Topic
Gastrotheca
About: Gastrotheca is a research topic. Over the lifetime, 63 publications have been published within this topic receiving 1129 citations.
Papers published on a yearly basis
Papers
TL;DR: The highland biphasic species have survived the catastrophic events that led to the disappearance of many other sympatric anurans, and are either Critically Endangered or Endangered because of their restricted distributions, habitat destruction and fragmentation, climate change, and pathogens.
Abstract: 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 sequences from mitochondrial (12S, 16S, and ND1) and nuclear (POMC and RAG-1) genes. We describe four new endemic biphasic species for Ecuador (Gastrotheca cuencana, G. elicioi, G. turnerorum, and G. yacuri). In addition, we redefine G. lojana, recently resurrected from the synonymy of G. monticola, and redescribe G. litonedis. Furthermore, we describe the tadpoles and ontogenetic color changes in six species (G. cuencana, G. elicioi, G. litonedis, G. lojana, G. pseustes, and G. turnerorum). Also, we describe the calls of seven species (G. cuencana, G. elicioi, G. litonedis, G. lojana, G. pseustes, G. testudinea, and G. yacuri). The phylogenetic relationships estimated here are congruent with previous phylogenetic hypotheses for the group, except for the placement of G. galeata, G. plumbea, G. orophylax, G. nicefori, and G. griswoldi. Because most sister species in Gastrotheca are allopatric, the evolutionarly scenarios that likely have intervened in shaping the diversity are the uplift of the Andes and the formation of cross-Andean river valleys, which probably promoted conditions that acted as dispersal barriers that led to speciation. Many species of Gastrotheca (44%) are highly threatened. Most monophasic species have not been seen since the late 1980s, whereas the highland biphasic species have survived the catastrophic events that led to the disappearance of many other sympatric anurans. Research and conservation actions are urgently needed for all surviving species treated herein, five of which are either Critically Endangered or Endangered because of their restricted distributions (10-1600 km2), habitat destruction and fragmentation, climate change, and pathogens. Two of the new species, G. cuencana, and G. elicioi, mostly are known from the cities of Cuenca and Loja, respectively, where urbanization threatens their survival. In order to call attention to conservation issues, we name one new species to refer to the Yacuri National Park, and the other three in honor of the people from Cuenca, the Turner family, and Elicio E. Tapia, whose actions are helping to halt amphibian extinctions.
123 citations
TL;DR: It is found that Gastrotheca species with complex life cycles are phylogenetically nested among species and genera with direct development, and that the tadpole stage has evolved from direct development within Gastro theca, the only known case of such a reversal in frogs.
Abstract: Using phylogeny-based methods to identify evolutionary transitions has become an integral part of evolutionary biology. Here, we demonstrate the potential for these methods to give statistically well-supported but misleading inferences about character evolution. We also show how inferences of character evolution can be informed using GIS-based methods to reconstruct ancestral environmental regimes. We reconstruct a phylogeny for marsupial frogs (Hemiphractidae) using nuclear and mitochondrial DNA sequences and estimate patterns of life-history evolution across the resulting tree. We find that Gastrotheca species with complex life cycles (i.e., egg, tadpole, and adult stages) are phylogenetically nested among species and genera with direct development (i.e., egg and adult stages only). Assuming a single rate for gains and losses in likelihood reconstructions, there is strong statistical support for the hypothesis that the tadpole stage was lost early in the phylogeny but reappeared within Gastrotheca. Assuming different rates of gain and loss, the model with significantly higher statistical support, the tadpole stage seems to have been lost multiple times but never regained. Given that both hypotheses cannot be correct, at least one reconstruction model must be giving well-supported but misleading results. Several lines of evidence (including GIS-based reconstructions of the ancestral climatic regime) suggest that the former hypothesis is correct, and that the tadpole stage has evolved from direct development within Gastrotheca, the only known case of such a reversal in frogs.
114 citations
TL;DR: Overall bacterial abundance was significantly higher post-metamorphosis and on species sampled at lower elevations, and further metagenomic studies are needed to evaluate the roles of host identity, life-history stage, and biogeography of the microbiota and their function in disease resistance.
Abstract: Amphibian populations are decreasing worldwide due to a variety of factors. In South America, the chytrid fungus Batrachochytrium dendrobatidis (Bd) is linked to many population declines. The pathogenic effect of Bd on amphibians can be inhibited by specific bacteria present on host skin. This symbiotic association allows some amphibians to resist the development of the disease chytridiomycosis. Here, we aimed (1) to determine for the first time if specific anti-Bd bacteria are present on amphibians in the Andes of Ecuador, (2) to monitor anti-Bd bacteria across developmental stages in a focal amphibian, the Andean marsupial tree frog, Gastrotheca riobambae, that deposits larvae in aquatic habitats, and (3) to compare the Bd presence associated with host assemblages including 10 species at sites ranging in biogeography from Amazonian rainforest (450 masl) to Andes montane rainforest (3200 masl). We sampled and identified skin-associated bacteria of frogs in the field using swabs and a novel methodology of aerobic counting plates, and a combination of morphological, biochemical, and molecular identification techniques. The following anti-Bd bacteria were identified and found to be shared among several hosts at high-elevation sites where Bd was present at a prevalence of 32.5%: Janthinobacterium lividum, Pseudomonas fluorescens, and Serratia sp. Bd were detected in Gastrotheca spp. and not detected in the lowlands (sites below 1000 masl). In G. riobambae, recognized Bd-resistant bacteria start to be present at the metamorphic stage. Overall bacterial abundance was significantly higher post-metamorphosis and on species sampled at lower elevations. Further metagenomic studies are needed to evaluate the roles of host identity, life-history stage, and biogeography of the microbiota and their function in disease resistance.
70 citations
TL;DR: The development of oral structures in egg‐brooding hylids provides insight into the phylogenetic significance of these charactes in other groups of anurans, and reinforces the idea that microhylids evolved from ranoidlike ancestors.
Abstract: Among egg-brooding hylid frogs there is much interspecific variation in the degree of development of the young at hatching. In certain species of Gastrotheca the eggs hatch into free-living tadpoles, whereas in others (and in the genera Amphignathodon, Cryptobatrachus, Stefania and Hemiphractus) the eggs hatch directly into frogs. We examined the oral anatomy of tadpoles and embryos of 22 species of egg-brooding hylids in order to determine the morphological differences between free-living larvae and embryos of species having direct development. All free-living Gastrotheca larvae are morphologically similar and have a large array of oral structures directly associated with a suspension feeding way of life. Among those egg-brooding hylids without free-living larvae there is a complete gradation from those with all of the free-living tadpole oral structures to those with none. Different lineages retain different vestiges of free-living larval morphology, suggesting that direct development has evolved multiple times among these frogs. All of the morphological patterns in the direct-developing embryos can be accounted for by simple truncation or acceleration of the normal tadpole developmental program. We explore the possibility that certain Gastrotheca species with tadpoles may have evolved from species that lack larval stages. The development of oral structures in egg-brooding hylids provides insight into the phylogenetic significance of these charactes in other groups of anurans. Most significantly they reinforce the idea that microhylids evolved from ranoidlike ancestors.
66 citations
Journal Article•
TL;DR: Analyses of data on allozymes, morphometrics, structural characters, and coloration resulted in the definition of nine species of Gastrotheca in the Andes of Ecuador and southern Colombia; some populations that previously were referred to G. riobambae are recognized as new species.
Abstract: Analyses of data on allozymes, morphometrics, structural characters, and coloration resulted in the definition of nine species of Gastrotheca in the Andes of Ecuador and southern Colombia. Some populations that previously were referred to G. riobambae are recognized as new species: G. espeletia from the paramos of southern Colombia and northern Ecuador, G. litonedis from the Cuenca Basin in Ecuador, and G. pseustes from the Andean cordilleras south to the Loja Basin. The range of G. riobambae is restricted to elevations mostly below 3000 m from the Rio Chonta south to the Riobamba Basin. Gastrotheca marsupiata lojana Parker, 1932 is placed in the synonymy of G. monticola Barbour and Noble, 1920, and G. cavia Duellman, 1974 is placed in the synonymy of G. riobambae (Fowler, 1913). A phylogeny based on shared derived electromorphs shows G. pseustes to be grouped with G. griswoldi and marsupiata from the Andes of Peru. Among all of the other species from the Andes of Ecuador, the two species having direct development (G. orophylax and plumbea) are most closely related to G. litonedis, monticola, and psychrophila from southern Ecuador; these five species together are related to G. espeletia, riobambae, and ruizi from northern Ecuador and southern Colombia.
63 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 3 |
| 2020 | 1 |
| 2019 | 2 |
| 2017 | 1 |
| 2016 | 2 |
| 2015 | 4 |