Evelyn Habit - Academia.edu (original) (raw)

Papers by Evelyn Habit

Biological Invasions, Dec 1, 2016

Salmonid invasions are currently recognized as one of the main threats to the conservation of fre... more Salmonid invasions are currently recognized as one of the main threats to the conservation of freshwater ecosystems in Patagonia. Although a number of salmonid species have been introduced to Patagonia over the last century not all species have succeeded at establishing widespread and large populations. To date, there are no reports of established self-sustaining Coho Salmon (Oncorhynchus kisutch) populations in southern Chile despite propagule pressure from aquaculture. Here, we assessed the natal origin of young-of-the-year Coho Salmon collected from estuaries and lakes associated with remote Patagonian fjords (51°S) by examining their otolith microchemical composition. Low strontium concentrations along a line transect from the otolith edge to its core in fish collected in one lake are consistent with freshwater residence until the moment of capture. Fish caught in estuaries displayed instead, relatively high strontium concentrations only at the otolith edge. This pattern suggests very recent movement from freshwater down to the estuary. Our findings are consistent with the hypothesis that the juvenile Coho Salmon collected in estuaries originated in the local freshwater system (lake) and provide the first ever evidence of recruitment and probable establishment of self-sustaining Coho Salmon population in Patagonia.

Geographic and genetic distance for Galaxias platei individuals from the San Pedro system. These ... more Geographic and genetic distance for Galaxias platei individuals from the San Pedro system. These distance matrices were used for the Mantel test

The present distribution of Patagonian species is the result of a complex history involving Quate... more The present distribution of Patagonian species is the result of a complex history involving Quaternary refugial populations, Holocene range expansions and demographic changes occurring during the Anthropocene. Invasive salmonids were introduced in Patagonia during the last century, occupying most rivers and lakes, preying on and competing with native species, including the fish Galaxias platei. Here, we used G. platei as a case study to understand how long-term (i.e. population differentiation during the Holocene) and short-term historical processes (salmonid introductions) affect genetic diversity. Using a suite of microsatellite markers, we found that the number of alleles is negatively correlated with the presence of salmonids (short-term processes), with G. platei populations from lakes with salmonids exhibiting significantly lower genetic diversity than populations from lakes without salmonids. Simulations (100 years back...

Conservation Genetics, 2021

The identification of closely related species with partially overlapping distributions is fundame... more The identification of closely related species with partially overlapping distributions is fundamental for effective conservation. Here we analyzed 28 sequenced microsatellites, mtDNA sequences, and morphological data, to describe the connectivity, genetic relationship, and distribution of Percilia gillissi and Percilia irwini , two endangered species inhabiting two contiguous watersheds in Chile (Itata and Biobío). We provide evidence of discordance in the spatial distribution of the two genomes (nuclear and mitochondrial). Three large clusters were identified with microsatellites, with one cluster straddling both watersheds. Three clusters were also evident in mtDNA with one cluster straddling both watersheds and the other two restricted to the Itata watershed’s northern reaches. Analyses of both microsatellite and mtDNA identified P. gillissi in the Itata watershed northern reaches and P. irwini in the Biobío watershed. Fish were detected in the Itata watershed that carried mtDNA characteristic of P. irwini but nuclear microsatellite profiles of P. gillissi suggesting an incomplete reproductive barrier between the species and connectivity between the watersheds. Additionally, fish were identified in the Itata northern reaches carrying mtDNA haplotypes sufficiently distinct from those of P. gillissi and P. irwini to suggest the existence of higher mtDNA diversity within P. gillissi than previously recognized. Finally, there was limited support for taxonomical classification based on morphological and meristic traits in this region.

Molecular Ecology, 2020

Diadromy is known for having major effects on the distribution and richness of aquatic species, a... more Diadromy is known for having major effects on the distribution and richness of aquatic species, and so does its loss. The loss of diadromy has led to the diversification of many species, yet research focusing on understanding its molecular basis and consequences are limited. This is particularly true for amphidromous species despite being the most abundant group of diadromous species. Galaxias maculatus, an amphidromous species and one of the most widely distributed fishes in the Southern Hemisphere, exhibits many instances of non-migratory or resident populations. The existence of naturally replicated resident populations in Patagonia can serve as an ideal system for the study of the mechanisms that lead to the loss of the diadromy and its ecological and evolutionary consequences. Here, we studied two adjacent river systems in which resident populations are genetically differentiated yet derived from the same diadromous population. By combining a reciprocal transplant experiment with genomic data, we showed that the two resident populations followed different evolutionary pathways by exhibiting a differential response in their capacity to survive in salt water. While one resident population was able to survive salt water, the other was not. Genomic analyses provided insights into the genes that distinguished 1) migratory from non-migratory populations, 2) populations that can vs. those that cannot survive a saltwater environment, and 3) between these resident populations. This study demonstrates that the loss of diadromy can be achieved by different pathways and that environmental (selection) and random (genetic drift) forces shape this dynamic evolutionary process.

Evolutionary Applications, 2019

This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Molecular Ecology, 2019

Understanding the evolutionary mechanisms that affect the genetic divergence between diadromous a... more Understanding the evolutionary mechanisms that affect the genetic divergence between diadromous and resident populations across heterogeneous environments is a challenging task. While diadromy may promote gene flow leading to a lack of genetic differentiation among populations, resident populations tend to be affected by local adaptation and/or plasticity. Studies on these effects on genomic divergence in non-model amphidromous species are scarce. Galaxias maculatus, one of the most widespread fish species in the Southern Hemisphere, exhibits two life histories, an ancestral diadromous, specifically, amphidromous form and a derived freshwater resident form. We examined the genetic diversity and divergence among 20 estuarine and resident populations across the Chilean distribution of G. maculatus and assessed the extent to which selection is involved in the differentiation among resident populations. We obtained nearly 4400 SNP markers using a RADcap approach for 224 individuals. As expected, collections from estuarine locations typically consist of diadromous individuals. Diadromous populations are highly differentiated from their resident counterparts by both neutral and putative adaptive markers. While diadromous populations exhibit high gene flow and lack site fidelity, resident populations appear to be the product of different colonization events with relatively low genetic diversity and varying levels of gene flow. In particular, the northernmost resident populations were clearly genetically distinct and reproductively isolated from each other suggesting local adaptation. Our study provides insights into the role of life history differences in the maintenance of genetic diversity and the importance of genetic divergence in species evolution.

Science of The Total Environment, 2021

Connectivity plays a crucial role in maintaining the structural and functional attributes of rive... more Connectivity plays a crucial role in maintaining the structural and functional attributes of river networks. Therefore, the loss of connectivity (fragmentation) alters the functioning and diversity patterns of the biota at local and regional scales. The global hydropower boom is one of the main drivers of river network fragmentation, with significant effects on the diversity of riverine biota. Analyses of beta diversity of fish assemblages in rivers with different degrees of fragmentation can give new insights into mechanisms that contribute to the responses of these assemblages to fragmentation. Here, fish beta diversity within six river networks of central Chile with different levels of fragmentation was studied to assess the responses of fish assemblages to fragmentation. A hypothesis of a significant effect of fragmentation on the beta diversity of native and non-native fish in riffles and pools was tested. This effect is expected to be modulated by both changes in environmental heterogeneity and direct obstruction of natural dispersal routes. Beta diversity based on variation of assemblage structure and environmental heterogeneity showed significant differences among river networks. Fish beta diversity showed a clear response to fragmentation in recently fragmented rivers. Specifically, the beta diversity of native fishes in pools and non-native fishes in riffles decreased with increase of the ratio between the longest non-fragmented sections of the river network to the total length of the network. These effects of fragmentation on fish assemblages were modulated by the biological features of each species, and open-water species were most severely affected. These results have significant implications for planning of the placement of new barriers in river networks subjected to hydropower boom. Planning of the placement of new barriers should consider the maintenance of long, connected sections within river networks in order to minimise the effects of fragmentation on fish biodiversity.

River Research and Applications, 2016

Frontiers in Environmental Science

The global increase in human population is driving a continuous conversion of land to anthropogen... more The global increase in human population is driving a continuous conversion of land to anthropogenic uses. This is a major threat to lotic ecosystems worldwide, as it compromises the biotic integrity and health of rivers and streams. Studies in the northern hemisphere have shown that the effects of urbanization on fish assemblages include decrease and/or loss of diversity and abundance of native species, and a proliferation of tolerant exotic species. Such effects have not been widely studied in developing countries like Chile, where urbanization has impacted several river ecosystems. Over decades, the lower zone of the Andalién River in Central Chile has gone over intense non-planned urbanization stemming from the city of Concepción, leading to several physical alterations. The native fish and lamprey fauna of this coastal river basin has been reported as very diverse, with a total of 16 native species. However, this fauna has been affected by multiple effects of different land uses...

E3S Web of Conferences, 2018

Hydropower is experiencing a development boom worldwide. However, at the same time, challenge sus... more Hydropower is experiencing a development boom worldwide. However, at the same time, challenge sustainability, mainly due to synergistic effects of several projects in the species distribution area. What and how hydroelectric projects will affect species, depends on a number of attributes. We analysed Chilean freshwater species distributed over 10 major basins of Central Chile threaten by 1124 plants (12,338 GW) planned in a hotspot of biodiversity. The exposure of the species to the planned hydropower projects was analyzed at the scale of species and as an assemblage. The hazardousness was evaluated by type, according to characteristics of planned hydropower plant: size, dam height and turbine type. Finally, considering species and assemblage exposition the most threaten genera were defined. Project analysed compile 45% of the exploitable potential, with a total of 198 (75.5%) project with capacities < 20MW, and 280 (88.1%) with low head dams (<20 m). 22.6% of the species are ...

Acta Limnologica Brasiliensia, 2019

Aim River systems of Central Chile are short, steep and fast flowing. They are characterized by d... more Aim River systems of Central Chile are short, steep and fast flowing. They are characterized by discharge regimes dominated by rainfall and snowmelt. Invertebrate fauna is highly endemic. This study aimed to describe the community structure of invertebrate in eight river systems in Central Chile (33-39°S) using species co-occurrence and niche sharing null models. Methods Invertebrate samples were collected from Central Chilean rivers (33-39°S), data were analyzed co-occurrence species and niche sharing null models for determine potential structuring patterns. Results The results revealed the presence of non-structured patterns in co-occurrence considering each site as well as all sites, that is most probably an effect of presence of many repeated species in the studied sites. Furthermore, we found the existence of niche overlap due to interspecific competition at each site and among all sites. The results obtained from these river systems corroborate observations from Chilean Patago...

Water

Exact knowledge of the physical structures of different river sections that govern their ecologic... more Exact knowledge of the physical structures of different river sections that govern their ecological structure and function is essential for the efficient conservation and management of riverine ecosystems. Eleven Andean river basins (Maipo, Rapel, Mataquito, Maule, Itata, Biobío, Toltén, Valdivia, Bueno and Puelo) comprise large scale latitudinal and altitudinal gradients and accommodate 71% of the Chilean population that strongly depend on their ecosystem services. Here, based on 16 hydrogeomorphic variables (on basin, valley and channel scales), we assessed the riverine landscapes (Functional Process Zones; FPZs) of these river basins using a top-down multivariate statistical approach. Two steep valley and downstream slope FPZs, three sinuous FPZs and two braided FPZs emerged in 8906 river sections. The proportion of the occurrence of FPZs was characterised by a clear latitudinal pattern which is strongly related to the proportions of each river basin within the large morphostruct...

Fig. 3. Three measures of movement of Diplomystes camposensis. The x-axis shows six individuals a... more Fig. 3. Three measures of movement of Diplomystes camposensis. The x-axis shows six individuals and the combined data during day (D) and night time (N). The y-axis shows values of a) distance from E0 (m); b) Cumulative directional movement (m), and c) Average movement (m), differentiating between displacements upstream (positive) or downstream (negative) in direction. Black squares show mean value and whiskers show standard error. Individual R 52 not included here due to the lack of night measurements.

The rise of the southern Andes and the Quaternary glacial cycles influenced the landscape of Pata... more The rise of the southern Andes and the Quaternary glacial cycles influenced the landscape of Patagonia, affecting the phylogeographic and biogeographic patterns of its flora and fauna. Here, we examine the phylogeography of the freshwater fish, Percichthys trucha, using 53 sequenced microsatellite DNA markers. Fish (N = 835) were collected from 16 river systems (46 locations) spanning the species range on both sides of the Andes. Eleven watersheds drain to the Pacific, five of which are trans-Andean (headwaters east of Andes). The remaining five drainages empty into the Atlantic. Three analytical approaches (neighbour-joining tree, hierarchical AMOVAs, STRUCTURE) revealed evidence of historic drainage reversals: Fish from four of the five trans-Andean systems (Puelo, Futalaufquen/Yelcho, Baker, Pascua) exhibited greater genetic similarity with Atlantic draining systems than with Pacific systems with headwate...

Water, 2022

The effects of human-induced stressors on riverine fish assemblages are still poorly understood, ... more The effects of human-induced stressors on riverine fish assemblages are still poorly understood, especially in species-poor assemblages such as those of temperate South American rivers. In this study we evaluated the effects of human-induced stressors on the taxonomic and functional facets of fish assemblages of two central-southern Chilean rivers: the Biobío River (flow regulated by multiple dams) and the Valdivia River (free-flowing). The study design considered reference condition, urban polluted, and urban-industrial polluted sites. To evaluate the effects of stressors on fish assemblages we assessed: (i) components of beta diversity; (ii) spatial and temporal patterns of fish structure using a multivariate approach; and (iii) functional diversity (specialization, originality, dispersion, and entropy) using linear models. We found a strong association between taxonomic and functional fish assemblage facets with a predominance of natural processes in the Valdivia River reflected ...

Sustainability, 2020

Recent international recognition of indigenous peoples, their rights and contributions to solving... more Recent international recognition of indigenous peoples, their rights and contributions to solving current challenges has directed academic attention to the way research is conducted in relation to them, what topics are studied, by whom, and using which methodologies. The Mapuche are the most numerous indigenous peoples in South America and have ancestrally inhabited a territory denominated Wallmapu. This study undertook a comprehensive revision and meta-analysis of the scientific literature related to the Mapuche and Wallmapu. Through quantification and visualization of the scientific landscape, the goal was to enhance the understanding of the themes and patterns that have guided research in this field of study. We found 1611 documents in Web of Science and SciELO collections published between 1975 and 2020. Using CiteSpace software, we analyzed the main conceptual hotspots, identified central authors and pivotal works, among other aspects of the scientific knowledge domain. The mai...