Xinjie Liang

With the increasing detection of micro- and nanoplastics (MNPs) in marine environments and the expanding body of related research, their environmental behavior and ecological effects have become central topics in marine environmental science. This review addresses the growing concern over MNP pollution in the marine realm, encompassing their primary sources, spatial accumulation and distribution, environmental transport and transformation dynamics, and ecotoxicological effects on marine organisms and ecosystems, as well as the ecological risks they pose within key habitats such as seagrass beds and coral reefs. We synthesize evidence on the biological impacts of MNPs, including oxidative stress, tissue accumulation, metabolic disturbances, and immune impairment, as well as the heightened risk of pathogen transmission facilitated by the so-called “Plastisphere”. Moreover, we explore the potential implications of MNP exposure on oceanic carbon cycling and net primary productivity. The reviewed literature suggests that MNPs are capable of long-range transport and progressive fragmentation into ultrafine particles, which are readily ingested and retained by a wide array of marine organisms, subsequently inducing toxicological effects and compromising both organismal health and ecological integrity. Such disturbances may undermine critical ecosystem services, including carbon sequestration capacity and food web stability. Finally, based on the current research landscape, we outline future research priorities: improving environmental detection and toxicological evaluation of MNPs, elucidating their long-term effects at the ecosystem scale, and investigating their interactions with co-occurring pollutants under complex, multi-stressor scenarios. These efforts are essential to support science-based assessment and effective management strategies for marine MNP pollution.

Mytilus coruscus, a commercially important mariculture mussel in China, has shown a marked decline in larval settlement and metamorphosis over the past decade, a trend often linked to environmental degradation and resource depletion. Numerous studies have identified bacterial biofilms as key modulators of mussel larval settlement. To investigate this, we deployed PVC plates in situ within aquaculture zones near Shengsi (Zhoushan, Zhejiang) and Lianjiang (Fuzhou, Fujian). After natural biofilm colonization on the plates, juvenile M. coruscus were introduced to assess settlement rates. The attached juveniles were homogenized, leading to the isolation of four dominant bacterial strains: Pseudomonas sp. LJBF001, Vibrio sp. LJBF002, Pseudomonas sp. LJBF003 and Bacillus sp. LJBF004. Compared to control PVC plates, natural biofilms significantly promoted juvenile settlement, with the Lianjiang (LJ) group reaching up to >29% under our assay conditions. In contrast, monospecific biofilms prepared from these isolates did not significantly increase larval metamorphosis; the numerically highest response (LJBF004) reached ~9% and was not significant versus the control. These contrasting outcomes are consistent with a threshold–multi-cue synergy mechanism, whereby cue diversity and partial redundancy in natural biofilms favour threshold crossing, while restricted cue sets in single-strain films often fall short. Guided by this framework, priority next steps include testing c-di-GMP delivery (soluble and via OMVs), probing EPS structure–function and EPS–OMV/LPS–free-fatty-acid blends alongside minimal multi-strain consortia, and adopting stage-gated assays with time-to-event endpoints and effect-size/CI reporting.

The phylogeny of species of Brachyura, particularly within the family Pinnotheridae, remains incompletely understood. To enhance the taxonomy and systematics of the Pinnotheridae, we conducted a comprehensive study aimed at elucidating the phylogenetic position of Arcotheres sinensis. Consequently, we sequenced and annotated the complete mitochondrial genome of A. sinensis, The results revealed that the circular mitogenome of A. sinensis spans 16 520 bp in length. Distinct from typical mitogenomes, A. sinensis contains 13 protein-coding genes (PCGs), 2 ribosomal RNA genes and 23 transfer RNA genes. The A + T content of the A. sinensis mitogenome is 71.63%, with both AT-skew and GC-skew being negative. The lengths of the 23 tRNA genes range from 62 to 72 bp. All tRNA genes exhibit typical cloverleaf structures, except for the trnS1 gene, which lacks the dihydrouridine (DHU) arm. Selection pressure analysis revealed that all PCGs are under evolutionary selection, with cox1 experiencing strongest purifying selection and atp8 undergoing weakest purifying selection. Compared to ancestral Brachyura, the gene order of A. sinensis has been rearranged from R-N--E to -E-N-R and the sequence I-Q-M has transitioned to Q-I-M. Phylogenetic analysis unequivocally positions A. sinensis within the taxonomic framework of the family Pinnotheridae, highlighting its intimate phylogenetic relationship with congeners within the same familial clade, notably Arcotheres purpureus and Pinnotheres excussus. These findings contribute to a better understanding of the status and evolutionary history of Pinnotheridae species.

Growth is a fundamental aspect of aquaculture breeding programs, pivotal for successful cultivation. Understanding the mechanisms that govern growth and development differences across various stages can significantly boost seedling production of economically valuable species, thereby enhancing aquaculture efficiency and advancing the aquaculture industry. Mytilus coruscus, a commercially vital marine bivalve, underscores this importance. To decipher the intricate molecular mechanisms dictating growth and developmental disparities in marine shellfish, we conducted transcriptome sequencing and meticulously analyzed gene expression variations and molecular pathways linked to growth traits in M. coruscus. This study delved into the molecular and gene expression variations across five larval development stages, with a specific focus on scrutinizing the differential expression patterns of growth-associated genes using RNA sequencing and quantitative real-time PCR analysis. A substantial number of genes—36,044 differentially expressed genes (DEGs)—exhibited significant differential expression between consecutive developmental stages. These DEGs were then categorized into multiple pathways (Q value < 0.05), including crucial pathways such as the spliceosome, vascular smooth muscle contraction, DNA replication, and apoptosis, among others. In addition, we identified two pivotal signaling pathways—the Hedgehog (Hh) signaling pathway and the TGF-beta (TGF-β) signaling pathway—associated with the growth and development of M. coruscus larvae. Ten key growth-related genes were pinpointed, each playing crucial roles in molecular function and the regulation of growth traits in M. coruscus. These genes and pathways associated with growth provide deep insights into the molecular basis of physiological adaptation, metabolic processes, and growth variability in marine bivalves.

We analysed the mitochondrial genome of Aristaeopsis edwardsiana (Johnson, 1868) to understand its origin and evolution. Our study uncovered new insights into its phylogenetic relationships and evolutionary history. The mitogenome of A. edwardsiana is 15 913 bp, contains 37 genes, including 13 protein-coding genes (PCGs), 2 ribosomal RNA genes (rRNA) and 22 transfer RNA genes (tRNA). The AT content is 64.98%, with negative AT and GC skews. Our analysis showed that the PCGs of A. edwardsiana and related Aristeidae species underwent purifying selection. The tRNA genes exhibited a typical structure, except trnC and trnS1. The gene order was conserved compared to ancestral decapods. Using species of Dendrobranchiata, we constructed a phylogenetic tree, revealing the relationship of A. edwardsiana within the family Aristeidae. These findings improve our understanding of Decapoda classification and Aristeidae’s evolutionary position, facilitating further phylogenetic investigations. This study may serve as a valuable reference for future research on species of Aristeidae.