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  1. Article ; Online: Covariation of taxonomic and functional facets of β-diversity in Chilean freshwater fish assemblages: Implications for current and future processes of biotic homogenization.

    Castro, Sergio A / Rojas, Pablo / Vila, Irma / Jaksic, Fabian M

    PloS one

    2023  Volume 18, Issue 2, Page(s) e0281483

    Abstract: The biodiversity of assemblages that experience the introduction and extinction of species may lead to responses in two important facets: The taxonomic and functional diversity. The way in which these facets are associated may reveal important ... ...

    Abstract The biodiversity of assemblages that experience the introduction and extinction of species may lead to responses in two important facets: The taxonomic and functional diversity. The way in which these facets are associated may reveal important implications and consequences for the conservation of those assemblages. Considering the critical situation of freshwater fishes in continental Chile (30° - 56° S), we analyzed how the taxonomic (TDβ) and functional (FDβ) facets of β-diversity, and their components of turnover and nestedness, are associated. We evaluated changes in β-diversity (ΔTDβ and ΔFDβ), turnover (ΔTDtur and ΔFDtur), and nestedness (ΔTDnes and ΔFDnes) in 20 fish assemblages from their historical (pre-European) to current composition. We also simulated future trends of these changes, assuming that native species with conservation issues would become extinct. Our results show that the fish assemblages studied are in a process of loss of β-diversity, both in taxonomic and functional facets (ΔTDβ = -3.9%; ΔFDβ = -30.4%); also, that these facets are positively correlated in the assemblages studied (r = 0.617; P < 0.05). Both components showed by loss in nestedness (ΔTDnes = -36.9%; ΔFDnes = -60.9%) but gain in turnover (ΔTDtur = 9.2%; ΔFDtur = 12.3%). The functional β-diversity decreased more than the taxonomic (ΔFDβ > ΔTDβ), which was caused chiefly by six exotic species of Salmonidae, whose geographical spread was wider and that at the same time shared several morpho-functional traits. Our forecasts, assuming an intensification in the extinction of Endangered and Vulnerable native species, indicate that the process of homogenization will continue, though at a lower rate. Our study shows that the freshwater ichthyofauna of continental Chile is undergoing biotic homogenization, and that this process involves the facets of taxonomic and functional β-diversity, which are show high correlation between historical and current compositions. Both facets show that process is influenced by nestedness, and while turnover contributes to differentiation (both taxonomic and functional), its importance is overshadowed by nestedness.
    MeSH term(s) Animals ; Chile ; Biodiversity ; Fresh Water ; Salmonidae ; Ecosystem
    Language English
    Publishing date 2023-02-09
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2267670-3
    ISSN 1932-6203 ; 1932-6203
    ISSN (online) 1932-6203
    ISSN 1932-6203
    DOI 10.1371/journal.pone.0281483
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Bacterioplankton Zonation Does Exist in High Elevation, Polymictic Lakes.

    Aguilar, Pablo / Vila, Irma / Sommaruga, Ruben

    Frontiers in microbiology

    2022  Volume 13, Page(s) 764566

    Abstract: The assessment of distribution patterns or zonation of planktonic microbes along the water column is a crucial step to interpret their function in the ecosystem. In lakes without seasonal thermal stratification or polymictic systems such as high ... ...

    Abstract The assessment of distribution patterns or zonation of planktonic microbes along the water column is a crucial step to interpret their function in the ecosystem. In lakes without seasonal thermal stratification or polymictic systems such as high elevation tropical lakes, planktonic bacterial taxa are probably homogeneously distributed in the water column in contrast to what is known for thermally stratified lakes. However, we know little about bacterial distribution patterns in polymictic lakes and their relation to environmental gradients other than temperature. Here we assessed the diversity, microdiversity, and bacterial community composition at different discrete depths in three high elevation lakes (4,400-4,550 m above sea level) from the Andean plateau to test whether bacterial zonation patterns exist along the water column. For this objective, we analyzed bulk DNA and the putatively active fraction (cDNA) of the 16S rRNA gene. Although a clear gradient of temperature and oxygen was not detected along the water column, a significant vertical spatial zonation of the bacterial communities was present in two out of the three lakes, with microdiversity contributing to such pattern. Our results provide a reference for understanding how changing environmental conditions could affect high elevation aquatic ecosystems, particularly when warming is amplified with elevation, accelerating changes in hydrological regimes and biodiversity. Finally, our results highlight the importance of incorporating the whole water column in ecological studies of aquatic ecosystems lacking temporal or permanent thermal stratification.
    Language English
    Publishing date 2022-02-17
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2587354-4
    ISSN 1664-302X
    ISSN 1664-302X
    DOI 10.3389/fmicb.2022.764566
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Book: Trabajos presentados al Taller Internacional sobre Ecología y Manejo de Peces en Lagos y Embalses

    Vila, Irma

    Santiago, Chile, 5 - 10 de noviembre de 1984

    (Documento técnico / COPESCAL : 4 ; 4)

    1986  

    Institution Taller Internacional sobre Ecología y Manejo de Peces en Lagos y Embalses
    Author's details ed. por Irma Vila
    Series title Documento técnico / COPESCAL : 4 ; 4
    Documento tećnico / COPESCAL
    Documento técnico / COPESCAL ; 4
    Collection Documento tećnico / COPESCAL
    Documento técnico / COPESCAL ; 4
    Keywords Süßwasserfische ; Ökologie ; Fischzucht
    Subject Fischhaltung ; Fische ; Umweltbiologie ; Ecology
    Size VI, 237 S. : graph. Darst., Kt.
    Publisher FAO
    Publishing place Roma
    Publishing country Italy
    Document type Book
    HBZ-ID HT003796482
    ISBN 92-5-302465-8 ; 978-92-5-302465-0
    Database Catalogue ZB MED Nutrition, Environment, Agriculture

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  4. Article: Length-weight relationships native fish of Southern Altiplano: Lauca National Park, Chile

    Rojas, Pablo / Pardo, Rodrigo / Vila, Irma

    Journal of freshwater ecology. 2021 Dec. 10, v. 36, no. 1

    2021  

    Abstract: Two genera of fish, Orestias (Cyprinodontidae) and Trichomycterus (Trichomicteridae), inhabit in the Lauca National Park, UNESCO Biosphere Reserve, located at the Andes highlands in northern Chile. The present study analyzed the length-weight ... ...

    Abstract Two genera of fish, Orestias (Cyprinodontidae) and Trichomycterus (Trichomicteridae), inhabit in the Lauca National Park, UNESCO Biosphere Reserve, located at the Andes highlands in northern Chile. The present study analyzed the length-weight relationship for four native species of Orestias (O. parinacotensis, O. laucaensis, O. chungarensis and O. piacotensis) and two native species of Tricomycterius (T. chungaraensis and T. laucaensis), obtained at seven different localities. Our results showed that the growth coefficient values “b” for Orestias ranged from 2.89 (O. parinacotensis) through 4.04 (O. piacotensis) and Trichomycterus between 2.53 (T. laucaensis in Parinacota wetland) through 3.14 (T. laucaensis in Caquena River). All length-weight relationships were significant (p < 0.01), with r ² higher than 0.82. O. laucaensis, O. piacotensis and T. chungaraensis showed positive allometric growth (b > 3). However, two species O. parinacotensis and T. laucaensis showed negative allometric growth (b < 3). Only O. chungarensis showed isometric growth with b = 3. Intense anthropic activity, exotic fish introduction, and climate change present important risks for a unique endemic fish community of the high Andes.
    Keywords Cyprinodontidae ; Trichomycterus ; United Nations Educational, Scientific and Cultural Organization ; allometry ; anthropogenic activities ; climate change ; conservation areas ; fish ; fish communities ; indigenous species ; limnology ; national parks ; rivers ; wetlands ; Andes region ; Chile
    Language English
    Dates of publication 2021-1210
    Size p. 285-291.
    Publishing place Taylor & Francis
    Document type Article
    ZDB-ID 2590659-8
    ISSN 2156-6941 ; 0270-5060
    ISSN (online) 2156-6941
    ISSN 0270-5060
    DOI 10.1080/02705060.2021.1971782
    Database NAL-Catalogue (AGRICOLA)

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  5. Article: Orestias ascotanensis Parenti 1984 (Pisces; Cyprinodontiformes), larval adaptations to extreme conditions in high Andes

    Lam, Natalia / Rojas, Pablo / Vila, Irma

    Environmental biology of fishes. 2021 Nov., v. 104, no. 11

    2021  

    Abstract: Orestias ascotanensis Parenti is a critically endangered endemic species of the Chilean high Andean systems, found only in the springs of the Ascotán saltpan. Considering the importance of reproduction and early life history stages in population ... ...

    Abstract Orestias ascotanensis Parenti is a critically endangered endemic species of the Chilean high Andean systems, found only in the springs of the Ascotán saltpan. Considering the importance of reproduction and early life history stages in population persistence in fishes, understanding these is essential for successful conservation efforts. We studied the larval development of O. ascotanensis under controlled temperature and photoperiod conditions. A total of 50 O. ascotanensis specimens were captured during 2014 and 2015 and moved to the laboratory to be kept under controlled conditions and diet. Females were subjected to hormone therapy using Ovaprim® to induce oviposition, which was followed by artificial fertilization under dry conditions. Water temperature was maintained at 20 °C (± 1 °C), conductivity values oscillated in the interval of 2800–3600 µS/cm³, and the photoperiod was established as 16:8 (light hours:dark hours). The larvae hatched within 14 to 18 days. Three larval stages were established: (i) flexion larva with yolk sac, (ii) flexion larva, and (iii) post-flexion larva. The newly hatched larvae were highly prepared for the free-living stage and they absorbed the yolk sac in 5–7 days. The intense pigmentation of O. ascotanensis eggs and larvae and the high degree of development at hatching may represent adaptations to extreme conditions, such as high levels of solar radiation and significant changes in daytime temperatures. A range of anthropogenic activities have caused the contraction and degradation of the habitat of O. ascotanensis, producing serious concern regarding the conservation status of the species.
    Keywords Cyprinodontiformes ; conservation status ; diet ; fish ; habitats ; hormone replacement therapy ; indigenous species ; larvae ; larval development ; life history ; oviposition ; pigmentation ; solar radiation ; water temperature ; yolk sac ; Andes region
    Language English
    Dates of publication 2021-11
    Size p. 1453-1459.
    Publishing place Springer Netherlands
    Document type Article
    ZDB-ID 196790-3
    ISSN 1573-5133 ; 0378-1909
    ISSN (online) 1573-5133
    ISSN 0378-1909
    DOI 10.1007/s10641-021-01180-x
    Database NAL-Catalogue (AGRICOLA)

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  6. Article: Rivers as a potential dispersing agent of the invasive tree Acacia dealbata

    Zamorano, Daniel / Labra, Fabio A. / Vila, Irma / Meier, Claudio I.

    Revista chilena de historia natural. 2022 Dec., v. 95, no. 1

    2022  

    Abstract: BACKGROUND: The silver wattle Acacia dealbata is a fast-growing tree from Australia that has become naturalised in different regions of the world, attaining invasive status in most of them. In Chile, A. dealbata reaches large abundances along banks and ... ...

    Abstract BACKGROUND: The silver wattle Acacia dealbata is a fast-growing tree from Australia that has become naturalised in different regions of the world, attaining invasive status in most of them. In Chile, A. dealbata reaches large abundances along banks and floodplains of invaded fluvial systems, suggesting that rivers may act as a vector for seed dispersal. As hydrochory has not been documented previously in this species, the aim of this study is to evaluate the potential for water dispersal of seeds of this invasive tree along rivers. METHODS: Seed samples from rivers were collected at three sites along two A. dealbata-invaded rivers within the Cachapoal basin, central Chile. Number of seeds collected was contrasted versus hydraulic and local conditions with RDA. Seed buoyancy and sedimentation velocity were determined and compared between sites with an ANCOVA. Finally, the probability of seed germination after long periods of immersion in water was assessed, simulating transport conditions in the flow. Germination results were tested with a GLM. RESULTS: Results indicate that increasing abundance of A. dealbata seeds in the flow is related to the level of turbulence of the flow. Seeds display high floatability but their sedimentation velocity is high when they do sink. Finally, silver wattle seeds can germinate after long periods (many weeks) of immersion in water; however, their probability of germination depends to a large extent on whether seeds are scarified or not. CONCLUSIONS: Based on the evidence collected, we suggest that the seeds of A. dealbata have the necessary traits to be dispersed by rivers, this being the first research testing this hypothesis. The success of hydrochory of A. dealbata would depend on river flow turbulence, and whether there are natural mechanisms for scarifying the seeds either before or during transport. The proposed methodology can be used to assess river hydrochory for any tree species.
    Keywords Acacia dealbata ; analysis of covariance ; basins ; hydrochory ; invasive species ; probability ; river flow ; rivers ; seed germination ; seeds ; trees ; turbulent flow ; Australia ; Chile
    Language English
    Dates of publication 2022-12
    Size p. 6.
    Publishing place BioMed Central
    Document type Article
    ZDB-ID 2091358-8
    ISSN 0717-6317
    ISSN 0717-6317
    DOI 10.1186/s40693-022-00109-7
    Database NAL-Catalogue (AGRICOLA)

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  7. Article: Meristic and morphological differentiation of Orestias species (Teleostei; Cyprinodontiformes) from the southern Altiplano

    Scott, Sergio / Rojas, Pablo / Vila, Irma

    Environmental biology of fishes. 2020 Aug., v. 103, no. 8

    2020  

    Abstract: Orestias is an endemic fish genus of lacustrine and lotic systems distributed on the Andes highland region (Altiplano) of Peru, Bolivia and Chile (9°S to 22°S). Based on morphological characters, taxonomic studies have recognized seven species on the ... ...

    Abstract Orestias is an endemic fish genus of lacustrine and lotic systems distributed on the Andes highland region (Altiplano) of Peru, Bolivia and Chile (9°S to 22°S). Based on morphological characters, taxonomic studies have recognized seven species on the Chilean western southern Altiplano region (17°S - 22°S). The current geographical distribution of Orestias would be associated with historical vicariant events and fluctuations in water levels since the Pleistocene. In this context, this group arises as an interesting model to assess Orestias morphological adaptations in Altiplano systems. Morphological and meristic analyses were performed on ten populations of Orestias in the southern Altiplano. The results showed significant differences among populations. The meristic and morphometric characters were related to physical and chemical properties of their habitat. We considered the systematic validation of the Orestias species and the possible future determination of new species of the populations of O. cf. agassii of Huasco saltpan, Isluga River and Chuviri wetland, which should be tested with trophic, genetic and karyotype analyses.
    Keywords Cyprinodontiformes ; Pleistocene epoch ; fish ; geographical distribution ; habitats ; indigenous species ; karyotyping ; lotic systems ; models ; morphometry ; new species ; physicochemical properties ; rivers ; wetlands ; Andes region ; Bolivia ; Chile ; Peru
    Language English
    Dates of publication 2020-08
    Size p. 939-951.
    Publishing place Springer Netherlands
    Document type Article
    ZDB-ID 196790-3
    ISSN 1573-5133 ; 0378-1909
    ISSN (online) 1573-5133
    ISSN 0378-1909
    DOI 10.1007/s10641-020-00995-4
    Database NAL-Catalogue (AGRICOLA)

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  8. Article: Bacterial Communities Associated With Spherical

    Aguilar, Pablo / Dorador, Cristina / Vila, Irma / Sommaruga, Ruben

    Frontiers in microbiology

    2019  Volume 10, Page(s) 483

    Abstract: Species of the ... ...

    Abstract Species of the genus
    Language English
    Publishing date 2019-03-21
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2587354-4
    ISSN 1664-302X
    ISSN 1664-302X
    DOI 10.3389/fmicb.2019.00483
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article: Embryological development of the high-altitude killifish Orestias ascotanensis Parenti 1984 (Teleostei: Cyprinodontidae)

    Macaya, Consuelo / Lam, Natalia / Vila, Irma

    Environmental biology of fishes. 2019 May, v. 102, no. 5

    2019  

    Abstract: Orestias ascotanensis Parenti is a critically-endangered fish species endemic to the Ascotán salt pan springs. Given the importance of reproduction and early development in effective conservation of fish populations, this study describes the embryonic ... ...

    Abstract Orestias ascotanensis Parenti is a critically-endangered fish species endemic to the Ascotán salt pan springs. Given the importance of reproduction and early development in effective conservation of fish populations, this study describes the embryonic development of O. ascotanensis under laboratory conditions. Between 2014 and 2015, 50 individuals were captured and maintained under controlled conditions, including temperature, photoperiod and feeding regimen, to induce spawning for artificial fertilization. Females were subjected to hormone therapy with Ovaprim®. Water temperature was maintained at 20 °C (± 1 °C), conductivity at 2800–3600 μS·cm−1 and photoperiod at 16:8 (light hours: dark hours). Males showed changes in color and courtship behavior, and females developed a slightly bulging belly. Eggs were 1.55–2.5 mm in diameter, with abundant yolk and dozens of adhesion filaments. Embryonic development lasted 14–18 days; it was divided into five periods, which can be sub-divided into 21 stages, from fertilization to hatching. O. ascotanensis showed indications of partial spawning species, including oocytes at different stages of development, relatively large eggs as compared to adult fish length and low batch spawning. Characteristics such as partial spawning, highly-pigmented eggs and larvae and advanced larval development at hatching could be adaptations to the extreme conditions of the salt pan springs, including high levels of ultraviolet radiation and salinity as well as significant daily temperature changes.
    Keywords Cyprinodontidae ; adhesion ; adults ; altitude ; color ; courtship ; early development ; eggs ; embryogenesis ; females ; fish ; fish communities ; hatching ; hormone replacement therapy ; laboratory experimentation ; larvae ; larval development ; males ; oocytes ; salinity ; spawning ; ultraviolet radiation ; water temperature
    Language English
    Dates of publication 2019-05
    Size p. 675-684.
    Publishing place Springer Netherlands
    Document type Article
    ZDB-ID 196790-3
    ISSN 1573-5133 ; 0378-1909
    ISSN (online) 1573-5133
    ISSN 0378-1909
    DOI 10.1007/s10641-019-00859-6
    Database NAL-Catalogue (AGRICOLA)

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  10. Article: Exotic species elicit decoupled responses in functional diversity components of freshwater fish assemblages in Chile

    Rojas, Pablo / Castro, Sergio A. / Vila, Irma / Jaksic, Fabian M.

    Ecological indicators. 2021 Dec., v. 133

    2021  

    Abstract: In the freshwater basins of central Chile, 28 exotic species have been introduced, which have contributed to increase taxonomic diversity. Nevertheless, how these species have modified the components of functional diversity in these assemblages, a key ... ...

    Abstract In the freshwater basins of central Chile, 28 exotic species have been introduced, which have contributed to increase taxonomic diversity. Nevertheless, how these species have modified the components of functional diversity in these assemblages, a key aspect in learning about their present and future stability within an ecosystem, is unknown. In this study, we analyzed how the introduction of exotic species affects the functional diversity components of richness (FRic), divergence (FDiv), specialization (FSpe), and functional originality (FOri). Additionally, we simulated the effect of the loss (extinction/extirpation) of threatened native species. To do so, we gathered information on the distribution and functional characters of native and exotic species. Through Principal Coordinates Analysis (PCo), we obtained three independent axes (PCoA1, PCoA2, and PCoA3), which allowed us to define a multidimensional space and then to calculate FRic, FDiv, FSpe, and FOri. Our results indicate that richness and functional originality have increased significantly with the introduction of exotic species (263% and 32%, respectively). In contrast, functional divergence and specialization have remained the same. The possible extinction of threatened native species may promote increases in functional originality, decreases in functional richness and divergence, and unchanged functional specialization. On the other hand, a subset of exotic species presents novel features, while another shows redundant features with native ichthyofauna. We emphasize that the possible extinction of native species currently classified as threatened may lead to the disappearance of unique functional groups, which puts at risk the persistence and stability of these assemblages.
    Keywords ecosystems ; extinction ; freshwater ; freshwater fish ; functional diversity ; indigenous species ; introduced species ; risk ; species diversity ; Chile
    Language English
    Dates of publication 2021-12
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 2036774-0
    ISSN 1872-7034 ; 1470-160X
    ISSN (online) 1872-7034
    ISSN 1470-160X
    DOI 10.1016/j.ecolind.2021.108364
    Database NAL-Catalogue (AGRICOLA)

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