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For 80 years, there were no sightings of the Andean frog, Telmatobius halli, due to the ambiguity with which its type locality was described (“warm spring near Ollagüe”, northern Chile). The type specimens were collected during the International High Altitude Expedition to Chile (IHAEC) in 1935 and were subsequently described in 1938. In 2018 and 2020, two studies independently reported the rediscovery of the species, but they reached different conclusions about its identity and geographic distribution. In fact, the populations identified as T. halli in those studies are more phylogenetically related to other species than to each other, so they clearly do not belong to the same taxon. Although the study of 2020 is more in line with the geographic information of the description, it does not consider some bibliographic details and the transport limitations of the IHAEC. Here, based on a detailed analysis of the chronicles of the IHAEC and other bibliographic sources, I first refute the proposals of the 2018 and 2020 studies and then provide a possible solution. The combined information from the chronicles indicates that the type locality of T. halli is found at the sources of the Loa River, a different place from those identified in the two previous studies. By also incorporating geographic information of the time, I conclude that its true type locality is Miño, an abandoned mining camp located near the origin of the Loa River, where currently no populations of the genus have been described.

Nine plants from the Puna ecoregion of northern Chile, traditionally used in ethnomedicine, were studied. The total content of phenolic compounds and their antioxidant capacity (ABTS, FRAP, and ORAC) were determined both in the dry material and in the infusions. To our knowledge, this is the first report on the antioxidant capacity for some of these plants and their infusions. Furthermore, these results show the diversity and complexity of the plants of the Chilean highlands with high potential to be used as a source of natural antioxidants in the reformulation and development of healthier foods.

Cancer is still one of the leading causes of death worldwide. Many chemotherapeutics from plants have been tested in cancer, such as vinblastine and paclitaxel. The north of Chile, Arica & Parinacota region, is characterized by its vegetal biodiversity due to its unique geographical and climatological conditions, offering an unexplored and unique source of naturally-derived compounds. The present research has considered a screening of 26 highland herbs using an in vitro growth inhibition model in a panel of six cancer cell lines from different tissues. 5 of the 26 studied ethanolic extracts shows strong activity at least in one cell line when tested at 10 µg mL-1. We present a group of plants worthy to be evaluated as promissory extracts. This work is part of the systematic attempt to find new candidates to be used in cancer therapies.

An innovative aquaculture project involving the thermal seawater effluent of a thermoelectric power plant and a recirculating aquaculture system (RAS) was implemented in the Atacama Desert, the driest in the world located in northern Chile to produce the warm water pelagic fish cobia (Rachycentron canadum Linnaeus, 1766). An experimental land-based fish farm was built consisting of nine independent RAS provided with adequate temperature (28°C) and salinity (32) for cobia growth and overall aquaculture performance. Under these conditions, cobia was raised from egg to an average weight of 4 ± 0.4 kg in 12 months. Growth rates were similarly high for all the batches, and mortalities from weaning up to harvest sizes never exceeded 6%. Besides, no antibiotics were ever used, and no infectious diseases ever detected during the four years experimental phase reported herein. The batches of eggs arrived in Chile in 2012 and 2014. After three years, 12 t of cobia were consistently produced per every eight months’ cycle. During this period, successful reproduction and routine volitional spawning of broodstock were achieved, producing offspring from F1 and F2 generations. The biological potential and economic feasibility of the RAS concept for raising cobia in temperate, desert regions was demonstrated and is described. Farm management, multi-trophic aquaculture, animal welfare, proactive health management, zero water effluent discharge, and total recycling of wastes are also discussed as a means of expanding the concept into a commercial phase.

Domoic acid (DA), the main toxin responsible for Amnesic Shellfish Poisoning, frequently affects the marine resources of Chile and other countries across the South Pacific, thus becoming a risk for human health. One of the affected resources is the scallop Argopecten purpuratus. Even though this species has a high commercial importance in Northern Chile and Peru, the characteristics of its DA depuration are not known. In this work, the DA depuration was studied by means of two experiments: one in controlled (laboratory) and another in natural conditions. All organs of A. purpuratus depurated the toxin very quickly in both experiments. In some organs, an increase or a very small decrease of toxin was detected in the early depuration steps. Several models were used to describe this kinetics. The one that included toxin transfer between organs and independent depuration from each organ was the model that best fit the data. It seems, therefore, that the DA in this species is quickly transferred from the digestive gland to all other organs, which release it into the environment. Physiological differences in the two experiments have been shown to have some effect on the depuration from each organ but the actual reasons are still unknown.

Observations on Chelonia mydas agassizii have been carried out on a monthly basis for the last 2 years along the Chinchorro beach in Arica (northern Chile), with the aim of monitoring and describing genetic and population parameters in this group of turtles. Eighteen Ch. mydas agassizii individuals were captured and marked from December 2011, to July 2013. These individuals had long carapace of 47 to 75.7 cm, of which 11 were identified as females and the rest were of undetermined sex (individuals of smaller sizes). We were only able to recapture one of such individuals 6 months later in the same feeding area. Sequencing of the mtDNA Control Region showed 4 haplotypes: 3 that had never been described before and one observed in several regions of the Pacific (Japan, Mexico and Ecuador). This information suggests that Ch. mydas agassizii may stay in the same feeding zone for months. Nevertheless, the genetic information did not indicate any association between the individuals captured from the Chinchorro Beach and a nesting area in the Pacific.

Artificial Neural Networks (ANN) are adjusted to predict monthly landings of anchovy (Engraulis ringens) and sardine (Sardinops sagax) in northern Chile (18°21'-24°00'S). Fishing effort (FE), landings and twelve environmental variables are considered from 1980 to 2012. External validation for the best models using all variables showed an R2 of 95% for anchovy and 99% for sardine, with an efficiency of 0.94 and 0.96, respectively. The models were simplified by considering only FE and sea surface temperature (SST) from NOAA satellites (SST-NOAA). Using these variables, very similar fits were achieved, comparing with the previous models, maintaining their predictive capacity. Downscaled SST for A2 climate change scenario (2015-2065) obtained by statistical regionalization from the Community Climate System Model (CCSM3) from National Center for Atmospheric Research (NCAR) and three FE scenarios (2010-2012 average, + 50% and −50%), were used as inputs for ANN simplified models. For A2 future climate change scenario (2015-2065) using 2010-2012 average FE as inputs, anchovy and sardine landings would increase 2.8% and 19.2% by 2065 respectively. With FE variations (-50%), sardine landings show the highest increase (22.6%) by 2065 when FE is decreased.

The influence of oceanic circulation and bathymetry on the fish larvae retention inside Mejillones Bay, northern Chile, was examined. Fish larvae were collected during two coastal upwelling events in November 1999 and January 2000. An elevated fish larvae accumulation was found near an oceanic front and a zone of low-speed currents. Three groups of fish larvae were identified: the coastal species (Engraulis ringens and Sardinops sagax), associated with high chlorophyll-a levels; larvae from the families Phosichthyidae (Vinciguerria lucetia) and Myctophidae (Diogenichthys laternatus and Triphoturus oculeus), associated with the thermocline (12°C), and finally, larvae of the families Myctophidae (Diogenichthys atlanticus) and Bathylagidae (Bathylagus nigrigenys), associated with high values of temperature and salinity. The presence of a seamount and submarine canyon inside Mejillones Bay appears to play an important role in the circulation during seasonal upwelling events. We propose a conceptual model of circulation and particles retention into Mejillones Bay. The assumption is that during strong upwelling conditions the flows that move along the canyon emerge in the centre of Mejillones Bay, producing a fish larvae retention zone. Understanding the biophysical interactions responsible to trap and/or concentrate particles is essential to protect these fragile upwelling ecosystems.

The hyper-arid Atacama Desert is one of the most extreme environments for life and only few species have evolved to survive its aridness. One such species is the tree Prosopis tamarugo Phil. Because Tamarugo completely depends on groundwater, it is being threatened by the high water demand from the Chilean mining industry and the human consumption. In this paper, we identified the most important biophysical variables to assess the water status of Tamarugo trees and tested the potential of WorldView2 satellite images to retrieve these variables. We propose green canopy fraction (GCF) and green drip line leaf area index (DLLAIgreen) as best variables and a value of 0.25 GCF as a critical threshold for Tamarugo survival. Using the WorldView2 spectral bands and an object-based image analysis, we showed that the NDVI and the Red-edge Chlorophyll Index (CIRed-edge) have good potential to retrieve GCF and DLLAIgreen. The NDVI performed best for DLLAIgreen (RMSE = 0.4) while the CIRed-edge was best for GCF (RMSE = 0.1). However, both indices were affected by Tamarugo leaf movements (leaves avoid facing direct solar radiation at the hottest time of the day). Thus, monitoring systems based on these indices should consider the time of the day and the season of the year at which the satellite images are acquired.

Indexación: Web of Science; Scopus. Microbial communities inhabiting high-altitude spring ecosystems are subjected to extreme changes in solar irradiance and temperature throughout the diel cycle. Here, using 16S rRNA gene tag pyrosequencing (cDNA) we determined the composition of actively transcribing bacteria from spring waters experimentally exposed through the day (morning, noon, and afternoon) to variable levels of solar radiation and light quality, and evaluated their influence on nutrient recycling. Solar irradiance, temperature, and changes in nutrient dynamics were associated with changes in the active bacterial community structure, predominantly by Cyanobacteria, Verrucomicrobia, Proteobacteria, and 35 other Phyla, including the recently described Candidate Phyla Radiation (e.g., Parcubacteria, Gracilibacteria, OP3, TM6, SR1). Diversity increased at noon, when the highest irradiances were measured (3.3-3.9 H', 1125 W m(-2)) compared to morning and afternoon (0.6-2.8 H'). This shift was associated with a decrease in the contribution to pyrolibraries by Cyanobacteria and an increase of Proteobacteria and other initially low frequently and rare bacteria phyla (< 0.5%) in the pyrolibraries. A potential increase in the activity of Cyanobacteria and other phototrophic groups, e.g., Rhodobacterales, was observed and associated with UVR, suggesting the presence of photo activated repair mechanisms to resist high levels of solar radiation. In addition, the percentage contribution of cyanobacterial sequences in the afternoon was similar to those recorded in the morning. The shifts in the contribution by Cyanobacteria also influenced the rate of change in nitrate, nitrite, and phosphate, highlighted by a high level of nitrate accumulation during hours of high radiation and temperature associated with nitrifying bacteria activity. We did not detect ammonia or nitrite oxidizing bacteria in situ, but both functional groups (Nitrosomona and Nitrospira) appeared mainly in pyrolibraries generated from dark incubations. In total, our results reveal that both the structure and the diversity of the active bacteria community was extremely dynamic through the day, and showed marked shifts in composition that influenced nutrient recycling, highlighting how abiotic variation affects potential ecosystem functioning. http://journal.frontiersin.org/article/10.3389/fmicb.2016.01823/full

Como aporte a la dinámica poblacional de especies que constituyen recursos pesqueros, se analizaron 160 muestras de zooplancton obtenidas con redes Bongo en 40 estaciones oceanógraficas entre Caldera y Coquimbo, en octubre y diciembre de 2005. De ellas se separó la totalidad de las larvas de crustáceos decápodos y se identificaron las de Heterocarpus reedi, Cervimunida johni y Pleuroncodes monodon. Las mayores abundancias de zoeas tempranas de las tres especies se encontraron en octubre en la zona de Coquimbo, mientras que en diciembre predominaron los estados más avanzados de desarrollo. En la zona de Caldera, en ambos meses de muestreo, predominaron los estados avanzados de desarrollo de H. reedi y P. monodon y zoeas tempranas de C. johni. La frecuencia de ocurrencia de las larvas de H reedi en la zona de Coquimbo fue similar en ambos meses, mientras que en la zona de Caldera fue mayor en octubre. La frecuencia de ocurrencia de las larvas de P. monodon y C. johni fue mayor en octubre en ambas zonas. Todas las megalopas capturadas en las dos zonas y meses de muestreo corresponden sólo a un morfotipo, con características morfológicas similares a los juveniles más pequeños de P. monodon. Sobre la base de la distribución y abundancia de larvas de las tres especies, se postula que el desove ocurre antes en la zona de Caldera que en la de Coquimbo, principalmente en zonas próximas a la costa, dada las diferencias de abundancia de los estados de desarrollo. To better understand the population dynamics of fishery resource species, 160 zooplankton samples were obtained with a Bongo net at 40 oceanographic stations around Caldera and Coquimbo in October and December, 2005, and analyzed. All crustacean decapod larvae were sorted, and Heterocarpus reedi, Cervimunida johni, and Pleuroncodes monodon larvae were identified. For all three species, the highest abundances of early zoea were found in October in Coquimbo, whereas advanced larval stages were predominant in December. In Caldera, advanced larval stages of H. reedi and P. monodon, and early zoeas of C johni were dominant during both sampling months. The frequency of occurrence of H. reedi larvae was similar during both sampling months in Coquimbo and greater in October in Caldera. The frequency of occurrence of the larvae of P. monodon and C johni was greater in both areas in October. All the megalops captured in both zones and sampling months corresponded to a single morphotype, with morphological characteristics similar to the smallest P. monodon juvenile specimens. Based on the larval distribution and abundance of these three species, it is postulated that spawning occurs earlier in the Caldera área than around Coquimbo, mainly in areas near the coast, given the differences in abundance of the developmental stages.

Geochemical characteristics of Ordovician basic volcanic rocks help to define the evolving tectonic setting of the Argentine Puna and northern Chile. Four spatially distinct magmatic groups are defined on geological, petrographical, geochemical and isotopic bases, each associated with particular geodynamic environments. The Tremadoc western group of subalkaline low K tholeiites with arc and modified MORB like signatures represent early stages of a back-arc basin, where spreading was incipient. The Arenig western group, medium K calc-alkaline basalts to andesites have volcanic arc in transition to back-arc signatures. The Tremadoc subalkaline basalts of the eastern group have REE patterns similar to E-MORB and at the same time weak subduction characteristics suggesting a rather mature supra-subduction zone (SSZ) basin. In contrast, the Late Tremadocian-Arenig basalts of the same group have intra-plate signatures, interpreted as magmas that ascended along pull apart regions associated with a transtensional regime. The geochemical patterns were applied to correlate basic sequences of doubtful geological setting. So, basalts from Chile were related to the Tremadocian western group, where they represent a slightly more mature stage of spreading of the basin. Basic rocks from Pocitos and part of Calalaste represent pre-Ordovician records of a back-arc system similar to that of the Tremadoc western group. Clearly similar arc patterns to those of the Arenig western group allow extending the arc environment to the southern Puna. The Tremadocian basalts from the eastern group were related to metabasites from the southern Puna, as part of a back-arc environment at that time. Fil: Coira, Beatriz Lidia Luisa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Jujuy; Argentina Fil: Koukharsky, Magdalena Maria L.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina Fil: Rivero Guevara, S.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Cisterna, Clara Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina

El melanismo en peces es poco frecuente, se expresa en una mayor cantidad de especies de aguas límnicas que marinas. Se reporta la captura de un ejemplar hembra de Cheilodactylus variegatus, con melanismo completo. El individuo fue capturado con arpón mediante buceo apnea, en la localidad de Caleta Piedra Azul, norte de Chile. Su longitud estándar es 33,6 cm y su peso total 960 g. Morfológicamente no hay diferencias con los ejemplares de coloración normal. La coloración general del cuerpo es gris oscura, con bandas verticales levemente más claras en el flanco. Las aletas no presentan en sus extremos la tonalidad anaranjada característica de la especie. Se discute la validez del efecto de una infección por tremátodos como agente causal del melanismo, debido a que es una mutación que ocurre en el receptor de melacortina (MC1R). La condición melánica en Ch. variegatus, es muy rara, es la primera vez que se reporta para esta especie, donde la expresión de un color oscuro, sería beneficiosa para ejemplares que habiten fondos con poca vegetación y entre grietas. Melanism in fish is rare; it is expressed in a greater number of limnetic species rather than marine. The capture of a Cheilodactylus variegatus female specimen with full melanosis is reported. The individual was captured with harpoon by apnea diving, in the Caleta Piedra Azul, northern Chile. Its standard length was 33.6 cm and a total weight of 960 g. There is no morphological difference if compared with normal color specimens. The general coloration of the body is dark gray, with slightly lighter vertical stripes on the flank. No fins show the orange hue characteristic of the species. The validity of trematode infection effect as a causal agent of melanosis is discussed, because it is a mutation in the melanocortin receptor (MC1R). The melanosis condition in Ch. variegatus, is very rare. It is the first time that this phenomenon is reported for this species, where the expression of a dark color, would be beneficial to specimens who reside on bottoms with little vegetation and among crevices.

Ammonites of the genus Santafecites Etayo-Sema and subgenus Olcostephanus (Viluceras) Aguirre-Urreta and Rawson are described for the first time from Chile. The succession of Olcostephaninae from the Chanarcillo Basin of northern Chile is described in the light of new collections and revision of historical material. The occurrence of mixed Andean and Mediterranean faunas supports the correlations proposed with the ammonite scales of the Neuquen Basin and the Mediterranean Province. Son descritos amonites del género Santafecites Etayo-Serna y del subgénero Olcostephanus (Viluceras) Aguirre-Urreta y Rawson, por primera vez en Chile. Se describe la sucesión de Olcostephaninae de la Cuenca de Chañarcillo en el Norte de Chile sobre la base de nuevas colecciones y revisión de material histórico. La ocurrencia de una mezcla de faunas andinas y mediterráneas sustenta las correlaciones propuestas con las escalas de amonites en la cuenca de Neuquén y la provincia Mediterránea.

Se analizaron las interacciones tróficas de 13 especies de peces intermareales, recolectadas en la región norte de Chile (20°18’S y 20°54’S) durante el período julio 1997 a julio 1998, a partir del contenido estomacal de 820 especímenes. La importancia de los ítemes presa, fue valorada a través de los métodos de frecuencia de aparición y gravimétrico y los índices de Shannon-Wiener (diversidad trófica) y Pianka (sobreposición trófica). Los resultados permitieron reconocer una asociación íctica compuesta por 46% de especies carnívoras, consumidoras principalmente de crustáceos porcelánidos, poliquetos y crustáceos menores, 23% de especies herbívoras, consumidoras mayoritariamente de algas clorófitas, feófitas y cianófitas y 31% de especies omnívoras, consumidoras principalmente de algas clorófitas, copépodos y gastrópodos. Los peces carnívoros Cheilodactylus variegatus, Helcogrammoides chilensis y Labrisomus philippii y el omnívoro Oplegnatus insignis registraron una tendencia a la eurifágia (H >2.0 bits), sin embargo la mayor superposicion trófica (>0.90) se observó entre los peces herbívoros y omnívoros. Finalmente se analizó el incremento de especies ícticas hacia latitudes bajas, y el aumento de los niveles de herbivoría y omnivoría en el intermareal rocosoThe trophic relationships of 13 intertidal fish species collected in northern Chile (20°18’S and 20°54’S) from July 1997 to July 1998, the stomach content analysis of 820 specimens, were investigated. The importance of the prey items was assessed by means of gravimetric and frequency of ocurrence methods, together with the Shannon-Wiener (trophic diversity) and Pianka (trophic overlap) indexes. The results allowed to recognize a fish assemblage composed of: 46% of carnivorous species, preying mainly on porcelain crabs, polichaetes and minor crustaceans; 23% of herviborous species, preying mainly on chlorophitic algae; 31% of omnivorous species, preying mainly on chlorophitic algae, Copepoda and Gastropoda. The carnivorous fishes Cheilodactylus variegatus, Helcogrammoides chilensis, Labrisomus philippii and the omnivorous Oplegnatus insignis showed euriphagic tendencies (>2.0 bits), however, the major trophic overlap (>0.90) was observed among herbivorous and omnivorous fishes. Finally, the increase of fish species towards lower latitudes and the increase of herbivory and omnivory levels in the rocky intertidal shore were analyzed

espanolEl genero Prosopis se distribuye ampliamente en diversos ecosistemas agroforestales, principalmente en climas aridos y semiaridos de America, Asia y Africa. Estas especies poseen un rol fundamental como fuente de alimento para un gran numero de comunidades de animales, como cabras y ovejas, las que consumen directamente sus semillas y flores. Asimismo, sus frutos tambien se utilizan para producir diversos productos, incluyendo harina y pulpa. En el norte de Chile, algunas especies del genero Prosopis estan en categoria de conservacion amenazada, hecho que apoya la inclusion de estas especies en diversos planes de reforestacion. Una fuente importante de informacion para la formulacion de dichas estrategias de reforestacion, es el analisis fisiologico de estas poblaciones y los efectos de los factores abioticos en parametros como la reproduccion y el crecimiento de los bosques de Prosopis del desierto de Atacama. En este articulo se destaca la importancia de los estudios ecofisiologicos en poblaciones del genero Prosopis y se analizan las principales estrategias adoptadas por estas comunidades vegetacionales en respuesta a la escasez de agua, hechos que resultan fundamentales para la supervivencia de estas comunidades en zonas aridas. Futuras investigaciones debieran abordar estas variables para proporcionar una mejor comprension de la conducta endogena de las especies del genero Prosopis, hecho que sera fundamental para la creacion de planes de forestacion para regenerar y preservar estos bosques. EnglishThe genus Prosopis is widely distributed in various agroforestry ecosystems, primarily in semiarid and arid climates of the Americas, Asia and Africa. These species serve as the food source for a large number of animal communities, such as goats and sheep, which consume their seeds and flowers. The seeds are also used to produce various products including flour and pulp. In northern Chile some species of Prosopis are threatened, which supports the inclusion of these species in reforestation plans. One critical source of information in the formulation of such reforestation strategies is the physiological analysis of these populations and the effects of abiotic factors on parameters such as reproduction and growth in the Prosopis forests of the Atacama Desert. In this note, we analyze the importance of ecophysiological studies of Prosopis populations and the main strategies adopted by these plants in response to water scarcity, which are critical to the survival of these desert communities. Future research must investigate these variables to provide an improved understanding of the endogenous behavior of species of Prosopis, which will be instrumental for creating forestation plans that will regenerate and preserve these woodlands.

The feeding habits of four species of mesopelagic fishes from northern Chile are described: Triphoturus mexicanus, Diogenichtys atlanticus, Vinciguerria lucetia and Cyclothone acclinidens. Samples were captured in September 1988 between 18°25’ and 19°09’S in the South West Pacific. The quantitative and qualitative analyses of the stomach content showed that the species have a zooplanktophagous opportunistic behavior, mainly predating on Crustaceans, especially on Copepods. The evaluation of the trophic spectrum and diversity of T. mexicanus and C. acclinidens suggests that these are nictoepipelagic species, while D. atlanticus and V. lucetia would be typical mesopelagic. Rev. Biol. Trop. 54(2): 613-622. Epub 2006 Jun 01.Se describen los hábitos alimenticios de cuatro especies de peces mesopelágicos del norte de Chile: Triphoturus mexicanus, Diogenichtys atlanticus, Vinciguerria lucetia and Cyclothone acclinidens. Las muestras fueron capturadas en setiembre de 1988 entre 18°25’ y 19°09’ S en el Pacífico suroeste. El análisis cualitativo y cuantitativo del contenido estomacal mostró que las especies tienen un comportamiento zooplantofago oportunista, depredando principalmente crustáceos, especialmente copépodos. La evaluación del espectro trófico y diversidad de T. mexicanus y C. acclinidens sugiere que estas son especies nictoepipelágicas, mientras que D. alanticus y V. lucetia serían mesopelágicas típicas.

Heliotropic leaf movement or leaf 'solar tracking' occurs for a wide variety of plants, including many desert species and some crops. This has an important effect on the canopy spectral reflectance as measured from satellites. For this reason, monitoring systems based on spectral vegetation indices, such as the normalized difference vegetation index (NDVI), should account for heliotropic movements when evaluating the health condition of such species. In the hyper-arid Atacama Desert, Northern Chile, we studied seasonal and diurnal variations of MODIS and Landsat NDVI time series of plantation stands of the endemic species Prosopis tamarugo Phil., subject to different levels of groundwater depletion. As solar irradiation increased during the day and also during the summer, the paraheliotropic leaves of Tamarugo moved to an erectophile position (parallel to the sun rays) making the NDVI signal to drop. This way, Tamarugo stands with no water stress showed a positive NDVI difference between morning and midday (ΔNDVI mo-mi) and between winter and summer (ΔNDVI W-S). In this paper, we showed that the ΔNDVI mo-mi of Tamarugo stands can be detected using MODIS Terra and Aqua images, and the ΔNDVI W-S using Landsat or MODIS Terra images. Because pulvinar movement is triggered by changes in cell turgor, the effects of water stress caused by groundwater depletion can be assessed and monitored using ΔNDVI mo-mi and ΔNDVI W-S. For an 11-year time series without rainfall events, Landsat ΔNDVI W-S of Tamarugo stands showed a positive linear relationship with cumulative groundwater depletion. We conclude that both ΔNDVI mo-mi and ΔNDVI W-S have potential to detect early water stress of paraheliotropic vegetation.

Three species of protistan and 22 species of metazoan parasites were obtained from a sample of 179 flatfish, (Paralichthys adspersus) taken-off Antofagasta, northern Chile. Prevalence of infection of seven parasites (Protista: 1, Copepoda: 2, Digenea: 1, Acantocephala: 1, Nematoda: 2) was significantly and positively correlated with host size. Host's sex do not seem to affect prevalence of infection, except for Nybelinia surmenicola, Capillaria sp. and Anisakis sp. (prevalence of infection significantly greater in males than females) and Philometra sp. (prevalence higher in females). Mean abundance is correlated with size in nine species (Protista: 1, Copepoda: 2, Digenea: 3, Acantocephala: 1, Nematoda: 2). Host's sex do not affect mean abundance, except for Cainocreadium sp. and Philometra sp.(mean abundance higher in females) and Nybelinia surmenicola, Capillaria sp. and Anisakis sp. (mean abundance higher in males).

A syntaxonomic overview of shrubland vegetation in the southern Andean regions of Peru is presented. For each plant community, information is given on physiognomy, floristic diversity, ecology and geographical distribution. The shrub vegetation on the slopes of the upper Tambo river valley includes annual herbs, grasses, cacti and ferns. In total, 151 vascular species have been documented from forty-six relevés made at altitudes between 3470 and 3700 m. After classification with TWINSPAN, one class, one order, one alliance, three associations, two subassociations typicum and three subassociations, one variant, and two communities are distinguished.Hierarchically the class Echinopsio schoenii-Proustietea cuneifoliae comprises the order Echinopsio schoenii-Proustetalia cuneifoliae, and the alliance Salvion oppositiflorae, occurring in the Prepuna dwarf scrubs. Within the alliance the following 3 new associations (with subassociations) have been distinguished: Senecioni arnaldii-Exhalimolobetum weddellii (thorny rosette-like dwarf shrubs), Mostacillastro gracile-Chuquiragetum spinosae (high cover of shrubs) and Anredero diffusae-Diplostephietum meyenii (high cover of clustered columnar cacti and patches of thorny shrubs).Two communities have been distinguished: Opuntia rosea and Helogyne ferreyrae, and the community of Ophryosporus heptanthus and Escallonia myrtilloides, which includes several introduced species growing on heavily grazed wet slopes. The basal communities of Stipa ichu and Nassella asplundii have been also identified.The most diverse families are Asteraceae, Poaceae and Cactaceae, followed by Solanaceae and Fabaceae. The vegetation includes endemic, native and a few introduced species. DCA was used to interpret the correlation between environmental variables and species composition. Species composition is best explained by altitude, inclination and vegetation cover.

18 pages, 5 figures, 2 tables, Microbial populations are involved in the arsenic biogeochemical cycle in catalyzing arsenic transformations and playing indirect roles. To investigate which ecotypes among the diverse microbial communities could have a role in cycling arsenic in salt lakes in Northern Chile and to obtain clues to facilitate their isolation in pure culture, sediment samples from Salar de Ascotán and Salar de Atacama were cultured in diluted LB medium amended with NaCl and arsenic, at different incubation conditions. The samples and the cultures were analyzed by nucleic acid extraction, fingerprinting analysis, and sequencing. Microbial reduction of As was evidenced in all the enrichments carried out in anaerobiosis. The results revealed that the incubation factors were more important for determining the microbial community structure than arsenic species and concentrations. The predominant microorganisms in enrichments from both sediments belonged to the Firmicutes and Proteobacteria phyla, but most of the bacterial ecotypes were confined to only one system. The occurrence of an active arsenic biogeochemical cycle was suggested in the system with the highest arsenic content that included populations compatible with microorganisms able to transform arsenic for energy conservation, accumulate arsenic, produce H2, H2S and acetic acid (potential sources of electrons for arsenic reduction) and tolerate high arsenic levels, This work was supported by funds provided by the BBVA Foundation project BIOARSENICO and the Chilean Government through FONDECYT Project 1100795 from the Science and Technology Chilean Commission (CONICYT). We also would like to thank the A. v. Humboldt Stiftung for the donation of part of the equipment used in this project, as well as V. Iturriaga, M. J. Demergasso and M.V. Coalova for their collaboration

Over a century after its first collection, Gentianella tarapacana (Gilg) T.N. Ho & S.W. Liu (Gentianaceae) was rediscovered at its type locality Amincha (Region ofAntofagasta, Province El Loa; 21°12'S; 68°20'W, 3850 m). The species is endemic to the Altiplano of northern Chile. It grows in wetland habitats. We designate a lectotype and provide a detailed description of the species, as well as an illustration and floristic information about its habitat at the type locality.

The coastal fringe off northern Chile (18o-23oS) is inhabited by numerous neritic fish species of which 249 are commonly observed during normal and cold La Nina (LN) conditions. During El Nino (EN) the ichthyofauna of northern Chile changes significantly due to about 100 invading fish species normally inhabiting lower latitudes, named "septentrional invaders" and "tropic-equatorial fishes". This results in a composition including 15 fish families and 86 genera. Analyses showed that species affected by EN were not the same between the last three EN events revealing that only the epipelagic species Anchoa naso, Albula vulpes, Atherinella nocturna and Scomberesox saurus stolatus behaved consistently. Off northern Chile, EN 1982/83, 1986/87, 1991/92, 1997/98, 2002/2003 and the not clearly EN defined 2004/2005 period with their aligned thermal abnormalities of each particular event were directly related to the number of invading/affected species. Most of the alien species (>50%) were epipelagic, 25% were typical for sandy beaches and 14.6% for rocky shores. The shore fish community did not show major changes during and after EN events, as only a few invading species were recorded; just Umbrina xantii was found during all events considered. In order to understand the response of the fish community to ENSO events a biogeographical analyses of 721 fish species reported for neritic habitats (coastal epipelagic and benthic) distributed between 0°-57°S (Gulf of Guayaquil to Cape Horn) was made. Their distribution ranges for normal oceanic conditions were taken from the very numereous existing literature. It is concluded that the north/south migration of Panamic and Peruvian warm water fishes during EN/LN events along the north Chilean coast between 18o-23oS, indicates that it represents a wide transition zone between the Peruvian and the Chilean ichthyogeographic provinces.

Although results have been controversial, understanding the tropical Pacific climatic state during the Pliocene warm interval ( c . 4.5–3.0 Ma) is crucial if insight is to be gained into the dynamic processes of present and future global warming. In the multi-proxy effort to reconstruct ancient climates, a critical role can be played by palaeoclimatic evidence provided by the spatial and temporal distribution of temperature-sensitive marine molluscs. Shallow-water strata of the Mejillones Peninsula, northern Chile (23°S), contain dense faunal assemblages in which molluscs exclusive to, or characteristic of, Pliocene deposits ( Chlamys simpsoni , Chlamys vidali , Chorus blainvillei , Concholepas nodosa , Fusinus remondi , Herminespina mirabilis ) coexist with surprisingly abundant and varied populations of extant warm-water species ( Bulla punctulata , Cerithium stercusmuscarum , Olivella sp., Turbo cf. fluctuosus , Anomia peruviana , Argopecten ventricosus , Donax peruvianus , Dosinia ponderosa , Mexicardia procera , Undulostrea megodon ), most of which have their current southern zoogeographical limit at 6°S. These tropical elements are reliable indicators of nearshore marine conditions and their abundant occurrence implies that sea surface temperatures (SST) along the northern Chile coast were at least 2 °C warmer in the mid-Pliocene than at present, and that these very different conditions lasted long enough to allow stable colonization of the area. Such a significantly warmer SST pattern strongly resembles general climatic conditions accompanying modern El Nino events, when warm tropical waters propagate southward along the western margin of South America; this supports the existence in this area of persistently El Nino-like conditions during the mid-Pliocene.

The Cordón de Lila is located immediately to the south of the Salar de Atacama, in northern Chile. The geology of the Cordón de Lila is characterized by extensive outcrops of Early Paleozoic volcanic and sedimentary rocks (Cordón de Lila Igneous and Sedimentary Complex; CISL) that form the 'Arco magmático occidental' (AMO) which is intruded by a multiple suite of Middle Ordovician to Lower Silurian granitoids. In this contribution we report the results of a sedimentological and paleontological study of a recently discovered 1,600 m thick marine Ordovician sedimentary sequence (Quebrada Grande Formation) which unconformably overlies the CISL. The Quebrada Grande Formation comprises three mayor facies associations. In stratigrafic order, these facies associations are: matrix-supported conglomerates (1), interbedded sandstones and siltstones (2) and clast-supported conglomerates (3). Facies association (1) is interpreted as debris flow deposits accumulated in a proximal marine fan-delta setting while the overlying sandstones and siltstones facies (2) represent open-marine platform deposits. Clast-supported conglomerates (3) are the record of high-energy sedimentary episodes during which coarse sediments reached the distal part of the fan-delta. The detrital fraction of the Quebrada Grande Formation is derived from the erosion of the Cambrian?-Lower Ordovician? CISL volcanic arc, the plutonio roots of the arc and its continental basement. The age of this formation is well constrained by the occurrence of brachiopods (Paralenorthis sp., Monorthis transversa Benedetto, and Mollesella? sp.) near the base and graptolites (Tetragraptus sp. and Cryptograptus? sp.) towards the middle of the succession. Both brachiopods and graptolites indicate an Arenigian to early Llanvirnian (Darriwilian) age. The brachiopod assemblage from Cordón de Lila displays affinities with the Famatina basin fauna of western Argentina. The absence of taxa in common between the AMO and the nearby 'Faja Eruptiva de la Puna Occidental' (FEPO) of NW Argentina may result from some kind of environmental barrier or some geographic separation from the Gondwana margin. According to the latter hypothesis, the Quebrada Grande succession developed on the allochtonous Arequipa-Antofalla Terrane En el Cordón de Lila, ubicado al sur del Salar de Atacama, en la Región de Antofagasta, aflora una sucesión volcánica y sedimentaria del Paleozoico más temprano (Complejo ígneo y Sedimentario del Cordón de Lila; CISL) que forma el 'Arco magmático occidental' (AMO), intruida por granitoides del Ordovícico medio-Silúrico inferior. En esta contribución se presenta un análisis sedimentológico y paleontológico de la recientemente reconocida Formación Quebrada Grande, una secuencia marina de ca. 1.600 m de espesor, que cubre, mediante discordancia angular, al CISL, y en la cual es posible definir tres asociaciones de facies que, en orden estratigráfico, son: 1) conglomerados matriz soportados, 2) intercalaciones de areniscas con lutitas y 3) conglomerados clastosoportados. La fracción detrítica deriva principalmente de la erosión del arco volcánico representado por el CISL (¿Cámbrico-Ordovícico inferior?), además de rocas plutónicas que formaron la raíz del arco, y de rocas metamórficas provenientes de su basamento continental. La facies (1), que constituye la parte inferior de la formación, se interpreta como el producto de flujos de detritos en posición proximal de un 'fan delta' marino. Las areniscas y lutitas (2), de la parte media de la formación, representan un ambiente de plataforma marina abierta. Los conglomerados clasto-soportados (3) corresponderían a flujos de alta energía que alcanzaron las partes más distales del delta. La edad de la Formación Quebrada Grande se puede precisar por la presencia de braquiópodos (Paralenorthis sp., Monorthis transversa Benedetto y Mollesella? sp.) en la base y de graptolitos (Tetragraptus sp. y Cryptograptus? sp.) en el medio de la sucesión, que indican el lapso Arenigiano-Llanvirniano inferior (Darriwiliano). La asociación de braquiópodos del Cordón de Lila presenta afinidades con las faunas de la cuenca de Famatina del oeste de Argentina. La ausencia de taxones comunes entre el AMO y la 'Faja Eruptiva de la Puna Occidental' (FEPO) del noroeste de Argentina podría deberse a algún tipo de barrera ambiental o a una separación geográfica respecto del margen de Gondwana. De acuerdo a la última hipótesis, la sucesión de Quebrada Grande podría haberse desarrollado sobre el Terrane alóctono de Arequipa-Antofalla

A work of gathering historical fishing (catch, fishing effort, CPUE, characteristics and operation of purseiner fleet) and satellite (NOAA, SeaStar and SeaWind) database of northern Chile, and fishing and oceanographic in situ sampling for validation purpose is made. With this information and the use of geographical information system (GIS) the distribution of pelagic resources and the associated environmental conditions (sea surface temperature, thermal gradients, chlorophyll concentration and wind fields) are analysed in order to develop a probable fishing ground (PFG) index prediction model. A PFG model of anchovy (Engraulins ringens) is operative for the northern Chile. The impact of the use of PFG charts was evaluated analyzing the operational efficiency of the involved purse seiner fleet. An availability index, independent from the present fishery activity, is estimated from the PFG index and images that depend on historical and present environmental conditions and historical catches. The management measures that assure the resources sustainability are present

El presente trabajo proporciona una primera descripcion taxonomica de las apendicularias colectadas durante septiembre y agosto de 1995 en la costa norte de Chile (18o23'-31o00' S). Se identificaron 15 especies de apendicularias pertenecientes a las familias Oikopleuridae (Oikopleura longicauda, O. cophocerca, O. dioica, O. rufescens, O. fusiformis, O. albicans, O. gracilis and Megalocercus abyssorum) y Fritillariidae (Fritillaria pellucida typica, F. pellucida omani, F. haplostoma F. tenella, F. formica digitata, F. venusta and F. fraudax). Todas las especies identificadas se registran por primera vez para aguas del norte de Chile y se amplia su distribucion en esta area del Pacifico Suroriental. Las especies mas abundantes fueron Oikopleura longicauda (56,1 %), O. gracilis (10,4 %), Fritillaria pellucida typica (6,7 %); O. albicans (5,0 %); F. pellucida omani (4,7 %); O. cophocerca (4,4 %) y F. venusta (4,1 %), mientras que las ocho especies restantes constituyeron el 8,6 % del total de apendicularias colectadas

Sediment samplings were carried across the intertidal of the beach at Hornitos, northern Chile (22°26´S) during August and November 1996 and March, July and November 1997 for a study of the reproductive and population biology of Emerita analoga (Stimpson) (Decapoda, Anomura) in a region of the Chilean coast characterized by persistent upwelling. The highest abundances of E. analoga occurred during March and December 1997. During November 1996, March and December 1997, the highest abundances occurred below the effluent line, while in July 1996 and August 1997, most of the stages of E. analoga occurred in higher abundances above the effluent line. Ovigerous females were recorded over the entire study period. Juveniles were also present during all sampling months, peaking during March 1997. Body size of ovigerous females varied between 12.6 and 26.4 mm. Fecundity increased significantly with body size of females in all samples analyzed. The analyses of recruitment pattern for males and females suggest the existence of two pulses in the recruitment of E. analoga at Hornitos: one between October and December, and another one between February and March. Growth analyses show that females have growth rates a maximum body sizes higher than males. Comparisons with similar studies carried out at the coast of south central Chile (ca. 39° S), a region where upwelling occurs occasionally, show that E. analoga from this region have similar growth rates but attain a greater maximum body size than in Hornitos. It is concluded that proximity to areas of persistent upwelling seems not to affect life history of E. analoga in northern Chile Se realizaron muestreos de sedimentos en la playa de Hornitos, norte de Chile (ca. 22°26´S) durante Agosto y Noviembre de 1996 y Marzo, Julio y Noviembre de 1997, con el objetivo de estudiar la biología reproductiva y poblacional de Emerita analoga (Stimpson) (Decapoda, Anomura) en una región de la costa Chilena, caracterizada por la presencia de surgencias persistentes. Las mayores abundancias de E. analoga ocurrieron durante Marzo y Diciembre de 1997. Durante Noviembre de 1996, Marzo y Diciembre de 1997, las abundancias más altas ocurrieron bajo la línea de efluente, mientras que durante Julio de 1996 y Agosto de 1997, la mayoría de las estadios E. analoga ocurrieron con mayor abundancia sobre esa línea. Se recolectaron hembras ovigeras durante todo el período de estudio. Los juveniles también estuvieron presentes durante todo el muestreo, registrándose las mayores abundancias durante Marzo de 1997. La talla de las hembras ovigeras varío entre 12,6 y 26,4 mm. La fecundidad aumentó significativamente con la talla de las hembras en cada período estacional analizado. El análisis del patrón de reclutamiento de machos y hembras sugiere la existencia de dos pulsos en el reclutamiento de E. analoga en Hornitos: uno entre Octubre y Diciembre, y otro entre Febrero y Marzo. Los análisis del crecimiento muestran que las hembras tienen tasas de crecimiento y tamaños corporales máximos mayores que los machos. Comparaciones con estudios similares realizados en la costa del centro sur de Chile (ca. 39° S), muestran similares tasas de crecimiento y tallas corporales máximas de E. analoga mayores en el sur que en la población de Hornitos. Por lo tanto, se concluye que la cercanía a áreas de surgencias persistentes parece no afectar la historia de vida de E. analoga en el norte de Chile

The trophic relatíons of five coastal Percifortlles at northern Chile were analyzed on the basis of 151 specimens of Acanthistius pictus, Paralabi·a.¡; humeralís, Pinguipes chilensis. Anisotremus scapularis ami Cheilodaetylus variegatus collected off Iquique, in April 1996, as a preliminary way to identify trophic guilds of subtidal fishes; A. pietus, P. humeralis and C. va riega tus, had the crustaceans Rhynehoeynetes t)pus, Pseudosquillopsis lessoni and Allopetrolisthes angulosus, respectively, as lhe best representeditems. In A. scapularis and P. chilensis the best represented items were the mollusks; however for the last species, the main food was ¡he crustacean Calleer setosus. These fish are essentially benthophagous carnivores with a variable trophic spectrum(8 to 36 ¡tems). The trophic relatíons of five coastal Percifortlles at northern Chile were analyzed on the basis of 151 specimens of Acanthistius pictus, Paralabi·a.¡; humeralís, Pinguipes chilensis. Anisotremus scapularis ami Cheilodaetylus variegatus collected off Iquique, in April 1996, as a preliminary way to identify trophic guilds of subtidal fishes; A. pietus, P. humeralis and C. va riega tus, had the crustaceans Rhynehoeynetes t)pus, Pseudosquillopsis lessoni and Allopetrolisthes angulosus, respectively, as lhe best representeditems. In A. scapularis and P. chilensis the best represented items were the mollusks; however for the last species, the main food was ¡he crustacean Calleer setosus. These fish are essentially benthophagous carnivores with a variable trophic spectrum(8 to 36 ¡tems).

Este estudio analiza los patrones de distribucion y abundancia de larvas de anchoveta (Engraulis ringens) en la zona norte de Chile (18°-24°S), dentro de la zona costera (0-100 mn), y su relacion con las condiciones oceanograficas en la capa superior (0-200 m de profundidad). Los datos utilizados se derivaron de cruceros realizados entre 1990 y 1995, durante cada invierno (julio-septiembre), la epoca de desove principal y de mayor abundancia de larvas. Durante el crucero de invierno de 1995 se realizo, ademas, un muestreo adicional con arrastres verticales a profundidades menores (