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Made available in DSpace on 2022-04-29T08:34:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-10-01 Consejo Nacional de Investigaciones Científicas y Técnicas Vocal sacs are among the most conspicuous features of anurans and are particularly striking in casque-headed treefrogs (Hylidae: Hylinae: Lophyohylini) with their wide array of morphologies. In this paper, we assessed the anatomy of vocal sacs in representatives of the Lophyohylini, described eight discrete characters and studied their evolution. We inferred that dorsolateral projections of the vocal sacs were already present during the early evolution of the tribe. Subsequently, they reached surprising volumes in some species, whereas in others they were notably reduced. We inferred between nine and 11 independent events of reduction of the size and lateral projections of the vocal sac, showing unprecedented levels of plasticity for the structure. Moreover, these events were strongly correlated with the colonization of phytotelmata as breeding sites, probably due to their confined space which hampers the inflation of large vocal sacs. Finally, we discuss the evolution of paired lateral vocal sacs in different groups of anurans, and the extent to which the paired and dorsally-projecting lobes of most Trachycephalus differ from those of distantly related taxa. Our findings highlight how variation in internal structure affects the shape of the inflated vocal sac and provides a framework applicable across the Anura. Laboratório de Herpetologia 11.330-900 Instituto de Biociências Campus Do Litoral Paulista Universidade Estadual Paulista, São Paulo División Herpetologiá Museo Argentino de Ciencias Naturales bernardino Rivadavia- CONICET, Avenida Ángel Gallardo 470 Departamento de Biodiversidad y Biologiá Experimental Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires Laboratório de Herpetologia 11.330-900 Instituto de Biociências Campus Do Litoral Paulista Universidade Estadual Paulista, São Paulo

Herein, we describe Panophrys congjiangensissp. nov. obtained from the Yueliangshan Nature Reserve, Congjiang County, Guizhou Province, China. Phylogenetic analyses based on the mitochondrial genes 16S rRNA and COI indicated that this new species represented an independent lineage, closely related to P. leishanensis. The uncorrected genetic distances between the new species and its closest congener, P. leishanensis, were 3.0% for 16S rRNA and 8.4% for COI. The new species is distinguished from its congeners by a combination of the following morphological characteristics (1) medium body size (SVL 28.6–33.4 mm in males and 38.4–40.2 mm in females); (2) a small horn-like tubercle at the edge of each upper eyelid; (3) the tympanum distinctly visible (TD/ED ratio 0.47–0.66); (4) vomerine teeth absent; (5) the tongue not notched behind; (6) a narrow and unobvious lateral fringe on toes; (7) relative finger lengths II < I < V < III; (8) rudimentary webs on toes; (9) hindlimbs slender, heels overlapping when thighs are positioned at right angles to the body; (10) two metacarpal tubercles on the palm, with the inner metatarsal tubercle long and oval-shaped; (11) the tibiotarsal articulation reaching the nostril when the leg is adpressed and stretched forward; (12) dorsal skin rough with numerous orange–red granules, ventral surface smooth; (13) a single internal subgular vocal sac present in males; and (14) in breeding males, weak gray-black nuptial pads with black nuptial spines present on the dorsal surface of the bases of the first and second fingers. To date, the new species is only known from the type locality.

Communication systems often include a variety of components, including those that span modalities, which may facilitate detection and decision-making. For example, female túngara frogs and fringe-lipped bats generally rely on acoustic mating signals to find male túngara frogs in a mating or foraging context, respectively. However, two additional cues (vocal sac inflation and water ripples) can enhance detection and choice behavior. To date, we do not know the natural variation and covariation of these three components. To address this, we made detailed recordings of calling males, including call amplitude, vocal sac volume and water ripple height, in 54 frogs (2430 calls). We found that all three measures correlated, with the strongest association between the vocal sac volume and call amplitude. We also found that multimodal models predicted the mass of calling males better than unimodal models. These results demonstrate how multimodal components of a communication system relate to each other and provide an important foundation for future studies on how receivers integrate and compare complex displays.

Although mate searching behavior in female túngara frogs (Physalaemus pustulosus) is nocturnal and largely mediated by acoustic cues, male signaling includes visual cues produced by the vocal sac. To compensate for these low light conditions, visual sensitivity in females is modulated when they are in a reproductive state, as retinal thresholds are decreased. This study tested whether estradiol (E2) plays a role in this modulation. Female túngara frogs were injected with either human chorionic gonadotropin (hCG) or a combination of hCG and fadrozole. hCG induces a reproductive state and increases retinal sensitivity, while fadrozole is an aromatase inhibitor that blocks hCG-induced E2 synthesis. In an analysis of scotopic electroretinograms (ERGs), hCG treatment lowered the threshold for eliciting a b-wave response, whereas the addition of fadrozole abolished this effect, matching thresholds in non-reproductive saline-injected controls. This suggests that blocking E2 synthesis blocked the hCG-mediated reproductive modulation of retinal sensitivity. By implicating E2 in control of retinal sensitivity, our data add to growing evidence that the targets of gonadal steroid feedback loops include sensory receptor organs, where stimulus sensitivity may be modulated, rather than more central brain nuclei, where modulation may affect mechanisms involved in motivation.

Animal choruses, such as those found in insects and frogs, are often intermittent. Thus females sampling males in the chorus might have to remember the location of the potential mates' calls during periods of silence. Although a number of studies have shown that frogs use and prefer multimodal mating signals, usually acoustic plus visual, it is not clear why they do so. Here we tested the hypothesis that preference for multimodal signals over unimodal signals might be due to multimodal signals instantiating longer memories than unimodal signals, particularly during the inter-chorus intervals. We tested this hypothesis in serrate-legged small treefrogs (Kurixalus odontotarsus) whose males produce advertisement calls accompanied by conspicuous vocal sac inflation. Females were tested with acoustic and acoustic + visual (video of inflating-deflating vocal sac) mating calls. We found that females prefer multimodal calls over unimodal, audio-only calls. Furthermore, multimodal calls are still preferred after a silent period of up to 30 seconds, a time that spans the average silent period of the chorus. This was not true of unimodal calls. Our results demonstrate that a multimodal signal can engage longer working memory than a unimodal signal, and thus female memory might favour the evolution of multimodal signals in males through sexual selection. Selection might also favor female preference for multimodal signals if longer memory facilitates mate searching and assessment. Our study does not allow us to elucidate the sequence of evolution of this trait and preference.

We describe a new species of the genus Kurixalus, Kurixalus raoi sp. nov ., from Guizhou Province, China, based on morphological and molecular evidence. Phylogenetically, the new species is sister to K. idiootocus, but is distinguishable from all known congeners by a combination of the following characters: small body size (snout-vent length 28.2‒32.2 mm in males; 38.6 mm in female); snout rounded, with no prominence on tip; single internal vocal sac; dorsal surface brown, rough, scattered with several small warts; chin clouded with blackish marking; pair of large symmetrical dark blotches on chest; vomerine teeth present; iris brown; tibiotarsal articulation reaching center of eye; nuptial pad slight; flank rough; mandibular symphysis weak; throat skin granular; and toes moderately webbed, formula I2‒2II1.5‒3III2‒3IV3‒2V. The genetic distances between the new species and K. idiootocus were 2.9% and 5.4% for 16S rRNA and COI, respectively.

A new species of the Asian horned toad genus Megophrys is described from Zhejiang Province, China, based on multiple data. Molecular phylogenetic analyses based on mitochondrial DNA indicated the new species as an independent clade deeply clustered into the Megophrys clade. The new species is identified from its congeners by a combination of the following characters: body size small (SVL 28.4–32.4 mm in males); vomerine teeth absent; tongue not notched behind; tympanum distinctly visible, oval; a small horn-like tubercle present at the edge of each upper eyelid; two metacarpal tubercles distinctly visible in hand; toes without webbing; heels overlapped when thighs are positioned at right angles to the body; tibiotarsal articulation reaching the level to middle of eye when leg stretched forward; an internal single subgular vocal sac in male; in breeding male, the nuptial pads present on the dorsal base of the first two fingers.

A new species of the genus Megophrys is described from Guizhou Province, China. Molecular phylogenetic analyses based on mitochondrial DNA indicated the new species as a clade clustered into the Megophrys clade. The new species can be distinguished from its congeners by a combination of the following characters: body size moderate (SVL 40.0–45.5 mm in males and 48.9–51.2 mm in females); vomerine teeth absent; tongue not notched behind; tympanum distinctly visible, oval; a small horn-like tubercle at the edge of each upper eyelid; two metacarpal tubercles in hand; toes with rudimentary webbing; heels overlapping when thighs are positioned at right angles to the body; tibiotarsal articulation reaching the level of mid-eye when leg stretched forward; in breeding males, an internal single subgular vocal sac present and brownish nuptial pads, made up of black nuptial spines, present on the dorsal base of the first two fingers.

Frequent biodiversity sampling and monitoring programs often lead to relevant taxonomic findings. Here, as a product of different field expeditions to two places in the northern Andes, we discover and describe two new species of rain frogs of the genus Pristimantis from the cloud forests of the Central Cordillera of Colombia. Pristimantis chocolatebari sp. nov. is diagnosed by having the following character states: dentigerous process of vomer triangular, snout large and protruding, dorsum smooth, vocal slits and vocal sac present, groin and hidden part of the thighs yellow. Pristimantis carylae sp. nov. is diagnosed by having iris copper red, dentigerous process of vomer oval, snout short and rounded, dorsum finely shagreen with scattered tubercles, double nuptial pad in males, groin and hidden part of thighs pink. We also infer, for the first time, the phylogenetic position of P. permixtus, P. platychilus, and two candidate new species. In addition, we emphasize not to use genetic distance as the only source of evidence for species delimitation, considering the high intraspecific diversity found in one of the species described here. Finally, we highlight the relevance of different habitat and ecosystem conservation strategies to promote amphibian diversity studies in the Andes.

We describe a new species of Rhinella from montane forests between 1788 and 2305 m a.s.l. in the Departamentos Amazonas and San Martín, Peru. We tentatively assign the new species to the Rhinella festae species Group based on morphological similarities with its other 19 members. It is characterised by large size (maximum SVL 91.6 mm in females), a pointed and protruding snout that is posteroventrally inclined, absence of a visible tympanic annulus and tympanic membrane, long parotoid glands in contact with upper eyelid, presence of a dorsolateral row of enlarged tubercles, outer dorsolateral tarsus surface with a subconical ridge of fused tubercles, and absence of subgular vocal sac and vocal slits in males. One specimen from Departamento Amazonas tested positive for Batrachochytrium dendrobatidis.

We describe a new species of Thoropa, previously identified as T. lutzi, from the northern region of the Serra da Mantiqueira in the Atlantic Forest domain in Southeast Brazil. The new species is diagnosed by the following combination of characters: small size; slender body; head longer than wide; dark colored nuptial pads on the inner side of the Finger I and on the internal carpal tubercle; nuptial pads with epidermic cone-shaped papillae measuring of 53.1–91.6 μm in diameter, and at a density of 14–32 papillary epidermic projections/mm2; presence of vocal sac and vocal slits; and advertisement call with 5–10 harmonics, duration of 0.23–0.42 s, and peak of frequency of 2060–4470 Hz. With the description of the new species, T. lutzi is now only known for the state of Rio de Janeiro.

A new species of green frog of the genus Euphlyctis Fitzinger, 1843 is described from West Bengal, a state of eastern India. A robust frog, SVL of male 86mm and that of female 132mm. The species is diagnosed by the presence of following characters: green dorsum and female with a greenish white mid-dorsal line, tibiotarsal articulation reaches eye, male with two vocal sac openings at the junction of jaw, female is larger than male though body parameters is proportionately longer in male, nostril snout length 3.45% of SVL, nostril much closer to snout tip than eye, units of hind limb i. e. thigh, shank and foot are almost equal in length, relative length of finger: II < IV < I < III.The new species is compared with existing eight species of the genus Euphlyctis.

Vocal sacs are present in most species of frogs and are the product of the interaction of three elements: the gular skin, the superficial submandibular musculature and an internal mucosa derived from the buccal floor. In this paper, we surveyed the structural diversity in the vocal sac of microhylids and related families in 109 exemplar species, including 11 of the 13 currently recognized subfamilies. We defined five characters related to anatomical and histological properties of the m. interhyoideus, as well as the relationship of this muscle and the vocal sac internal mucosa. We describe a vocal sac configuration characterized by highly abundant elastic fibres in association with muscle fibres, a very unusual structure in animal tissues. We discuss the evolution of novel structures in a phylogenetic context and identify new synapomorphies for Microhylidae and internal clades. Furthermore, we comment on the functional implications that these features have in vocal sac inflation.

A new species of the genusGracixalus,Gracixalusyunnanensissp. n., is described based on a series of specimens collected from southwestern and southern Yunnan, China. This species is distinguished from all other known congeners by a combination of the following characters: relatively small body size in adult males (SVL 26.0–34.2 mm); dorsal surface yellow brown or red brown; distinctive conical asperities on dorsum; males with an external subgular vocal sac and linea masculina; throat, chest, and belly nearly immaculate; venter surface orangish with yellow spots, semi-transparent; snout rounded; supratympanic fold distinct; iris bronze; lack of white patch on temporal region; tibiotarsal projection absent; sides of body nearly smooth with no black blotch; finger webbing rudimentary; and toe webbing formula I1.5–2II1.5–2.7III.5–3IV2.5–1.5V. Genetically, the new species diverges from its congeners by 2.2%–14.1% (uncorrected p-distance) and is closest toG.guangdongensis. However, the new species can morphologically be separated fromG.guangdongensisby distinctive conical tubercles on dorsum (versus absent), lateral surface nearly smooth with no black blotches on ventrolateral region (versus lateral surface rough, scattered with tubercles and black blotches on ventrolateral region), snout rounded (versus triangularly pointed), iris bronze (versus iris brown), and ventral surface orangish (versus throat and chest creamy white and belly light brown).

A new bush frog species, Raorchestes cangyuanensis sp. nov. , from Cangyuan, Yunnan Province, China, is described based on morphological and molecular analyses. It differs from all known congeners by a combination of the following characters: body size small, adult snout-vent length (SVL) 16.1–20.0 mm in males (n=3); tympanum indistinct; tips of all fingers and toes expanded into discs with circummarginal grooves; rudimentary webbing between toes; fingers and toes with lateral dermal fringes; inner and outer metacarpal tubercles present; heels meeting when limbs held at right angles to body; crotch with a distinct black patch; discs of fingers and toes orange; male with external single subgular vocal sac and reddish nuptial pad at the base of first finger.

Made available in DSpace on 2021-06-25T10:48:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-06 We describe a new species of the Scinax ruber clade from Northeastern Brazil that occurs in widely separated geographic areas in the Atlantic Forest of southern Bahia state and the Highland Humid Forest of Serra de Baturité, northeast Ceará state. Scinax tropicalia sp. nov. (holotype coordinates: -14.795694°, -39.172645°) is diagnosed from all 75 currently recognize species of the S. ruber clade by bioacoustical and morphological adult traits, such as duration (0.11–0.31 s) and dominant frequency (1.59–1.85 kHz) of the advertisement call, snout shape rounded, nearly rounded, or semi-circular in dorsal view and rounded to slightly protruding in profile, bilobate vocal sac, absence of pectoral glands and spicule-shaped papillary epidermal projections on nuptial pads, and color pattern on the dorsum of body and hidden surfaces of hindlimbs. Programa de Pós-Graduação em Zoologia Universidade Estadual de Santa Cruz, Rodovia Jorge Amado, Km 16 División Herpetología Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”—CONICET, Av. Ángel Gallardo 470 Programa de Pós-graduação em Biologia de Ambientes Aquáticos Continentais Laboratório de Vertebrados Instituto de Ciências Biológicas Universidade Federal do Rio Grande—FURG, Av. Itália, Km 8 Departamento de Biologia Universidade Federal do Ceará, Avenida Mister Hull, s/n, Núcleo Regional de Ofiologia, Bloco 905, Pici Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160 Laboratório de Herpetologia Departamento de Biodiversidade and Centro de Aquicultura (CAUNESP) Universidade Estadual Paulista—UNESP, Av. 24 A, 1515, Bairro Bela Vista Laboratório de Herpetologia Departamento de Biodiversidade and Centro de Aquicultura (CAUNESP) Universidade Estadual Paulista—UNESP, Av. 24 A, 1515, Bairro Bela Vista

A new species of the genus Megophrys is described from Guizhou Province, China. Molecular phylogenetic analyses supported the new species as an independent clade nested into the Megophrys. The new species could be distinguished from its congeners by a combination of the following characters: body size moderate (SVL 49.3–58.2 mm in males); vomerine ridges present distinctly, vomerine teeth present; tongue feebly notched behind; tympanum distinctly visible, oval; two metacarpal tubercles in hand; toes with one-third webbing and wide lateral fringes; heels overlapped when thighs are positioned at right angles to the body; tibiotarsal articulation reaching the level between tympanum and eye when leg stretched forward; an internal single subgular vocal sac present in male; in breeding male, the nuptial pads with large and sparse black nuptial spines present on the dorsal bases of the first two fingers.

In animal communication, receivers benefit from signals providing reliable information on signallers’ traits of interest. Individuals involved in conflicts, such as competition between rivals, should pay particular attention to cues that are ‘unfakeable’ by the senders due to the intrinsic properties of the production process. In bioacoustics, the best-known example of such ‘index signals’ is the relationship between a sender’s body size and the dominant frequency of their vocalizations. Dominant frequency may however not only depend on an animal’s morphology but also on the interaction between the sound production system and its immediate environment. Here, we experimentally altered the environment surrounding calling frogs and assessed its impact on the signal produced. More specifically, we altered water level, which forced frogs to float on the surface and tested how this manipulation affected the shuttling of air between the lungs and the vocal sac, and how this in turn impacted the calls’ dominant frequency. Our results show that frogs that are floating are able to fully inflate their lungs and vocal sacs, and that the associated change in airflow or air pressure is correlated with a decrease of call dominant frequency.

A new species of the genus Megophrys is described from Guizhou Province, China. Molecular phylogenetic analyses based on mitochondrial DNA and nuclear DNA sequences all strongly supported the new species as an independent clade sister to M. minor and M. jiangi. The new species could be distinguished from its congeners by a combination of the following characters: body size moderate (SVL 43.4–44.1 mm in males, and 44.8–49.8 mm in females; vomerine teeth absent; tongue not notched behind; a small horn-like tubercle at the edge of each upper eyelid; tympanum distinctly visible, rounded; two metacarpal tubercles on palm; relative finger lengths II < I < V < III; toes without webbing; heels overlapping when thighs are positioned at right angles to the body; tibiotarsal articulation reaching the level between tympanum and eye when leg stretched forward; in breeding males, an internal single subgular vocal sac in male, and the nuptial pads with black spines on dorsal surface of bases of the first two fingers.

Recent studies have shown that species diversity of the South American frog genus Dendropsophus is significantly underestimated, especially in Amazonia. Herein, through integrative taxonomy a new species of Dendropsophus from the east bank of the upper Madeira River, Brazil is described. Based on molecular phylogenetic and morphological analyses, the new species is referred to the D. microcephalus species group, where it is differentiated from its congeners mainly by having a green bilobate vocal sac and an advertisement call comprising 1–4 monophasic notes emitted with a dominant frequency of 8,979–9,606 Hz. Based on intensive sampling conducted in the study area over the last ten years, the new species is restricted to the east bank of the upper Madeira River, although its geographic range is expected to include Bolivian forests close to the type locality.

A new species of the genusMegophrysfrom Zhejiang Province, China is described. Molecular phylogenetic analyses supported the new taxon as an independent clade nested into theMegophrysclade and sister toM. lishuiensis. The new species could be distinguished from its congeners by a combination of the following morphological characteristics: (1) small size (SVL 31.0–36.3 mm in male and 41.6 mm in female); (2) vomerine ridge present and vomerine teeth absent; (3) tongue not notched behind; (4) a small horn-like tubercle at the edge of each upper eyelid; (5) tympanum distinctly visible, rounded; (6) two metacarpal tubercles in hand; (7) relative finger lengths: II < I < IV < III; (8) toes with rudimentary webbing at bases; (9) heels overlapping when thighs are positioned at right angles to the body; (10) tibiotarsal articulation reaching tympanum to eye when leg stretched forward; (11) an internal single subgular vocal sac in male; (12) in breeding male, the nuptial pads with black nuptial spines on the dorsal bases of the first and second fingers.

A new species of Megophrys is described from Cao Bang Province, northeastern Vietnam based on morphological and molecular data. Morphologically, the new species is distinguishable from its congeners by a combination of the following characters: Size small (SVL 34.9–38.9 mm in males); tympanum visible; vomerine teeth absent; tongue not notched posteriorly; male with a single vocal sac; toes with rudimentary webbing; subarticular tubercles and lateral fringes absent on all digits; nuptial pads present on fingers I and II in males, with spicules; dorsal skin with scattered granules and tubercles; flank with tubercles; dorsum with a X-shaped dorsal ridge; dorsolateral folds prominent; a small horn-like tubercle present at the outer edge of the eyelid; dorsal surface yellowish brown with a dark brown triangle between the eyes, and a dark brown marking along the X-shaped ridge on the back. In the phylogenetic analyses, the new species is unambiguously nested within the subgenus Panophrys with interspecific uncorrected genetic p-distances (16S rRNA gene) varying from 4.26% (compared with M. rubrimera) to 10.80% (compared with M. acuta).

We describe a new species of Zhangixalus from southern Yunnan of China, Vietnam, and Thailand based on morphological and molecular evidence. The new species had been confused with Zhangixalus smaragdinus (Blyth, 1852) in the past. Zhangixalus pachyproctus sp. nov. can be distinguished from Z. smaragdinus morphologically by the protruding vent in adult males, large thick grey reticular mottles below the white stripe on flank, more oblique snout in profile and wider head, longer snout, greater internarial distance, larger tympanum and longer hindlimb. The new species can be distinguished from other species of Zhangixalus with green dorsum by the following combination of characters: body size larger (SVL of adult males: 74.2–83.3 mm; SVL of adult female: 102.4 mm); dorsum smooth; narrow white stripes along edge of the lower jaw, body sides, outer side of limbs and above the vent; absence of brown bands on canthus rostralis, upper eyelid and supratympanic fold; webbing between fingers and toes complete except between the first two fingers; and internal single subgular vocal sac. Phylogeny based on comparison of 16S rRNA sequences suggests that the new species is the sister taxon to Z. smaragdinus and the two species differ by 7.63% in the uncorrected pairwise distance of 16S sequences.

Made available in DSpace on 2020-12-12T01:49:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Universidade Estadual Paulista We describe a new species of Ischnocnema from the Serra da Bocaina mountain range, state of São Paulo, southeastern Brazil, based on morphological, bioacoustic, and mtDNA data. The new species is retrieved with high support values within the I. lactea species series as the sister species of I. spanios. Ischnocnema bocaina sp. nov. is characterized by its medium size (18.6–19.0 mm), a smooth venter, a rounded snout in dorsal view and acuminate in lateral view, a slightly expanded subgular, single vocal sac, a round and whitish, poorly-developed glandular-appearing nuptial pad on the dorsal surface of the thumb, and a nonpulsed advertisement call with 9 to 18 notes. We raise to 38 the number of Ischnocnema species, the 12th described in the past 10 years. Instituto de Biociências UNESP – Universidade Estadual Paulista Câmpus Rio Claro Departamento de Zoologia e Centro de Aquicultura (CAUNESP), Cx. Postal 199 Instituto de Ciências Biológicas UFMG – Universidade Federal de Minas Gerais Departamento de Zoologia Laboratório de Herpetologia, Avenida Antônio Carlos, 6627, Pampulha Museu de Zoologia da Universidade de São Paulo, Avenida Nazaré 481 Instituto de Biociências UNESP – Universidade Estadual Paulista Câmpus Rio Claro Departamento de Zoologia e Centro de Aquicultura (CAUNESP), Cx. Postal 199

A new species of the genus Kurixalus (Anura: Rhacophoridae) is described from western Yunnan, China. Genetically the new species, Kurixalusyangi sp. n., is closer to Kurixalusnaso than to other known congeners. Morphologically the new species is distinguished from all other known congeners by a combination of the following characters: smaller ratios of head, snout, limbs, IND, and UEW to body size; male body size larger than 30 mm; curved canthus rostralis; weak nuptial pad; brown dorsal color; absence of large dark spots on surface of upper-middle abdomen; presence of vomerine teeth; gold brown iris; single internal vocal sac; serrated dermal fringes along outer edge of limbs; granular throat and chest; rudimentary web between fingers; and presence of supernumerary tubercles and outer metacarpal tubercle.

Animals choosing particular display sites often balance sexual and natural selection pressures. Here we assess how physical properties of display sites can alter this balance by influencing signal production and attractiveness of the túngara frog (Physalaemus pustulosus). Males that call from very shallow water bodies (few mm depth) benefit from reduced predation risk, but by manipulating water levels, we show that this comes at a cost of reduced attractiveness to females. Our data show that calling from shallower water reduces a male’s ability to float, limits the inflation of his vocal sac, and consequently reduces signal conspicuousness in terms of amplitude and complexity. Our results demonstrate that display site properties can set limits on signal production and attractiveness and may hence influence signal evolution. Signallers may shift between sites or engineer their display location, which can play a crucial role in signal divergence and speciation, particularly in a rapidly changing world., Animal sexual signals should be conspicuous to mates but not to enemies. Here, the authors show that call site properties can set limits on the attractiveness of male frogs' advertisement call, but that males may balance sexual success over predation risk by digging deeper puddles.

Multimodal communication has received increasing attention in recent years. While much is understood about how intended receivers (such as potential mates) respond to multimodal displays, less is known about how eavesdropping predators perceive and interpret these cues. The male túngara frog, Physalaemus pustulosus, is a neotropical anuran that attracts females with an acoustic call and a dynamically inflating/deflating vocal sac. However, the túngara frog's multimodal courtship display also attracts eavesdropping predators, such as fringe-lipped bats, Trachops cirrhosus. We utilized robotic frog models to expose fringe-lipped bats to multimodal túngara frog courtship displays. The models varied in call amplitude and/or the presence of vocal sac cues. In a two-choice test, we show that fringe-lipped bats more often attack higher-amplitude calls. Additionally, coupling the inflating vocal sac cues to the lower-amplitude frog call increased the probability that a bat would attack this less attractive call. Previous studies have demonstrated that vocal sac cues do not increase the attractiveness of low-amplitude calls to female P. pustulosus. Thus, although natural selection, through the bats, and sexual selection, through the female frogs, exert counter-selection forces on the male's sexual display, the strength of these forces are not symmetrical. We discuss possible explanations for why this might be the case. This study underlines the importance of understanding the contribution of both intended and unintended receivers on signal evolution, and it helps explain how selection pressures might vary across sensory modalities.