Temperature is one of the most important drivers to affect marine ectotherms in the context of anthropogenic climate change modifying seasonal cycles in temperate regions. To reliably predict the ...impact of climate variability on marine ectotherms, their capacity to adapt to rapid change needs to be understood. Due to fast transmission between generations, transgenerational effects may enable populations to moderate stressors. We examined reproduction across three temperature scenarios and three generations of asexual
Aurelia aurita
polyps: transgenerational warming, transgenerational cooling, and stable temperatures. Polyps were incubated at three temperatures (15, 17, 19°C) encountered in summertime in Southampton Water. In the first two polyps generations, temperature remained the main driver of polyp reproduction. However, in the third generation parental and grandparental temperature influenced offspring production. These effects appeared most strongly in cooling scenarios: polyps who experienced rapid cooling between generations displayed an immediate drop in reproductive output as opposed to polyps who remained at the same temperature as their parents. Our results highlight that transgenerational effects may require more extreme temperatures or increased numbers of generations to have a measurable impact on a population, highlighting the vulnerability of these organisms to continued climate change.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Silver nanoparticles (Ag-NPs) are increasingly used in a wide range of consumer products and such an extensive use raises questions about their safety and environmental toxicity. We investigated the ...potential toxicity of Ag-NPs in the marine ecosystem by analyzing the effects on several organisms belonging to different trophic levels. Algae (Dunaliella tertiolecta, Skeletonema costatum), cnidaria (Aurelia aurita jellyfish), crustaceans (Amphibalanus amphitrite and Artemia salina) and echinoderms (Paracentrotus lividus) were exposed to Ag-NPs and different end-points were evaluated: algal growth, ephyra jellyfish immobilization and frequency of pulsations, crustaceans mortality and swimming behavior, and sea urchin sperm motility. Results showed that all the end-points were able to underline a dose-dependent effect. Jellyfish were the most sensitive species, followed by barnacles, sea urchins, green algae, diatoms and brine shrimps. In conclusion, Ag-NPs exposure can influence different trophic levels within the marine ecosystem.
•Ag-NP effects were investigated in marine species at different trophic levels.•Algae, cnidarians, crustaceans and echinoderms were exposed to Ag-NP suspensions.•Acute and behavioral end-points were evaluated to detect Ag-NP toxicity.•All end-points underlined a dose-dependent effect at any level of the trophic chain.•Ag-NPs exposure influenced different trophic levels within the marine ecosystem.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The Red Sea is a rich ecosystem with thousands of species containing a variety of bioactive compounds that have potential pharmacological applications. This study will highlight the potential ...importance of sea urchins and jellyfish extracts. The gas chromatography-mass spectrometry (GC–MS) revealed many phenolic compounds in the extracts of the sea urchin (Diadema savignyi) and jellyfish (Aurelia aurita). The extracts were also tested for their potential radical scavenging activity as well as their safety and toxicity in vitro and in vivo. Both extracts showed significant total antioxidant capacity (P-value < 0.0001), and free radical scavenging activity (DPPH) compared to ascorbic acid and butylated hydroxyanisole (BHA, P-value < 0.0001). They were found to be safe in vitro and enhanced cell proliferation of fibroblast cells (L929) (P-value < 0.0001), and neuronal cell lines (neuroblastoma SH-SY5Y) (P-value < 0.0001).
Intraperitoneal administration of both extracts did not show any significant morbidity within tested concentrations. Liver enzymes (ALT and AST) and renal functions showed no significant changes compared to control. No significant histological changes in the liver or kidney tissues were observed. The current study proved the safety of both sea urchins and jellyfish extracts in vitro and in vivo, which paves the way for further studies on the biomedical application of both extracts in areas of neuroprotection and cancer treatment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Multicellular organisms can be regarded as metaorganisms, comprising of a macroscopic host interacting with associated microorganisms. Within this alliance, the host has to ensure attracting ...beneficial bacteria and defending against pathogens to establish and maintain a healthy homeostasis. Here, we obtained several lines of evidence arguing that Aurelia aurita uses interference with bacterial quorum sensing (QS) - quorum quenching (QQ) - as one host defense mechanism. Three A. aurita-derived proteins interfering with bacterial QS were identified by functionally screening a metagenomic library constructed from medusa-derived mucus. Native expression patterns of these host open reading frames (ORFs) differed in the diverse life stages (associated with different microbiota) pointing to a specific role in establishing the developmental stage-specific microbiota. Highly increased expression of all QQ-ORFs in germ-free animals further indicates their impact on the microbiota. Moreover, incubation of native animals with pathogenic bacteria induced expression of the identified QQ-ORFs arguing for a host defense strategy against confronting bacteria by interference with bacterial QS. In agreement, immobilized recombinant QQ proteins induced restructuring of polyp-associated microbiota through changing abundance and operational taxonomic unit composition. Thus, we hypothesize that additional to the immune system host-derived QQ-activities potentially control bacterial colonization.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Jellyfish nerve nets provide insight into the origins of nervous systems, as both their taxonomic position and their evolutionary age imply that jellyfish resemble some of the earliest ...neuron-bearing, actively-swimming animals. Here, we develop the first neuronal network model for the nerve nets of jellyfish. Specifically, we focus on the moon jelly
and the control of its energy-efficient swimming motion. The proposed single neuron model disentangles the contributions of different currents to a spike. The network model identifies factors ensuring non-pathological activity and suggests an optimization for the transmission of signals. After modeling the jellyfish's muscle system and its bell in a hydrodynamic environment, we explore the swimming elicited by neural activity. We find that different delays between nerve net activations lead to well-controlled, differently directed movements. Our model bridges the scales from single neurons to behavior, allowing for a comprehensive understanding of jellyfish neural control of locomotion.
Despite the diversity and oftentimes large biomass of jellyfish in marine systems, their ecological role remains poorly understood. We here provide the first systematic review of studies on jellyfish ...trophic ecology in the Baltic Sea (a regional marine system under strong multiple global and regional anthropogenic pressures). In total, we identified 57 peer-reviewed publications, with notable taxonomic bias towards two species (Aurelia aurita; non-indigenous Mnemiopsis leidyi) and spatial bias towards five areas (Bornholm Basin, Kiel Bight, Kertinge Nor, Lim- and Gullmarsfjord). The studies provide evidence for diverse trophic roles of jellyfish as predators and as competitors of other jellyfish, zooplankton and fish species. In combination, the studies also highlight potentially large impacts via top-down (grazing) and bottom-up (nutrient excretion) effects, but also, strong spatio-temporal variability in the magnitude of these effects, depending on the occurrence of jellyfish blooms. Studies on the role of jellyfish as prey for fish, seabirds or marine mammals, and for benthic systems via food-falls, were limited or lacking for the Baltic Sea, despite increasing focus on these topics globally. Improved understanding of the temporal (seasonal, inter-annual, long-term) and spatial variability of blooms and corresponding trophic effects, would provide more systematic understanding of the ecological role of jellyfish in the spatio-temporally variable Baltic Sea. A broader spatial coverage, inclusion of more jellyfish taxa and under-studied early life history stages, as well as the implementation and continuation of long-term data series would represent important steps towards this goal.
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Presettlement processes likely influence the geographical distribution and abundance of scyphozoan jellyfish medusae. In East Asian coastal waters, Aurelia aurita s.l. spawning coincides with the ...summer monsoon season, and extreme rainfall events subject planulae to hyposaline conditions, presumably jeopardizing their survival and settlement. In this study, laboratory experiments were conducted to determine how prolonged exposure to hyposalinity (25, 20, and 15, in addition to control salinity 32) affects swimming speed, survivorship and settlement of planula larvae, and subsequent development of metamorphosed polyps. Nearly all planulae (≥95%) in 32, 25, and 20 were geonegative during the first 4h of exposure to respective salinities, but the majority of planulae (70%) in 15 were geopositive. Although no mortality was induced, hyposaline conditions affected larval behavior and the sequence of post-metamorphosis events. Salinity of 15 significantly increased planktonic larval duration and settled polyps had morphological deformities. At a salinity of 20, settled polyps had delayed tentacle development compared to control and 25 treatments. These anomalous results demonstrate that the response of planulae to environmental stress is more complex than previously assumed and may depend on the ability of the settled polyps to develop viable feeding tentacles. Salinity is proposed to be a principal factor influencing planulae dispersion and distribution in temperate monsoon regions.
•Tested salinities (15–32) reflective of temperate monsoon on planulae ecophysiology•A. aurita s.1 planulae survived prolonged exposure (≥6d) to salinity of 15.•Salinities <20 caused geopositive response of planulae.•Larval duration prolonged by severe hyposalinity, reduced by moderate hyposalinity.•Salinities ≤20 caused deviations from normal sequence of post-metamorphosis events.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Gelatinous zooplankton are known for their capacity to excrete copious amounts of mucus that can be utilized by other organisms. The release of mucus is exacerbated by stressful conditions. Despite ...the recognized importance of cnidarian mucus to production and material flux in marine ecosystems, the role of gelatinous zooplankton in influencing the fate of oil spills is unknown. In this study we used laboratory experiments to observe the influence of mucus from the moon jellyfish (Aurelia aurita) on the aggregation and degradation of crude oil. The results show that jellyfish swimming in a dispersed solution of oil droplets produced copious amounts of mucus and the mucus aggregates that were shed by the animals contained 26 times more oil than the surrounding water. Incubation experiments showed that hydrocarbon degrading bacteria cell densities more than doubled in the presence of mucus and after 14days, resulted in a significant increase in oil degradation. These results suggest that jellyfish can aggregate dispersed oil droplets and embed them within a matrix that favors hydrocarbon degrading bacteria. While this study lends support to the hypothesis that the presence of gelatinous zooplankton can impact oil spills large scale mesocosm studies will be needed to fully quantify the influence on a natural system.
•Jellyfish produce copious amounts of mucus in response to crude oil encounter.•Oil droplets accumulate in mucus and is shed by the animals.•Oil concentrations in mucus aggregates are many times that surrounding water.•Hydrocarbon degrading bacteria grow faster in these mucus aggregates.•Bacteria breakdown the oil significantly faster when jellyfish mucus is present.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The associated microbiota of marine invertebrates plays an important role to the host in relation to fitness, health, and homeostasis. Cooperative and competitive interactions between bacteria, due ...to release of, for example, antibacterial substances and quorum sensing (QS)/quorum quenching (QQ) molecules, ultimately affect the establishment and dynamics of the associated microbial community. Aiming to address interspecies competition of cultivable microbes associated with emerging model species of the basal animal phyla Cnidaria (Aurelia aurita) and Ctenophora (Mnemiopsis leidyi), we performed a classical isolation approach. Overall, 84 bacteria were isolated from A. aurita medusae and polyps, 64 bacteria from M. leidyi, and 83 bacteria from ambient seawater, followed by taxonomically classification by 16S rRNA gene analysis. The results show that A. aurita and M. leidyi harbor a cultivable core microbiome consisting of typical marine ubiquitous bacteria also found in the ambient seawater. However, several bacteria were restricted to one host suggesting host‐specific microbial community patterns. Interbacterial interactions were assessed by (a) a growth inhibition assay and (b) QS interference screening assay. Out of 231 isolates, 4 bacterial isolates inhibited growth of 17 isolates on agar plates. Moreover, 121 of the 231 isolates showed QS‐interfering activities. They interfered with the acyl‐homoserine lactone (AHL)‐based communication, of which 21 showed simultaneous interference with autoinducer 2. Overall, this study provides insights into the cultivable part of the microbiota associated with two environmentally important marine non‐model organisms and into interbacterial interactions, which are most likely considerably involved in shaping a healthy and resilient microbiota.
The associated microbiota of marine invertebrates plays an important role in their fitness, health, and homeostasis. Cooperative as well as competitive interactions between bacteria affect the establishment and dynamics of the microbiota. Consequently, we assessed such interactions by growth inhibition and QS interference assays using isolated bacteria associated with emerging model species of the basal animal phyla Cnidaria (Aurelia aurita) and Ctenophora (Mnemiopsis leidyi).
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
In this study, size compositions of Aurelia aurita (Linnaeus, 1758), Pleurobrachia pileus (O. F. Müller, 1776) and Mnemiopsis leidyi A. Agassiz, 1865 were presented seasonally between March 2015 and ...February 2016 at the Sinop Peninsula of Black Sea. Sampling was carried out monthly at the 6 stations by plankton net (50 cm diameter mouth opening, 500 mm mesh size for horizontal tows, 210 mm mesh size for vertical tows). Small sized individuals of A. aurita, M. leidyi and P. pileus were found dominant in summer. Bigger size individuals were observed for A. aurita in spring, M. leidyi in winter, and P. pileus in autumn. A. aurita ˂4 cm was determined as 57%, M. leidyi ˂2 cm was 58% and P. pileus ˂ 0.6 was determined as 67%. Maximum and minimum lengths were measured 28 cm and 0.5 cm for A. aurita, 2 cm and 0.2 cm for P. pileus, 9 cm and 0.2 cm for M. leidyi, respectively. The size distribution of A. aurita, M. leidyi and P. pileus showed significantly different (ANOVA, p˂0.05) between seasons.
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