Hyla Research Articles

The phylogeography of Middle Eastern tree frogs in Israel.

Western Palearctic treefrogs of the genus Hyla provide an example of a morphologically and ecologically cryptic group. Up to three distinct Hyla species have been proposed as resident in Israel and this number has consistently been subject to taxonomical debates. Here, we analyzed 16S rRNA and COI gene fragments of 658 individuals sampled at 47 pools in nine regions across Israel and the West Bank in order to resolve the taxonomic status of Hyla frogs. We generated both Bayesian and Maximum Likelihood phylogenies, and constructed time-calibrated trees to provide an evolutionary and historical context of sequence variations. We further applied SAMOVA as well as Monmonier's maximum-difference algorithm to study the genetic structure among populations and to identify potential zones acting as barriers to gene flow across locations. Our results revealed two distinct haplogroups for each gene fragment, with 95% CI divergence times dated from 8.9-17.1 Mya (16S) and 7.1-23.6 Mya (COI), respectively. SAMOVA and barrier analyses partitioned the populations into three groups. Our results highlight that, while there are probably only two Hyla species in Israel, one population of one of the species might qualify as a separate evolutionarily significant unit. Our findings elucidate the taxonomic status of Hyla frogs in Israel and provide the basis for determining appropriate management and conservation priorities.

Female preferences for the spectral content of advertisement calls in Cope's gray treefrog (Hyla chrysoscelis).

Amphibians have inner ears with two sensory papillae tuned to different frequency ranges of airborne sounds. In frogs, male advertisement calls possess distinct spectral components that match the tuning of one or both sensory papillae. Female preferences for the spectral content of advertisement calls can depend on signal amplitude and can vary among closely related lineages. In this study of Cope's gray tree frog (Hyla chrysoscelis), we investigated the amplitude dependence of female preferences for the spectral content of male advertisement calls, which have a "bimodal" spectrum with separate low-frequency (1.25kHz) and high-frequency (2.5kHz) components. In two-alternative choice tests, females generally preferred synthetic calls with bimodal spectra over "unimodal" calls having only one of the two spectral components. They also preferred unimodal calls with a high-frequency component over one with the low-frequency component. With few exceptions, preferences were largely independent of amplitude across both a 30dB range of overall signal amplitude and an 11dB range in the relative amplitudes of the two spectral components. We discuss these results in the context of evolutionary lability in female preferences for the spectral content of advertisement calls in North American tree frogs in the genus Hyla.

The valid nomen for the tree frog (genus Hyla) of Tunisia and Eastern Algeria.

Mediterranean tree frogs, Hyla gr. meridionalis Boettger, 1874 (Anura: Hylidae) are widespread around the Western Mediterranean Basin, where they naturally occur across the Maghreb (Morocco, Algeria, Tunisia). Individuals of diverse Moroccan origins have been introduced and have expanded throughout the Iberian Peninsula, southern France and northern Italy (Liguria), but also on the Canary and Balearic archipelagos (Recuero et al. 2007; Dufresnes et al. 2019). Early molecular studies uncovered several mitochondrial lineages and suggested a major cryptic diversification within this taxon, with Tunisian and eastern Algerian (Numidia) populations carrying deeply divergent haplotypes compared with the rest of the range (Recuero et al. 2007; Stöck et al. 2008; Stöck et al. 2012). While intron markers showed little differentiation (Stöck et al. 2008; Stöck et al. 2012), genome-wide data obtained from RAD-sequencing have supported the deep split suspected from mtDNA (Dufresnes et al. 2018).

Molecular phylogenetic relationships and generic placement of Dryaderces inframaculata Boulenger, 1882 (Anura: Hylidae)

Dryaderces inframaculata Boulenger, 1882, is a rare species known only from a few specimens and localities in the southeastern Amazonia rainforest. It was originally described in the genus Hyla, after ~ 130 years transferred to Osteocephalus, and more recently to Dryaderces. These taxonomic changes were based solely on the similarity of morphological characters. Herein, we investigate the phylogenetic relationships and generic placement of D. inframaculata using molecular data from a collected specimen from the middle Tapajos River region, state of Para, Brazil. Two mitochondrial DNA fragments (16S and COI) were assessed among representative species in the subfamily Lophiohylinae (Anura: Hylidae) to reconstruct phylogenetic trees under Bayesian and Maximum Likelihood criteria. Our results corroborate the monophyly of Dryaderces and the generic placement of D. inframaculata with high support. Dryaderces inframaculata is sister to an undescribed taxon, Dryaderces pearsoni Ca1 Jungfer et al., 2013, and both are sister to Dryaderces pearsoni Gaige, 1929. These findings are relevant for further research on the systematics and biogeography of the genus.

Estimating abundance of the Stripeless tree-frog Hyla meridionalis by means of replicated call counts

The Stripeless tree-frog Hyla meridionalis reaches its eastern-most European distributional limit in NW Italy, and specifically in the Cinque Terre National Park. Here for two consecutive years, we estimated tree-frog population abundance by call surveys at 24 sites. Data were analysed in the framework of N-mixture open population models based on repeated counts of calling males. The results obtained by this statistical approach were effective in estimating population size together with annual recruitment and survival. The tree-frog male population size remained constant between years and site abundance was inversely related with altitude. On the bases of these findings, our application of N-mixture models to tree-frog calling males was successful and is a promising cost-effective method to obtain long-term monitoring data on this species over large geographic areas.

Assessing the resistance of a breeding amphibian community to a large wildfire

Socioeconomic and global climate changes are modifying fire regimes towards larger and more intense fires. Studying the response of organisms to the occurrence of large fires is crucial to anticipate shifts in patterns of biodiversity in fire-prone regions. Amphibia is the most threatened terrestrial vertebrate taxon, although it is also the least studied in relation to its response to fire. We evaluated the resistance to fire (similarity in species composition before and after fire) and reproductive success during the first breeding season after a fire of an amphibian community at the Mediterranean basin. We sampled 33 aquatic habitats, including ponds and streams located inside and outside the perimeter of the fire, and reported the presence of adult amphibians and their reproductive success. The community composition in burnt and unburnt areas was compared by similarity analysis. Generalized Linear Models were used to test the effects of fire (burnt or unburnt area), habitat type (stream or pond), distance to the perimeter of the wildfire, and altitude on total and breeding species richness. We did not find significant differences in amphibian community composition between burnt and unburnt areas, or in total species richness per water point. Of the 12 species found in the study area, only frogs of the genus Hyla declined in the burnt area due to the destruction of their preferred microhabitat, i.e. vegetation surrounding ponds. In contrast, breeding occurrence and breeding species richness declined in burnt streams and ponds. These results suggest a high amphibian resistance to fire at the community level, although the reduction of breeding activity can threaten the persistence of a rich community in future scenarios of increased recurrence of megafires.

Diet Composition of Japanese Tree Frog (Hyla japonica) in a Rice Paddy, South Korea

Diet Composition of Japanese Tree Frog (Hyla japonica) in a Rice Paddy, South Korea

Identification, chemical synthesis and heterologous expression of an antinociceptive peptide from the veined tree frog Trachycephalus typhonius

Abstract A proteinic fraction from the skin secretion of Trachycephalus typhonius showed antinociceptive activity in mice when tested by the Hot Plate method. This fraction was purified, and a peptide named Tt7 with a molecular mass of 6,509.7 Da was identified. The primary structure of Tt7 was elucidated. Comparing Tt7 with the structure of other analgesic peptides, it exhibits a strong relationship with the family of anntoxins, which are peptides isolated from the skin secretions of Asian frogs of the genus Hyla, whereas T. typhonius is located only in the Americas. Tt7 contains a disulfide pattern Cys1-Cys4/Cys2-Cys3, a secondary structure defined by a β-hairpin, and a N-terminal α-helix, which are characteristic motifs of Kunitz-type structures. The peptide Tt7 was both chemically and biologically synthesized. The recombinant peptides (rTt7 and HisrTt7) showed analgesic effects. Electrophysiological analyses of Tt7 on the voltage-gated sodium channel (Na v ) subtype 1.7 reduced the Na + current by ca 10%. Further studies showed that Tt7 inhibits the pH gated Ca-fluorescence increase in dorsal root ganglion neurons of the rat, indicating an inhibitory action of Tt7 in the acid gated currents which may account for the observed analgesic action of Tt7, suggesting that this peptide might affect various pain-related receptors.

Evidence for directional testes asymmetry in Hyla gongshanensis jindongensis

The compensation hypothesis predicts that one testis may grow more for compensating for a reduced function in the other testis, thus exhibiting a directional asymmetry in testis size. In this study, we tested the prediction of the compensation hypothesis in the Chinese endemic Tree Frog Hyla gongshanensis jingdongensis in a population in Kegong Reserve site of Yunan Province in western China. For fifty-three male samplings, we found that the left testis size was significantly bigger than the right testis, which exhibited a significantly directional testis asymmetry, consistent with the evidence that mainly the left testis is functional with the right testis having a compensatory role, i.e. the left testis would increase in size if the right testis became non-functional. However, the relative testes size and the degree of testes asymmetry were not correlated with body condition in this species, suggesting that the testes asymmetry can not reflect male quality: high-quality individuals would not have more asymmetric testes.

Effects of Habitat Environment and Land Use on the Abundance of Japanese Tree Frog (Hyla japonica) in Incheon, Korea

Effects of Habitat Environment and Land Use on the Abundance of Japanese Tree Frog (Hyla japonica) in Incheon, Korea

Sound source localization and segregation with internally coupled ears: the treefrog model.

Acoustic signaling plays key roles in mediating many of the reproductive and social behaviors of anurans (frogs and toads). Moreover, acoustic signaling often occurs at night, in structurally complex habitats, such as densely vegetated ponds, and in dense breeding choruses characterized by high levels of background noise and acoustic clutter. Fundamental to anuran behavior is the ability of the auditory system to determine accurately the location from where sounds originate in space (sound source localization) and to assign specific sounds in the complex acoustic milieu of a chorus to their correct sources (sound source segregation). Here, we review anatomical, biophysical, neurophysiological, and behavioral studies aimed at identifying how the internally coupled ears of frogs contribute to sound source localization and segregation. Our review focuses on treefrogs in the genus Hyla, as they are the most thoroughly studied frogs in terms of sound source localization and segregation. They also represent promising model systems for future work aimed at understanding better how internally coupled ears contribute to sound source localization and segregation. We conclude our review by enumerating directions for future research on these animals that will require the collaborative efforts of biologists, physicists, and roboticists.

Hematophagous insects as vectors for frog trypanosomes.

Experimental infections of three hematophagous arthropods (Rhodnius prolixus, Aedes aegypti, and Culex pipiens) with a trypanosome of the Trypanosoma rotatorium complex found in the frogs Hyla crepitans and Leptodactylus insularum revealed that A. aegypti is a good host for the flagellate; the course of development in the intestinal tract of the mosquito is described from 15 minutes to 168 hours. C. pipiens showed only low intestinal infections and R. prolixus did not permit development of the parasite. It is postulated that, in addition to the transmission of T. rotatorium by leeches, batrachophilic mosquitoes may transmit the parasite to frogs of more terrestrial habits by being ingested by these anurans.

Anurans of the Tagay Locality (Baikal Lake, Russia; Miocene): Bombinatoridae, Hylidae, and Ranidae

The Miocene (MN 5) locality of Tagay (Baikal Lake, Russia) yielded isolated bones of five anuran taxa: Bombina sp. (Bombinatoridae), Hyla sp. (Hylidae), Pelophylax sp. and Rana sp. (Ranidae), Bufo mirus (Bufonidae), the first four of which are described here. In Tagay anuran assemblage, Ranidae are dominant, whereas Hylidae and Bombinatoridae are extremely rare. The Tagay Bombina and Hyla represent the oldest records of these genera in Asia. The Tagay Bombina possibly belongs to an ancestral Bombina lineage, which originated in Asia by the Oligocene-Miocene boundary. The Tagay Hyla could be an early member of the East Palearctic species-group of Hylidae that originated during the early Miocene in Asia. Pelophylax sp. and Rana sp. are among the earliest records of the lineages of green and brown frogs, respectively, in Asia.

Distribution patterns and habitat suitability for three species ofthe genus Hyla Laurenti, 1768 in the Western Palearctic

Distribution patterns and habitat suitability for three species ofthe genus Hyla Laurenti, 1768 in the Western Palearctic

Sequencing and analysis of the complete mitochondrial genome of Hyla ussuriensis (Anura: Hylidae)

In this study, the complete mitogenome sequence of Hyla ussuriensis (Anura: Hylidae) is first determined using long PCR. It is a circular molecule of 18 023 bp in length (GenBank accession no. KT964710). Similar to the typical mtDNA of amphibians, the complete mtDNA sequence of Hyla ussuriensis contained two rRNA genes (12S rRNA and 16S rRNA), 22 tRNA genes, 13 protein-coding genes (PCGs), and a control region (D-loop). The nucleotide composition was 29.9% A, 25.4% C, 14.5% G, and 30.2% T. Mitochondrial genomes analyses based on NJ method yield phylogenetic trees, indicating 13 reported Anura frogs belonging to five families (Hylidae, Bufonidae, Microhylidae, Ranidae, and Rhacophoridae). These molecular data presented here provide a useful tool for systematic analyses of genus Hyla and family Hylidae.

Amphibians crossing the Bering Land Bridge: Evidence from holarctic treefrogs (Hyla, Hylidae, Anura)

Based on an updated, time-calibrated phylogeny and applying biogeographical model testing and diversification analysis, we re-examined systematics and biogeography of the Holarctic treefrog genus Hyla with a focus on the East Asian species. We analyzed four mitochondrial genes (12S and 16S rRNA, tRNALeu, ND1) and one nuclear gene (POMC) for 192 samples representing 30 species of Hyla. Based on our results we suggest that H. ussuriensis is a synonym of H. japonica. Specimens from Sakhalin and Kunashir Islands might represent a cryptic species within H. japonica. We confirm earlier hypotheses that the genus Hyla originated during the Eocene to Early Oligocene and that Eurasian species originated from two independent dispersal events from North America via the Bering Land Bridge. Middle Eocene to Oligocene dispersal gave rise to the most recent common ancestor of the West Palearctic H. arborea-group and the East Palearctic, newly defined, H. chinensis-group. The Northeast Asian H. japonica-group resulted from a second wave of colonization from the Nearctic. A trans-Atlantic dispersal route could be excluded. Dispersal of the H. arborea-group to the western Palearctic coincides with the closure of the Turgai Strait at the end of the Oligocene. Diversification of Hyla decreased at the end of the Middle Miocene, possibly coinciding with the end of the Mid Miocene Climatic Optimum and the advent of cooler and drier climates in the Northern Hemisphere.

Fossil Frogs of the Late Clarendonian (Late Miocene) Pratt Slide Local Fauna of Nebraska, with the Description of a New Genus

Abstract The Pratt Slide fossil site of Brown County, Nebraska has yielded a diverse frog fauna from the late Clarendonian North American Land Mammal Age (late Miocene; ca. 10.5–9.5 Ma). The fauna includes the extant genera Spea, Rana, Bufo, Hyla, and cf. Acris, the second record of the late Clarendonian genus Tregobatrachus, and a new, unique genus of frog. The fauna was dominated by Rana (at least 39 individuals). Overall, the taxonomic composition of the Pratt Slide frog fauna supports suggestions by others that the frog fauna of the Great Plains was predominantly modern at the generic level by ca. 10 Ma. Fossil evidence also suggests that the extinct toad Bufo pliocompactilis was common in the Great Plains during the late Miocene, and the extant genus Hyla occupied a larger Great Plains distribution during the late Miocene than today.

Treefrogs as animal models for research on auditory scene analysis and the cocktail party problem

The perceptual analysis of acoustic scenes involves binding together sounds from the same source and separating them from other sounds in the environment. In large social groups, listeners experience increased difficulty performing these tasks due to high noise levels and interference from the concurrent signals of multiple individuals. While a substantial body of literature on these issues pertains to human hearing and speech communication, few studies have investigated how nonhuman animals may be evolutionarily adapted to solve biologically analogous communication problems. Here, I review recent and ongoing work aimed at testing hypotheses about perceptual mechanisms that enable treefrogs in the genus Hyla to communicate vocally in noisy, multi-source social environments. After briefly introducing the genus and the methods used to study hearing in frogs, I outline several functional constraints on communication posed by the acoustic environment of breeding “choruses”. Then, I review studies of sound source perception aimed at uncovering how treefrog listeners may be adapted to cope with these constraints. Specifically, this review covers research on the acoustic cues used in sequential and simultaneous auditory grouping, spatial release from masking, and dip listening. Throughout the paper, I attempt to illustrate how broad-scale, comparative studies of carefully considered animal models may ultimately reveal an evolutionary diversity of underlying mechanisms for solving cocktail-party-like problems in communication.

Morphology and Biometric Study of Skin of Hyla orientalis Bedriaga, 1890 (Anura, Hylidae)

The dorsal and ventral skin of the Eastern tree frog, Hyla orientalis, was investigated by light microscopy. Histochemistry was carried out with use of various staining methods, and microscopic observations revealed the morphological characteristics of the skin with squamous epithelium in the epidermis and connective tissue in the dermis, subdivided into stratum spongiosum and stratum compactum. Two types of skin glands (mucous and granular) were observed in both dorsal and ventral skin. The percentage of dermal glands was calculated and diameters of granular and mucous glands were measured per animal in both dorsal and ventral regions. The parameters were compared by one-way ANOVA and subsequently by Mann-Whitney U test in terms of statistical differences in the diameters of dermal glands. The histochemical properties and morphological characteristics with qualitative and quantitative features for each region (dorsal and ventral integuments) did not show individual variation and may be considered as important features for taxonomic, phylogenetic and ecological studies.

ADDITIONAL NOTES TO «AMPHIBIANS OF ARGENTINA»: AN UPDATE, 1980–1986

SUMMARY AND CONCLUSIONS As was explained in the Introduction, the purpose of these «Additional notes» is to present the new information that has appeared since the publication of the Monograph «Amphibians of Argentina» (CEI, 1980a). These notes update the systematics of Argentine amphibians and briefly describe the new species that have been reported. In this analysis several genera stand out as poorly known and consequently probably subject to future changes in nomenclature. The most obvious examples of this are Elachistocleis, Alsodes, Telmatobius, Leptodactylus, Physalaemus, Odontophrynus and the supergenus Hyla. Other genera that may be suject to lesser modifications are Bufo, Melanophryniscus, Ceratophrys, Lepidobatrachus, Pleurodema, Pseudopaludicola, Atelognathus, Batrachyla, Pseudis, Gastrotheca or Phyllomedusa. Some of the monotypic or relictual genera such as Dermatonotus, Rhinoderma, Chacophrys, Crossodactylus, Somuncuria, Hylorina, Eupsophus, Limnomedusa, Argenteohyla, Osteocephalus, Phrynohya...