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[Ecophysiological study on the parasitic action of Cymothoids (author's transl)].

An ecophysiological study on certain parasitisms by Cymothoids allows the elucidation of the following points: --occurrence of oesophagien-side glands producing an anticoagulant effect on the blood of host, the absorption and metabolism of haemoglobin derivatives (hematin and iron) are performed by the hepatopancreas; --existence of immunological reactions between host and Cymothoids; --existence of biochemical, histological, haemotological and biometrical variations among fishes infected by these parasites.

Animals

Ecophysiological hierarchies.

Among bovids, antelopes, rodents and marsupials--in fact, probably in most animals--the rates of energy and water turnover are linked to salt tolerance, renal concentration and protein synthesis rates. Evolution in wet areas is associated with high turnover rates and low salt tolerance, while desert derivation goes with low rate functions and high salt tolerance. This basic ecophysiology changes slowly, and animals that migrate to different environments may retain ancient patterns in areas where they seem inappropriate--so that cattle keep their high rates of energy and water use in arid zones, or llamas remain low in energy and water turnover after three million years in cool or wet environments. The rate functions may be linked through gene-controlled rates of protein synthesis and turnover, which evolved to run at high rates in well-supplied areas, and at low rates in the face of the sparse resources of the desert.

Animals

Studies on ecophysiology of fish parasites: effect of trypanosome infection on the serum cholesterol levels of fishes.

Serum cholesterol levels of six species of fresh water fishes were lowered due to trypanosome infection. The percentage of infection in the different species of hosts ranged from 3.27% in Clarias batrachus to 16.66% in Wallago attu. Loss in serum cholesterol level was highest (42.39%) in the spiny eel Mastocembelus armotus and lowest in the carp Cirrhina mrigala (4.56%). Thus hypocholesterolemia was evidently caused in the fishes by trypanosomes.

Animals

Harnessing fern stress adaptations: From evolution and ecophysiology to molecular biology.

Ferns are the second most diverse vascular plant lineage after angiosperms and have been a key ecological component of Earth's biodiversity for more than 380 million years. Importantly, ferns are sister to seed plants, providing a critical outgroup for understanding the evolution of seed plant features. Ferns are remarkably resilient to abiotic and biotic stresses due to a long evolutionary history with adaptations to diverse habitats, stresses, and herbivores. As a result, ferns produce a multitude of secondary metabolites with unique bioactivities; these chemicals are potentially linked to the adaptation of ferns to herbivory, various abiotic and biotic stresses, and changing environments. Assembled reference genomes and the identification of key metabolic compounds of multiple ferns have already made significant contributions to human health and well-being. Here, we review the recent scientific advances in fern research, including evolution, stress resistance, metabolites and medicinal utilization, and comparative multi-omics applications. We propose that integrated investigations involving ecological, physiological, and molecular techniques will facilitate the future research translation of fern resources in diverse areas including soil remediation, biopesticides, and medicine. Advances in our understanding of fern molecular biology will provide new insights into the evolution of land plants and promote the utilization of ferns for heightened environmental restoration, crop protection and human health.

Ferns

Benthic dinoflagellates from the coral reef lagoon of Mayotte Island (S-W Indian Ocean); identification, toxicity and preliminary ecophysiological study.

The community of benthic dinoflagellates of Mayotte Island is similar to those of other regions. Four clones of Gambierdiscus toxicus and of other benthic dinoflagellates species (Prorocentrum spp., Ostreopsis sp., Amphidinium spp.) have been isolated and screened for their crude toxicity using mouse-test. The toxigenic reservoir seems moderated. One toxic clone of G. toxicus has been studied for factors governing growth and photosynthetic activity of this species: salinity, temperature, light intensity and nutrients with bioassays.

Animals

[The ecophysiology of Agama mutabilis Merren, in southern Tunisia].

The behavioural thermoregulation and rate of water turnover of the lizard Agama mutabilis were studied in southern Tunisia in summer and compared with another agamid, Amphibolurus inermis, Which occuies a similar habitat in Australia. The thermoregulatory sequence differs little between the two species although Agama mutabilis lacks a burrow and is probably more resistant to elevated body temperatures. Agama mutabilis has an extremely low rate of water turnover for such a small lizard [3,37 ml (100 g.day)-1] and ins probably, on the whole, better-adapted physiologically to desert conditions than Amphibolurus inermis.

Animals

Direct calorimetry in ecological energetics. Long term monitoring of aquatic animals.

The measurement of heat production represents the most general approach to the estimation of energy flow through biological systems. While aerobic energy metabolism is most conveniently studied by polarographic oxygen determination, direct calorimetry presents the only unspecific method for quantitative comparison of aerobic and anoxic metabolism in animals. In flow calorimeters constant experimental conditions may be controlled for practically unlimited periods of time, and transitions of the environmental regime may be repeatedly performed during one experiment. The merits of a direct calorimetric flow system are demonstrated in case studies of anoxic and aerobic animal metabolism and discussed in the context of current biochemical and ecophysiological concepts.

Aerobiosis

A CCD-OMA device for the measurement of complete chlorophyll fluorescence emission spectra of leaves during the fluorescence induction kinetics.

A new device for the measurement of complete laser induced fluorescence emission spectra (maxima near 690 and 735 nm) of leaves during the induction of the chlorophyll fluorescence is described. In this the excitation light (cw He/Ne laser, 632.8 nm) is switched on by a fast electro-mechanical shutter which provides an opening time of 1 ms. The emitted fluorescence is imaged onto the entrance slit of a multichannel spectrograph through a red cut-off filter (greater than 645 nm). A charge coupled device (CCD) sensor with 2048 elements simultaneously detects the complete chlorophyll fluorescence emission spectrum in the 650-800 nm wavelength range. Scanning is accomplished electronically and the integration time for a complete fluorescence emission spectrum can be selected from 10 ms up to 260 ms. Shutter, detector system and data acquisition are controlled by an IBM-PC/AT compatible computer. A maximum of 32 spectra can be measured at selected times during the fluorescence induction kinetics with the shortest time resolution of 10 ms. The instrument permits the determination of various fluorescence parameters: a) the rise-time of the fluorescence to the maximum level fm, b) the changes in the shape of the fluorescence emission spectra during the induction kinetics, c) the induction kinetics in the fluorescence ratio F690/F735 as well as d) the fluorescence decrease ratio Rfd at any wavelength between 650 to 800 nm. These fluorescence parameters provide information about the functioning of photosynthesis. The ratio F690/F735 allows the non-destructive determination of the chlorophyll content of leaves. The application of this instrument in ecophysiological research and stress physiology of plants is outlined.

Chlorophyll

Bioaccumulation processes in ecosystems.

The fate of environmental pollutants--the various isotopes of elements, and inorganic or organic compounds--is a fundamental aspect of ecology and ecotoxicology, and bioaccumulation is a phenomenon often discussed in this context. Human activities have drastically altered natural concentrations of many substances in the environment and added numerous new chemicals. An understanding of the processes of bioaccumulation is important for several reasons. 1) Bioaccumulation in organisms may enhance the persistence of industrial chemicals in the ecosystem as a whole, since they can be fixed in the tissues of organisms. 2) Stored chemicals are not exposed to direct physical, chemical, or biochemical degradation. 3) Stored chemicals can directly affect an individual's health. 4) Predators of those organisms that have bioaccumulated harmful substances may be endangered by food chain effects. While former theories on the processes of bioaccumulation focused on single aspects that affect the extent of accumulation (such as the trophic level within the food chain or the lipophilicity of the chemical), modern theories are based on compartmental kinetics and the integration of various environmental interactions. Concepts include results from quantitative structure-activity relationships (QSAR), pharmacokinetics, ecophysiology and general biology, molecular genetic aspects and selection, and finally the structure of communities and man-made alterations in them.

Animal Population Groups

Marine Vibrio Biocatalysts as Unique Green Transformation (GX) Tools at the Time to Sustainable Development Goals (SDGs).

Vibrios have sustained various types of ocean ecosystems, being key players in marine mineral cycles and essential partners in specific groups of marine life. Observed genome plasticity and metabolic versatility are some of the unique biological features of vibrios, and these traits could contribute in expanding their ecological niche in marine environments. Vibrios are now recognized as ecophysiologically essential microbial species for our planet. At the time to "Sustainable Development Goals" (SDGs), their genome plasticity and metabolic versatility have also been studied with the aim of solving global issues such as energy production and plastic pollution by creating new microbial biocatalysts. Here, we introduce recent progress on the application of vibrios aiming towards green transformation (GX).

Vibrio

Picocyanobacteria in the Chesapeake Bay: isolation, diversity, and adaptation.

Tiny unicellular cyanobacteria or picocyanobacteria (0.5-3 µm) are important due to their ecological significance. Chesapeake Bay is a temperate estuary that contains abundant and diverse picocyanobacteria. Studies of Chesapeake Bay picocyanobacteria in the past 20 years led to the finding of new members of subcluster 5.2 Synechococcus. They laid the foundation for revealing the ecophysiology, biogeography, genomics, and molecular evolution of picocyanobacterial in the Chesapeake Bay and other coastal estuaries. The Bay picocyanobacteria are known to better tolerate the changes in temperature, salinity, and heavy metals compared to their coastal and open-ocean counterparts. Many picocyanobacteria isolated from the Bay contain rich toxin-antitoxin (TA) genes, suggesting that the TA system may provide them with a genetic advance to cope with variable estuarine environments. Distinct winter and summer picocyanobacteria are present in the Bay, suggesting a dynamic seasonal shift of the picocyanobacterial community in the temperate estuary. While the Bay contains subcluster 5.2 Synechococcus, it also contains freshwater Synechococcus, Cyanobium, and marine Synechococcus due to river influx and the ocean's tidal influence. Some Chesapeake Bay picocyanobacterial clades were found in the Bering Sea and Chukchi Sea, showing a link between the Bay and polar picocyanobacteria. Genomic sequences of estuarine picocyanobacteria provide new insight into the taxonomy and evolution of freshwater, estuarine, and marine unicellular cyanobacteria. Estuaries connect freshwater and marine ecosystems. This overview attempts to extend what we learned from Chesapeake Bay picocyanobacteria to picocyanobacteria in freshwater and marine waters.

Chesapeake Bay

From comparative physiology to toxicological risk assessment.

1. Comparative physiology may help to improve the toxicologists' ability to assess and predict toxicological risks of chemicals. 2. Three main lines of approach have been distinguished, A: comparative research concerning the toxicokinetics of chemicals in different species; B: research concerning ecophysiological characteristics and C: studies aimed at the identification of biological markers that can be used to signal toxic effects in both experimental and free living populations of organisms. 3. Some remarks are made on limiting conditions to be fulfilled in order to make comparative physiology valuable from a toxicological point of view.

Animals

Microbial metagenomes from Lake Soyang, the largest freshwater reservoir in South Korea.

Lake ecosystems play a fundamental role in the global biogeochemical cycling of essential elements such as carbon, nitrogen, and phosphorus. Microorganisms within these ecosystems mediate key processes that regulate these cycles. Metagenomic analyses provide valuable insights into the taxonomic and functional diversity of microbial communities in various environments, including freshwater habitats. Here, we present a comprehensive metagenomic dataset derived from Lake Soyang, the largest freshwater reservoir in South Korea. A total of 28 metagenomes were generated from water samples collected across two distinct sampling periods: the first set (n = 8) was obtained between April 2014 and January 2015 from two depths (1 m and 50 m) in four different seasons, while the second set (n = 20) was collected between January 2019 and November 2019 from five depths (1, 10, 20, 40, and 90 m) over four seasons. Metagenomic sequencing yielded 9.3-21.8 Gbp per sample. This dataset provides a valuable resource for future studies exploring the ecophysiological characteristics of microbial communities in pelagic freshwater environments.

Republic of Korea

Bacterial extracellular vesicles exhibit distinct functional potential across biogeographic provinces of the South Pacific Ocean.

Bacterial extracellular vesicles (BEVs) are nanoscale membranous structures released by diverse types of bacteria, and are capable of transporting and delivering biological compounds between cells. Experimental investigation of BEVs in laboratory model systems indicates that these nanoparticles may play a number of roles in the ecophysiology of marine bacterial communities, but their functional potential in the environment remains unclear. Here we describe the proteomic composition of BEV populations over more than 5000 nautical miles of surface waters in the South Pacific, linking BEV cargoes to the bacterial communities producing them. The presence of marine BEVs was consistently observed across a range of biogeochemical conditions, with an overall abundance comparable to that of bacterial cells (up to 108 BEVs L-1). The protein cargo of marine BEVs, however, differed significantly among ocean regions. The BEV populations were enriched in carbohydrate transporters under phytoplankton bloom conditions, and contained iron uptake-related proteins in nutrient-limited waters. These data suggest that BEVs could enable cells to perform key extracellular functions in the marine environment. Our observations highlight the ubiquity of marine BEVs and biogeographic patterns in their ecological potential across oceanic scales.

Extracellular Vesicles

Climatic data sources and limitations of ecological niche models impact the estimations of historical ranges and niche overlaps in distantly related Korean salamanders.

BACKGROUND: Ecological niche models (ENMs) and analyses of niche overlap/divergence have become popular methods in ecology and evolutionary biology. These analyses rely on environmental data available from several databases. However, the influence of data sources on these analyses is rarely tested. Here, we test the impact of climatic data choice on the prediction of current and Plio-Pleistocene suitable habitats for two distantly related, but broadly sympatric, salamanders endemic to the Korean Peninsula. We ran MaxEnt separately on WorldClim and CHELSA climate data. We then hindcasted ENMs to five time periods of the Plio-Pleistocene, bracketing the estimated intraspecific divergence times for these species. We then quantified the differences in predictions between WorldClim- and CHELSA-based models. Also, given the sympatry and similar habitat requirements of the two species, we tested for niche overlaps using niche identity and background tests and tested the sensitivity of the results to climatic data choice. RESULTS: The ENMs successfully predicted contemporary suitable habitats for the two species. However, the predictions were highly sensitive to climatic data choice as well as variable combinations. The hindcasted ENMs produced contrasting predictions depending on the choice of climatic dataset and failed to predict suitable habitats for some Pleistocene time periods regardless of the climatic data choice. The niche analyses were also sensitive to climatic data choice, with results suggesting either niche overlaps or divergence depending on the climatic dataset used for the analyses. CONCLUSIONS: Our study highlights the influence of climatic data choice on the outcomes of ENMs and niche analyses. Our results also underscore the limitations of macroclimate-based ENMs, especially when the species is likely buffered from macroclimatic changes by microhabitat. We argue for the need for additional ecological, ecophysiological, and population genomic studies to better understand the range formation of these enigmatic species.

Animals