Stomatopoda) have a strong vitality and ability to resist disease. To study the tolerance mechanism of mantis shrimp, transcriptome analyses were conducted in hepatopancreas of O. oratoria under LPS challenge investigation. Totally, 84 547 044 clean reads were obtained from transcriptomes (43 159 230 in OP (control), 41 387 814 in OL (treatment), respectively). Unigenes, the longest transcript of each gene, with a total length of 68 318 880 bp and the total number of 100 978 were obtained. 8369 (8.28%) of unigenes were successfully annotated in all databases and 54 888 (54.35%) were annotated in at least one database. Finally, 1012 differentially expressed genes (DEGs) including 439 and 573 showed significantly upregulated and downregulated were determined between OL and OP, respectively. Moreover, those DEGs only expressed in OL or OP accounted for 8.99%. The functional classification based on GO and KEGG indicated that the common enrichment categories for the DEGs are “amino sugar metabolic” and “cellular homeostasis” and that the progress of nutrient metabolic and homeostasis in cells is important in facing variable environmental conditions. Protein–protein interaction analysis elucidated proteins, β-actin (ACTB_G1), T-complex protein subunits (TCPs), heat shock proteins (HSPs), hydroxysteroid dehydrogenase-like protein 2 (HSDL2), kinesin family member 5 (KIF5), methylglutaconyl-CoA hydratase (AUH), and myosin heavy chain (MYH) may play key roles in response to an LPS challenge. This study laid a foundation to further investigate the possible adaptation way that O. oratoria survives in a bacterial challenge.

Laevichaulis alte is a slug in the order Systellommatophora that evolved from aquatic ancestors and now faces strong challenges from desiccation, respiration on land, and novel pathogens. Its mucus is essential for water retention, locomotion, and defense. To link terrestrial adaptation with mucus biosynthesis, we generated a gap‐free genome assembly of L. alte using PacBio HiFi reads, Oxford Nanopore ultra‐long reads, and Hi‐C data. The genome shows low heterozygosity and holocentromeric chromosomes. Functional metabolomics revealed marked metabolic shifts between L. alte and the closely related aquatic species Peronia verruculata . In L. alte , differential metabolites were enriched in lipid metabolism, immune regulation, and stress response pathways, consistent with life in a dry and microbe‐rich terrestrial environment. Comparative genomics and transcriptomics identified candidate genes linked to mucus secretion and physiological adaptation, including VEGF , ASGR2 , and COL6A6 . Further analyses highlighted the vascular endothelial growth factor (VEGF) gene family as a key regulator connecting angiogenesis, tissue remodeling, and mucus production pathways in L. alte . Together, this gap‐free genome and multi‐omics dataset establish a molecular framework that links genomic innovation, mucus biology, and terrestrial adaptation in Systellommatophora, and they offer a basis for understanding ecological niche specialization in land molluscs.