1 °C warming increases spatial competition frequency and complexity in Antarctic marine macrofauna

AbstractEnvironmental conditions of the Southern Ocean around Antarctica have varied little for >5 million years but are now changing. Here, we investigated how warming affects competition for space. Little considered in the polar regions, this is a critical component of biodiversity response. Change in competition in response to environment forcing might be detectable earlier than individual species presence/absence or performance measures (e.g. growth). Examination of fauna on artificial substrata in Antarctica’s shallows at ambient or warmed temperature found that, mid-century predicted 1°C warming (throughout the year or just summer-only), increased the probability of individuals encountering spatial competition, as well as density and complexity of such interactions. 2°C, late century predicted warming, increased variance in the probability and density of competition, but overall, competition did not significantly differ from ambient (control) levels. In summary only 1°C warming increased probability, density and complexity of spatial competition, which seems to be summer-only driven.

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Disentangling the role of shared ancestry and the environment on leaf stable isotopes

10.32942/osf.io/mfhve ◽

2019 ◽

Author(s):

Marko J. Spasojevic ◽

Sören Weber1

Keyword(s):

Stable Isotopes ◽

Environmental Conditions ◽

Evolutionary History ◽

Environmental Control ◽

Phylogenetic Signal ◽

Individual Species ◽

Habitat Types ◽

Δ13c And Δ15n ◽

Environmental Controls ◽

Shared Ancestry

Stable carbon (C) and nitrogen (N) isotopes in plants are important indicators of plant water use efficiency and N acquisition strategies. While often regarded as being under environmental control, there is growing evidence that evolutionary history may also shape variation in stable isotope ratios (δ13C and δ15N) among plant species. Here we examined patterns of foliar δ13C and δ15N in alpine tundra for 59 species in 20 plant families. To assess the importance of environmental controls and evolutionary history, we examined if average δ13C and δ15N predictably differed among habitat types, if individual species exhibited intraspecific trait variation (ITV) in δ13C and δ15N, and if there were a significant phylogenetic signal in δ13C and δ15N. We found that variation among habitat types in both δ13C and δ15N mirrored well-known patterns of water and nitrogen limitation. Conversely, we also found that 40% of species exhibited no ITV in δ13C and 35% of species exhibited no ITV in δ15N, suggesting that some species are under stronger evolutionary control. However, we only found a modest signal of phylogenetic conservatism in δ13C and no phylogenetic signal in δ15N suggesting that shared ancestry is a weaker driver of tundra wide variation in stable isotopes. Together, our results suggest that both evolutionary history and local environmental conditions play a role in determining variation in δ13C and δ15N and that considering both factors can help with interpreting isotope patterns in nature and with predicting which species may be able to respond to rapidly changing environmental conditions.

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Pre-akinete formation in Zygnema sp. from polar habitats is associated with metabolite re-arrangement

Journal of Experimental Botany ◽

10.1093/jxb/eraa123 ◽

2020 ◽

Vol 71 (11) ◽

pp. 3314-3322 ◽

Cited By ~ 2

Author(s):

Erwann Arc ◽

Martina Pichrtová ◽

Ilse Kranner ◽

Andreas Holzinger

Keyword(s):

Environmental Conditions ◽

Morphological Changes ◽

Tca Cycle ◽

Survival Strategies ◽

Polar Regions ◽

Akinete Formation ◽

Metabolite Profiles ◽

Dividing Cells ◽

Storage Products ◽

Chloroplast Morphology

Abstract In streptophytic green algae in the genus Zygnema, pre-akinete formation is considered a key survival strategy under extreme environmental conditions in alpine and polar regions. The transition from young, dividing cells to pre-akinetes is associated with morphological changes and the accumulation of storage products. Understanding the underlying metabolic changes could provide insights into survival strategies in polar habitats. Here, GC-MS-based metabolite profiling was used to study the metabolic signature associated with pre-akinete formation in Zygnema sp. from polar regions under laboratory conditions, induced by water and nutrient depletion, or collected in the field. Light microscopy and TEM revealed drastic changes in chloroplast morphology and ultrastructure, degradation of starch grains, and accumulation of lipid bodies in pre-akinetes. Accordingly, the metabolite profiles upon pre-akinete formation reflected a gradual shift in metabolic activity. Compared with young cells, pre-akinetes showed an overall reduction in primary metabolites such as amino acids and intermediates of the tricarboxylic acid (TCA) cycle, consistent with a lower metabolic turnover, while they accumulated lipids and oligosaccharides. Overall, the transition to the pre-akinete stage involves re-allocation of photosynthetically fixed energy into storage instead of growth, supporting survival of extreme environmental conditions.

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A Worm's World: Ecological Flexibility Pays Off for Free-Living Nematodes in Sediments and Soils

BioScience ◽

10.1093/biosci/biz086 ◽

2019 ◽

Vol 69 (11) ◽

pp. 867-876 ◽

Cited By ~ 4

Author(s):

Michaela Schratzberger ◽

Martijn Holterman ◽

Dick van Oevelen ◽

Johannes Helder

Keyword(s):

Environmental Conditions ◽

Food Sources ◽

Polar Regions ◽

Soil Processes ◽

Free Living ◽

Ecological Flexibility ◽

Ecological Success ◽

The Tropics ◽

Animal Communities ◽

The Impact

Abstract Free-living nematodes, an ancient animal phylum of unsegmented microscopic roundworms, have successfully adapted to nearly every ecosystem on Earth: from marine and freshwater to land, from the polar regions to the tropics, and from the mountains to the ocean depths. They are globally the most abundant animals in sediments and soils. In the present article, we identify the factors that collectively explain the successful ecological proliferation of free-living nematodes and demonstrate the impact they have on vital sediment and soil processes. The ecological success of nematodes is strongly linked to their ability to feed on various food sources that are present in both sediments and soils, and to proliferate rapidly and survive in contrasting environmental conditions. The adaptations, roles, and behaviors of free-living nematodes have important implications for the resilience of sediments and soils, and for emergent animal communities responding to human alterations to ecosystems worldwide.

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Productivity

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1962.0019 ◽

1962 ◽

Vol 265 (1322) ◽

pp. 341-346 ◽

Cited By ~ 1

Keyword(s):

Organic Matter ◽

Primary Productivity ◽

Environmental Conditions ◽

Individual Species ◽

Initial Stage ◽

Resultant Effect

When we speak of productivity of the sea, it is generally accepted that we are speaking of the primary productivity, the primary rate of formation of organic matter. We must not confuse this with say the productivity of zooplankton or fish for as yet, owing to the complexity of the organic cycle, we are unable to define any correlations between these and the primary productivity. At present we have to confine ourselves to studying the simpler, but yet still complex physiology of the initial stage of the organic cycle, the photosynthesis. This process is of interest both to the cellular physiologist and the ecologist, but whereas the first is able to isolate individual species and parameters, the latter endeavours to reach conclusions about the resultant effect of the interaction of many different species and varying environmental conditions. Clearly both these approaches must be complementary and furthermore the ecologist must co-operate closely with the botanical and zoological taxonomists if he is to reach any real understanding of the interrelationships between the plants and the animals and the production of higher forms in the sea.

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Nestling Phenology of Anseriformes in the Baikal Siberia Region, Russia

South of Russia ecology development ◽

10.18470/1992-1098-2020-1-145-150 ◽

2020 ◽

Vol 15 (1) ◽

pp. 145-150

Author(s):

E. N. Badmaeva ◽

I. Yu. Deulin ◽

M. A. Gulyaeva ◽

L. D. Bazarov ◽

T. Z. Dorzhiev ◽

...

Keyword(s):

Lake Baikal ◽

Environmental Conditions ◽

Time Frame ◽

Aggregate Data ◽

Egg Laying ◽

Individual Species ◽

Visual Methods ◽

Time Period ◽

Extended Time Period ◽

Species Ecology

Aim. The goal was to aggregate data on the nesting phenology of the range of Anseriformes in the Baikal Siberia region – using the example of Lake Baikal itself.Material and methods. In preparing the materials we used data from our own observations based on foot and car‐based survey assessments and that of other authors for the entire known period of bird research on Lake Baikal, including data from the literature. Standard ornithological visual methods of accounting, registration and description are used.Results. The ecology of Anseriformes nesting has been sufficiently studied, but information on the oviposition phenology is not generalized. During the nesting periods of Anseriformes on Lake Baikal (in particular) the laying of eggs occurs over an extended time period. This prolongation egg‐laying time is normal and is a response to the death of clutches from inundations as well as being a characteristic of some ducks which re‐nest repeatedly. These subsequently lead to a later taking to flight of young birds. Conclusion. The earliest clutches are found among mallard and ruddy shelduck from the end of April, when ponds are still ice‐bound, while the latest are laid up to midJuly by the European widgeon, the white‐winged scoter and the red‐breasted merganser. Mass oviposition of all species occurs in the period from mid‐May to mid‐June. Overall, the egg‐laying period of Lake Baikal Anseriformes lasts from 20 days to 3.1 months. The timing and period of egg‐laying depends on regional environmental conditions and the specifics of individual species’ ecology and biology. Although the general ovipositional time‐frame of Anseriformes regionally is prolonged, the period of mass egg‐laying is quite concentrated and occurs within a period of 20‐30 days.

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The tardigrade cuticle

Limnological Review ◽

10.2478/limre-2021-0012 ◽

2021 ◽

Vol 21 (3) ◽

pp. 127-146

Author(s):

Michaela Czerneková ◽

Stanislav Vinopal

Keyword(s):

Life Cycle ◽

Chemical Composition ◽

Genetic Manipulation ◽

Individual Species ◽

Extreme Conditions ◽

Critical Component ◽

Ultrastructural Characteristics ◽

The Relationship ◽

Insight Into ◽

Cuticle Ultrastructure

Abstract Tardigrades (phylum Tardigrada) are aquatic microecdysozoans that have adapted to survive extreme conditions through the formation of cysts or ametabolic tuns. Their body is covered by a cuticle that plays an important role in their life cycle, including their response and adaptation to environmental challenges. Cuticular characteristics are a critical component of tardigrade taxonomy. Therefore, research has often been focused on the relationship between cuticular morphology and ultrastructure and the evolutionary and phylogenetic positioning of the phylum and individual species herein. However, a deeper insight into the ultrastructural characteristics and chemical composition of the tardigrade cuticle is needed. This knowledge is important not only for a better understanding of tardigrade physiology and ecology but also for the development of efficient microinjection and/or electroporation techniques that would allow for genetic manipulation, opening new avenues in tardigrade research. Here, we review data on cuticle ultrastructure and chemical composition. Further, we discuss how the cuticle is affected during moulting, encystment, cyclomorphosis, and anhydrobiosis. Our work indicates that more systematic studies on the molecular composition of the tardigrade cuticle and on the process of its formation are needed to improve our understanding of its properties and functions.

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Metagenomics of Antarctic Marine Sediment Reveals Potential for Diverse Chemolithoautotrophy

mSphere ◽

10.1128/msphere.00770-21 ◽

2021 ◽

Author(s):

Arkadiy I. Garber ◽

Jessica R. Zehnpfennig ◽

Cody S. Sheik ◽

Michael W. Henson ◽

Gustavo A. Ramírez ◽

...

Keyword(s):

Climate Change ◽

Marine Sediment ◽

Biogeochemical Cycles ◽

Inorganic Nutrients ◽

Polar Regions ◽

Freshwater Runoff ◽

Antarctic Marine ◽

Benthic Ecosystems ◽

Increasing Temperature ◽

Impacts Of Climate Change

The impacts of climate change in polar regions, like Antarctica, have the potential to alter numerous ecosystems and biogeochemical cycles. Increasing temperature and freshwater runoff from melting ice can have profound impacts on the cycling of organic and inorganic nutrients between the pelagic and benthic ecosystems.

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Final Note of Special Issue “Tardigrades Taxonomy, Biology and Ecology”

Diversity ◽

10.3390/d12050169 ◽

2020 ◽

Vol 12 (5) ◽

pp. 169

Author(s):

Łukasz Kaczmarek

Keyword(s):

Broad Spectrum ◽

Environmental Conditions ◽

Polar Regions ◽

Special Issue ◽

Community Structures ◽

Interpopulation Variability ◽

Final Note ◽

Terrestrial Habitats ◽

Almost All ◽

Water Bears

Tardigrada (water bears) are microscopic invertebrates inhabiting aquatic (freshwater and marine) and terrestrial habitats. They are thriving in almost all Earth ecosystems from deepest oceans to highest mountains, from tropics to polar regions. Water bears are probably most famous for their cryptobiotic abilities, which allow them to survive a broad spectrum of extreme environmental conditions. The Special Issue on tardigrades was launched to popularize research on these fascinating microinvertebrates. The published papers were focused on (a) marine and terrestrial tardigrades diversity, (b) interpopulation variability of Antarctic eutardigrade Paramacrobiotus fairbanksi, (c) encystment in freshwater eutardigrade Thulinius ruffoi and (d) use of a metabarcoding approach to community structures studies in microenvironments.

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Structure, function and molecular adaptations of haemoglobins of the polar cartilaginous fish Bathyraja eatonii and Raja hyperborea

Biochemical Journal ◽

10.1042/bj20050305 ◽

2005 ◽

Vol 389 (2) ◽

pp. 297-306 ◽

Cited By ~ 17

Author(s):

Cinzia Verde ◽

M. Cristina De Rosa ◽

Daniela Giordano ◽

Donato Mosca ◽

Donatella De Pascale ◽

...

Keyword(s):

Cartilaginous Fish ◽

The Arctic ◽

Polar Regions ◽

Seasonal Temperature ◽

Physiological Adaptations ◽

Antarctic Marine ◽

Haem Protein ◽

And Function ◽

The Antarctic ◽

Regional Histories

Cartilaginous fish are very ancient organisms. In the Antarctic sea, the modern chondrichthyan genera are poorly represented, with only three species of sharks and eight species of skates; the paucity of chondrichthyans is probably an ecological consequence of unusual trophic or habitat conditions in the Southern Ocean. In the Arctic, there are 26 species belonging to the class Chondrichthyes. Fish in the two polar regions have been subjected to different regional histories that have influenced the development of diversity: Antarctic marine organisms are highly stenothermal, in response to stable water temperatures, whereas the Arctic communities are exposed to seasonal temperature variations. The structure and function of the oxygen-transport haem protein from the Antarctic skate Bathyraja eatonii and from the Arctic skate Raja hyperborea (both of the subclass Elasmobranchii, order Rajiformes, family Rajidae) is reported in the present paper. These species have a single major haemoglobin (Hb 1; over 80% of the total). The Bohr-proton and the organophosphate-binding sites are absent. Thus the haemoglobins of northern and southern polar skates appear functionally similar, whereas differences were observed with several temperate elasmobranchs. Such evidence suggests that, in temperate and polar habitats, physiological adaptations have evolved along distinct pathways, whereas, in this case, the effect of the differences characterizing the two polar environments is negligible.

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Decapod Crustaceans of the Kara Sea: species composition and peculiarities of distribution

Proceedings of the Zoological Institute RAS ◽

10.31610/trudyzin/2021.325.3.364 ◽

2021 ◽

Vol 325 (3) ◽

pp. 364-372

Author(s):

O.L. Zimina

Keyword(s):

Species Composition ◽

Environmental Conditions ◽

Kara Sea ◽

Individual Species ◽

Snow Crab ◽

Western Slope ◽

Depth Range ◽

Ecological Groups ◽

Decapod Crustaceans ◽

Wide Range

This paper presents data on species composition and peculiarities of distribution of Decapoda in the southern part of Kara Sea obtained during trawl surveys in 2012 and 2016. In total, 11 species of decapod crustaceans were collected. In the last decade the fauna has been enriched by the invasion of the snow crab Chionoecetes opilio. Brief information on the environmental conditions of occurrence and maps of distribution in the studied area are presented for each species. The highest values of species richness (up to 6 species per catch), biomass and abundance of decapods were detected on the western slope of Priyamal shallow at 50–150 m depth range. According to the patterns of distribution and environmental conditions, three groups of species were distinguished: associated with cold and salty waters of Novaya Zemlya Trough; inhabiting lower salinity waters with a wide temperature range of the Priyamal and Ob-Yenisei shallows; and a group that is widespread within the area in wide range of conditions. In comparison with the neighboring Barents Sea, the decapod fauna of the Kara Sea is qualitatively and quantitatively depleted. The obtained data on the distribution of individual species and ecological groups can be used for the background assessment of the state of the decapod fauna, including the period of population formation of the alien species.

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