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Ecology and Evolution Jul 2024Access to high-quality food is critical for long-distance migrants to provide energy for migration and arrival at breeding grounds in good condition. We studied effects...
Access to high-quality food is critical for long-distance migrants to provide energy for migration and arrival at breeding grounds in good condition. We studied effects of changing abundance and availability of a marine food, common eelgrass ( L.), on an arctic-breeding, migratory goose, black brant ( Lawrence 1846), at a key non-breeding site, Bahía San Quintín, Mexico. Eelgrass, the primary food of brant, is consumed when exposed by the tide or within reach from the water's surface. Using an individual-based model, we predicted effects of observed changes (1991-2013) in parameters influencing food abundance and availability: eelgrass biomass (abundance), eelgrass shoot length (availability, as longer shoots more within reach), brant population size (availability, as competition greater with more birds), and sea level (availability, as less food within reach when sea level higher). The model predicted that the ability to gain enough energy to migrate was most strongly influenced by eelgrass biomass (threshold January biomass for migration = 60 g m dry mass). Conversely, annual variation in population size (except for 1998), was relatively low, and variation in eelgrass shoot length and sea level were not strongly related to ability to migrate. We used observed data on brant body mass at Bahía San Quintín and annual survival to test for effects of eelgrass biomass in the real system. The lowest observed values of body mass and survival were in years when biomass was below 60 g m, although in some years of low biomass body mass and/or survival was higher. This suggests that the real birds may have some capacity to compensate to meet their energy demands when eelgrass biomass is low. We discuss consequences for brant population trends and conservation.
PubMed: 38952665
DOI: 10.1002/ece3.11619 -
Ecology and Evolution Jul 2024Marine sponges are predicted to be winners in the future ocean due to their exemplary adaptive capacity. However, while many sponge groups exhibit tolerance to a wide...
Marine sponges are predicted to be winners in the future ocean due to their exemplary adaptive capacity. However, while many sponge groups exhibit tolerance to a wide range of environmental insults, calcifying sponges may be more susceptible to thermo-acidic stress. To describe the gene regulatory networks that govern the stress response of the calcareous sponge, (class Calcarea, order Clathrinida), individuals were subjected to warming and acidification conditions based on the climate models for 2100. Transcriptome analysis and gene co-expression network reconstruction revealed that the unfolded protein response (UPR) was activated under thermo-acidic stress. Among the upregulated genes were two lineage-specific homologs of X-box binding protein 1 (), a transcription factor that activates the UPR. Alternative dimerization between these gene products suggests a clathrinid-specific mechanism to reversibly sequester the transcription factor into an inactive form, enabling the rapid regulation of pathways linked to the UPR in clathrinid calcareous sponges. Our findings support the idea that transcription factor duplication events may refine evolutionarily conserved molecular pathways and contribute to ecological success.
PubMed: 38952658
DOI: 10.1002/ece3.11652 -
Scientific Reports Jul 2024Sea-ice microalgae are a key source of energy and nutrient supply to polar marine food webs, particularly during spring, prior to open-water phytoplankton blooms. The...
Sea-ice microalgae are a key source of energy and nutrient supply to polar marine food webs, particularly during spring, prior to open-water phytoplankton blooms. The nutritional quality of microalgae as a food source depends on their biomolecular (lipid:protein:carbohydrate) composition. In this study, we used synchrotron-based Fourier transform infra-red microspectroscopy (s-FTIR) to measure the biomolecular content of a dominant sea-ice taxa, Nitzschia frigida, from natural land-fast ice communities throughout the Arctic spring season. Repeated sampling over six weeks from an inner (relatively stable) and an outer (relatively dynamic) fjord site revealed high intra-specific variability in biomolecular content, elucidating the plasticity of N. frigida to adjust to the dynamic sea ice and water conditions. Environmental triggers indicating the end of productivity in the ice and onset of ice melt, including nitrogen limitation and increased water temperature, drove an increase in lipid and fatty acids stores, and a decline in protein and carbohydrate content. In the context of climate change and the predicted Atlantification of the Arctic, dynamic mixing and abrupt warmer water advection could truncate these important end-of-season environmental shifts, causing the algae to be released from the ice prior to adequate lipid storage, influencing carbon transfer through the polar marine system.
Topics: Seasons; Ice Cover; Arctic Regions; Climate Change; Microalgae; Diatoms; Spectroscopy, Fourier Transform Infrared; Phytoplankton
PubMed: 38951587
DOI: 10.1038/s41598-024-65273-0 -
Nature Communications Jul 2024The impact of ocean warming on fish and fisheries is vigorously debated. Leading theories project limited adaptive capacity of tropical fishes and 14-39% size reductions...
The impact of ocean warming on fish and fisheries is vigorously debated. Leading theories project limited adaptive capacity of tropical fishes and 14-39% size reductions by 2050 due to mass-scaling limitations of oxygen supply in larger individuals. Using the world's hottest coral reefs in the Persian/Arabian Gulf as a natural laboratory for ocean warming - where species have survived >35.0 °C summer temperatures for over 6000 years and are 14-40% smaller at maximum size compared to cooler locations - we identified two adaptive pathways that enhance survival at elevated temperatures across 10 metabolic and swimming performance metrics. Comparing Lutjanus ehrenbergii and Scolopsis ghanam from reefs both inside and outside the Persian/Arabian Gulf across temperatures of 27.0 °C, 31.5 °C and 35.5 °C, we reveal that these species show a lower-than-expected rise in basal metabolic demands and a right-shifted thermal window, which aids in maintaining oxygen supply and aerobic performance to 35.5 °C. Importantly, our findings challenge traditional oxygen-limitation theories, suggesting a mismatch in energy acquisition and demand as the primary driver of size reductions. Our data support a modified resource-acquisition theory to explain how ocean warming leads to species-specific size reductions and why smaller individuals are evolutionarily favored under elevated temperatures.
Topics: Animals; Coral Reefs; Body Size; Global Warming; Oceans and Seas; Fishes; Indian Ocean; Oxygen; Temperature; Hot Temperature; Fisheries
PubMed: 38951524
DOI: 10.1038/s41467-024-49459-8 -
Parasite (Paris, France) 2024Myxidium rhodei Léger, 1905 (Cnidaria: Myxozoa) is a kidney-infecting myxosporean that was originally described from the European bitterling Rhodeus amarus....
Myxidium rhodei Léger, 1905 (Cnidaria: Myxozoa) is a kidney-infecting myxosporean that was originally described from the European bitterling Rhodeus amarus. Subsequently, it has been documented based on spore morphology in more than 40 other cypriniform species, with the roach Rutilus rutilus being the most commonly reported host. This study introduces the first comprehensive data assessment of M. rhodei, conducted through morphological, ecological and molecular methods. The morphological and phylogenetic analyses of SSU rDNA sequences of Myxidium isolates obtained from European bitterling and roach did not support parasite conspecificity from these fish. In fact, the roach-infecting isolates represent three distinct parasite species. The first two, M. rutili n. sp. and M. rutilusi n. sp., are closely related cryptic species clustering with other myxosporeans in the freshwater urinary clade, sharing the same tissue tropism. The third one, M. batuevae n. sp., previously assigned to M. cf. rhodei, clustered in the hepatic biliary clade sister to bitterling-infecting M. rhodei. Our examination of diverse cypriniform fishes, coupled with molecular and morphological analyses, allowed us to untangle the cryptic species nature of M. rhodei and discover the existence of novel species. This underscores the largely undiscovered range of myxozoan diversity and highlights the need to incorporate sequence data in diagnosing novel species.
Topics: Animals; Myxozoa; Phylogeny; Parasitic Diseases, Animal; Fish Diseases; Host Specificity; Cypriniformes; DNA, Ribosomal; Kidney; Cyprinidae
PubMed: 38949637
DOI: 10.1051/parasite/2024030 -
BioRxiv : the Preprint Server For... Jun 2024The marine annelid is a model organism used in many research areas including evolution and development, neurobiology, ecology and regeneration. Here we present the...
The marine annelid is a model organism used in many research areas including evolution and development, neurobiology, ecology and regeneration. Here we present the genomes of and of the closely related and , to facilitate comparative genomic approaches and help explore biology. We used long-read sequencing technology and chromosomal-conformation capture along with extensive transcriptomic resources to obtain and annotate a draft genome assembly of ∼1.47 Gbp for , of which more than half represent repeat elements. We predict around 29,000 protein-coding genes, with relatively large intron sizes, over 38,000 non-coding genes, and 580 miRNA loci. We further explore the high genetic variation (∼3% heterozygosity) within the species complex. Gene ontology reveals the most variable loci to be associated with pigmentation, development and immunity. The current work sets the stage for further development of genomic resources.
PubMed: 38948846
DOI: 10.1101/2024.06.21.600153 -
Biofilm Jun 2024platforms capable of mimicking the hydrodynamic conditions prevailing in natural aquatic environments have been previously validated and used to predict the fouling...
platforms capable of mimicking the hydrodynamic conditions prevailing in natural aquatic environments have been previously validated and used to predict the fouling behavior on different surfaces. Computational Fluid Dynamics (CFD) has been used to predict the shear forces occurring in these platforms. In general, these predictions are made for the initial stages of biofilm formation, where the amount of biofilm does not affect the flow behavior, enabling the estimation of the shear forces that initial adhering organisms have to withstand. In this work, we go a step further in understanding the flow behavior when a mature biofilm is present in such platforms to better understand the shear rate distribution affecting marine biofilms. Using 3D images obtained by Optical Coherence Tomography, a mesh was produced and used in CFD simulations. Biofilms of two different marine cyanobacteria were developed in agitated microtiter plates incubated at two different shaking frequencies for 7 weeks. The biofilm-flow interactions were characterized in terms of the velocity field and shear rate distribution. Results show that global hydrodynamics imposed by the different shaking frequencies affect biofilm architecture and also that this architecture affects local hydrodynamics, causing a large heterogeneity in the shear rate field. Biofilm cells located in the streamers of the biofilm are subjected to much higher shear values than those located on the bottom of the streamers and this dispersion in shear rate values increases at lower bulk fluid velocities. This heterogeneity in the shear force field may be a contributing factor for the heterogeneous behavior in metabolic activity, growth status, gene expression pattern, and antibiotic resistance often associated with nutrient availability within the biofilm.
PubMed: 38948680
DOI: 10.1016/j.bioflm.2024.100204 -
MLife Jun 2024
PubMed: 38948138
DOI: 10.1002/mlf2.12124 -
IScience Jun 2024Sulfate-reducing bacteria (SRB) are ubiquitously distributed across various biospheres and play key roles in global sulfur and carbon cycles. However, few deep-sea SRB...
Sulfate-reducing bacteria (SRB) are ubiquitously distributed across various biospheres and play key roles in global sulfur and carbon cycles. However, few deep-sea SRB have been cultivated and studied , limiting our understanding of the true metabolism of deep-sea SRB. Here, we firstly clarified the high abundance of SRB in deep-sea sediments and successfully isolated a sulfate-reducing bacterium (zrk46) from a cold seep sediment. Our genomic, physiological, and phylogenetic analyses indicate that strain zrk46 is a novel species, which we propose as . We found that supplementation with sulfate, thiosulfate, or sulfite promoted strain zrk46 growth by facilitating energy production through the dissimilatory sulfate reduction, which was coupled to the oxidation of organic matter in both laboratory and deep-sea conditions. Moreover, metatranscriptomic results confirmed that other deep-sea SRB also performed the dissimilatory sulfate reduction, strongly suggesting that SRB may play undocumented roles in deep-sea sulfur cycling.
PubMed: 38947506
DOI: 10.1016/j.isci.2024.110095 -
IScience Jun 2024As a research infrastructure with a mission to provide services for bioinformatics, ELIXIR aims to identify and inform its target audiences. Here, we present a survey on...
As a research infrastructure with a mission to provide services for bioinformatics, ELIXIR aims to identify and inform its target audiences. Here, we present a survey on a community of researchers studying the environment with omics approaches in Greece, one of the youngest member countries of ELIXIR. Personal interviews followed by quantitative and qualitative analysis were employed to document interactions and practices of the community and to perform a gap analysis for the transition toward multiomics and systems biology. Environmental omics in Greece mostly concerns production of data, in large majority on microbes and non-model organisms. Our survey highlighted (1) the popularity and suitability of targeted hands-on training events; (2) data quality and management issues as important elements for the transition to multiomics, and (3) lack of knowledge and misconceptions regarding interoperability, metadata standards, and pre-registration. The publicly available collected answers represent a valuable resource in view of future strategic planning.
PubMed: 38947499
DOI: 10.1016/j.isci.2024.110062