Larval habitat of Ochlerotatus albifasciatus (Diptera: Culicidae) in the southern edge of the Americas, Tierra del Fuego Island

The information about ecological topics of mosquitoes at the southernmost tip of South America is fragmentary and scarce. The present study evaluates lentic freshwater habitat located in the surroundings of main roads of the Argentine sector of Tierra del Fuego as larval habitat of Ochlerotatus albifasciatus, also analyzes the relationships between their presence and several environmental variables: water turbidity, percentage of gramineans, percentage of macrophytes, presence of crustaceous cyanobacteria, and filamentous chlorophyceans. Mosquito inmatures were collected with dip nets. A generalized linear model (GLM) with negative binomial error distribution was used to determine the effects of different variables of the water bodies on abundance of Oc. albifasciatus in the larval habitats. Collections were made in 45 lentic freshwater bodies. Preimaginal stages were found in 17.70% of the studied habitats. Oc. albifasciatus was the only culicid registered. The GLM explained 93.17% of the variability, and showed a negative relationship between the abundances of Oc. albifasciatus and water turbidity, and a positive relationship with percentage of gramineans. The gramineans would improve food supply, because the plants are providing suitable substrate for different types of microbiota, a layer of leaves would protect eggs from extreme temperatures, and could help the larvae to hide from potential predators. The negative association between abundance of this species with water turbidity could be related to the presence of vegetation that favors retaining the substrate, reducing water turbidity.Fil: Burroni, Nora Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Loetti, María Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Marinone, María Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Freire, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Schweigmann, Nicolas Joaquin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin

The plankton communities from peat bog pools: structure, temporal variation and environmental factors

This is the first characterization of the structure and temporal variation of the plankton communities comprising the complete food web in five peat bog pools related to environmental factors over two consecutive ice-free periods in Tierra del Fuego (548S). Remarkably, picophytoplankton was composed solely of eukaryotic cells, surpassing the dominance expectations for these acidic water bodies, whereas testaceans were virtually absent, even as tychoplankters. Abundances of the different planktonic communities were slightly higher than those reported for Northern Hemisphere peat bogs and humic lakes. Mixotrophic nutrition prevailed among nano- and microphytoplankters, a strategy also common in humic lakes. The structures in spring of the planktonic communities were similar. In contrast, in late summer there were differences in the abundance and biomass of the different trophic compartments among small, shallow water bodies and large ones. These seem to be dictated by distinct pool size-driven patterns of water temperature variation. A general shift in the control of heterotrophic flagellates abundance in the pools occurred, changing from bottom-up regulation in spring to top-down control in late summer related to temperature-dependant variations in zooplankton abundance and composition. We hypothesize that changes in the trophic interactions affecting the entire food web occur over the open water period in these aquatic ecosystems, and that these are dictated by pool morphometry and related abiotic features.Facultad de Ciencias Naturales y MuseoInstituto de Limnología "Dr. Raul A. Ringuelet

Influence of fish introduction and water level decrease on lakes of the arid Patagonian plateaus with importance for biodiversity conservation

Biodiversity loss in shallow lakes is associated to several factors among which water level decrease and fish introduction are indicated as potential stressors. The Patagonian basaltic plateaus, located in one of the most arid regions of South America, hold thousands of shallow lakes and ponds and some large lakes, where vegetated lakes are the prime habitat for waterbirds, including endemic threatened species. We studied 31different lakes at the two main Patagonian plateaus (Strobel and Buenos Aires) during successive spring-summer field trips from 2007 to 2016. We focused on the differences between fishless and stocked lakes under contrasting hydrologic regimes (relatively stable waters and decreasing water level. Our survey evidenced the effect of fish introduction and water level decrease on the limnological features of the lakes and their phyto and zooplankton communities. Arheic shallow lakes showed a decreased water level accompanied by an increased conductivity, and several shifted from a clear-vegetated state to a more turbid condition, with increased algal biomass and demise in submerged macrophytes. Fishless lakes presented higher total zooplankton and macrozooplankton biomass and lower phytoplankton biomass than fish stocked lakes. Our findings provide evidence that under a scenario of climate change, the effect of the decrease in water level may enhance the adverse effects of fish introduction.Fil: Izaguirre, Irina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Lancelotti, Julio Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Saad, Juan Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Porcel, Elisa María Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: O'farrell, Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Marinone, María Cristina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Asociación Ornitológica del Plata; ArgentinaFil: Roesler, Carlos Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Dieguez, Maria del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Fotobiología; Argentin

Structure of plankton and waterbird communities under water level fluctuations: two case studies in shallow lakes of the Patagonian steppe

The Buenos Aires Lake Plateau, a unique semi-arid environment and priority area for waterbird conservation in Argentina, has recently shown reductions in lake sizes due to scarce rainfall. This study assessed the impact of contrasting hydrological conditions on the abiotic variables of lakes Chapu and Cervecero, as well as on the structure of plankton and how this affected the use of the lakes by waterbirds. We show that hydrological conditions shape the abiotic and biological features of these lakes. In 2015, both lakes were vegetated, but by 2016, their water level had dropped, causing decreased macrophyte coverage. In 2017, the lakes dried up completely, but were refilled the following year. The partial drought of 2015-2016 led to reduced concentrations of nutrients and food that support a high density and richness of birds, which are mostly aquatic and terrestrial feeders. After the extreme drought in 2017 and refilling phase in 2018, there was an improvement in the water quality of lake Chapu, as indicated by its increased clarity compared to that in 2015, while Cervecero remained turbid. Increased homogenization in plankton and waterbird species composition became evident in both lakes. There was a cyanobacteria bloom in Cervecero, while in Chapu Gammaproteobacteria were dominant. Both lakes supported few waterbirds, of which aquatic-terrestrial feeders and terrestrial herbivores were dominant. The abundance of the endemic and endangered hooded grebe (Podiceps gallardoi Rumboll 1974) declined with the cover of macrophytes, which these birds use when establishing their colonies. In sum, this study revealed changes in the conditions of lakes Chapu and Cervecero and their plankton communities in response to hydrological shifts, with implications for waterbird assemblages and, thus, biodiversity conservation.Fil: Porcel, Elisa María Sol. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Limnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Saad, Juan Francisco. Universidad Nacional del Comahue. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". - Provincia de Río Negro. Ministerio de Agricultura, Ganadería y Pesca. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Centro Nacional Patagónico. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni"; ArgentinaFil: Sabio y García, Carmen Alejandra. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Limnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Saraceno, Martín. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Limnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marinone, María Cristina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Fasola, Laura. Direccion Regional Patagonia Norte ; Direccion Nacional de Conservacion ; Administracion de Parques Nacionales ; Ministerio de Ambiente y Desarrollo Sostenible; . Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Roesler, Carlos Ignacio. Direccion Regional Patagonia Norte ; Direccion Nacional de Conservacion ; Administracion de Parques Nacionales ; Ministerio de Ambiente y Desarrollo Sostenible; . Fundación Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lancelotti, Julio Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Izaguirre, Irina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Limnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The plankton communities from peat bog pools: structure, temporal variation and environmental factors

This is the first characterization of the structure and temporal variation of the plankton communities comprising the complete food web in five peat bog pools related to environmental factors over two consecutive ice-free periods in Tierra del Fuego (548S). Remarkably, picophytoplankton was composed solely of eukaryotic cells, surpassing the dominance expectations for these acidic water bodies, whereas testaceans were virtually absent, even as tychoplankters. Abundances of the different planktonic communities were slightly higher than those reported for Northern Hemisphere peat bogs and humic lakes. Mixotrophic nutrition prevailed among nano- and microphytoplankters, a strategy also common in humic lakes. The structures in spring of the planktonic communities were similar. In contrast, in late summer there were differences in the abundance and biomass of the different trophic compartments among small, shallow water bodies and large ones. These seem to be dictated by distinct pool size-driven patterns of water temperature variation. A general shift in the control of heterotrophic flagellates abundance in the pools occurred, changing from bottom-up regulation in spring to top-down control in late summer related to temperature-dependant variations in zooplankton abundance and composition. We hypothesize that changes in the trophic interactions affecting the entire food web occur over the open water period in these aquatic ecosystems, and that these are dictated by pool morphometry and related abiotic features.Facultad de Ciencias Naturales y MuseoInstituto de Limnología "Dr. Raul A. Ringuelet

The Hyalella (Crustacea: Amphipoda) species cloud of the ancient Lake Titicaca originated from multiple colonizations

The final publication is available at Elsevier via https://doi.org/10.1016/j.ympev.2018.03.004. © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Ancient lakes are renowned for their exceptional diversity of endemic species. As model systems for the study of sympatric speciation, it is necessary to understand whether a given hypothesized species flock is of monophyletic or polyphyletic origin. Here, we present the first molecular characterization of the Hyalella (Crustacea: Amphipoda) species complex of Lake Titicaca, using COI and 28S DNA sequences, including samples from the connected Small and Large Lakes that comprise Lake Titicaca as well as from a broader survey of southern South American sites. At least five evolutionarily distant lineages are present within Lake Titicaca, which were estimated to have diverged from one another 12–20 MYA. These major lineages are dispersed throughout the broader South American Hyalella phylogeny, with each lineage representing at least one independent colonization of the lake. Moreover, complex genetic relationships are revealed between Lake Titicaca individuals and those from surrounding water bodies, which may be explained by repeated dispersal into and out of the lake, combined with parallel intralacustrine diversification within two separate clades. Although further work in deeper waters will be required to determine the number of species present and modes of diversification, our results strongly indicate that this amphipod species cloud is polyphyletic with a complex geographic history.Natural Sciences and Engineering Research Council || Discovery Grant 2012-327509Natural Sciences and Engineering Research Council || Discovery Grant 386591-2010Natural Sciences and Engineering Research Council || Undergraduate Student Research AwardsNatural Sciences and Engineering Research Council || Postdoctoral FellowshipCatholic University of Temuco, Research Direction || Limnology Project DGI-DCA 2007-01, Project MECESUP UCT 080

A case of phoresis of sphaeriids by corixids: First report for the Americas

En este trabajo describe el hallazgo del bivalvo Sphaerium (Musculium) lauricochae (Philippi, 1869) adheridos a las patas del  corixido Ectemnostega (Ectemnostegella) quechua Bachmann, 1961. Los bivalvos fueron hallados adheridos a las uñas tarsales del segundo par de patas del insecto. La fuerte adhesión de los bivalvos es capaz de generar daños tanto en las uñas de los insectos, como en el margen de las valvas de los moluscos.  El presente hallazgo representa el primer registro de sphaeridos transportados por insectos en el continente americano.Fil: Zelaya, Diego Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Marinone, María Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

Review of the Eulimnadia (Branchiopoda: Spinicaudata: Limnadiidae) from Argentina with the description of a new species

Marinone, María Cristina, Urcola, Juan Ignacio, Rabet, Nicolas (2016): Review of the Eulimnadia (Branchiopoda: Spinicaudata: Limnadiidae) from Argentina with the description of a new species. Zootaxa 4158 (3): 419-432, DOI: http://doi.org/10.11646/zootaxa.4158.3.

Taxonomic Diversity of the Freshwater Zooplankton in Argentina: A Review

Argentina, an extensive country located in southern South America, encompasses a considerable range of latitude and altitude, with a high diversity of lowland and highland waterbodies. Our study is aimed at providing information regarding the current taxonomic diversity of the main groups of the country's inland-water zooplankton. A total of 242 Protozoa, 375 Rotifera Monogononta, 170 Cladocera, and 120 Copepoda species and subspecies are reported. We submit considerations of the current level of taxonomic knowledge, the regional distribution of the species, and the biogeographical (or zoogeographical) aspects. Since most research was focused on a few regions or a small number of water bodies within large regions, many habitats have been scarcely studied, particularly in areas with wide seasonal or interannual variability. We assume that the potential species number in all groups is much higher than currently recognized. Further studies at wider spatial and temporal scales and at a higher taxonomical resolution as well, are needed in order to provide a full picture of the zooplankton diversity of Argentina.Fil: Jose, Susana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Marinone, María Cristina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Kuppers, Gabriela Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Claps, María Cristina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Paggi, Juan Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentin