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Povzetek: The fan mussel Pinna nobilis is the largest bivalve species in the Mediterranean Sea and provides numerous ecosystem services. It is classified as critically endangered by IUCN (International Union for Conservation of Nature) due to severe mass mortality events throughout the Mediterranean. The aims of this work are as follows: (i) to assess the current recruitment potential of the species, (ii) to enhance recruitment by keeping juveniles in controlled conditions before releasing them back into the sea, and (iii) to assess the health status of recruits. In the period 2022–2023, larval collectors were set up in the Gulf of Trieste as part of the LIFE Pinna project. The collected individuals were kept in aquaria in two different facilities under different conditions: (a) a closed system with constant water temperature, live phytoplankton, and commercial food and (b) an open system with ambient seawater temperature and commercial food. A clear temporal and spatial variability in recruitment was observed: 13 recruits were found in 2022 and 50 recruits in 2023. The live specimens were between 0.5 and 8 cm in size upon collection and larger in 2023. The growth and survival rate did not differ significantly between the two systems, but the average monthly growth and survival rate were related to the initial size of the juveniles.
Ključne besede: pen shell, ex situ maintenance, in situ maintenance, Haplosporidium pinnae, Mycobacterium, conservation, marine biology
Objavljeno v DiRROS: 08.10.2025; Ogledov: 405; Prenosov: 188
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Povzetek: Seagrasses are unique marine flowering plants that provide critical ecological services and can serve as valuable reservoirs of bioactive compounds with potential health benefits. This review explores the bioactive metabolites found in four seagrass species native to European marine waters: Cymodocea nodosa, Posidonia oceanica, Zostera marina, and Nanozostera noltei. These species exhibit diverse chemical properties, including antioxidants, antimicrobials, and anti-inflammatory agents, making them promising candidates for pharmaceutical, nutraceutical, and cosmetic applications. Despite their promising applications in biotechnology, their full potential remains underexplored due to research and technological limitations. Future studies should focus on optimizing extraction methods, exploring synergistic interactions, and ensuring sustainable utilization of these valuable marine resources.
Ključne besede: seagrasses, European marine waters, bioactive compounds, human health applications, pharmaceutics, nutriceutics, cosmetics, marine biology
Objavljeno v DiRROS: 03.07.2025; Ogledov: 710; Prenosov: 302
Celotno besedilo (1,70 MB)
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Povzetek: Canopy-forming brown macroalgae (Fucales) offer numerous key ecosystem services in Mediterranean coastal areas. However, anthropogenic pressures and climate change have significantly impacted their habitats, leading to an extensive population decline. Interactions between algae and microbiota are a major ecological aspect, yet they represent a significant knowledge gap. In our baseline study, we describe the diversity and host specificity of the microbiome of two genetically identical but morphologically distinct populations of Gongolaria barbata from anthropogenically impacted northern Adriatic Sea. Our preliminary results showed that the microbiomes of G. barbata exhibited low host specificity, with 75% of the algae-associated amplicon sequence variants (ASVs) being part of the core coastal ecosystem microbiome. However, microbiomes of specific algal parts, ambient seawater, and sediment differed significantly in terms of alpha diversity and composition. In contrast, the holdfast and axis show higher similarity with sediment microbiomes, indicating potential horizontal transmission pathways. Microbiomes associated with deciduous parts of morphologically distinct G. barbata populations showed no difference in alpha diversity and composition. In contrast, higher variation in alpha diversity and lower sequence proportion of shared ASVs were observed in the holdfast and axis of the two distinct populations. Our observational study provides valuable new insights and baseline for future hypothesis-driven research on the interactions between algae and associated microbiota—a knowledge gap that needs to be addressed in the future for better understanding of the ecological and evolutionary dynamics of coastal ecosystems.
Ključne besede: ecosystem services, anthropogenic pressures, microbiome, host specificity, alpha diversity, marine biology, ecology
Objavljeno v DiRROS: 18.04.2025; Ogledov: 707; Prenosov: 597
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Povzetek: Algal blooms impact trophic interactions, community structure and element fluxes. Despite playing an important role in the demise of phytoplankton blooms, only few viruses infecting diatoms have been cultured. Pseudo-nitzschia is a widespread diatom genus that commonly blooms in coastal waters and contains toxin-producing species. This study describes the characterization of a novel virus infecting the toxigenic species Pseudo-nitzschia galaxiae isolated from the northern Adriatic Sea. The ssRNA virus PnGalRNAV has 29.5 nm ± 1.2 nm icosahedral virions and a genome size of 8.8 kb. It belongs to the picorna-like Marnaviridae family and shows high specificity for P. galaxiae infecting two genetically and morphologically distinct strains. We found two genetically distinct types of this virus and screening of the global virome database revealed matching sequences from the Mediterranean region and China, suggesting its global distribution. Another virus of similar shape and size infecting Pseudo-nitzschia calliantha was found, but its genome could not be determined. In addition, we have obtained and characterized a new virus that infects Chaetoceros tenuissimus. The replicase protein of this virus is very similar to the previously described ChTenDNAV type-II virus, but it has a unique genome and infection pattern. Our study is an important contribution to the collective diatom virus culture collection and will allow further investigation into how these viruses control diatom bloom termination, carbon export and toxin release in the case of Pseudo-nitzschia.
Ključne besede: algal blooms, diatoms, virus, PnGalRNAV, genome, Adriatic Sea, marine virology, phytoplankton ecology, marine biology
Objavljeno v DiRROS: 23.10.2024; Ogledov: 1132; Prenosov: 1328
Celotno besedilo (8,37 MB)
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Povzetek: It was once believed that only microbes and viruses inhabited the subseafloor crust beneath hydrothermal vents. Yet, on the seafloor, animals like the giant tubeworm Riftia pachyptila thrive. Their larvae are thought to disperse in the water column, despite never being observed there. We hypothesized that these larvae travel through the subseafloor via vent fluids. In our exploration, lifting lobate lava shelves revealed adult tubeworms and other vent animals in subseafloor cavities. The discovery of vent endemic animals below the visible seafloor shows that the seafloor and subseafloor faunal communities are connected. The presence of adult tubeworms suggests larval dispersal through the recharge zone of the hydrothermal circulation system. Given that many of these animals are host to dense bacterial communities that oxidize reduced chemicals and fix carbon, the extension of animal habitats into the subseafloor has implications for local and regional geochemical flux measurements. These findings underscore the need for protecting vents, as the extent of these habitats has yet to be fully ascertained.
Ključne besede: subseafloor, hydrothermal vents, tubeworms, larvae, vent fluids, bacterial communities, geochemical flux, geochemistry, marine biology
Objavljeno v DiRROS: 22.10.2024; Ogledov: 871; Prenosov: 1416
Celotno besedilo (4,15 MB)
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