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Context: Mountain-top associated instream fauna with restricted ranges and limited dispersal capability are especially vulnerable to extinction under global warming and climate extremes. Aims: Rescue and housing of multiple cold-water taxa on short timelines in reaction to extreme drought. Methods: We undertook multi-species rescue (fishes: Gadopsis marmorata , n = 50; Galaxias olidus , n = 150; and a crayfish Euastacus sulcatus , n = 50) from the headwaters of the Condamine–Balonne catchment, temporarily holding animals in small (200 L) and large (1000 L) aquaria in single- and mixed-species contexts, at below 23°C. Key results: Galaxias olidus was successfully kept in one of the small aquaria, but did not survive in mixed-species aquaria, partly being due to predation by other species. Euastacus sulcatus showed decreased survivorship at moulting (predation). Large Gadopsis marmorata (>100-mm total length, TL) was aggressive, whereas maintaining smaller individuals and using large aquaria served to dampen overall aggression levels. Conclusions: Holding mixed taxa following field rescues requires attention to detail, including developmental-stage combinations within and across species, enclosure volume and availability of structure. Implications: The simultaneous rescue of multiple co-occurring endemic taxa represents a promising aspect of research and adaptive management in the era of global climate change. We rescued and temporarily housed multiple cold-water fauna (mountain-top associated fishes and crayfish) in reacting to extreme drought. In captivity, predation and aggression both within and among species reduced survivorship. Further experimentation, adaptive management and infrastructure development is required to prepare for future rescues of cold-water fauna, based on likely climate-change scenarios. This article belongs to the collection Environmental flows in northern Murray–Darling Basin: what we know about the science and management after a decade of practice. [ABSTRACT FROM AUTHOR]

The use of barriers in freshwater systems to mitigate invasions, known as isolation management, has been increasingly implemented as a protection strategy for native fish. Barriers are crucial for securing vulnerable populations, but much remains to be learnt about the drivers of success and the implications of deliberate fragmentation.In Aotearoa‐New Zealand, henceforth Aotearoa, native non‐migratory galaxiid (NMG) fishes are characterized by a disproportionate number of threatened species with introduced salmonids (trout) identified as a key driver of NMG declines.We conducted a qualitative review of barriers protecting NMG in Aotearoa, illustrating varying outcomes and current knowledge gaps with case studies. Barrier types ranged from natural bedrock waterfalls, shallow velocity chutes and drying reaches to deliberately engineered structures (known commonly as exclusion barriers). Barriers were typically located in headwater streams or spring systems. NMG species secured by fragmentation often have high conservation value and barriers are essential for their protection.Despite the critical role of these barriers, the isolated NMG populations above them are at risk of stochastic extirpation, invasion, or re‐invasion. Exclusion barriers may restrict access to habitat for native migratory fish species and can sometimes alter or remove ideal mesohabitat from protected populations.Overall, when using exclusion barriers, managers must assess extinction risk for individual populations by isolation or invasion, balancing benefits and consequences. However, these assessments are frequently based on incomplete data and hindered by lack of general understanding of the underpinning processes. Despite well‐documented benefits to NMG population survival, key knowledge gaps such as long‐term viability of isolated populations, combinations of physical barrier parameters conferring exclusion under all flow regimes and extent of habitat loss to other native species still exist. [ABSTRACT FROM AUTHOR]

Identification of taxonomically cryptic species is essential for the effective conservation of biodiversity. Freshwater‐limited organisms tend to be genetically isolated by drainage boundaries, and thus may be expected to show substantial cryptic phylogenetic and taxonomic diversity. By comparison, populations of diadromous taxa, that migrate between freshwater and marine environments, are expected to show less genetic differentiation. Here we test for cryptic diversity in Australasian populations (both diadromous and non‐diadromous) of two widespread Southern Hemisphere fish species, Galaxias brevipinnis and Galaxias maculatus. Both mtDNA and nuclear markers reveal putative cryptic species within these taxa. The substantial diversity detected within G. brevipinnis may be explained by its strong climbing ability which allows it to form isolated inland populations. In island populations, G. brevipinnis similarly show deeper genetic divergence than those of G. maculatus, which may be explained by the greater abundance of G. maculatus larvae in the sea allowing more ongoing dispersal. Our study highlights that even widespread, 'high‐dispersal' species can harbour substantial cryptic diversity and therefore warrant increased taxonomic and conservation attention. [ABSTRACT FROM AUTHOR]

Abstract Identification of taxonomically cryptic species is essential for the effective conservation of biodiversity. Freshwater‐limited organisms tend to be genetically isolated by drainage boundaries, and thus may be expected to show substantial cryptic phylogenetic and taxonomic diversity. By comparison, populations of diadromous taxa, that migrate between freshwater and marine environments, are expected to show less genetic differentiation. Here we test for cryptic diversity in Australasian populations (both diadromous and non‐diadromous) of two widespread Southern Hemisphere fish species, Galaxias brevipinnis and Galaxias maculatus. Both mtDNA and nuclear markers reveal putative cryptic species within these taxa. The substantial diversity detected within G. brevipinnis may be explained by its strong climbing ability which allows it to form isolated inland populations. In island populations, G. brevipinnis similarly show deeper genetic divergence than those of G. maculatus, which may be explained by the greater abundance of G. maculatus larvae in the sea allowing more ongoing dispersal. Our study highlights that even widespread, ‘high‐dispersal’ species can harbour substantial cryptic diversity and therefore warrant increased taxonomic and conservation attention.

Este artigo tem como objetivo verificar a terceira lei de Kepler para diferentes sistemas astronômicos em diversas escalas de distância, tais como Júpiter e suas quatro luas Galileanas, bem como o Sistema Solar, exoplanetas e galáxias. No caso de Júpiter utilizamos dados reais e simulados usando o programa Contemporary Laboratory in Astronomy (CLEA) valendo-se da equivalência entre o movimento harmônico simples (MHS) e movimento circular uniforme (MCU). Para o Sistema Solar e exoplanetas usamos dados das missões espaciais da NASA, e para galáxias, usamos dados do movimento de estrelas próximas do buraco negro Sargittarius A* da Via Láctea. A lei de Kepler é verificada nas escalas lunares, planetárias e exoplanetárias, sendo aproximadamente satisfeita também para Sargittarius A*. Por outro lado, a Terceira lei de Kepler não se verifica para o movimento geral de estrelas ao redor dos centros galácticos, pois as curvas de rotação de galáxias apresentam comportamento diferente do estabelecido pela lei do inverso do quadrado e é possível que a influência da componente de matéria escura seja dominante nestes sistemas.

Although some migratory fsh species are broadly distributed across large-spatial scales, they might only attain high abundance in certain areas. This can be attributed to local habitat conditions and variation in recruitment strength, which can be related to distance from spawning or larval-rearing habitats. The presence of pelagic compartments in riverine systems can enhance the abundance of some migratory fsh species by providing abundant food and habitat for larval development. In this study, we examined the composition and fne-scale abundance of migratory Galaxias brevipinnis Günther, 1866 (Teleostei: Galaxiidae) and non-migratory Galaxias spp. in relation to the presence and absence of downstream lakes and upstream distance of sites from lakes. Fish abundance and microhabitat use were estimated from randomly selected point samples (about 1 m²) from twenty-two streams in South Island, New Zealand. The total length of G. brevipinnis individuals was also measured to examine possible changes in their size-frequency distribution with increasing distance from lakes. Galaxias brevipinnis was found in almost all of the stream reaches surveyed upstream of lakes, while none were recorded in no-lake stream sites. The mean abundance of G. brevipinnis was considerably higher than non-migratory Galaxias species at sites upstream of lakes. Lotic habitats closer to the lakes also supported a higher abundance of G. brevipinnis than habitats sampled further away from the lakes, suggesting that recruitment limitation with distance from the larval supply is more important than the effect of microhabitats for this species. Furthermore, G. brevipinnis size-distribution patterns differed greatly with distance upstream, with a higher proportion of smaller (younger) individuals found mainly within 2 km upstream of lakes, suggesting strong recruitment of this species close to lake recruitment sources. Although non-migratory species made up all of the Galaxias species caught in non-lake streams, they also occurred in streams upstream of lakes, but only at low abundance in stream sites close to the lakes. However, their abundance tended to be higher at sites further away from lakes, where G. brevipinnis was less abundant. Declining recruitment of G. brevipinnis with distance inland from lake, and competitive interactions with non-migratory species, are likely the main determinants of the adult abundances and composition of these stream fsh at large spatial scales, and these effects may outweigh the role of microhabitat characteristics and preferences in such river basins. [ABSTRACT FROM AUTHOR]

Apresentamos aqui uma discussão pedagógica do processo de formação de estruturas (galáxias e além) no Universo, com um mínimo de formalismo e ênfase nas ideias físicas que colocam a instabilidade gravitacional como o principal agente do mesmo. O papel fundamental da matéria escura para a formação de estrutura é enfatizado e exemplificado. Finalmente, discutimos brevemente algumas observações recentes que desafiam o cenário aceito, o que mostra com clareza o caráter científico da Cosmologia atual.

The unprecedented loss of global biodiversity is linked to multiple anthropogenic stressors. New conservation technologies are urgently needed to mitigate this loss. The rights, knowledge and perspectives of Indigenous peoples in biodiversity conservation—including the development and application of new technologies—are increasingly recognised. Advances in germplasm cryopreservation and germ cell transplantation (termed ‘broodstock surrogacy’) techniques offer exciting tools to preserve biodiversity, but their application has been underappreciated. Here, we use teleost fishes as an exemplar group to outline (1) the power of these techniques to preserve genome‐wide genetic diversity, (2) the need to apply a conservation genomic lens when selecting individuals for germplasm cryobanking and broodstock surrogacy and (3) the value of considering the cultural significance of these genomic resources. We conclude by discussing the opportunities and challenges of these techniques for conserving biodiversity in threatened teleost fish and beyond. [ABSTRACT FROM AUTHOR]

Amphidromy is a distinctive life‐history strategy of some fish species that involves spawning in fresh or brackish water followed by dispersal to sea by newly hatched larvae, where they develop for a short period. Individuals then return to freshwater as juveniles, where they feed and grow, before maturing and spawning. Six amphidromous species from the Southern Hemisphere genus Galaxias (G. truttaceus, G. fasciatus, G. argenteus, G. postvectis, G. brevipinnis, G. maculatus) are recreationally, culturally, and economically important as the juveniles are harvested. Due to ongoing population declines and a lack of critical demographic information, there is growing concern about the management of the species. Here, we used semi‐quantitative review, culturomics, and bibliometric tools to analyse peer‐reviewed research conducted on the six amphidromous species of Galaxias to: (i) understand how spatiotemporal patterns of research have shifted over the last five decades, and (ii) identify critical research gaps. Forty percent of studies (n = 295) covered a spatial extent of 10 km or less and 87% of studies lasted less than 2 years – studies were largely small and short relative to the species' ranges and their longevity. Additionally, we found important research gaps; for example, studies on the effects of climate change and the associated effects of disturbance, and the marine phase are scarce in the peer‐reviewed literature. Finally, we suggest that quantitative models have been underutilized as tools for studying amphidromous galaxiids and should be embraced to answer questions not readily addressed with field and laboratory‐based techniques. If these species are to be effectively managed, their population dynamics across spatiotemporal scales must be understood and critical and long‐standing gaps in research knowledge addressed. [ABSTRACT FROM AUTHOR]

We present here a pedagogical discussion of the process of structure formation (galaxies and beyond) in the Universe, with a minimal formalism and emphasis on the physical ideas that put the gravitational instability as the main agent. The key role of dark matter for the structure formation is stressed and exemplified. Finally, we briefly discuss some recent observations which defy the accepted scenario, and show clearly the scientific character of contemporary Cosmology. [ABSTRACT FROM AUTHOR]

Normal spiral galaxies have a nucleus, disk, bulge, halo, and spiral arms. These systems arouse a lot of curiosity, attraction, and scientific questions and, consequently, many studies and techniques are proposed for the analysis of such structures. In this work, we implement the two-dimensional Fourier Transform method to analyze the spiral structures of galaxies and for that, a Python program was developed. The algorithm was tested using three images: a two-armed logarithmic spiral, a three-armed logarithmic spiral, and an image of the galaxy NGC 4321. With this technique we were able to determine the dominant components in each of the spiral structures, being m = 2, m = 3 and m = 2, respectively. [ABSTRACT FROM AUTHOR]

As galáxias espirais normais possuem um núcleo, disco, bojo, halo e braços espirais. Esses sistemas despertam muita curiosidade, atração e questionamentos científicos e consequentemente, muitos estudos e técnicas são propostas para análise destas estruturas. Neste trabalho implementamos o método da Transformada de Fourier bidimensional para a análise das estruturas espirais das galáxias e para isso, foi desenvolvido um programa em Python. O algoritmo foi testado usando três imagens: uma espiral logarítmica de dois braços, uma espiral logarítmica de três braços e uma imagem da galáxia NGC 4321. Com esta técnica conseguimos determinar as componentes dominantes em cada uma das estruturas espirais, sendo elas, respectivamente, m=2, m=3 e m=2.

Native freshwater fish of Australia have a diverse but largely undescribed endemic pathogen and parasite fauna. However, due to long-shared evolutionary histories and virulence/transmissibility trade-offs, effects of these endemic pathogens and parasites appear to be subtle: significant impacts are rarely observed and epizootics have not been recorded. In contrast, a number of alien pathogens and parasites are now established across southern Australia, causing manifestly harmful effects to native fish species and known or suspected epizootics in native fish populations. Undetected and/or undescribed alien viral pathogens are also suspected of being present. Alien pathogens and parasites were introduced to Australia with imports of live alien fish or their fertilised eggs. A review of the scientific and historical evidence indicates that they have had, and continue to have, greater impacts on native fish species than previously realised—especially for freshwater species. This review also documents a previously unknown, Murray-Darling-Basin-wide epizootic of Murray cod Maccullochella peelii in 1929–30, which may have contributed to strong declines in the related eastern freshwater cod Maccullochella ikei. A serious Chilodonella epizootic of M. peelii in 1982 is also examined. In addition, a possible role for alien viruses of the family Iridoviridae (Ranavirus and Megalocytivirus) in the general decline of the critically endangered silver perch Bidyanus bidyanus, and the rapid collapse of two specific native fish populations—upper Murrumbidgee River B. bidyanus and Shoalhaven River Macquarie perch Macquaria australasica—is suggested. It is argued that the severity of the impact of the virulent alien oomycete Saprolegnia parasitica, both historical and present day, has been underestimated. Finally, action is recommended against emerging new pathogen and parasite threats, and the extreme risk current alien fish importations pose in introducing them. These will further threaten already stressed native fish populations in southern Australia, particularly across the Murray-Darling Basin. [ABSTRACT FROM AUTHOR]

In this paper we investigate how the Reionization process is affected by early galaxy formation in different cosmological scenarios. We use a semi-analytic model with suppressed initial power spectra to obtain the UV Luminosity Function in thermal Warm Dark Matter and sterile neutrino cosmologies. We retrace the ionization history of intergalactic medium with hot stellar emission only, exploiting fixed and variable photons escape fraction models (fesc). For each cosmology, we find an upper limit to fixed fesc, which guarantees the completion of the process at z < 6.7. The analysis is tested with two limit hypothesis on high-z ionized hydrogen volume fraction, comparing our predictions with observational results. [ABSTRACT FROM AUTHOR]

We use an up-to-date compilation of Tully-Fisher data to search for transitions in the evolution of the Tully-Fisher relation. Using an up-to-date data compilation, we find hints at ≈3σ level for a transition at critical distances Dc ≃ 9 Mpc and Dc ≃ 17 Mpc. We split the full sample in two subsamples, according to the measured galaxy distance with respect to splitting distance Dc, and identify the likelihood of the best-fit slope and intercept of one sample with respect to the best-fit corresponding values of the other sample. For Dc ≃ 9 Mpc and Dc ≃ 17 Mpc, we find a tension between the two subsamples at a level of Δχ²x2 > 17 (3.5σ). Using Monte Carlo simulations, we demonstrate that this result is robust with respect to random statistical and systematic variations of the galactic distances and is unlikely in the context of a homogeneous dataset constructed using the Tully-Fisher relation. If the tension is interpreted as being due to a gravitational strength transition, it would imply a shift in the effective gravitational constant to lower values for distances larger than Dc by ΔG/G ≃ -0.1. Such a shift is of the anticipated sign and magnitude but at a somewhat lower distance (redshift) than the gravitational transition recently proposed to address the Hubble and growth tensions ( ΔG/G ≃ -0.1 at the transition redshift of zt ≲ 0.01 (Dc ≲ 40 Mpc)). [ABSTRACT FROM AUTHOR]

Understanding historical distribution patterns of freshwater fishes prior to human impacts is crucial for informing effective strategies for biodiversity conservation. However, incomplete information on species occurrence records, the existence of cryptic species and sensitivity to small sample sizes limit the application of historical records in natural history collections as well as conventional species distribution modelling algorithms to infer past distributions of species.This study used molecular data as an alternative and objective approach to reconstruct the historical distribution ranges of four stream fishes from the Breede River system in the Cape Fold Ecoregion, a global hotspot of imperilled endemic freshwater biodiversity in southern Africa.The study used 249 occurrence records and 208 mitochondrial cytochrome b sequences to reconstruct the potential historical ranges of four taxa: Galaxias sp. 'zebratus nebula', Galaxias sp. 'zebratus Riviersonderend', Pseudobarbus sp. 'burchelli Breede' and Pseudobarbus skeltoni.All four taxa historically had broader distribution ranges across the Breede River system before human impacts, but they have suffered severe attrition as the main‐stem populations have been extirpated.The severe decline in the historical ranges of these four taxa is a result of multiple impacts, particularly hydrological modification, habitat degradation and the introduction of non‐native species, which are also global challenges for freshwater ecosystems.The approach presented in this study has great potential for reconstructing historical ranges of stream‐dwelling taxa from disparate regions where fragmentation has resulted from human‐mediated impacts. This information is crucial for identifying appropriate conservation strategies such as river rehabilitation and eradication of non‐native species, as well as guiding reintroductions and informing assisted gene flow where these are deemed necessary interventions. [ABSTRACT FROM AUTHOR]

En la primera parte de este escrito presento una aproximación a Galáxias de Haroldo de Campos como un proyecto en prosa que explora nuevas posibilidades en un campo artístico paradojal, surgido en los años 60, que he denominado semi-abstracto. Sin renunciar a principios básicos del arte abstracto, esta nueva prosa se orientaría hacia la vida cotidiana retomando principios figurativos. En la segunda parte, trabajando dentro de este marco histórico-artístico, he analizado dos pasajes de Galáxias con el propósito de elaborar el sentido de crisis que los textos tardíos de esta obra pueden provocar.

Closely related species may have different patterns of distribution and spatial population structure in common landscapes, which can have implications for conservation of the species if they are vulnerable. The Australian mountain galaxias species complex has recently been split into 15 described species, 11 of which are threatened. In this study, we assessed the distribution and landscape genetic structure of two mountain galaxias species (Galaxias olidus and Galaxias oliros) in the Goulburn–Broken catchment (Murray–Darling Basin) in relation to hydrographic descriptors of river terrain, network and hydrology. We also assessed small‐scale population structure in juvenile G. oliros in tributary streams of the Goulburn River (the Granite Creeks).Analyses of distribution revealed that G. olidus mostly occurs in smaller streams at high elevations with steep valley slopes and high stream gradients downstream, whereas G. oliros mostly occurs in larger downstream waterways with higher magnitude and variability of stream flow.Population genetic structure in G. olidus was much greater than for G. oliros, with 17 of the 19 sampled locations resolved as genetically distinct populations for G. olidus, but only a single population revealed for G. oliros. Results for both species did not reflect the expectations of the stream hierarchy model or isolation‐by‐distance model. However, small‐scale spatial population structure in juvenile G. oliros in the Granite Creeks reflected the expectations of both stream hierarchy and isolation‐by‐distance models, suggesting that population structure of juveniles of this species reflects some level of spatial aggregation of closely related individuals that probably diminishes as the population ages.Higher landscape genetic structure in G. olidus was correlated with steeper stream and valley slopes, whereas no population genetic correlations were significant for G. oliros. Genetic diversity in G. olidus was higher in areas of greater hydrological variability, suggesting that populations in hydrologically variable areas function as a metapopulation and have a more diverse gene pool than populations in areas with lower hydrological variability. In contrast, genetic diversity in G. olidus was lower in higher elevation areas with steep valley slopes, suggesting that smaller but more stable populations occur in high elevation streams with high perenniality and low interannual variability of flows.Our results are consistent with other studies that highlight the importance of supporting natural hydrological regimes and natural patterns of hydrological connectivity for conservation of vulnerable freshwater fish. [ABSTRACT FROM AUTHOR]

Free-living species often receive greater conservation attention than the parasites they support, with parasite conservation often being hindered by a lack of parasite biodiversity knowledge. This study aimed to determine the current state of knowledge regarding parasites of the Southern Hemisphere freshwater fish family Galaxiidae, in order to identify knowledge gaps to focus future research attention. Specifically, we assessed how galaxiid–parasite knowledge differs among geographic regions in relation to research effort (i.e., number of studies or fish individuals examined, extent of tissue examination, taxonomic resolution), in addition to ecological traits known to influence parasite richness. To date, ~50% of galaxiid species have been examined for parasites, though the majority of studies have focused on single parasite taxa rather than assessing the full diversity of macro- and microparasites. The highest number of parasites were observed from Argentinean galaxiids, and studies in all geographic regions were biased towards the highly abundant and most widely distributed galaxiid species, Galaxias maculatus. Parasite diversity generally increased with the number of studies and individual fish examined, however studies which examined parasites from all body tissues could overcome the effects of low study effort. In order to promote further understanding of galaxiid–parasite biodiversity, we provide a series of recommendations, including the use of molecular techniques to verify parasite identity, and highlight the future roles both fish biologists and parasitologists can play.

South American galaxiids occupy both Patagonia and the ichthyogeographic Chilean Province, encompassing glacial Andean deep lakes, shallow plateau lakes, reservoirs, short Pacific rivers and long Atlantic rivers. The total fish fauna includes 29 species, comprising Neotropical fishes (siluriforms and characids), galaxiids, percichthyids, atherinopsids and mugilids, two lamprey species, and several exotic fishes (salmonids, Gambusia spp. and common carp). The family Galaxiidae shares a common ancestry with the Gondwanan temperate fish fauna, played a major role in the post-glacial colonization of Andean lakes and streams, and contributes key species to the food webs. Galaxiid species occupy an enormous latitudinal gradient, show a wide variety of life history patterns and are the southernmost native freshwater fishes of the world. Knowledge of South American galaxiids has improved notably, but new challenges arise due to climate change, biological invasions, damming, aquaculture and contamination. In this changing environment, the future of South American galaxiids should be carefully considered as a legacy of the old Gondwana and a unique attribute of the freshwaters of southern South America.

This article is based on the application of supercomputing techniques through an example in the investigation of the astronomical phenomena of evolution of galactic nuclei and black holes within the time period of the Universe’s existence. Numerical models of stellar dynamics simulations on supercomputers are essential in this area of research. This work was done in various research centers around the world, and the software employed uses N-body techniques in C ++, CUDA (Compute Unifi ed Device Architecture) and parallelized by using a MPI (Message Passing Interface). The scalability of the problem allows one to access accurate numerical models regarding the evolution of the systems of millions of stars. The results show that black holes, in all its variations, defi ne the shape and dynamics of galaxies, at times comparable to the age of the Universe, and have, for that reason, consequences in the destiny of itself.

Abstract: It is well documented that hydropower plants can affect the dynamics of fish populations through landscape alterations and the creation of new barriers. Less emphasis has been placed on the examination of the genetic consequences for fish populations of the construction of dams. The relatively few studies that focus on genetics often do not consider colonization history and even fewer tend to use this information for conservation purposes. As a case study, we used a 3‐pronged approach to study the influence of historical processes, contemporary landscape features, and potential future anthropogenic changes in landscape on the genetic diversity of a fish metapopulation. Our goal was to identify the metapopulation's main attributes, detect priority areas for conservation, and assess the consequences of the construction of hydropower plants for the persistence of the metapopulation. We used microsatellite markers and coalescent approaches to examine historical colonization processes, traditional population genetics, and simulations of future populations under alternate scenarios of population size reduction and gene flow. Historical gene flow appeared to have declined relatively recently and contemporary populations appeared highly susceptible to changes in landscape. Gene flow is critical for population persistence. We found that hydropower plants could lead to a rapid reduction in number of alleles and to population extirpation 50–80 years after their construction. More generally, our 3‐pronged approach for the analyses of empirical genetic data can provide policy makers with information on the potential impacts of landscape changes and thus lead to more robust conservation efforts. [ABSTRACT FROM AUTHOR]

Abstract: Galaxias maculatus is a riparian spawning fish that supports an important recreational fishery in New Zealand, with spawning habitat requirements strongly structured by salinity gradients at river mouths. This study reports changes to the spawning habitat following a series of large earthquakes that resulted in the widespread deformation of ground surfaces in the vicinity of waterways. Assessments of habitat recovery focused on two river systems, the Avon and Heathcote, with pre‐disturbance data available over a 20‐year period. Recovery dynamics were assessed by field survey and mapping of spawning habitat prior to and on seven occasions after the disturbance event. Riparian land‐use and management patterns were mapped and analysed using overlay methods in a geographical information system (GIS). Habitat migration of up to 2 km occurred in comparison with all previous records, and several anthropogenic land uses have become threats because of changed patterns of co‐occurrence. Incompatible activities now affect more than half of the spawning habitat in both rivers, particularly in areas managed for flood control purposes and recreational use. The results are an example of landscape‐scale responses to salinity and water‐level changes driven by tectonic dynamics. These dynamics are not the source of the stress per se; rather, they have increased the exposure of the species to pre‐existing stressors. The case illustrates important principles for managing subtle, yet widespread, change. Adaptive conservation methods and investments in information are priorities for avoiding management failure following environmental change. [ABSTRACT FROM AUTHOR]

The aim of this work was to analyze the thermal responses of Odontesthes nigricans, Eleginops maclovinus and diadromous Galaxias maculatus, key species in estuarine areas of the Beagle Channel (Tierra del Fuego, Argentina), under a climate change scenario. We hypothesized that in the southernmost limit of the species’ distribution, individuals are more likely to be affected by indirect consequences of climate change rather than direct temperature mortality. Their thermal tolerance limits were assessed using the Critical Thermal Methodology and their preferred temperatures, using a thermal gradient. Additionally, the Fulton’s condition factor and the energy density of individuals were analyzed as a proxy of the condition of fishes acclimated to different temperatures. Results showed that species analyzed have the ability to acclimate to the different temperatures, intermediate to large tolerance polygons and positive relationships between preferred and acclimation temperatures, indicating their eurythermic nature. Thus, O. nigricans, E. maclovinus and diadromous G. maculatus populations from Tierra del Fuego could experience enhanced performances because of moderate warming being and, as it was hypothesized, be influenced by indirect consequences of climate change (habitat degradation or changes in trophic structure) since they are living in environments that are widely cooler than their maximum tolerance. [ABSTRACT FROM AUTHOR]

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dibaxu es un poemario "bilingüe" que consta de 29 textos en idioma ladino, o judezmo, o sefardí, de la poeta Franco-bosnia Clarisse Nicoîsky, vertidos al castellano por Juan Gelman. Con Haroldo de Campos considero que la traducción de Gelman es "transcreación", que es como ha re-nombrado a la traducción literaria. Tanto los poemas originales como la transcreación de Gelman son en realidad un ars poetica, y ambos tienen lugar en la diáspora. Aquí se produce un encuentro entre Ética y Poética.

The native freshwater fish Galaxias platei shows a wide latitudinal distribution in Patagonia, being found on both sides of the Andes. Currently, climate change poses one of the main threats to native fish, and its effects are appearing faster in high southern latitudes. The aim of this work was to analyse the possible effects of climate change in G. platei through its thermal responses. We hypothesized that juveniles of this species would be affected by indirect rather than by direct consequences of climate change. We determined the thermal tolerance polygon using Critical Thermal Methodology and preferred temperatures using a thermal gradient. Additionally, we evaluated routine metabolic rate using stop-flow respirometry. Results showed an intermediate to large polygon, with a non-negligible portion acquired through acclimation. Preferred temperatures and routine metabolic rates were positively related to acclimation temperature. Results suggest that G. platei thermal tolerance is dependent on its prior thermal history, have a eurythermal nature but maintain high levels of cold tolerance. Moreover, G. platei would be better suited at maintaining homeostasis at highest temperatures where more energy could be available for growth. This is the first time that thermal ecology data are registered for this species at its southernmost distribution. [ABSTRACT FROM AUTHOR]

Body mass and temperature are primary determinants of metabolic rate in ectothermic animals. Oxygen consumption of post-larvalGalaxias maculatuswas measured in respirometry trials under different temperatures (5–21 °C) and varying body masses (0.1–>1.5 g) spanning a relevant range of thermal conditions and sizes. Specific respiration rates (Rin g O2g−1d−1) declined as a power function of body mass and increased exponentially with temperature and was expressed as:R = 0.0007 *W−0.31*e0.13 * T. The ability of this model to predict specific respiration rate was evaluated by comparing observed values with those predicted by the model. Our findings suggest that the respiration rate ofG. maculatusis the result of multiple interactive processes (intrinsic and extrinsic factors) that modulate each other in ‘meta-mechanistic’ ways; this would help to explain the species’ ability to undergo the complex ontogenetic habitat shifts observed in the lakes of the Andean Patagonic range. [ABSTRACT FROM AUTHOR]