Search Results (100)

The white-spotted jellyfish, Phyllorhiza punctata, is an invasive species with significant ecological and economic relevance spreading across various regions. While its ecological impact is well-documented, its molecular and biochemical characteristics remain poorly understood. In this study, we integrate proteomic data generated by LC-MS/MS with publicly available transcriptomic information to characterize P. punctata, analyzing differential protein expression across three distinct tissues: oral arms, mantle, and gonads. A total of 2764 proteins and 25,045 peptides were identified, including several venom components such as jellyfish toxins (JFTs) and phospholipase A2 (PLA2), which were further investigated and compared to toxins from other species. Enrichment analyses revealed clear tissue-specific functions. Additionally, deep learning and machine learning tools identified 274 promising AMP candidates, including the α-helical, β-sheet, and αβ-motif peptides. This dataset provides new insights into the protein composition of P. punctata and highlights strong AMP candidates for further characterization, underscoring the biotechnological potential of underexplored cnidarian species. Full article

A moon jellyfish (Aurelia aurita) is a representative of the phylum Cnidaria, commonly found in the northern seas of the globe. The regenerative abilities of cnidarians have recently been associated with extracellular vesicles (EVs) secreted by these organisms. In this study, a method for the isolation of EVs from the oral arms of A. aurita is presented. The methodology includes differential centrifugation, size-exclusion chromatography, and ultrafiltration. The isolates were characterized with tunable resistive pulse sensing, cryogenic transmission electron microscopy, capillary electrophoresis (CE), and electrophoretic light scattering (ELS). Small (<150 nm in diameter) EVs were abundant in the isolates. The EVs were found to carry nucleic acids, indicating their role in signaling. Additionally, the difference in zeta potential values measured with ELS and CE indicates high glycation in the vesicles analyzed. Although the method developed was effective in isolating EVs from small sample volumes (0.5 mL), the EV yield was insufficient for omics analysis. Thus, the scaling up of the isolation process is required for comprehensive biochemical analysis and biological activity assessment in A. aurita-derived EVs. Full article

Ocean acidification, caused by increased atmospheric CO₂, threatens marine organisms that depend on calcium-based structures such as jellyfish statoliths. This study investigated the effects of low pH on the morphology and statolith formation of ephyrae in Aurelia coerulea, comparing two developmental pathways to form ephyra: polyp-strobilation and planula-strobilation. Under the pH 6.8 condition, polyps failed to produce viable ephyrae, whereas planula-strobilation succeeded in releasing ephyrae with normal morphology, though statoliths were absent. Under the pH 7.8 condition, both strobilation types produced normal-shaped ephyrae with reduced statolith size but increased statolith number compared with the control (pH 8.1), suggesting a compensatory response to acidification. Statolith morphology differed between pathways: planula-strobilated ephyrae had needle-shaped statoliths with high aspect ratios, indicating a rapid, early-stage crystallization process. Despite their minimal body size and statolith development, planula-strobilated ephyrae maintained the functional mass of statoliths necessary for survival. This rapid, morphologically minimized development suggests that planula-strobilation is an adaptive reproductive strategy in response to environmental stress. Our findings suggest that A. coerulea possesses a flexible life history strategy that may facilitate its resilience to ongoing ocean acidification scenarios. Full article

Industry currently generates numerous substances, such as food additives, whose environmental impacts, particularly in marine environments, remain inadequately assessed. This study employed Aurelia aurita for the first time as a model organism to evaluate the toxicity of such compounds. The main goal was to evaluate the toxicity of two food additives, 2-methyl-1-phenylpropan-2-ol (S1) and 1-phenylethan-1-ol (S2), on A. aurita ephyrae, comparing the results with other organisms representing different trophic levels, specifically the alga Phaeodactylum tricornutum and the crustacean Artemia salina. Acute toxicity tests were conducted on each organism. In A. aurita, S1 exhibited high toxicity (LC₅₀ ≈ 10 mg/L), while S2 had lower toxicity (LC₅₀ ≈ 80 mg/L). The pulsation frequency data for A. aurita revealed that S1 initially increased the pulsation rates at lower concentrations (maximum at 10 mg/L), followed by a significant decrease at higher concentrations. Conversely, S2 showed a steady decrease in pulsation rates up to 10 mg/L, with a slight increase at concentrations of 15, 20, and 25 mg/L. The results demonstrate varying sensitivities to the toxic effects of the two compounds across different trophic levels, with A. aurita ephyrae being the most sensitive. This suggests the potential efficacy of jellyfish as novel ecotoxicological models due to their heightened sensitivity, enabling the detection of lower contaminant concentrations in test samples. Further research is required to enhance the efficiency of ecotoxicological assays using this model. Full article

Skin health must be ensured at all times in the case of wounds when the skin is subjected to traumatic actions that require multiple wound-healing measures. Wound healing is a complex, multi-phase biological process critical for restoring skin integrity after trauma. This study investigates the development and evaluation of a novel composite hydrogel formulated from collagen peptides extracted from the jellyfish Rhizostoma pulmo and hydroethanolic extracts from the brown alga Cystoseira barbata, both sourced from the Romanian Black Sea coast. Throughout the work, the characteristics due to the biochemical compositions of the extracts from the brown alga C. barbata and from the jellyfish R. pulmo are highlighted as important, emphasizing the content of polysaccharides, proteins, and lipids. Total phenol content was analyzed for three extracts from natural products. The biochemical composition, antioxidant, antimicrobial, and in vitro wound-healing properties of the components and their composite (JPC-ALG) were assessed. The rheological behavior and optical microscopy studies of collagen hydrogels were prepared. The general mechanisms of wound healing with the involvement of polysaccharides and collagen peptides existing in all categories of extracts were highlighted. The study of the effects of JPC-ALG composites and individual extracts on fibroblast and keratocyte cell lines is also presented. Results demonstrated that the composite exhibited synergistic effects, enhancing fibroblast and keratinocyte migration and proliferation, key factors in wound closure. The findings support the potential application of this marine-derived bioactive composite as a promising biomaterial for wound-healing therapies. Full article

The National Institute of Fisheries Science in Korea is developing marine mammal bycatch reduction devices (BRDs) for midwater trawl gear. In this study, we tested two BRD-type guide nets (inclined net panel) with 30° and 45° tilt angles to prevent marine mammals from reaching the codend and facilitating their escape from the net. Fishing operations were conducted along the east and south coasts of South Korea, and cameras were installed in front of the BRDs to monitor their performance. The catch loss of herring with the 30° guide net was 13% and 11% in number and weight. The catch loss of hairtail was 53% and 51% in number and weight with the 30° guide net. Mackerel showed a 97% catch loss in number and weight with the 45° guide net. The 30° guide net resulted in lower catch loss for rudderfish and jack mackerel compared to the 45° guide net. The jellyfish discard rate of the BRD was 5% and 7% in number and weight with the 30° guide net and 12% and 11% with the 45° guide net, indicating that the 30° guide net was more effective at discarding jellyfish. Mesh selectivity was not strongly related to target species body length. Full article

Jellyfish stings, as one of the most prevalent forms of marine injury, have increasingly become a subject of concern. Despite their simple morphology and structure, jellyfish possess a complex venom composition that can inflict varying degrees of damage on multiple human physiological systems. Consequently, the clinical symptoms associated with jellyfish stings are highly intricate. Although antivenoms have been developed for certain jellyfish species (e.g., C. fleckeri), specific antivenoms targeting the mechanisms of most jellyfish venoms remain understudied. To effectively prevent, treat, and cure jellyfish stings, we adhere to the principle of knowing their nature and their reasons. It is essential to investigate the emission mechanism of jellyfish nematocysts and the composition of their venom. Understanding these factors is crucial for the development of targeted treatment strategies. This review delves into the venom emission mechanism of jellyfish stinging cells, the symptoms resulting from jellyfish stings, and the comprehensive treatment strategies post-sting. It offers a scientific reference for comprehending jellyfish stings and establishes a theoretical foundation for subsequent research endeavors. Full article

In this study, we investigate the diversity and spatiotemporal distribution of gelatinous zooplankton (GZ) in the central Baltic Sea (coastal waters of Gotland and adjacent Eastern and Western Gotland Basins), a region characterised by low salinity and ecological sensitivity. Despite the Baltic Sea being the largest brackish water body globally, knowledge about its GZ, specifically, medusae and ctenophores, is limited. Our research synthesises the existing literature, open-access data, and local reports. Three to five GZ species occur within the studied area, with the common jellyfish Aurelia aurita dominating. Peak sightings of A. aurita happen between July and October, whereas the ctenophore Mertensia ovum and scyphozoan Cyanea capillata display sporadic occurrences. We identify notable gaps in understanding GZ phenology and food web impacts due to historical neglect and insufficient monitoring, particularly under low-salinity conditions (between 5 and 8), which restricts species richness. Jellyfish and ctenophores fall under the Essential Ocean Variable (EOV) “Zooplankton Biomass and Diversity” governed by the Global Ocean Observing System, UNESCO-IOC. EOVs are an approach for globally usable data and adhere to Findable, Accessible, Interoperable, and Reusable (FAIR) data principles. Including EOVs in routine collection and reporting would significantly enhance regional and global understanding, contributing to a holistic ecosystem view. Thus, we advocate for global ocean observation frameworks to comprehensively monitor GZ populations and their ecological, biogeochemical, and socioeconomic roles. Our findings serve as a crucial step towards understanding the implications of climate change for GZ assemblages in the Baltic Sea, promoting a holistic approach to marine ecosystem management. Full article

Cnidarian jellyfish (Medusozoa) comprise approximately 3800 known species which play important roles for marine ecosystem. This study aimed to understand the diversity of cnidarian jellyfish and symbiosis among marine organisms. The taxonomy of the family Zancleidae (Hydrozoa, Anthoathecata) has been problematic because of the limited differences in morphological characteristics between species. This family comprises approximately 40 species belonging to four genera: Apatizanclea, Halocoryne, Zanclea, and Zanclella. In this study, we describe a new species of hydromedusa belonging to the family Zancleidae found in Japanese waters. Zanclea innocens sp. nov. can be distinguished from other Zanclea species by the presence of nematocyst clusters on the exumbrella, slightly thickened apical projection, four narrow exumbrellar nematocyst pouches on ridges often reaching the umbrella apex, four marginal bulbs, and two tentacles. Additionally, Zanclea medusopolypata was recorded for the first time in Japanese waters. This paper provides taxonomic keys for the identification of species in the genus Zanclea. Full article

Microplastics have emerged as a pervasive marine contaminant, with extreme concentrations reported in deep-sea sediments (e.g., 1.9 million particles/m²) and localized accumulations near Antarctic research stations. Particular concern has been raised regarding their synergistic effects with co-occurring antibiotics, which may potentiate toxicity and facilitate antibiotic resistance gene dissemination through microbial colonization of plastic surfaces. To investigate these interactions, a 185-day controlled exposure experiment was conducted using Aurelia aurita polyps. Factorial combinations of microplastics (0, 0.1, 1 mg/L) and tetracycline (0, 0.5, 5 mg/L) were employed to simulate environmentally relevant pollution scenarios. Microbiome alterations were characterized using metagenomic approaches. Analysis revealed that while alpha and beta diversity measures remained unaffected at environmental concentrations, significant shifts occurred in the relative abundance of dominant bacterial taxa, including Pseudomonadota, Actinomycetota, and Mycoplasmatota. Metabolic pathway analysis demonstrated perturbations in key functional categories including cellular processes and environmental signal transduction. Furthermore, microplastic exposure was associated with modifications in polyp life-stage characteristics, suggesting potential implications for benthic–pelagic population dynamics. These findings provide evidence for the impacts of microplastic–antibiotic interactions on cnidarian holobionts, with ramifications for predicting jellyfish population responses in contaminated ecosystems. Full article

The present dataset served to evaluate the plankton community composition and abundance in Nuevo Gulf (42°42′ S, 64°30′ W), a World Heritage Site in Argentinian Patagonia and part of the Valdés Biosphere Reserve. It reports zooplankton abundance (>300 µm) and phytoplankton concentration (10–200 μm) during the spring and summer seasons from 2019 to 2021. Special attention was given to the taxonomic classification of zooplankton, leading to the first identification of jellyfish species within the Gulf and the detection of an unreported copepod for the area (Drepanopus forcipatus). Samples were collected at two depths—a surface and a deeper layer—to assess vertical distribution patterns of plankton communities and explore potential environmental drivers influencing their variability. This dataset provides a valuable baseline for future studies analyzing temporal variations in the Gulf’s plankton communities. Moreover, it encourages the local scientific community to contribute data and promote open access to marine biodiversity records in the region. Full article

Pelagia noctiluca blooms are a significant ecological event in the Mediterranean, with profound implications for marine ecosystems and coastal economies. This study aims to investigate the interannual and seasonal variability of Pelagia noctiluca bloom patterns along the Moroccan, Algerian, and Tunisian Mediterranean coasts, focusing on the influence of environmental factors such as sea surface temperature, nutrient availability, and oceanographic conditions on bloom intensity and distribution. The analysis reveals significant seasonal and interannual fluctuations in bloom size across the three regions, with the most substantial blooms occurring from June to August during the warmer months. In 2014 and 2018, peak bloom sizes of up to 775 jellyfish per unit area were recorded in Morocco and Algeria, while Tunisia also experienced notable blooms, particularly in 2015 and 2017. However, from 2020 to 2023, a marked decline in bloom intensity was observed across all three regions, with bloom sizes dropping, particularly in Tunisia and Morocco. Correlation analysis of environmental variables showed weak to moderate relationships between bloom size and key factors. Sea surface temperature showed a positive correlation (r = 0.13), suggesting that warmer waters contribute to increased bloom intensity. Nitrate and current direction also exhibited weak positive correlations (r = 0.12 and r = 0.27), indicating that nutrient availability and ocean circulation patterns could enhance bloom formation. The correlations with carbon (r = 0.08) and phosphate (r = 0.04) further suggest that organic matter and nutrient availability play a minor role in supporting bloom growth. On the other hand, negative correlations with factors such as oxygen (r = −0.04), solar radiation (r = −0.04), and wave height (r = −0.05) suggest that these factors may slightly inhibit bloom intensity, possibly by influencing nutrient dynamics and dispersing jellyfish populations. Notably, pH level (r = −0.29) and current speed (r = −0.23) exhibited stronger negative correlations, indicating a more pronounced inhibitory effect. In conclusion, this research highlights the complex and multifactorial nature of Pelagia noctiluca bloom dynamics, where temperature, nutrient availability, and oceanographic conditions interact to influence bloom size and distribution across the Moroccan, Algerian, and Tunisian coasts. While these environmental factors contribute to bloom variability, other ecological and anthropogenic factors likely play a significant role. Further research is necessary to better understand the synergistic effects of climate change, nutrient loading, and biological interactions on jellyfish bloom dynamics in the Mediterranean, with implications for effective management strategies. Full article

Predation is a fundamental ecological process that shapes marine ecosystem dynamics. This study reveals a novel predator–prey interaction between the giant Caribbean sea anemone Condylactis gigantea and the two jellyfish species Cassiopea sp. and Aurelia sp., challenging traditional understanding of sea anemone feeding habits. Observations from citizen science platforms and field recordings documented C. gigantea successfully capturing and consuming these gelatinous marine organisms. The research highlights the trophic plasticity of C. gigantea, demonstrating its ability to prey on larger gelatinous organisms beyond its traditionally known diet. This predation event represents a possible benthic–pelagic coupling mechanism and underscores the value of citizen science in capturing rare ecological interactions. Full article

Photosynthetic organisms are primary sources of marine-derived molecules, particularly ω3 fatty acids (FAs), which influence the quality of marine foods. It is reported that tropical organisms possess lower FA nutritional quality than those from colder oceans. However, the high biodiversity known for tropical areas may help compensate for this deficiency by producing a high diversity of molecules with nutritional benefits for the ecosystem. Here we addressed this aspect by analyzing the FA profiles of 20 photosynthetic organisms from the salty and warm Red Sea, a biodiversity hot spot, including cyanobacteria, eukaryotic microalgae, macroalgae, mangrove leaves, as well as three selected reef’s photosymbiotic zooxanthellate corals and jellyfish. Using direct transesterification, gas chromatography-mass spectrometry, FA absolute quantification, and nutritional indexes, we evaluated their lipid nutritional qualities. We observed interspecific and strain-specific variabilities in qualities, which the unique environmental conditions of the Red Sea may help to explain. Generally, eukaryotic microalgae exhibited the highest nutritional quality. The previously unanalyzed diatoms Leyanella sp. and Minutocellus sp. had the highest eicosapentaenoic acid (EPA) contents. The bioprospected Red Sea photobiota exhibited pharmaceutical and nutraceutical potential. By sourcing and quantifying these bioactive compounds, we highlight the untapped rich biodiversity of the Red Sea and showcase opportunities to harness these potentials. Full article

Overcoming the growing challenge of antimicrobial resistance (AMR), which affects millions of people worldwide, has driven attention for the exploration of marine-derived antimicrobial peptides (AMPs) for innovative solutions. Cnidarians, such as corals, sea anemones, and jellyfish, are a promising valuable resource of these bioactive peptides due to their robust innate immune systems yet are still poorly explored. Hence, we employed an in silico proteolysis strategy to search for novel AMPs from omics data of 111 Cnidaria species. Millions of peptides were retrieved and screened using shallow- and deep-learning models, prioritizing AMPs with a reduced toxicity and with a structural distinctiveness from characterized AMPs. After complex network analysis, a final dataset of 3130 Cnidaria singular non-haemolytic and non-toxic AMPs were identified. Such unique AMPs were mined for their putative antibacterial activity, revealing 20 favourable candidates for in vitro testing against important ESKAPEE pathogens, offering potential new avenues for antibiotic development. Full article