A NEW SNOUTED TREEFROG OF THE GENUS SCINAX (ANURA, HYLIDAE) FROM THE WHITE-SAND FORESTS OF CENTRAL AMAZONIA

Integrative analyses, long-term studies, and access to remote areas in Amazonia have led to new hypotheses and increased resolution of the systematics and taxonomy of the small nurse frog genus Allobates (family Aromobatidae). During anuran sampling in the Middle Tapajós River region, state of Pará, Brazil, we collected data on a new cryptically colored species of Allobates with a cricket-like advertisement call. Here, we name and describe this new species, following an integration of phenotypic, ecological, and molecular analyses. The results of a phylogenetic analysis based on mitochondrial and nuclear DNA placed the new species as the sister taxon of Allobates grillisimilis. Genetic pdistances between the two sister taxa at the 16S region of the mitochondrial DNA ranged from 7% to 9%. A sister-species relationship between the new species and A. grillisimilis is also supported by phenotypic evidence. Adults of the new species are small (snout–vent length 15.2–16.8 mm in males and 16.5–17.7 mm in females), with a dorsum uniformly tan to reddish brown, a dark brown lateral stripe and a white ventrolateral stripe, arms pale tan brown and legs greyish-brown, and venter yellowish colored, with variable extension and shades of yellow, paler on the throat. The advertisement call is a trill with a mean peak frequency of 5830.2 Hz, arranged in series of short, closely spaced, pulses (mean of 24.3 pulses/s), and followed by silent intervals of variable duration. We discuss the putative drivers generating and maintaining the distinctiveness between the new species and the allopatrically distributed sister taxon, and on threats to the persistence of the new species. With this species description, the Middle Tapajós River region is consolidated as having one of the highest alpha diversities for the genus Allobates in Amazonia.

Advertisement calls may contain information about the callers and the calling spot, which can be used during mate selection. The relationships between variations in advertisement call characters and age, snout-vent length (SVL), and water temperature were analyzed for the black-spotted pond frog (Rana nigromaculata). After recording the advertisement calls, we measured the SVL of the callers and the water temperature of the calling spot, then we collected a toe clipping from each of the 25 individuals recorded. The age of each frog was determined using the skeletochronological method. The frogs were two to eight years old and the asymptotic size was 6.3 cm when fitted to the von Bertalanffy growth equation. Age was not linearly correlated with SVL. In the analysis of 743 recorded advertisement calls from 25 individuals, the water temperature caused a decrease in males’ call duration with more pulse groups, each having higher pulse rates, irrespective of age and SVL. Older males produced calls with more pulse groups and shorter pulse-group duration, which led to increasing call durations irrespective of the water temperature. Larger males produced lower dominant frequency, irrespective of the water temperature. Advertisement calls of the black-spotted pond frog provide information about the quality of males and the manner in which females use this information during mate selection. In this study, we provide information on how frequency reflects male size while temporal characters reflect age.

Aspects of the biology and natural history of the endemic anuran Crossodactylus dantei remain unknown even almost 30 years since its description. In this study, we describe its larval stage, along with the advertisement and territorial calls, and assess its phylogenetic positioning based on a fragment of the 16S rRNA mitochondrial gene. The larval stage of C. dantei follows the morphological pattern of Hylodidae, corroborating the relatively uniform larval morphology of the family. However, it is still possible to observe characters that distinguish C. dantei from other species in the genus, such as the elliptical body in dorsal view, nostrils located closer to the snout than to the eyes, an elongated pre-nasal arena, and the absence of taenia tecti medialis and taenia tecti transversalis in the chondrocranium. Its advertisement call is characterised by a sequence of about 23 pulsed notes, with ascending amplitude modulation, and has a mean duration of 2.5 seconds, with a dominant frequency of 3356 Hz. The territorial call has a mean duration of 23 seconds, a dominant frequency of 3160 Hz, and two distinct types of notes. Phylogenetic analysis indicated the existence of two main lineages in the genus. Crossodactylus dantei was recovered with high statistical support as a sister species to the clade composed of C. gaudichaudii and C. timbuhy. Furthermore, the group formed by these three species was recovered as the sister lineage of C. trachystomus. In summary, the information presented here represents a significant advance in the knowledge of this enigmatic and rare species of the northern Atlantic Forest, providing baseline data for future ecological and evolutionary studies of this unique frog. Keywords: tadpole, oral anatomy, chondrocranium, calls, phylogeny, Atlantic Forest

The small nurse frogs of the genus Allobates (Anura, Aromobatidae) represent one of the most challenging taxonomic issues of the Neotropics. During several amphibian surveys in the Middle Tapajós River region, state of Pará, Brazil, we collected phenotypic, ecological, and molecular data on species of this genus, leading to the identification of a new species included in the Allobates masniger-nidicola complex. The new species is characterized by a large body size (snout-vent length 19.2-21.7 mm in males and 19.3-22.0 mm in females), finger III not swollen in adult males; cryptic external coloration, with dorsum uniformly ochre; a dark brown lateral stripe and a pale cream ventrolateral stripe; limbs ranging from ochre to orange; throat and chest violaceous in males and yellowish in females. The advertisement call is usually arranged in bouts of four closely spaced notes, which we term 4-pulsed units of repetition (UR), 0.317 s long on average, followed by silent intervals, and an average dominant frequency of 4.163 kHz. The new species also has exotrophic tadpoles with a unique fin morphology, which begins after the body-tail insertion and is deeper posteriorly to half of the caudal length. Sequencing of the 16S and COI regions of the mitochondrial DNA show a genetic p-distance of approximately 6-10% compared to closely related congeners. We discuss the biogeography of the new species based on phylogenetic relationships of the species within the Allobates masniger-nidicola complex and the allopatric geographic distribution in relation to sister taxa. Functional characteristics and geographic restrictions make this species particularly sensitive to the increasing human impact in eastern Amazonia.

Variation in dominant frequency, pulse rate, and duration of advertisement and release calls was investigated in populations of Bufo woodhousii australis and B. w. woodhousii. Temperature had a significant influence on all three advertisement call variables in both populations. The positive relationship between pulse rate and temperature was similar in both populations, as was the negative relationship between call duration and temperature. Although temperature-adjusted call durations were equal, adjusted pulse rates were slightly but significantly different between the two populations. When adjusted for body temperature, dominant frequency was the only call variable significantly (negatively) correlated with snout-vent length in either population. The two populations differed in adjusted dominant frequency but not in the negative relationship between frequency and snout-vent length. Analysis of temperature related variation in release calls was not possible, and the two populations differed signifi- cantly only in mean pulse rate. It is suggested that sympatric congeners may have influenced divergence in advertisement call frequency among subspecies of B. woodhousii.

Mating system structure, variation in advertisement and release calls, and calling behavior were investigated during a three-year period in Bufo americanus in east-central Maine. Although the breeding season was relatively brief, chorus size was small, and males participated in chorus activity for an average of six or seven nights within a season. Pulse rate and duration of the advertisement call were significantly correlated with temperature, but neither frequency nor call rate was influenced by temperature over a 10 C range. Dominant frequency was the only advertisement call variable significantly (negatively) correlated with snout-vent length in one of two years for one of two populations studied. Similarly, dominant frequency was the only release call variable significantly (negatively) correlated with male size (snout-vent length and mass). Males exhibited consistency in both call rate and call duration as measured over a series of nights of chorus activity: repeatability (intraclass correlation coefficient) was 0.52 for call duration and 0.24 for call rate. Females did not discriminate between high and low frequency calls in discrimination experiments; however, females did prefer calls broadcast at relatively high call efforts (rate x duration).

A new, brightly colored species of Physalaemus similar to P. deimaticus and P. rupestris is described from the Parque Estadual do Itacolomi, Municipality of Ouro Preto, State of Minas Gerais, southeastern Brazil. The new species is characterized by its small size (snout–vent length 23.2 mm in male, 26.2–26.6 mm in females) and by having the snout rounded in the dorsal view and protruding in profile; large inguinal glands, ovoid, light brown with a black ocellus outlined with white on their posterior half; light grayish brown dorsum with elongate longitudinal dark grayish brown stripes and blotches; venter white with gray mottling; and bright red on groin and ventral surfaces of arms, hands, thighs, tibiae, and feet.

We describe a new species of tree frog related to the Bokermannohyla circumdata group, the northernmost record from Atlantic Forest remnants in eastern Bahia, northeastern Brazil, within regions known as Vale do Jiquiriçá, Baixo Sul, and Litoral Sul. The new species is diagnosed by medium size (snout–vent length 46.8–64.1 mm), head longer than wide, small tympanum, posterior surfaces of thighs with dark brown transverse stripes without additional thin stripes between them, vocal slits in adult males, and distinct advertisement call with a single note composed of 30–110 pulses distributed within 2–9 pulse groups, similar to the bleating of a goat. The new species is morphologically similar to B. hylax and B. lucianae, but is readily distinguished by the presence of barred posterior surfaces on the thighs without thin stripes between them (immaculate in B. lucianae; thin stripes intercalated with wider stripes in B. hylax) and by its distinct vocalization.

Abstract. A new species of the Hypsiboas polytaenius clade is described from Itapecerica da Serra (23°43′S, 46°51′W, 906 m elevation; datum WGS84), State of São Paulo, Southeastern Brazil. The new species is characterized by its medium snout-vent length (SVL) for the group (SVL 27.1–29.1 mm in males; 31.2 mm in female), head width 31.1–33.9% of SVL in males, 37.8% in female, snout rounded in dorsal and lateral views, calcar appendix and supra-cloacal crest absent, webbing poorly developed between fingers, moderately developed between toes, and dorsal color pattern composed of four wide pale brown stripes, intercalated by three brown stripes, arranged longitudinally. The four pale brown stripes join to form two stripes anterior to the eyes and then join again at the tip of snout. Within these pale brown stripes, narrow longitudinal brown lines, complete or broken, occur. The pale brown marginal stripes show, on the external border, a white line passing over the canthus rostralis, edge of the upper eyelid, and along the flank to the groin, contrasting with a broad dark brown lateral stripe. This dark brown stripe extends from the tip of snout to the eye and from the posterior border of the eye, passing on the tympanum, to the groin. The ventral half of the loreal region is pale brown with a dark brown longitudinal line, continuing as a white stripe below and contrasting to the dark brown lateral stripe, to the groin. The new species is distributed in the extreme south of the State of Rio de Janeiro and northeastern State of São Paulo, above 400 m altitude.

BackgroundSpecies-specific advertisement calls are the main mechanism of transmitting information between individuals in anuran amphibians and are therefore indispensable for anuran survival and reproduction. Survey methods that monitor these calls can be used for rapid species recognition, behavioral experiments, and conservation monitoring. In this study, we described in detail 10 call parameters from three sympatric species in the genus Microhyla and analyzed the differences in call parameter among these species to provide a basis for systematic monitoring, acoustic analysis and taxonomic study of this genus.MethodsThe quantitative analyses of temporal and spectral call parameters were used in our study for the advertisement calls of three sympatric Microhyla species (M. beilunensis, M. fissipes and M. heymonsi) in Zhejiang Province, East China.ResultsOur results showed the following: (1) Significant differences existed among the three sympatric Microhyla species in call duration (CD), call interval (CI), number of pulses (NP), pulse rate, call intensity (CIT), dominant frequency (DF) and frequency of the first to fourth formants (F1, F2, F3 and F4). (2) Some spectral parameters (DF, F1 and F3) were negatively correlated with the body size of the vocalizing individuals in each species. (3) The coefficients of variation within individuals (CVw) for CIT, DF and F1–F4 were smaller than 5%, whereas the CVW for CI was larger than 10% in each species. (4) The principal component analysis and discriminant function analysis showed that call parameters could distinguish the three Microhyla species. (5) The phylogenetic generalized least squares analysis showed that phylogenetic relationships affected CD and NP against snout-vent length (SVL), DF and NP against CD, and NP against DF, but not of DF against SVL; based on the phylogenetic analysis, CD and NP were not related to SVL, but DF was negatively related to SVL.

Urbanization has a significant influence on amphibian communities, populations, and individuals because of habitat loss, degradation of habitat quality, and habitat fragmentation. Advertisement calls of anurans are used for communication and play an important role in reproduction; however, how anthropogenic noise and habitat change caused by urbanization affect anuran advertisement calls is less well known. In this study, we examined changes in the advertisement calls of two frog species, the ornamented pygmy frog (Microhyla fissipes) and rice frog (Fejervarya multistriata), during the breeding season along an urban–rural gradient in Shanghai, China. We used the percentage of impervious area (including buildings and roads) in each 2 km-radius landscape to represent the urbanization index of 34 study sites. We then measured five advertisement call parameters (call duration, call interval, call rate, pulse rate, and dominant frequency) of these two species (100 males of F. multistriata and 89 males of M. fissipes) in each study site from May to July in 2020 and 2021. We explored how the urbanization index and other variables (air temperature, snout–vent length and calling situation (one frog species calling, or two frog species calling together)) in each study site affected these call parameters. The results showed that the dominant frequency of M. fissipes was significantly negatively related to urbanization index, and call duration and call interval were significantly negatively related to air temperature; furthermore, call rate and pulse rate were significantly positively related to air temperature, and call duration was also significantly positively related to snout–vent length. For F. multistriata, pulse rate was significantly negatively related to urbanization index, snout–vent length, and situation (two frog species calling together), but significantly positively related to air temperature; by contrast, call interval was significantly positively related to snout–vent length. We suggested that these two frog species had different responses to urbanization, which could help us to better understand the change of anuran breeding behaviors and reproductive life-history strategies in the face of rapid urbanization.

A new species of the Bokermannohyla circumdata group, B. diamantina sp. nov., is described from Serra dos Barbados, Municipality of Abaíra, State of Bahia, Brazil. This locality belongs to Chapada Diamantina, a semiarid region in central Bahia. This is the first record of a species of the B. circumdata group from the Brazilian semiarid. Bokermannohyla diamantina is diagnosed by the medium size (snout-vent length 47.0–51.7 mm in adult specimens); head length 2.8–2.9 times smaller than snout-vent length; tympanum medium-sized, its diameter 1.3–1.5 times smaller than eye diameter (tympanum diameter/snout-vent length 0.07); thigh and tibia lengths 0.48–0.52 and 0.49–0.51 of snout-vent length, respectively; dorsum medium to blackish brown, with weak transverse dark brown bars; flanks, anterior, and posterior surfaces of thighs with dark transverse brown stripes, lacking additional thin stripes between them; distinct vocal slits in adult males; advertisement call with 2–4 notes, and dominant frequency from 0.39–0.56 kHz.

The vocalizations of H. raniceps (Cope, 1826) and their functions are described, including an analysis of the influence of temperature, weight, or SVL (snout-vent length) of males on the acoustic parameters. The vocalizations were recorded in three areas in Fazenda Lagoa Grande, Municipality of Pontalina, State of Goias, central Brazil. Males began their vocalizations just before sunset, extending them, in some cases, to dawn of the following day. The peak of activities happened between 21h and 23h. The height of calling sites varied plenty, being the position horizontal in about 50% of them. Males defended sites in different areas during consecutive nights. Rain and strong winds interrupted the calling activities. Males emitted three vocalizations: advertisement, territorial and distress calls. The advertisement call has pulsionated structures and it is the most common, being emitted in the presence/absence of females. Significant correlation was found between number of notes and air temperature, notes duration and both male weight and air temperature, calling rate and both male SVL or weight, and frequency and male weight.

Stephen A. Perrill, William J. Shepherd, Spatial Distribution and Male-Male Communication in the Northern Cricket Frog, Acris crepitans blanchardi, Journal of Herpetology, Vol. 23, No. 3 (Sep., 1989), pp. 237-243

One of the most important resources for reproduction in frogs is the acoustic space since the advertisement call, which is mostly used to attract females, may suffer interference when the acoustic space is widely filled. Other important resources are calling sites and adequate climatic conditions. We analyzed herein three dimensions of the acoustic niche of anurans (advertisement calls, calling period, and calling sites). We recorded 11 calling species of frogs in a tropical community. Species richness was negatively related to temperature, and daily activity was positively related to humidity. We also observed a greater niche overlap than expected by chance in calling periods. These results indicate that the climatic conditions should act as an environmental filter, synchronizing the calling period. The calling site was not shared among species, and no clear pattern of substrate use was observed. Regarding the acoustic dimension, we observe a phylogenetic signal in the dominant frequency of advertisement calls. Hierarchical cluster analysis also indicated a congruence between acoustic distances and phylogenetic relationships. Therefore, the dominant frequency of advertisement calls was constrained by phylogenetic relationships, indicating that it affects the partitioning and use of acoustic resources, an important dimension in reproductive activity in anurans.