Intersexual Differences in the Gene Expression of Phoneutria depilata (Araneae, Ctenidae) Toxins Revealed by Venom Gland Transcriptome Analyses.

The wandering spider, Phoneutria depilata, is one of Colombia's most active nocturnal arthropod predators of vertebrates and invertebrates. Its venom has been a relevant subject of study in the last two decades. However, the scarcity of transcriptomic data for the species limits our knowledge of the distinct components present in its venom for linking the mainly neurotoxic effects of the spider venom to a particular molecular target. The transcriptome of the P. depilata venom gland was analyzed to understand the effect of different diets or sex and the impact of these variables on the composition of the venom. We sequenced venom glands obtained from ten males and ten females from three diet treatments: (i) invertebrate: Tenebrio molitor, (ii) vertebrate: Hemidactylus frenatus, and (iii) mixed (T. molitor + H. frenatus). Of 17,354 assembled transcripts from all samples, 65 transcripts relating to venom production differed between males and females. Among them, 36 were classified as neurotoxins, 14 as serine endopeptidases, 11 as other proteins related to venom production, three as metalloprotease toxins, and one as a venom potentiator. There were no differences in transcripts across the analyzed diets, but when considering the effect of diets on differences between the sexes, 59 transcripts were differentially expressed. Our findings provide essential information on toxins differentially expressed that can be related to sex and the plasticity of the diet of P. depilata and thus can be used as a reference for venomics of other wandering spider species.

The Genus Thionia Stål, 1859 (Hemiptera: Auchenorrhyncha: Issidae) in Colombia: Highlighting the Value of Entomological Collections.

Entomological collections represent a key source of information about the biological heritage of a country. However, the taxonomy and knowledge of many arthropods from megadiverse countries are underrepresented in these natural history collections as is the case with several planthoppers of the suborder Auchenorrhyncha. Issidae are fulgoromorphs distributed worldwide, except the poles and Greenland. Despite this ubiquity, Colombian planthoppers remain very poorly known and studied. Our objective was to provide the first consolidated records and distributional data for Colombian Issidae. We used reports of the representative genus Thionia deposited in biological collections in Colombia. In addition, we linked voucher specimen information and Olson's life zones showing an inter-Andean valley and Eastern Andean Cordillera distribution within Colombia. Our survey of Colombian biological collections revealed 55 individuals of the genus Thionia Stål, 1859 (53 adults, 2 immatures [nymphs]), which were collected by different methods; however, many of those records may be opportunistic. This genus (and its species) needs further study, with systematic and ecological revision, as is the case with other terrestrial Colombian hemipterans. Our consolidated records represent an advance to the knowledge of Issidae (and Thionia specifically) for the Neotropics and Colombia in particular, and a baseline for further study of distributional and biogeographic patterns of the suborder Auchenorrhyncha.

Bats and their vital ecosystem services: a global review.

Bats play crucial ecosystem services as seed dispersers, pollinators, controllers of insects, and nutrient recyclers. However, there has not been a thorough global review evaluating these roles in bats across all biogeographical regions of the world. We reviewed the literature published during the last two decades and identified 283 relevant studies: 78 dealt with the control of potential insect pests by bats, 80 related to the suppression of other arthropods, 60 on the dispersal of native or endemic seeds, 11 dealt with the dispersal of seeds of introduced plants, 29 on the pollination of native or endemic plants, 1 study on pollination of introduced plants, and 24 on the use of guano as fertilizer. Our literature search showed that queries combining the terms "seed dispersal," "insectivorous bats," "nectarivorous bats," "use of guano," and "ecosystem services" returned 577 studies, but half were experimental in nature. We found that the evaluation of ecosystem services by bats has been mostly conducted in the Neotropical and Palearctic regions. To detect differences across relevant studies, and to explain trends in the study of ecosystem services provided by bats, we performed generalized linear mixed models (GLMM) fitted with a Poisson distribution to analyze potential differences among sampling methods. We identified 409 bat species that provide ecosystem services, 752 insect species consumed by bats and 549 plant species either dispersed or pollinated by bats. Our review summarizes the importance of conserving bat populations and the ecological services they provide, which is especially important during the current pandemic.

Skull Morphology, Bite Force, and Diet in Insectivorous Bats from Tropical Dry Forests in Colombia.

In Neotropical bats, studies on bite force have focused mainly on differences in trophic ecology, and little is known about whether factors other than body size generate interspecific differences in bite force amongst insectivorous bats and, consequently, in their diets. We tested if bite force is related to skull morphology and also to diet in an assemblage of Neotropical insectivorous bats from tropical dry forests in the inter-Andean central valley in Colombia. It is predicted that the preference of prey types among insectivorous species is based on bite force and cranial characteristics. We also evaluated whether skull morphology varies depending on the species and sex. Cranial measurements and correlations between morphological variation and bite force were examined for 10 insectivorous bat species. We calculated the size-independent mechanical advantage for the mandibular (jaw) lever system. In all species, bite force increased with length of the skull and the jaw more than other cranial measurements. Obligate insectivorous species were morphologically different from the omnivorous Noctilio albiventris, which feeds primarily on insects, but also consumes fish and fruits. Our results show that bite force and skull morphology are closely linked to diets in Neotropical insectivorous bats and, consequently, these traits are key to the interactions within the assemblage and with their prey.

Foraging strategies, craniodental traits, and interaction in the bite force of Neotropical frugivorous bats (Phyllostomidae: Stenodermatinae).

Bats in the family Phyllostomidae exhibit great diversity in skull size and morphology that reflects the degree of resource division and ecological overlap in the group. In particular, the subfamily Stenodermatinae has high morphological diversification associated with cranial and mandibular traits that are associated with the ability to consume the full range of available fruits (soft and hard).We analyzed craniodental traits and their relationship to the bite force in 343 specimens distributed in seven species of stenodermatine bats with two foraging strategies: nomadic and sedentary frugivory. We evaluated 19 traits related to feeding and bite force in live animals by correcting bite force with body size.We used a generalized linear model (GLM) and post hoc tests to determine possible relationships and differences between cranial traits, species, and sex. We also used Blomberg's K to measure the phylogenetic signal and phylogenetic generalized least-squares (PGLS) to ensure the phylogenetic independence of the traits.We found that smaller nomadic species, A. anderseni and A. phaeotis , have a similar bite force to the large species A. planirostris and A. lituratus; furthermore, P. helleri registered a bite force similar to that of the sedentary bat, S. giannae. Our study determined that all the features of the mandible and most of the traits of the skull have a low phylogenetic signal. Through the PGLS, we found that the diet and several cranial features (mandibular toothrow length, dentary length, braincase breadth, mastoid breadth, greatest length of skull, condylo-incisive length, and condylo-canine length) determined bite force performance among Stenodermatiane.Our results reinforce that skull size is a determining factor in the bite force, but also emphasize the importance of its relationships with morphology, ecology, and phylogeny of the species, which gives us a better understanding of the evolutionary adaptions of this highly diverse Neotropical bat group.

Deciphering the diet of a wandering spider (Phoneutria boliviensis; Araneae: Ctenidae) by DNA metabarcoding of gut contents.

Arachnids are the most abundant land predators. Despite the importance of their functional roles as predators and the necessity to understand their diet for conservation, the trophic ecology of many arachnid species has not been sufficiently studied. In the case of the wandering spider, Phoneutria boliviensis F. O. Pickard-Cambridge, 1897, only field and laboratory observational studies on their diet exist. By using a DNA metabarcoding approach, we compared the prey found in the gut content of males and females from three distant Colombian populations of P. boliviensis. By DNA metabarcoding of the cytochrome c oxidase subunit I (COI), we detected and identified 234 prey items (individual captured by the spider) belonging to 96 operational taxonomic units (OTUs), as prey for this wandering predator. Our results broaden the known diet of P. boliviensis with at least 75 prey taxa not previously registered in fieldwork or laboratory experimental trials. These results suggest that P. boliviensis feeds predominantly on invertebrates (Diptera, Lepidoptera, Coleoptera, and Orthoptera) and opportunistically on small squamates. Intersex and interpopulation differences were also observed. Assuming that prey preference does not vary between populations, these differences are likely associated with a higher local prey availability. Finally, we suggest that DNA metabarcoding can be used for evaluating subtle differences in the diet of distinct populations of P. boliviensis, particularly when predation records in the field cannot be established or quantified using direct observation.

Density and diversity of macroinvertebrates in Colombian Andean streams impacted by mining, agriculture and cattle production.

BACKGROUND: Mining, agriculture and cattle production are activities that threaten the quality and quantity of water resources in the Colombian Andes. However, many drainage basins in this region have not been subjected to simultaneous evaluation of the impact these activities have on the density, diversity and composition of aquatic macroinvertebrates (AMI). The first two of these ecological variables are expected to decrease drastically from zones with no apparent impact towards areas with anthropogenic activity, which areas with mining will present the most impoverished AMI community. METHODS: We evaluated the density, diversity and composition dissimilarity of AMI in streams impacted by gold mining, agriculture and cattle production. Two reference streams were also studied. Six benthic samplings were conducted bimonthly (Feb 2014-Feb 2015) using a Surber net. Water samples were taken in order to make environmental evaluation among the aforementioned streams, including hydrological, physicochemical and bacteriological parameters (HPCB). Diversity was evaluated as the effective number of RTUs-recognizable taxonomic units-by comparing the richness, typical diversity, and effective number of the most abundant RTUs. Compositional dissimilarity was examined with nMDS and CCA analysis. RESULTS: A total of 7,483 organisms were collected: 14 orders, 42 families and 71 RTUs. Our prediction regarding the density and diversity of AMI (Reference > Cattle production > Agriculture > Mining) was partially fulfilled, since the agriculture-dominated stream presented a more impoverished AMI community than that of the gold mining stream. However, these streams presented lower diversity than the cattle production and reference streams, and the AMI density only differed significantly between one reference stream and the agriculture stream. The AMI composition in the agriculture-dominated stream clearly differed from that of the other streams. DISCUSSION: The observation of a more impoverished AMI community in agricultural production areas compared to those with mining or cattle production may reflect the importance of the remaining riparian vegetation, which was scarce at the stream with agricultural activity. Moreover, the low diversity, and mainly the reduced AMI richness, in the agriculture stream coincided with the absence of insect genera are intolerant to deterioration of the biological and physicochemical conditions of the water (e.g. Anacroneuria). CONCLUSIONS: The results suggest that the local impact of agricultural activities may be of equal or greater magnitude than that of mining in terms of AMI density, diversity and composition, in the Colombian Andean riverscape. Future studies should systematically evaluate, throughout the annual cycle, the relative effects of the productive land use, the remaining native vegetation cover and the consequent changes in the HPCB parameters of the water on AMI communities in Colombian Andean basins.

Distribution and habitat use intensity of the Neotropical Otter (Lontra longicaudis) in a Colombian hydroelectric dam

Introduction: The Neotropical Otter, Lontra longicaudis, is a semi-aquatic mammal that ranges from Mexico to Argentina inhabiting near-pristine watercourses, but also human-dominated aquatic and riparian landscapes. Objective: We assessed the distribution and habitat use frequency of L. longicaudis in La Miel I hydroelectric power dam and its influence area in the Department of Caldas, Colombia. Methods: We carried out diurnal surveys across standardized transects between 2014 and 2018 looking for records (sightings, faeces, tracks, and dens) that indicate the presence of the species. Each yearly survey was done during 12 consecutive days over three seasonal sampling periods assessing the upstream, reservoir, and downstream waterscape areas. Results: We sampled a total of 875 km in a five-year period across the three main waterscape areas (upstream -103 km, reservoir -582 km, and downstream -190 km) registering a total of 1 496 records. Faeces were the most common record (~ 95 %) across the whole study area followed by sightings, dens (1.7 % each), and tracks (1.3 %). Spatial distribution analyses suggest that L. longicaudis prefers dwelling upstream watercourses (hot spots areas; Gi Z-score = 4.46, p < 0.001) and in a lesser extent, areas around the water reservoir (cold spot areas; Gi Z-score = -2.69, p = 0.007). Signs of otters were also recorded at downstream area, but these records were non-significant within the analysis (Gi Z-score = -0.11, p = 0.48), suggesting L. longicaudis uses this area opportunistically. Cluster and outlier analysis showed that even though L. longicaudis was commonly found upstream and in the reservoir area, only some specific sectors (Moro, La Miel and Tasajos rivers) had high (LMI Z-score = 5.63, p = 0.001) and low (LMI Z-score = 2.12, p = 0.001) clusters. Conclusions: The upstream waterscape area is key for the survival of L. longicaudis in this regulated system, likely providing enough shelter and food for the species to carry out living activities and have resident populations. In contrast, downstream areas require specific attention to understand in a better way the effects of caused by the dam on the species dynamics, also defining management strategies that avoid population fragmentation and movement reduction.

Introducción : La nutria neotropical Lontra longicaudis, es un mamífero semiacuático que se distribuye desde México hasta Argentina; habita en paisajes acuáticos y ribereños prístinos, pero también hábitats dominados por el hombre. Objetivo : Se evaluó la distribución e intensidad de uso del hábitat de L. longicaudis en la hidroeléctrica La Miel I y su área de influencia en el Departamento de Caldas, Colombia. Métodos: Se realizaron transectos diurnos estandarizados entre 2014 y 2018 en busca de registros (avistamientos, heces, huellas y madrigueras) que indicaban la presencia de la especie. Cada muestreo anual se realizó durante 12 días consecutivos en tres períodos de muestreo estacional (36 días), evaluando las áreas aguas arriba, el embalse y aguas abajo de la presa. Resultados : Se muestreó un total de 875 km a través de las tres áreas principales con un total de 1 496 rastros. Las heces fueron el registro más común (~ 95 %) en toda el área de estudio, seguido de avistamientos, madrigueras (1.7 % cada una), y huellas (1.3 %). Los análisis de distribución espacial sugieren que L. longicaudis prefiere los afluentes aguas arriba (áreas de puntos calientes; Gi Z-score = 4.46, p < 0.001) y, en menor medida, las zonas alrededor del embalse (áreas de puntos fríos; Gi Z-score = -2.69, p = 0.007). El área aguas abajo también mostró presencia de nutrias; sin embargo, esos registros no fueron significativos dentro del análisis (Gi Z-score = -0.11, p = 0.48), sugiriendo que L. longicaudis usa esta área esporádicamente. El análisis de conglomerados y datos atípicos mostró que, aunque L. longicaudis se encuentra comúnmente aguas arriba y en el área del embalse, solo algunos sectores específicos (ríos Moro, La Miel y Tasajos) tienen valores altos (LMI Z-score = 5.63, p= 0.001) y bajos (LMI Z-score = 2.12, p = 0.001) de conglomerados. Conclusiones : El paisaje y las características hidrológicas aguas arriba son claves para la supervivencia de la nutria neotropical en este sistema regulado, probablemente aportando suficiente refugio y alimento para que la especie lleve a cabo sus actividades vitales, permitiéndole tener poblaciones residentes. Se debe enfocar la atención en la zona aguas abajo para comprender el efecto de la presa en la dinámica de la especie, definiendo estrategias de manejo que eviten la fragmentación de la población y la reducción de los movimientos.

Prey and Venom Efficacy of Male and Female Wandering Spider, Phoneutria boliviensis (Araneae: Ctenidae).

Spiders rely on venom to catch prey and few species are even capable of capturing vertebrates. The majority of spiders are generalist predators, possessing complex venom, in which different toxins seem to target different types of prey. In this study, we focused on the trophic ecology and venom toxicity of Phoneutria boliviensis F. O. Pickard-Cambridge, 1897, a Central American spider of medical importance. We tested the hypothesis that its venom is adapted to catch vertebrate prey by studying its trophic ecology and venom toxicity against selected vertebrate and invertebrate prey. We compared both trophic ecology (based on acceptance experiments) and toxicity (based on bioassays) among sexes of this species. We found that P. boliviensis accepted geckos, spiders, and cockroaches as prey, but rejected frogs. There was no difference in acceptance between males and females. The venom of P. boliviensis was far more efficient against vertebrate (geckos) than invertebrate (spiders) prey in both immobilization time and LD50. Surprisingly, venom of males was more efficient than that of females. Our results suggest that P. boliviensis has adapted its venom to catch vertebrates, which may explain its toxicity to humans.

Photafish system: An affordable device for fish photography in the wild.

This paper describes the Photafish System, an innovative technique for capturing high-quality digital images of live freshwater fishes and other aquatic organisms in the field. This system may improve and facilitate the visual documentation of such organisms to illustrate guidebooks, populate online databases and support scientific papers, particularly taxonomic ones. The system was designed and tested to produce Taxonomically Informative Photos (TIPs) of living specimens and employs an Aquarium Assembly for Photography (AAP) distinguished by its portability and low cost. Using Neotropical freshwater fishes as a model, we propose an optimized protocol for documenting the morphology of live specimens to support taxonomy, as well as awareness and conservation of freshwater biodiversity. This paper addresses the technical aspects and challenges of field studio photography in remote locations. Tricks gleaned from personal experiences with nature photography are also shared. Finally, we briefly discuss the advantages and weaknesses of our approach.

Conocimiento popular y perspectivas de conservación sobre las tortugas continentales en la parte baja del río la miel(colombia) / Popular knowledge and conservation perspectives on the inland turtles at the lower part of la miel river(colombia)

La parte baja de la cuenca del río La Miel está ubicada al nororiente del departamento de Caldas y alberga cinco de las especies de tortugas continentales registradas para Colombia. Durante mayo a septiembre de 2014 se recopiló información mediante la aplicación de un cuestionario semiestructurado a 101 residentes de la cuenca hidrográfica, acerca del conocimiento y uso de las tortugas (alimento, comercio y mascota) en la zona. La encuesta incluyó información personal de acuerdo con el sexo, ocupación principal (ama de casa, pescador/lanchero, agricultor/jornalero, mayordomo), tipo de habitante (nativos, extranjeros) y conocimiento y uso de las tortugas. Los resultados sugieren que las tortugas de agua dulce en la zona de estudio, se han reducido debido a una aparente larga historia de utilización por el hombre; principalmente para alimento, uso como mascotas y ocasionalmente por el comercio. Sin embargo, estos datos también sugieren que a pesar del impacto humano el río La Miel podría concentrar un número alto de tortugas a lo largo de la cuenca, lo que resalta la importancia de este sistema acuático como uno de los hábitats más importantes para la conservación de las tortugas de agua dulce en el país. Asimismo, los resultados muestran algunas relaciones relevantes hombre-fauna silvestre, que pueden ser utilizadas para avanzar en nuevos esfuerzos hacia la gestión de la conservación de las tortugas de agua dulce bajo un contexto local y nacional.

The lower part of La Miel River, located at the north-east of the Department of Caldas, hosts five Colombian inland turtle species. Information about knowledge and turtles' use (for food, trade, or pets) was recorded using a semi-structured questionnaire applied to 101 watershed residents, from May to September 2014. The survey included personal, knowledge, and use information accordingly to sex, principal work (housewife, fisherman/boatman, farmer/laborer, steward) and inhabitant type (native, foreign). Our results suggest that freshwater turtles in the study area have declined due an apparent long history of human consumption; mainly for food, pet, and occasionally for trade. However, these data also suggest that despite human impact, La Miel River could support a large number of turtles along the basin, underscoring the importance of this aquatic system as one of the most important habitats for the conservation of freshwater turtles in the country. In addition, our results illustrate some relevant human-wildlife relationships, which can be used to advance new efforts toward freshwater turtle management under local and national context.

APORTE DE HOJARASCA DEL MANGLE NEGRO (Avicennia germinans L. ) EN EL CARIBE COLOMBIANO / CONTRIBUTION OF BLACK MANGROVE (Avicennia germinans L. ) FALLEN LEAVES IN THE COLOMBIAN CARIBBEAN AREA

A pesar que los manglares son reconocidos a nivel mundial como ecosistemas altamente productivos y ecológicamente importantes, en la actualidad, su extensión se ha reducido significativamente debido a las actividades humanas en las zonas costeras. Por lo tanto, es necesario investigar su dinámica y respuestas bajo el creciente y sostenido impacto del cambio climático y antropogénico. Durante dos estaciones climáticas contrastantes (sequía, lluvia) se estudió la producción de hojarasca del mangle negro Avicennia germinans L. en la bahía El Uno cerca al municipio de Turbo, noroccidente de Colombia (8º N). El aporte de materia orgánica fue separado por estructuras (hojas, ramas, flores y frutos) donde se registró un aporte significativamente mayor de hojas. La biomasa seca total durante ambas estaciones fue de 7,09±9,66 y 5,36±5,67 g m-2día-1. Los valores mínimos y máximos fueron de 0,63-8 y 0,49-3,65 g m-2día-1 durante la estación seca y lluviosa, respectivamente. Se detectaron diferencias significativas entre las estructuras orgánicas pero no entre las estaciones climáticas analizadas. Se discuten algunos impactos naturales y antropogénicos pasados y actuales, que afectan la dinámica de los manglares, al igual que la importancia de la producción de hojarasca para la productividad primaria y secundaria, en zonas altamente perturbadas del Caribe colombiano.

Although mangroves are recognized worldwide as highly productive and ecologically important ecosystems , at present its extent has been significantly reduced due to human activities in coastal areas. Therefore, it is necessary to investigate their dynamics and responses under the growing and sustained climatic and anthropogenic impacts. During two contrasting seasons (drought, rain) the fallen leaves production of the black mangrove Avicennia germinans L. was investigated at El Uno Bay, near Turbo Municipality, North-Western Colombia (8º N). Organic matter input was sorted by structure (leaves, branches, flowers, fruits) with leaves registering the highest significant values. Total dry biomass during both seasons was 7.09±9.66 and 5.36±5.67 g m-2day-1. The lowest and highest organic matter values were 0.63-8 and 0.49-3.65 g m-2day-1 during the dry and rainy season, respectively. Significant differences between organic structures but not between seasons analyzed were detected. Some relevant past and present natural and anthropogenic impacts affecting the mangroves dynamics are discussed, as well as the importance of fallen leaves input to the primary and secondary production in highly disturbed zones of the Colombian Caribbean area.

Evaluación ambinntal estratégica para cuencas pioritarias de los andes Colombiianos: dilemas, desafíos y necesidades / Strategic Environmental Assessment for Priority Basins of the Colombian Andes: Dilemmas, Challenges and Necessities

En Colombia muchos ríos y otros sistemas acuáticos continentales, especialmente en la región Andina (la más poblada del país), sufren varios impactos antropogénicos relacionados con cambios en la cobertura vegetal y el uso y manejo del suelo, que comprometen su calidad y cantidad de agua, y el suministro de otros bienes y servicios ecosistémicos para el futuro. Es necesario que el gobierno colombiano formule nuevas y actualice las políticas, planes o programas, en consulta y cooperación constante con otras instituciones, autoridades civiles y ambientales, e investigadores del país (o del exterior), para alcanzar una corresponsabilidad sobre la gestión sostenible de los ríos en esta región. Esto permitiráimplementar una evaluación más integral de la cuenca y de otros aspectos ribereños, para el uso y manejo del agua dulce, en los actuales, o antes del inicio de nuevos proyectos de desarrollo. La toma de decisión sobre soluciones concertadas se debe integrar desde el nivel más bajo posible, e idealmente con participación de todos los grupos de interés, en un marco de evaluación ambiental estratégica (EAE). En este artículo se plantea una reflexión sobre cómo todos los colombianos y particularmente aquellos de la región Andina, pueden contribuir conjuntamente con el gobierno bajo la visión e implementación de una EAE, para lograr una gestión sostenible, eficaz e integrada, de las cuencas hidrográficas de dicha región y del país en general. Para apoyar la reflexión, se destacan algunos aspectos biofísicos y sociales relativos de la cuenca del río Coello en la zona central del país (departamento del Tolima).

In Colombia many rivers and other inland aquatic systems, especially into the Andean Region (the most populated of the country), suffer several anthropogenic impacts related to land use and land cover compromising their water quality and quantity, and the provision of other goods and ecosystem services for the future. It is imperative that the Colombian government may initiate new and updated policies, plans, programs in constant consultation and cooperation with other institutions, civilian and environmental authorities, and researchers from the country (or elsewhere), to obtain amply responsibility on the sustainable river management, especially in this region. Thus, a more integrative watershed river assessment and related riverine issues are necessaries for the current freshwater use and management, and before that new development projects going to start. Decision making regarding concerted solutions should be carried out at the lowest appropriate level, ideally involving all stakeholders into a strategic environmental assessment framework (SEA). This article discusses several issues about how all Colombians and mainly Andean people, can contribute by working together in partnerships with government under the vision and implementation of a SEA, towards a more effective and integrated sustainable management of river basins in the Andean Region and throughout country. This point-of-view is supported by a biophysical and social vision related to the Coello River Basin in Central Colombia (Department of Tolima).

Trophic interactions of the endangered Southern river otter (Lontra provocax) in a Chilean Ramsar wetland inferred from prey sampling, fecal analysis, and stable isotopes.

Non-invasive methodological approaches are highly recommended and commonly used to study the feeding ecology of elusive and threatened mammals. In this study, we use multiple lines of evidence to assess the feeding strategies of the endangered Southern river otter, by determining seasonal prey availability (electrofishing), analysis of undigested prey remains (spraints), and the use of stable isotopes (δ(15)N and δ(13)C) in otter spraints (n = 262) and prey in a wetland ecosystem of southern Chile (39°49'S, 73°15'W). Fecal and isotopic analyses suggest that the otter diet is restricted to a few prey items, particularly the less-mobile, bottom-living, and larger prey such as crayfish (Samastacus spinifrons, 86.11%) and crabs (Aegla spp., 32.45%), supplemented opportunistically by cyprinids (Cyprinus carpio, 9.55%) and catfish (Diplomystes camposensis, 5.66%). The results suggest that the river otter is highly specialized in bottom foraging. Isotopic signatures of food sources and feces revealed a mid-upper trophic position for the Southern river otter, with either higher or lower δ(15)N values than their potential prey items. δ(13)C values for river otters were less enriched than their potential food resources. We suggest that due to their narrow trophic niche and possible dependence on only a few food items, this species may be highly vulnerable to the reduction in its prey populations. Finally, maintaining the ecological interactions between Southern river otters and their prey is considered a central priority for the survival of this endangered carnivore mammal.

Hardening of the national flower of Colombia, the threatened Cattleya trianae (Orchidaceae), from in vitro culture with previous invigoration phase

Cattleya trianae is an endemic species from the tropical rainforest in the Colombian Andes. Its survival is currently threatened due to habitat loss and commercial overexploitation. This study evaluates ten substrates, some organic (pine bark, coconut fiber and wood shavings), some inert icopor (polystyrene foam), vegetable coal and their combinations, and the effects these have on morphometric and phenotypic traits in the hardening phase of 250 plants of C. trianae cultivated in vitro. Recorded data include percent survival, length of longest leaf, biomass (wet weight) and number of roots and leaves at the beginning and at the end of the experiment. After the hardening phase, the plants were taken to a greenhouse and later to the natural environment. Coconut fiber alone or mixed in equal parts with pine bark and coal was the most efficient substrate when percent survival (80±SE=0.3742), biomass, and leaf length were evaluated. Hardened plants displayed qualitative characteristics such as vigor, hardness and waxy texture, strength of green coloration in the leaves, and velamen formation. Under greenhouse conditions, plants grew better with filtered light, relative humidity bordering on 80 %, permanent aeration, misting with water, and an average temperature of 25±2 °C. Invigorated plants were firmly anchored on their host trees. Rev. Biol. Trop. 55 (2): 681-691. Epub 2007 June, 29.

Cattleya trianae es una especie endémica de los bosques tropicales de los Andes colombianos. Actualmente se encuentra amenazada por la disminución de su hábitat natural y la sobreexplotación con fines comerciales. En este estudio se evaluó el efecto de diez tratamientos con sustratos biológicos (corteza de pino, fibra de coco y viruta) e inertes (esferitas de "icopor" y carbón vegetal) en diferentes combinaciones, sobre aspectos morfométricos y fenotípicos en la etapa de endurecimiento de 250 vitroplantas de C. trianae. Se registró porcentaje de supervivencia, longitud de la hoja, biomasa en peso fresco, número de raíces y hojas al inicio y al final del experimento. Al finalizar la fase de endurecimiento, las vitroplantas fueron llevadas a invernadero y posteriormente a ambiente natural. La fibra de coco sola ó mezclada en partes iguales con pino y carbón vegetal, fue el sustrato más eficiente cuando se evaluó el porcentaje de supervivencia (80 % ±SE=0.3742), biomasa en peso fresco y longitud de hoja. Las plantas endurecidas mostraron características cualitativas como vigorosidad, textura coriácea y cerosa, verdor intenso en sus hojas y velamen. En condiciones de invernadero las plantas se desarrollan mejor con luz filtrada, humedad relativa alrededor del 80 %, aireación continua, nebulización y temperatura promedio de 25±2 °C. Las plantas vigorizadas mostraron buen anclaje y adaptación en árboles.

Hardening of the national flower of Colombia, the threatened Cattleya trianae (Orchidaceae), from in vitro culture with previous invigoration phase.

Cattleya trianae is an endemic species from the tropical rainforest in the Colombian Andes. Its survival is currently threatened due to habitat loss and commercial overexploitation. This study evaluates ten substrates, some organic (pine bark, coconut fiber and wood shavings), some inert icopor (polystyrene foam), vegetable coal and their combinations, and the effects these have on morphometric and phenotypic traits in the hardening phase of 250 plants of C. trianae cultivated in vitro. Recorded data include percent survival, length of longest leaf, biomass (wet weight) and number of roots and leaves at the beginning and at the end of the experiment. After the hardening phase, the plants were taken to a greenhouse and later to the natural environment. Coconut fiber alone or mixed in equal parts with pine bark and coal was the most efficient substrate when percent survival (80+/-SE=0.3742), biomass, and leaf length were evaluated. Hardened plants displayed qualitative characteristics such as vigor, hardness and waxy texture, strength of green coloration in the leaves, and velamen formation. Under greenhouse conditions, plants grew better with filtered light, relative humidity bordering on 80 %, permanent aeration, misting with water, and an average temperature of 25+/-2 degrees C. Invigorated plants were firmly anchored on their host trees.