Molecular phylogeny of stream treefrogs (Hylidae:Hyloscirtus bogotensisGroup), with a new species from the Andes of Ecuador

Revealing hidden biodiversity: Novel insights on reptile and amphibian distribution in western Ecuador

We present notable distributional updates for 14 species from western Ecuador (seven amphibians and seven reptiles). Our findings include the northernmost confirmed sighting of Pristimantis kuri and the southernmost documented record of Imantodes inornatus and Lepidoblepharis buchwaldi. Additionally, we document new records and notes on the distribution range of Agalychnis spurrelli, Hyloscirtus alytolylax, Engystomops montubio, Pristimantis muricatus, Pristimantis nyctophylax, Pristimantis walkeri, Chironius flavopictus, Chironius grandisquamis, Dendrophidion graciliverpa, Ninia schmidti, and Urotheca fulviceps. These observations significantly contribute to filling information gaps in our understanding of these species' distributions. The data, derived from samples collected across diverse forested areas in the western region of Ecuador (provinces of Bolívar, Cañar, Guayas, El Oro, and Los Ríos), provide valuable insights into the ecology and conservation of these species.

A spectacular new species of Hyloscirtus (Anura: Hylidae) from the Cordillera de Los Llanganates in the eastern Andes of Ecuador

We have discovered a spectacular new species of frog in the genus Hyloscirtus, belonging to the H. larinopygion species group. The adult female is characterized by a mostly black body with large bright red spots on the dorsal and ventral surface, extremities, and toe pads. The adult male is unknown. Small juveniles are characterized by a yellow body with variable black markings on the flanks; while one larger juvenile displayed irregular orange or yellow marks on a black background color, with light orange or yellow toe pads. Additional distinctive external morphological features such as cloacal ornamentation are described, and some osteological details are imaged and analyzed. The performed phylogeny places the new species as the sister to a clade consisting of ten taxa, all of which are part of the H. larinopygion group. We use genetic distances to fit the new species into a published time-calibrated phylogeny of this group; our analysis based on the published chronology suggests that the divergence of the new species from its known congeners pre-dates the Quaternary period. The new species is currently only known only from Cerro Mayordomo, in Fundación EcoMinga´s Machay Reserve, at 2,900 m in the eastern Andes of Tungurahua province, Ecuador, near the southern edge of Los Llanganates National Park, but its real distribution may be larger.

A new Andean treefrog (Amphibia: Hyloscirtus bogotensis group) from Ecuador: an example of community involvement for conservation

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. Hyloscirtus conscientia sp. nov. is described from the montane forests of the Mira River basin in the extreme northwestern Ecuador. The new species is characterized as follows: tympanic annulus conspicuous, tip of snout in dorsal view subacuminate, middorsal stripe formed by melanophores larger and less dense, dorsal skin with individual iridophores forming dots, scarcely distributed across dorsum. Our study also highlights the importance of the Mira River Valley as a biogeographic barrier; suggesting research efforts north and south of the valley are likely to reveal additional endemic cryptic diversity. Finally, our partnership with Reserva: The Youth Land Trust, Rainforest Trust and EcoMinga Foundation has produced a novel and meaningful way to connect young people with biodiversity discovery and habitat conservation.

High-throughput DNA sequencing of museum specimens sheds light on the long-missing species of the Bokermannohyla claresignata group (Anura: Hylidae: Cophomantini)

The two species of the Bokermannohyla claresignata species group (Anura: Hylidae) have not been collected for the last four decades. It is the only species group of the hyline tribe Cophomantini that has not yet been analysed genetically. Its phylogenetic position is thus uncertain, and it has a combination of adult and larval character states that make this group a crucial missing piece that hinders our understanding of Cophomantini phylogenetics and character evolution. We obtained DNA sequences from a museum larval specimen of Bok. claresignata, using specialized extraction methods and high-throughput DNA sequencing, and combined the molecular phylogenetic results with available phenotypic information to provide new insights into the taxonomy and phylogenetic relationships of its species group. Our phylogenetic results place Bok. claresignata as sister to the Boana pulchella group, supporting its inclusion in Boana, together with Bokermannohyla clepsydra. In light of this new finding, we recognize a newly defined Boana claresignata group to accommodate these species, thus resolving both the polyphyly of Bokermannohyla and the paraphyly of Boana. Considering the phylogenetic relationships of the Boana claresignata group, we also discuss the evolution of suctorial tadpoles and mature oocyte/egg pigmentation in Cophomantini.

A new treefrog from Cordillera del Cóndor with comments on the biogeographic affinity between Cordillera del Cóndor and the Guianan Tepuis (Anura, Hylidae, Hyloscirtus)

The Hyloscirtuslarinopygion group is a clade of 16 species of large hylids that inhabit cascading Andean streams. They have brown coloration that, in most species, contrasts with bright marks. Herein morphological and genetic evidence is used to describe a new species of the group from Cordillera del Cóndor, a sub-Andean mountain chain that has phytogeographic affinities with the Guianan Tepuis. The new species is characterized by dark-brown coloration with contrasting bright orange flecks and by the presence of an enlarged and curved prepollex protruding as a spine. The new species is closely related to H.tapichalaca and an undescribed species from the southern Andes of Ecuador. The genetic distance between H.hillisi sp. n. and its closest relative, H.tapichalaca, is 2.9% (gene 16S mtDNA). Our phylogeny and a review of recently published phylogenies show that amphibians from Cordillera del Cóndor have close relationships with either Andean or Amazonian species. Amphibians do not show the Condor-Guianan Tepuis biogeographic link that has been documented in plants.

Chromosome evolution in Cophomantini (Amphibia, Anura, Hylinae)

The hylid tribe Cophomantini is a diverse clade of Neotropical treefrogs composed of the genera Aplastodiscus, Boana, Bokermannohyla, Hyloscirtus, and Myersiohyla. The phylogenetic relationships of Cophomantini have been comprehensively reviewed in the literature, providing a suitable framework for the study of chromosome evolution. Employing different banding techniques, we studied the chromosomes of 25 species of Boana and 3 of Hyloscirtus; thus providing, for the first time, data for Hyloscirtus and for 15 species of Boana. Most species showed karyotypes with 2n = 2x = 24 chromosomes; some species of the B. albopunctata group have 2n = 2x = 22, and H. alytolylax has 2n = 2x = 20. Karyotypes are all bi-armed in most species presented, with the exception of H. larinopygion (FN = 46) and H. alytolylax (FN = 38), with karyotypes that have a single pair of small telocentric chromosomes. In most species of Boana, NORs are observed in a single pair of chromosomes, mostly in the small chromosomes, although in some species of the B. albopunctata, B. pulchella, and B. semilineata groups, this marker occurs on the larger pairs 8, 1, and 7, respectively. In Hyloscirtus, NOR position differs in the three studied species: H. alytolylax (4p), H. palmeri (4q), and H. larinopygion (1p). Heterochromatin is a variable marker that could provide valuable evidence, but it would be necesserary to understand the molecular composition of the C-bands that are observed in different species in order to test its putative homology. In H. alytolylax, a centromeric DAPI+ band was observed on one homologue of chromosome pair 2. The band was present in males but absent in females, providing evidence for an XX/XY sex determining system in this species. We review and discuss the importance of the different chromosome markers (NOR position, C-bands, and DAPI/CMA3 patterns) for their impact on the taxonomy and karyotype evolution in Cophomantini.

Comparative Phylogeography Reveals Cryptic Diversity and Repeated Patterns of Cladogenesis for Amphibians and Reptiles in Northwestern Ecuador

Comparative phylogeography allow us to understand how shared historical circumstances have shaped the formation of lineages, by examining a broad spectrum of co-distributed populations of different taxa. However, these types of studies are scarce in the Neotropics, a region that is characterized by high diversity, complex geology, and poorly understood biogeography. Here, we investigate the diversification patterns of five lineages of amphibians and reptiles, co-distributed across the Choco and Andes ecoregions in northwestern Ecuador. Mitochondrial DNA and occurrence records were used to determine the degree of geographic genetic divergence within species. Our results highlight congruent patterns of parapatric speciation and common geographical barriers for distantly related taxa. These comparisons indicate similar biological and demographic characteristics for the included clades, and reveal the existence of two new species of Pristimantis previously subsumed under P. walkeri, which we describe herein. Our data supports the hypothesis that widely distributed Chocoan taxa may generally experience their greatest opportunities for isolation and parapatric speciation across thermal elevational gradients. Finally, our study provides critical information to predict which unstudied lineages may harbor cryptic diversity, and how geology and climate are likely to have shaped their evolutionary history.