Dai-Zhen Zhang

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.

Histia rhodope is a defoliating pest that feeds mainly on the ornamental garden plant Bischofia polycarpa. Recently, frequent outbreaks of H. rhodope in Southern China have severely affected cityscapes and people’s lives. To provide a predictive early-warning program for the spread risk of H. rhodope in China and reduce damage to B. polycarpa, we used the MaxEnt model to investigate the potentially suitable spread characteristics of H. rhodope and its host B. polycarpa under different climate scenarios for the years 2050 and 2070. The results showed that the potentially suitable habitat of H. rhodope under the SSP5-8.5 scenario will reach an area of 3174.55 × 10³ km² in the 2070s, an increase of 1010 × 10³ km² from the current distribution. The potentially suitable habitat of B. polycarpa under the SSP5-8.5 scenario will reach 2618.01 × 10³ km² in the 2070s (an increase of 464 × 10³ km²). The potentially suitable habitats of H. rhodope and B. polycarpa are expected to shift to higher elevations under future climate scenarios. We also identified ten key environmental factors, of which Precipitation of Warmest Quarter (bio18) had the greatest influence on the probability of moth and host plant occurrence. Our results highlight the risk of further expansion of the potentially suitable area for H. rhodope and the important role of the host plant in this process, and provide a firm scientific basis for the monitoring and management of H. rhodope and B. polycarpa.

Crabs encompass the infra-orders Brachyura and Anomura, collectively constitute the clade Meiura within order Decapoda. Despite their considerable diversity, genomic resources for crabs remain scarce, hindering our understanding of their phylogeny and genetic mechanisms underlying such unique traits as carcinization. To address these questions, here we sequenced genomes of 10 crab species covering all currently controversial taxonomies at section level. Our whole-genome phylogenetic results support Raninoida is closer to Eubrachyura rather than Dromiacea, challenging the traditional classifications. Notably, the freshwater crab subsection Potamoida, represented by S. planum, is found to be more closely related to subsection Thoracotremata than to Heterotremata as previously suggested, indicating that crab classification based solely on morphology may be misleading. Our results also clarify that the family Gecarcinidae should be classified into Thoracotremata, contrary to previous placements in Heterotremata. Comparative genomic analyses identified lineage-specific families related to crab traits, including ionotropic glutamate receptors, neurotransmitters, and energy metabolism. Additionally, transcriptomic studies of Chinese mitten crab larval stages suggest that some lineage-specific genes such as ghrA, and TCB2, may account for the prominent carcinization in brachyurans. This study not only significantly expands the genomic repository for crabs, but also provides insights into the phylogeny and trait evolution of crabs.