Juan M. Guayasamin

Juan M. Guayasamin
Universidad San Francisco de Quito (USFQ) · College of Biological and Environmental Sciences

PhD Evolutionary Biology

About

301
Publications
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Publications

Publications (301)
Article
Full-text available
The genus Atractus includes 146 species of cryptozoic snakes occurring from Panama to northeastern Argentina. Here, a molecular phylogeny of this genus is presented, which encompasses 29% (= 42; six are included here for the first time) of the species currently recognized. Morphological and phylogenetic support is found for three new species of gro...
Technical Report
Full-text available
This report on geology and geo diversity of the Amazon belongs to the: Science Panel for the Amazon/Amazon Assessment Report 2021 The Science Panel for the Amazon is an unprecedented initiative convened under the auspices of the United Nations Sustainable Development Solutions Network (SDSN). The SPA is composed of over 200 preeminent scientists a...
Article
Full-text available
Background The Tropical Andes is the world’s most biodiverse hotspot. This region contains >1,000 amphibian species, more than half of which are endemic. Herein we describe two new glassfrog species (Centrolenidae: Hyalinobatrachium ) that we discovered within relatively unexplored and isolated localities of the Ecuadorian Andes. Methods We employ...
Article
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En el presente trabajo, tuvimos como objetivo registrar la diversidad y distribución altitudinal de los anfibios de la cordillera de Toisán, en el noroccidente de Ecuador. Para ello, realizamos cuatro transectos de 400x4 metros (m), desde los 2536 hasta los 2911 metros sobre el nivel del mar (msnm). Nuestro muestreo abarcó los distintos microhábita...
Article
Full-text available
We describe a new species of terrestrial-breeding frog of the genus Noblella from the northwestern slopes of the Andes of Ecuador, in the province of Pichincha, Ecuador, and report a new locality for the recently described N. worleyae. We include a detailed description of the osteology of both species and discuss their phylogenetic relationships. T...
Article
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In 2008, Ecuador recognized the Constitutional Rights of Nature in a global first. This recognition implies a major shift in the human-nature relationship, from one between a subject with agency (humans) and an exploitable object (nature), to a more equilibrated relationship. However, the lack of a standard legal framework has left room for subject...
Book
Full-text available
The Science Panel for the Amazon (SPA) is an unprecedented initiative convened under the auspices of the United Nations Sustainable Development Solutions Network (SDSN). The SPA is composed of over 200 preeminent scientists and researchers from the eight Amazonian countries, French Guiana, and global partners. These experts came together to debate,...
Article
Full-text available
In recent decades, the development of new sampling techniques has allowed us to more easily collect novel samples that enrich our knowledge of the specimens we study. In this sense, audiovisual samples, especially acoustic signal recordings, have become an essential part of herpetological research. The correct storage of these specimens is key to s...
Chapter
Full-text available
Scientists have not been able to estimate, to the nearest order of magnitude, the number of species in the Amazon. Although the Amazon includes one of the largest forests in the world, it is also one of the least known biologically. Documenting its biodiversity is challenging because of its immense size, heterogeneity, and limited access. Based on...
Chapter
Full-text available
This Report provides a comprehensive, objective, open, transparent, systematic, and rigorous scientific assessment of the state of the Amazon’s ecosystems, current trends, and their implications for the long-term well-being of the region, as well as opportunities and policy relevant options for conservation and sustainable development.
Chapter
Full-text available
This Report provides a comprehensive, objective, open, transparent, systematic, and rigorous scientific assessment of the state of the Amazon’s ecosystems, current trends, and their implications for the long-term well-being of the region, as well as opportunities and policy relevant options for conservation and sustainable development.
Article
Galápagos marine iguanas are primarily associated with the marine environment and show special nutritional adaptations. They are the only lizards worldwide that forage on marine macroalgae. Until now, consumed algae have been identified by direct observations during their feeding activities and microscopic identification in faeces samples. In this...
Preprint
Full-text available
In 2008, Ecuador recognized the Constitutional Rights of Nature in a global first. This recognition implies a major shift in the human-nature relationship, from one between a subject with agency (humans) and an exploitable object (Nature), to a more equilibrated relationship of respect. However, the lack of a standard legal framework has left room...
Article
Full-text available
We provide several lines of evidence to delimit a new species of Hyloscirtus and define its phylogenetic position inside the Hyloscirtus bogotensis group. The new species is the sister taxon to Hyloscirtus mashpi and is related to a clade formed by H. alytolylax and a putative new species from the province of El Oro in, southwestern Ecuador. Hylosc...
Article
Full-text available
Shark fishing, driven by the fin trade, is the primary cause of global shark population declines. Here, we present a case study that exemplifies how industrial fisheries are likely depleting shark populations in the Eastern Tropical Pacific Ocean. In August 2017, the vessel Fu Yuan Yu Leng 999, of Chinese flag, was detained while crossing through t...
Article
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"Cochranella" megista is an Endangered and rarely encountered species of glass frog that, until now, had been only registered in the Colombian Andes. Here we report this species for the first time in Ecuador expanding its known distribution ca. 530 km south of its original range. Additionally, we include C. megista in a molecular phylogeny for the...
Article
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The human ingestion of mercury (Hg) from sea food is of big concern worldwide due to adverse health effects, and more specifically if shark consumption constitutes a regular part of the human diet. In this study, the total mercury (THg) concentration in muscle tissue were determined in six sympatric shark species found in a fishing vessel seized in...
Article
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Ecuador is one of the most biodiverse countries in the world, but faces severe pressures and threats to its natural ecosystems. Numerous species have declined and require to be objectively evaluated and quantified, as a step towards the development of conservation strategies. Herein, we present an updated National Red List Assessment for amphibian...
Article
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Herein we report the second known record of Emmochliophis fugleri Fritts & Smith, 1969, present the first color images of the species, extend its known distribution and elevational range, provide the snout-vent and tail lengths of the holotype, and demonstrate that the condition of fused prefrontals is an unreliable diagnostic character for the gen...
Article
Full-text available
Parental care is costly, thus theory predicts that parents should avoid caring for unrelated offspring. However, alloparenting has been reported in many taxa because it may increase the caregiver mating success or offspring survival. We experimentally investigated the existence of allopaternal care in two glassfrog species, Hyalinobatrachium chirri...
Article
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We describe a new glandular terrestrial frog of the Pristimantis (Anura: Craugastoridae) genus. The new species inhabits the high montane forests of the Cañar province in southern Ecuador. It differs from other terrestrial frogs by having a striking dark gray and red dorsal coloration, dorsal skin with a corrugated texture, a small tubercle on the...
Book
We present the book “Reptiles of Ecuador,” a comprehensive monographic catalogue about every single one of Ecuador’s 485 non-avian reptiles. This updated field guide is designed to be used primarily as tool to identify species in the field and is written so that it can be easily understood by any reader. It includes photographs, illustrations, and...
Preprint
Full-text available
International socioeconomic relationships form the background that underlies the history of invasive species. Species with economic value, such as the North American bullfrog (Lithobates catesbeianus), are more likely to become internationally distributed and to be subsequently introduced to non-native areas and, consequently, become more difficult...
Article
Full-text available
Although most male frogs call to attract females, vocalizations alone can be ineffective long-range signals in certain environments. To increase conspicuousness and counter the background noise generated by rushing water, a few frog species around the world have evolved visual communication modalities in addition to advertisement calls. These speci...
Article
Full-text available
A fundamental gap in climate change vulnerability research is an understanding of the relative thermal sensitivity of ectotherms. Aquatic insects are vital to stream ecosystem function and biodiversity but insufficiently studied with respect to their thermal physiology. With global temperatures rising at an unprecedented rate, it is imperative that...
Chapter
This book is designed to be used as a field guide by anyone interested in the reptiles of Ecuador. The information is presented in the form of individual accounts to help identify each species of reptiles in Ecuador.
Article
Full-text available
With the third most biodiverse amphibian fauna in the world, Ecuador has bolstered this claim with a particularly high rate of species descriptions in recent years. Many of the species being described are already facing anthropogenic threats despite being discovered within privately protected reserves in areas previously not sampled. Herein we desc...
Article
Taxon names are at the core of communication related to biodiversity. Thus, systems that regulate such names should prevent unnecessary changes. Unfortunately, the current regulatory codes have some articles that produce confusion or, even, generate name instability. To promote nomenclatural stability, while maintaining a system that effectively co...
Article
Full-text available
The recently established Río Manduriacu Reserve, located on the Andean slopes in northwestern Ecuador, has proven to be a site of high conservation importance for amphibians. It harbors a range of threatened species, including the only known population of the Critically Endangered Tandayapa Andes Toad, Rhaebo olallai, as well as those of two recent...
Article
Full-text available
Glassfrogs (family: Centrolenidae) represent a fantastic radiation (~150 described species) of Neotropical anurans that originated in South America and dispersed into Central America. In this study, we review the systematics of Ecuadorian glassfrogs, providing species accounts of all 60 species, including three new species described herein. For all...
Article
Full-text available
Aquaculture, the farming of fish for human consumption and/or trade, is a growing industry throughout the world. The effects of farming on local ecosystems and wildlife are understudied, particularly in regions where farms are often limited to subsistence practices with little to no government regulation. The influence of Rainbow Trout (Oncorhynchu...
Article
We present data showing that the number of salamander species in Amazonia is vastly underestimated. We used DNA sequences of up to five genes (3 mitochondrial and 2 nuclear) of 366 specimens, 189 corresponding to 89 non-Amazonian nominal species and 177 Amazonian specimens, including types or topotypes, of eight of the nine recognized species in th...
Article
Full-text available
Lambert et al . question our retrospective and holistic epidemiological assessment of the role of chytridiomycosis in amphibian declines. Their alternative assessment is narrow and provides an incomplete evaluation of evidence. Adopting this approach limits understanding of infectious disease impacts and hampers conservation efforts. We reaffirm th...
Preprint
Full-text available
A fundamental gap in climate change vulnerability research is an understanding of the relative thermal sensitivity of tropical and temperate organisms. Aquatic insects are vital to stream ecosystem function and biodiversity. With global temperatures rising at an unprecedented rate, it is imperative that we understand how sensitive aquatic insects a...
Preprint
Background: Differences in the trophic niche often underlie ecological specialization of individuals and can promote ecological speciation of populations, but studies showing a link between differences in the trophic niche and genetic differentiation of populations are rare. On the island of San Cristóbal (Galapágos archipelago), a strong genetic d...
Article
Full-text available
Anthropogenic threat maps are commonly used as a surrogate for the ecological integrity of rivers in freshwater conservation, but a clearer understanding of their relationships is required to develop proper management plans at large scales. Here, we developed and validated empirical models that link the ecological integrity of rivers to threat maps...
Chapter
Full-text available
Description of two new species of geckos from Isabela Island. Arteaga, Bustamante, Vieira, Tapia and Guayasamin, 2019.
Article
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Abstract The study of current distribution patterns of amphibian species in South America is of particular interest in areas such as evolutionary ecology and conservation biology. These patterns could be playing an important role in biological interactions, population size, and connectivity, and potential extinction risk in amphibians. Here, we tes...
Article
Full-text available
We describe a new species of terrestrial frog of the genus Noblella from the eastern versants of the Ecuadorian Andes in the upper Pastaza watershed. Noblella naturetrekii sp. n. differs from its Ecuadorian congeners by the presence of a differentiated tympanic membrane and a weakly defined tympanic annulus, and eyelids with rounded tubercles. In a...
Article
Full-text available
We describe a new species of terrestrial frog of the genus Noblella from the eastern versants of the Ecuadorian Andes in the upper Pastaza watershed. Noblella naturetrekii sp. n. differs from its Ecuadorian congeners by the presence of a differentiated tympanic membrane and a weakly defined tympanic annulus, and eyelids with rounded tubercles. In a...
Article
Full-text available
Alexander von Humboldt conducted his best‑known work on the slopes of the Ecuadorian Andes. He did this by applying his own characteristic brand of multidisciplinary scientific approach. This consisted of thorough data collection while synthesizing and visualizing the data in innovative formats. Also important for his scientific success in South Am...
Article
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Alexander von Humboldt is often regarded as the "Father of Biogeography". Although the very concept that any discipline has a founder may be disputed, von Humboldt´s contributions are, without a doubt, enormous, integrative and global. His lucid writing was widely read, he built up a huge network of correspondents, he assisted many young researcher...
Article
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Representation of women in science drops substantially at each career stage, from early student to senior investigator. Disparities in opportunities for women to contribute to research metrics, such as distinguished speaker events and authorship, have been reported in many fields in the U.S.A. and Europe. However, whether female representation in s...
Article
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Anthropogenic trade and development have broken down dispersal barriers, facilitating the spread of diseases that threaten Earth's biodiversity. We present a global, quantitative assessment of the amphibian chytridiomycosis panzootic, one of the most impactful examples of disease spread, and demonstrate its role in the decline of at least 501 amphi...
Article
We review the systematics of the species of Gastrotheca (Anura: Hemiphractidae) in the highlands of the southern Ecuadorian Andes. We analyzed phylogenetic, morphological, ecological, and acoustic data from populations in the region. We provide an updated phylogenetic hypothesis inferred from a database that contains 42 species of Gastrotheca, and...
Article
Full-text available
We describe a new glassfrog from Río Manduriacu Reserve, Imbabura Province, on the Pacific slopes of the Ecuadorian Andes. The new species can be distinguished from most other glassfrogs by having numerous yellow spots on the dorsum and lacking membranes among fingers. Both morphological and molecular data support the placement of the species in th...
Article
Full-text available
Artificial prey techniques—wherein synthetic replicas of real organisms are placed in natural habitats—are widely used to study predation in the field. We investigated the extent to which videography could provide additional information to such studies. As a part of studies on aposematism and mimicry of coral snakes ( Micrurus ) and their mimics, o...
Article
Full-text available
Major threats to freshwater ecosystems in the Andean-Amazon region include agriculture, point and nonpoint source pollution, hydroelectric dams, oil extraction, mining and road building, yet little is known about the baseline values and current state of rivers and streams, or how expanding urban, industrial and agricultural activities could affect...