Beneath the Earth's surface lies a network of interconnected caves, voids, and systems of fissures forming in rocks of sedimentary, igneous, or metamorphic origin. Although largely inaccessible to humans, this hidden realm supports and regulates services critical to ecological health and human well-being. Subterranean ecosystems are integral to major biogeochemical cycles, sustain diverse surface habitats, and serve as the primary source of irrigation and drinking water. They also offer non-material benefits, including scientific discovery, education, and cultural practices. Yet, these contributions often go unrecognised, partly due to the lack of a unified synthesis of ecosystem services across terrestrial, freshwater, and marine subterranean compartments. This gap limits effective communication of their value to scientists, practitioners, and the public. Through a systematic expert-based review, we show that subterranean ecosystems contribute to up to 75% of classified ecosystem services. Notably, many of these contributions are described only qualitatively, lacking numerical or economic quantification. Next, we list examples of the main ecosystem services provided by subterranean systems to offer a global overview of their multifaceted value and vulnerability to environmental change. We believe this synthesis provides researchers and practitioners with concrete examples to communicate more effectively the importance of subterranean ecosystems to diverse audiences.
The spread of aquatic non-indigenous species (NIS) is recognised as a major threat to the recipient regions ecosystems. The present study reviewed all NIS that have been introduced to the marine waters of the European Union (EU) until 2021, and their introduction pathways. Further, the study statistically analysed temporal trends in new NIS introductions and addressed uncertainties in relation to transporting pathways. Time-series analyses indicated that the observed trends in new NIS introductions have followed smoothly increasing trajectories for the entire study area, Mediterranean Sea, North-East Atlantic Ocean, and the Baltic Sea, whereas abrupt increase was detected for the Black Sea. It is noteworthy that the increasing trends started to slow down at the end of 2010s. Strongly increased research interest towards marine invasions since the early 2000s, and new environmental policies likely affected the observed trends. Future updates will be key to assessing whether this slowdown is truly a persisting trend or only an anomaly in the long term. The pathway assessment suffered from notable uncertainties, as the assigned confidence levels for pathways were low or unassigned for a large proportion of the introduced NIS in all study regions. Transport by shipping vectors was assigned as the most common pathway (51%) for new NIS introductions to EU seas, although there was very rarely direct evidence of this. The study highlights the need to overcome the pathway uncertainties, as robust information on introduction pathways is critical to manage new NIS introductions effectively.
The family Pontarachnidae is found worldwide, mainly in coastal marine habitats; however, the diversity (and especially the ecology) of this poorly studied and mostly neglected group of marine meiofauna still awaits discovery. In this study, we present data on Mediterranean pontarachnids based on extensive material from the Adriatic and Tyrrhenian seas. Up to now, only one sequence of a pontarachnid mite from the Mediterranean was present in GenBank; we are adding 81 new pontarachnid mite barcodes from these Mediterranean areas to the DNA barcode library. Our study, using the DNA barcode fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene, shows that the coast of Slovenia harbours at least six genetic lineages representing distinct Molecular Operational Taxonomic Units (MOTUs), corresponding with six species of pontarachnid mites (three Litarachna Walter, 1925 and three Pontarachna; Philippi, 1840). The material from the Adriatic Sea (Piran, Slovenia) also revealed a new species, Litarachna cursusmaritima sp. nov., clearly separated from the hitherto known species by COI and by a very conspicuous dorsal colour pattern. Finally, the finding of two species, L. communis and P. punctulum, each represented by two Barcode Index Numbers (BINs) with relatively high genetic distance between morphologically similar populations from the Adriatic and the Tyrrhenian Sea, clearly shows the necessity of finding and using new morphological characters, such as colour pattern and applying new markers such as nuclear genes, to reveal possible cryptic or pseudocryptic diversity in pontarachnid mites.
Potyviruses are the largest group of plant positive-sense single-stranded RNA viruses and represent a major economic burden worldwide. Their coat protein (CP) forms a filamentous, flexible capsid around the genomic RNA. However, information is still lacking on the mechanisms of virion assembly, disassembly and stability, which is central to understanding virus biology and control. Here, we investigate the role of CP in these processes using structural, biochemical and biophysical studies of five potyviral CPs from three phylogenetic clades combined with bioinformatics and in planta experiments. Our results suggest that, while potyviruses have a conserved virion structure, the amino acids forming the CP-CP and CP-RNA interactions leading to this structure are species-specific. We show that the species-specific CP sequence also determines the architecture of RNA-free virus-like particles (VLPs) and the degree of their structural polymorphism. We identify the residues that determine this specificity at distinct S1-S4 interaction sites. In contrast, a highly conserved charged amino acid triad at the CP-CP interface is essential for the stability of virions and RNA-free VLPs. These results contribute to understanding the molecular mechanism of potyviral virion assembly and highlight the significance of the amino acid sequence of selected CPs in potential biotechnological or biomedical applications.
Jellyfish are increasingly recognized as a significant contributor to marine organic matter (OM) on a global scale, with implications for ecosystem dynamics. While the role of jellyfish detritus in microbial nutrient cycling has been explored, the contribution of OM released by live jellyfish—primarily as mucus (hereinafter referred to as mucus-associated OM, or MAOM)—remains understudied. This study investigates the release of organic and inorganic nutrients through MAOM from live jellyfish and their effects on ambient microbial communities in the northern Adriatic Sea using a series of leaching and short-term microcosm experiments. Our results show that per gram of MAOM dry weight from the jellyfish Aurelia spp, approximatively 2 µmol of phosphate, 4 µmol of dissolved inorganic nitrogen, 18 µmol dissolved organic nitrogen, 134 µmol of dissolved organic carbon and 15 µmol of dissolved free amino acids can be released in the ambient seawater in 24 h. Almost half of the OM is released as dissolved OM (DOM), of which a substantial part is low molecular weight (<1 kDa) molecules. During the first 20 h, the DOM fraction of MAOM was rapidly consumed by the ambient microbial community without a corresponding increase in biomass, likely due to nitrogen limitation. In the subsequent 22 h, microbial growth accelerated to 0.19 ± 0.03 h−1 until phosphate became limiting, leading to a sharp decline in microbial production. Our metagenomics analysis revealed that the MAOM-degrading microbial community, dominated by Gammaproteobacteria opportunistic copiotrophs, exhibited increased functional capacity for nutrient assimilation and OM degradation, particularly in the transport and metabolism of amino acids (particularly glycine and taurine) and phosphorus. These traits mirror those found in detritus-degrading microbial communities, suggesting that jellyfish blooms promote the emergence of specialized microbial consortia with shared metabolic capabilities. Taken together, our findings highlight that live jellyfish, through the release of OM, play an active and previously underappreciated role in shaping ambient microbial community dynamics and nutrient fluxes in marine systems affected by jellyfish blooms.
