Resumen: Del estudio de la taxonomía, la historia natural y la ecología como principales ramas de... more Resumen: Del estudio de la taxonomía, la historia natural y la ecología como principales ramas de la investigación de los fenómenos naturales hemos pasado rápidamente a preocuparnos por generar la ciencia de la conservación, ya que en los últimos 70 años ha venido creciendo la cantidad de especies en peligro alrededor de mundo. Los anfibios son uno de los grupos más amenazados, por una serie de factores ambientales y humanos, lo que ha diezmado a muchas especies de estos vertebrados. Afortunadamente, además de que muchas especies han logrado sobreponerse, existen una serie de acciones, pilares de la conservación, las cuales han mostrado su efectividad en mejorar las condiciones de los anfibios. Aplicar estas acciones para evitar la desaparición de más especies es uno de los principales retos de la conservación en la actualidad. Conocer, coordinar y aplicar los esfuerzos y estrategias provenientes de diferentes actores sociales y ramas de la ciencia puede llevar a los nuevos investig...
Introducción: El sapo arlequín, Atelopus varius, se encuentra en peligro crítico y fue declarada ... more Introducción: El sapo arlequín, Atelopus varius, se encuentra en peligro crítico y fue declarada “aparentemente extinta” en Costa Rica en 1996. Una de las posibles causas fue el hongo patógeno Batrachochytrium dendrobatidis. En 2008 se redescubrió una población viva en Las Tablas y aquí analizamos la situación con este hongo. Objetivo: Evaluar prevalencia y probabilidad de infección del sapo por B. dendrobatidis. Métodos: Se recolectaron hisopados de piel de individuos vivos (para pruebas de ADN) y trozos histológicos de individuos muertos (para observación microscópica directa). Resultados: De 363 animales, solo el 6% tenía el hongo, particularmente los subadultos. Conclusión: La población de sapos parece estable, pero se debe tener cuidado de no propagar el hongo, aunque este sea actualmente escaso.
Amphibians are globally threatened by emerging infectious diseases, and ranaviruses are among the... more Amphibians are globally threatened by emerging infectious diseases, and ranaviruses are among the most concerning pathogens to threaten species in the wild. We sampled for ranaviruses in wild amphibians at 8 sites in Costa Rica, spanning broad climatic zones and taxonomic associations. Seven of these sites are inhabited by highly threatened amphibian species that persist at low global population sizes after population declines due to amphibian chytridiomycosis. One of the surveyed sites is occupied by an introduced amphibian species, which is relatively rare in Central America but may be an important pathway for long-distance transport of ranaviruses. We detected ranavirus using quantitative polymerase chain reaction in 16.3% of the 243 individuals and among 5 of our 8 sites, but not at the site with the introduced species. Infection prevalence varied among species and sites, but not with mean annual temperature or mean annual precipitation. Infection intensity did not vary with spe...
Amphibians have declined around the world in recent years, in parallel with the emergence of an e... more Amphibians have declined around the world in recent years, in parallel with the emergence of an epidermal disease called chytridiomycosis, caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). This disease has been associated with mass mortality in amphibians worldwide, including in Costa Rica, and Bd is considered an important contributor to the disappearance of this group of vertebrates. While many species are susceptible to the disease, others show tolerance and manage to survive infection with the pathogen. We evaluated the pathogen Bd circulating in Costa Rica and the capacity of amphibian skin bacteria to inhibit the growth of the pathogen in vitro. We isolated and characterized – genetically and morphologically – several Bd isolates from areas with declining populations of amphibians. We determined that the circulating chytrid fungus in Costa Rica belongs to the virulent strain Bd-GPL-2, which has been related to massive amphibian deaths worldwide; however, the is...
C O N S E R V A T I O N A L E R T World’s Mammals in Crisis ...................................... more C O N S E R V A T I O N A L E R T World’s Mammals in Crisis ............................................................................................................................................................. 220 More Than Mammals ...................................................................................................................................................................... 223 The “Dow Jones Index” of Biodiversity ........................................................................................................................................... 225
A new species of hylid frog is described from Tapir Valley Nature Reserve, located on the Caribbe... more A new species of hylid frog is described from Tapir Valley Nature Reserve, located on the Caribbean slope of Tenorio Volcano in Bijagua, Alajuela Province, Costa Rica. A molecular phylogenetic analysis supports its inclusion in the genus Tlalocohyla. Morphological, morphometric, larval, and acoustic characteristics further distinguish it from other species in the genus and support its uniqueness. The new species is closely related to T. picta and T. smithii, and is separated by at least 500 kilometers from the nearest known occurrence of a population of T. picta in southern Honduras. The new species is readily distinguished from all other Tlalocohyla by its brilliant green coloration marked with a pronounced, incomplete light dorsolateral stripe that is bordered above by a diffuse reddish-brown stripe. Its dorsum is marked with bold reddish brown spots and its ventral skin is fully transparent. This new Tlalocohyla is currently only known from the type locality, where it inhabits a ...
Amphibian skin is a suitable environment for rich communities of microorganisms, both beneficial ... more Amphibian skin is a suitable environment for rich communities of microorganisms, both beneficial and detrimental to the host. The amphibian cutaneous microbiota has been hypothesized to play an important role as symbionts, protecting their hosts against disease. Costa Rica has one of the most diverse assemblages of amphibians in the world and we know very little about the microbiota of these tropical animals. For comparison with other studies, we explore the diversity of the skin bacterial communities employing16S rRNA amplicon sequencing of swab samples from twelve species of frogs at La Selva Biological Station in Sarapiquí, Heredia province. The predominant phylum detected in our studies was Proteobacteria, followed by Bacteroidetes and Actinobacteria, with these three phyla representing 89.9% of the total bacterial taxa. At the family level, Sphingobacteriaceae and Comamonadaceae were highly represented among samples. Our results suggest that host species and host family are sig...
is a toad native to South America that has been introduced in the Antilles, likely carrying high ... more is a toad native to South America that has been introduced in the Antilles, likely carrying high loads of microorganisms, potentially impacting local community diversity. The amphibian skin is involved in pathogen defense and its microbiota has been relatively well studied, however, research focusing on the cane toad microbiota is lacking. We hypothesize that the skin microbial communities will differ between toads inhabiting different geographical regions in Central America and the Caribbean. To test our hypothesis, we compared the microbiota of three populations oftoads, two from Costa Rican (native) and one Puerto Rican (exotic) locations. In Costa Rica, we collected 11 toads, 7 in Sarapiquí and 4 from Turrialba while in Puerto Rico, 10 animals were collected in Santa Ana. Separate swab samples were collected from the dorsal and ventral sites resulting in 42 samples. We found significant differences in the structure of the microbial communities between Puerto Rico and Costa Rica....
Global amphibian declines and extinction events are occurring at an unprecedented rate. While sev... more Global amphibian declines and extinction events are occurring at an unprecedented rate. While several factors are responsible for declines and extinction, the fungal pathogen Batrachochytrium dendrobatidis (Bd) has been cited as a major constituent in these events. While the effects of this chytrid fungus have been shown to cause broad scale population declines and extinctions, certain individuals and relict populations have shown resistance. This resistance has been attributed in part to the cutaneous bacterial microbiome. Here, we present the first study characterizing anti-Bd bacterial isolates from amphibian populations in Costa Rica, including the characterization of two strains of Serratia marcescens presenting strong anti-Bd activity. Transcriptome sequencing was utilized for delineation of shifts in gene expression of the two previously uncharacterized strains of S. marcescens grown in three different treatments comprising Bd, heat-killed Bd, and a no Bd control. These resul...
Changes in anuran (Amphibia: Anura) community composition in Cerro Chompipe, Costa Rica. Amphibia... more Changes in anuran (Amphibia: Anura) community composition in Cerro Chompipe, Costa Rica. Amphibian diversity in Costa Rica has declined over the past 40 years, mostly at higher elevations. Cerro Chompipe in the Central Volcanic Cordillera has suffered an extraordinary loss of these species. To measure the degree of contemporary impacts and their effects on anuran communities, I conducted diurnal and nocturnal amphibian surveys for one year at Cerro Chompipe and surrounding sites (from February 2010). Data were compared with species lists reported from the literature in the 1970s. In this survey I recorded only 7 of the 18 species reported originally for Cerro Chompipe, representing a 61% loss of diversity. The most common species recorded were Craugastor podiciferus, Diasporus hylaeformis, Isthmohyla picadoi, I. pseudopuma, Incilius holdridgei and Lithobates taylori. In this survey, the presence of I. holdridgei, a critically endangered toad, was confirmed. Different species composi...
In Costa Rica, the Premontane Forest is very reduced and fragmented for which its herpetofaunal c... more In Costa Rica, the Premontane Forest is very reduced and fragmented for which its herpetofaunal characterization is limited. The composition of amphibians and reptiles in El Rodeo zone (canton of Mora, San Jose, Costa Rica) was analyzed from samples taken during the years 2007 and 2008. A total of 80 species were recorded, of which 44 come from sampling and 36 correspond to specimens collected previously in the zone. The composition of herpetofauna of El Rodeo is a mixture that includes significant representation of species of Tropical Dry Forest and Tropical Moist Forest of the country, as well as of the Premontane Moist Forest. Similar to what occurs in dry forest during dry season of the year both amphibians and reptiles are found in the margins of rivers and in the rainy season are distributed throughout the forest. Environmental factors such as orography and zone seasonality have an influence in the distribution and detection of species inside of the dynamism of community. The obtained information increased to 125 species the knowledge of herpetofauna from Premontane Forest, many of which were abundant in Metropolitan Area and now are relegated to plantations, gardens or altered rivers in the cities. Monitoring surrounding areas with higher altitude will better understand consequences of fragmentation and forest loss on fauna of the Central Valley.
Some riparian forests and plantations in Metropolitan Area still have remnants of premontane fore... more Some riparian forests and plantations in Metropolitan Area still have remnants of premontane forest where there is a significant diversity of species of amphibians and reptiles, many of which have adapted to living near human settlements. El Rodeo zone, west of Central Valley, has an altitude and representative climate of areas of San Jose, Alajuela and Heredia, below 1 200 m. The natural history of many species found in El Rodeo helps to understand how they survive with increased urbanization. Amphibians are considered fragile groups to environmental perturbations, but at the same time many species are highly tolerant to habitat changes. Similarly, many reptiles such as snakes, are benefiting from their move to open areas or plantations, where their dams such as rodents may increase. Based on 25 families representing the herpetofauna of El Rodeo, information of natural history of each group in the Central Valley of the country is presented. The high contamination of Virilla basin river, garbage dumps and growing urbanization in this region constitute a serious threat to herpetofaunal diversity of the Central Valley. Resumen. Algunos bosques riparios y plantaciones del Área Metropolitana aún mantienen remanentes de Bosque Premontano donde existe una diversidad importante de especies de anfibios y reptiles, muchas de las cuales se han adaptado a vivir cerca de asentamientos humanos. La zona de El Rodeo, al oeste del Valle Central, presenta una altitud y clima representativo de los sectores de San José, Alajuela y Heredia, por debajo de los 1 200 m. La historia natural de muchas especies encontradas en El Rodeo ayuda a comprender como sobreviven ante el aumento del urbanismo. Los anfibios son considerados grupos frágiles a las perturbaciones del medio, pero a su vez muchas especies son altamente tolerantes a las modificaciones del
Resumen: Del estudio de la taxonomía, la historia natural y la ecología como principales ramas de... more Resumen: Del estudio de la taxonomía, la historia natural y la ecología como principales ramas de la investigación de los fenómenos naturales hemos pasado rápidamente a preocuparnos por generar la ciencia de la conservación, ya que en los últimos 70 años ha venido creciendo la cantidad de especies en peligro alrededor de mundo. Los anfibios son uno de los grupos más amenazados, por una serie de factores ambientales y humanos, lo que ha diezmado a muchas especies de estos vertebrados. Afortunadamente, además de que muchas especies han logrado sobreponerse, existen una serie de acciones, pilares de la conservación, las cuales han mostrado su efectividad en mejorar las condiciones de los anfibios. Aplicar estas acciones para evitar la desaparición de más especies es uno de los principales retos de la conservación en la actualidad. Conocer, coordinar y aplicar los esfuerzos y estrategias provenientes de diferentes actores sociales y ramas de la ciencia puede llevar a los nuevos investig...
Introducción: El sapo arlequín, Atelopus varius, se encuentra en peligro crítico y fue declarada ... more Introducción: El sapo arlequín, Atelopus varius, se encuentra en peligro crítico y fue declarada “aparentemente extinta” en Costa Rica en 1996. Una de las posibles causas fue el hongo patógeno Batrachochytrium dendrobatidis. En 2008 se redescubrió una población viva en Las Tablas y aquí analizamos la situación con este hongo. Objetivo: Evaluar prevalencia y probabilidad de infección del sapo por B. dendrobatidis. Métodos: Se recolectaron hisopados de piel de individuos vivos (para pruebas de ADN) y trozos histológicos de individuos muertos (para observación microscópica directa). Resultados: De 363 animales, solo el 6% tenía el hongo, particularmente los subadultos. Conclusión: La población de sapos parece estable, pero se debe tener cuidado de no propagar el hongo, aunque este sea actualmente escaso.
Amphibians are globally threatened by emerging infectious diseases, and ranaviruses are among the... more Amphibians are globally threatened by emerging infectious diseases, and ranaviruses are among the most concerning pathogens to threaten species in the wild. We sampled for ranaviruses in wild amphibians at 8 sites in Costa Rica, spanning broad climatic zones and taxonomic associations. Seven of these sites are inhabited by highly threatened amphibian species that persist at low global population sizes after population declines due to amphibian chytridiomycosis. One of the surveyed sites is occupied by an introduced amphibian species, which is relatively rare in Central America but may be an important pathway for long-distance transport of ranaviruses. We detected ranavirus using quantitative polymerase chain reaction in 16.3% of the 243 individuals and among 5 of our 8 sites, but not at the site with the introduced species. Infection prevalence varied among species and sites, but not with mean annual temperature or mean annual precipitation. Infection intensity did not vary with spe...
Amphibians have declined around the world in recent years, in parallel with the emergence of an e... more Amphibians have declined around the world in recent years, in parallel with the emergence of an epidermal disease called chytridiomycosis, caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). This disease has been associated with mass mortality in amphibians worldwide, including in Costa Rica, and Bd is considered an important contributor to the disappearance of this group of vertebrates. While many species are susceptible to the disease, others show tolerance and manage to survive infection with the pathogen. We evaluated the pathogen Bd circulating in Costa Rica and the capacity of amphibian skin bacteria to inhibit the growth of the pathogen in vitro. We isolated and characterized – genetically and morphologically – several Bd isolates from areas with declining populations of amphibians. We determined that the circulating chytrid fungus in Costa Rica belongs to the virulent strain Bd-GPL-2, which has been related to massive amphibian deaths worldwide; however, the is...
C O N S E R V A T I O N A L E R T World’s Mammals in Crisis ...................................... more C O N S E R V A T I O N A L E R T World’s Mammals in Crisis ............................................................................................................................................................. 220 More Than Mammals ...................................................................................................................................................................... 223 The “Dow Jones Index” of Biodiversity ........................................................................................................................................... 225
A new species of hylid frog is described from Tapir Valley Nature Reserve, located on the Caribbe... more A new species of hylid frog is described from Tapir Valley Nature Reserve, located on the Caribbean slope of Tenorio Volcano in Bijagua, Alajuela Province, Costa Rica. A molecular phylogenetic analysis supports its inclusion in the genus Tlalocohyla. Morphological, morphometric, larval, and acoustic characteristics further distinguish it from other species in the genus and support its uniqueness. The new species is closely related to T. picta and T. smithii, and is separated by at least 500 kilometers from the nearest known occurrence of a population of T. picta in southern Honduras. The new species is readily distinguished from all other Tlalocohyla by its brilliant green coloration marked with a pronounced, incomplete light dorsolateral stripe that is bordered above by a diffuse reddish-brown stripe. Its dorsum is marked with bold reddish brown spots and its ventral skin is fully transparent. This new Tlalocohyla is currently only known from the type locality, where it inhabits a ...
Amphibian skin is a suitable environment for rich communities of microorganisms, both beneficial ... more Amphibian skin is a suitable environment for rich communities of microorganisms, both beneficial and detrimental to the host. The amphibian cutaneous microbiota has been hypothesized to play an important role as symbionts, protecting their hosts against disease. Costa Rica has one of the most diverse assemblages of amphibians in the world and we know very little about the microbiota of these tropical animals. For comparison with other studies, we explore the diversity of the skin bacterial communities employing16S rRNA amplicon sequencing of swab samples from twelve species of frogs at La Selva Biological Station in Sarapiquí, Heredia province. The predominant phylum detected in our studies was Proteobacteria, followed by Bacteroidetes and Actinobacteria, with these three phyla representing 89.9% of the total bacterial taxa. At the family level, Sphingobacteriaceae and Comamonadaceae were highly represented among samples. Our results suggest that host species and host family are sig...
is a toad native to South America that has been introduced in the Antilles, likely carrying high ... more is a toad native to South America that has been introduced in the Antilles, likely carrying high loads of microorganisms, potentially impacting local community diversity. The amphibian skin is involved in pathogen defense and its microbiota has been relatively well studied, however, research focusing on the cane toad microbiota is lacking. We hypothesize that the skin microbial communities will differ between toads inhabiting different geographical regions in Central America and the Caribbean. To test our hypothesis, we compared the microbiota of three populations oftoads, two from Costa Rican (native) and one Puerto Rican (exotic) locations. In Costa Rica, we collected 11 toads, 7 in Sarapiquí and 4 from Turrialba while in Puerto Rico, 10 animals were collected in Santa Ana. Separate swab samples were collected from the dorsal and ventral sites resulting in 42 samples. We found significant differences in the structure of the microbial communities between Puerto Rico and Costa Rica....
Global amphibian declines and extinction events are occurring at an unprecedented rate. While sev... more Global amphibian declines and extinction events are occurring at an unprecedented rate. While several factors are responsible for declines and extinction, the fungal pathogen Batrachochytrium dendrobatidis (Bd) has been cited as a major constituent in these events. While the effects of this chytrid fungus have been shown to cause broad scale population declines and extinctions, certain individuals and relict populations have shown resistance. This resistance has been attributed in part to the cutaneous bacterial microbiome. Here, we present the first study characterizing anti-Bd bacterial isolates from amphibian populations in Costa Rica, including the characterization of two strains of Serratia marcescens presenting strong anti-Bd activity. Transcriptome sequencing was utilized for delineation of shifts in gene expression of the two previously uncharacterized strains of S. marcescens grown in three different treatments comprising Bd, heat-killed Bd, and a no Bd control. These resul...
Changes in anuran (Amphibia: Anura) community composition in Cerro Chompipe, Costa Rica. Amphibia... more Changes in anuran (Amphibia: Anura) community composition in Cerro Chompipe, Costa Rica. Amphibian diversity in Costa Rica has declined over the past 40 years, mostly at higher elevations. Cerro Chompipe in the Central Volcanic Cordillera has suffered an extraordinary loss of these species. To measure the degree of contemporary impacts and their effects on anuran communities, I conducted diurnal and nocturnal amphibian surveys for one year at Cerro Chompipe and surrounding sites (from February 2010). Data were compared with species lists reported from the literature in the 1970s. In this survey I recorded only 7 of the 18 species reported originally for Cerro Chompipe, representing a 61% loss of diversity. The most common species recorded were Craugastor podiciferus, Diasporus hylaeformis, Isthmohyla picadoi, I. pseudopuma, Incilius holdridgei and Lithobates taylori. In this survey, the presence of I. holdridgei, a critically endangered toad, was confirmed. Different species composi...
In Costa Rica, the Premontane Forest is very reduced and fragmented for which its herpetofaunal c... more In Costa Rica, the Premontane Forest is very reduced and fragmented for which its herpetofaunal characterization is limited. The composition of amphibians and reptiles in El Rodeo zone (canton of Mora, San Jose, Costa Rica) was analyzed from samples taken during the years 2007 and 2008. A total of 80 species were recorded, of which 44 come from sampling and 36 correspond to specimens collected previously in the zone. The composition of herpetofauna of El Rodeo is a mixture that includes significant representation of species of Tropical Dry Forest and Tropical Moist Forest of the country, as well as of the Premontane Moist Forest. Similar to what occurs in dry forest during dry season of the year both amphibians and reptiles are found in the margins of rivers and in the rainy season are distributed throughout the forest. Environmental factors such as orography and zone seasonality have an influence in the distribution and detection of species inside of the dynamism of community. The obtained information increased to 125 species the knowledge of herpetofauna from Premontane Forest, many of which were abundant in Metropolitan Area and now are relegated to plantations, gardens or altered rivers in the cities. Monitoring surrounding areas with higher altitude will better understand consequences of fragmentation and forest loss on fauna of the Central Valley.
Some riparian forests and plantations in Metropolitan Area still have remnants of premontane fore... more Some riparian forests and plantations in Metropolitan Area still have remnants of premontane forest where there is a significant diversity of species of amphibians and reptiles, many of which have adapted to living near human settlements. El Rodeo zone, west of Central Valley, has an altitude and representative climate of areas of San Jose, Alajuela and Heredia, below 1 200 m. The natural history of many species found in El Rodeo helps to understand how they survive with increased urbanization. Amphibians are considered fragile groups to environmental perturbations, but at the same time many species are highly tolerant to habitat changes. Similarly, many reptiles such as snakes, are benefiting from their move to open areas or plantations, where their dams such as rodents may increase. Based on 25 families representing the herpetofauna of El Rodeo, information of natural history of each group in the Central Valley of the country is presented. The high contamination of Virilla basin river, garbage dumps and growing urbanization in this region constitute a serious threat to herpetofaunal diversity of the Central Valley. Resumen. Algunos bosques riparios y plantaciones del Área Metropolitana aún mantienen remanentes de Bosque Premontano donde existe una diversidad importante de especies de anfibios y reptiles, muchas de las cuales se han adaptado a vivir cerca de asentamientos humanos. La zona de El Rodeo, al oeste del Valle Central, presenta una altitud y clima representativo de los sectores de San José, Alajuela y Heredia, por debajo de los 1 200 m. La historia natural de muchas especies encontradas en El Rodeo ayuda a comprender como sobreviven ante el aumento del urbanismo. Los anfibios son considerados grupos frágiles a las perturbaciones del medio, pero a su vez muchas especies son altamente tolerantes a las modificaciones del
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