Nuptial Pads Research Articles

A new colorful species of Pristimantis (Anura: Craugastoridae) from the eastern flank of the Cordillera Central in Colombia.

We describe a new species of Pristimantis from the humid forests on the eastern flank of the northern Cordillera Central in Colombia (6º 23' 19.3554" N, 75º 1' 24.0594" W; ca. 1150 m.a.s.l.). Pristimantis jaguensis sp. nov. is characterized by an extraordinary variation in color and is readily distinguished from congeneric species by lacking nuptial pads, discoidal fold and conical calcar tubercles; flanks and belly white to cream without blotches as well as iris yellow ocher to copper with thick brown reticulation and cream sclera. Molecular phylogenetic analyses recovered the new species in a clade with species mostly distributed in Ecuador. Our finding suggests that new taxa can still be discovered in the Middle Magdalena River valley of Colombia despite the extensive sampling this region has received during the last decades.

A new species of the Scinax catharinae Group (Anura: Hylidae) from Northeastern Brazil.

We describe a new species of the Scinax catharinae Group from Municipality of Porto Seguro, State of Bahia northeastern Brazil. The new species is mainly characterized by its small size, nuptial pad dark colored, and compound pectoral fold. Additionally, we describe the structure of its nuptial pad and compare it with that of S. agilis. We also briefly discuss its phylogenetic relationships within Scinax.

A new species of Phrynopus (Anura: Craugastoridae) from the central Peruvian Andes.

We describe a new species of Phrynopus from the humid grassland of Distrito de Comas, Provincia Concepcion, Department of Junin. The new species is diagnosed by the lack of dentigerous processes of vomers, tympanic annulus and membrane imperceptible through the skin, males with nuptial pads and vocal slits, warty dorsal skin, and aerolate throat, belly and ventral surfaces of thighs, by possessing pronounced subconical tubercles in the post-tympanic area, by having rounded finger and toe tips with no disc structure, and by its overall dark brown to black coloration with few white and yellow spots in the dorsum and a dark-brown belly with white to gray blotches. Specimens were found under stones at a single area of the central Peruvian Andes at elevations between 4205-4490 m.a.s.l. The eggs had an average diameter of 4.3 mm. With the description and naming of the new species, the genus Phrynopus now contains 26 species, all of them endemic to Peru, and five of which are restricted to Departamento Junin.

Body size, nuptial pad size and hormone levels: potential non-destructive biomarkers of reproductive health in wild toads (Bufo bufo)

Amphibians are declining and fertility/fecundity are major drivers of population stability. The development of non-destructive methods to assess reproductive health are needed as destructive measures are fundamentally at odds with conservation goals for declining species. We investigated the utility of body size, nuptial pad size and forelimb width as non-destructive biomarkers of internal reproductive physiology, by analysing correlations with commonly used destructive methods in adult male toads (Bufo bufo) from a low human impact and a high human impact site. Principal component analyses revealed that size was the most important variable for explaining inter-individual differences in other measured endpoints, both non-destructive and destructive, except for hormone levels and nuptial pad, which were independent of size. Toads from the LI and the HI site differed in almost all of the measured endpoints; this was largely driven by the significantly smaller size of toads from the HI site. Correlational analyses within sites revealed that size was correlated with several reproductive endpoints in toads from the HI site but not the LI site, indicating a possible limiting effect of size on reproductive physiology. Intersex was observed in 33% of toads from the HI site and incidence was not related to any other measured endpoint. In conclusion, we provide evidence that size is associated with reproductive physiology and that nuptial pad/hormone levels have potential as additional markers due to their independence from size. We also show that human activities can have a negative effect on reproductive physiology of the common toad.

Two new species of Kalophrynus Tschudi, 1838 (Anura: Microhylidae) from the Annamite mountains in southern Vietnam

We describe two new mountain-dwelling microhylid species of the genus Kalophrynus from the southern part of the Annamite Mountains in Vietnam. The two new species differ from all known congeners in morphological characters and mtDNA; phylogenetically, they form a sister clade to the large-bodied K. interlineatus (1009 bp, 16S rRNA gene, mtDNA). Both species share the following characteristics: snout pointed in dorsal and lateral views, slightly sloping in profile; tympanum distinct, smaller than eye in diameter; toe webbing moderate; outer metatarsal tubercle present; light dorsolateral line absent. Kalophrynus cryptophonus sp. nov. from Loc Bao, Lam Dong Province is a small-sized species distinguishing from its congeners by a combination of: SVL 27.9-30.4 mm in males, 23.4 mm in female; canthus rostralis indistinct; males with large sharp conical spines on the skin covering mandible margins and finely asperous nuptial pads on the dorsal surface of fingers I-III; dark ocelli in the inguinal region usually present, small, without a light border; anterior palatal dermal ridge short, restricted to medial part of palate. Kalophrynus honbaensis sp. nov. from Hon Ba, Khanh Hoa Province is a medium-sized Kalophrynus, distinguishing from its congeners by a combination of: SVL 26.7-36.8 mm in males; canthus rostralis distinct; males without distinguishable spines on the mandible margins nor the nuptial pads; dark ocelli in the inguinal region present, large, without a distinct light border, anterior palatal dermal ridge developed, parallel to posterior one. Kalophrynus cryptophonus sp. nov. reproduces in hollow bamboo stems; we describe larval morphology and bioacoustics of this species in relation to phytotelm breeding. A review of the distribution of the genus Kalophrynus in Indochina is provided.

A new rainfrog of the Pristimantis myersi Group (Amphibia, Craugastoridae) from Volcán Pichincha, Ecuador.

A new frog of the Pristimantis myersi Group is described from a bamboo patch within the Reserva Ecológica Verdecocha (0°5'46.9"S, 78°36'15.3"W; 2851 m), located at northwestern flank of the Volcán Pichincha, in the vicinities of Quito, Ecuador. The new species is known from eight adult males, whereas the females remain unknown; it can be readily distinguished from all species of the P. myersi Group that inhabit the highlands of the Ecuadorian Andes by the unique combination of the following characters: body small (adult male SVL 14.9-19.7 mm; females unknown); dorsal skin shagreen, with a barely visible middorsal raphe, scapular and dorsolateral folds; tympanum small but well-defined; upper eyelid with one enlarged tubercle; males with prominent vocal slits, but without nuptial pads on thumbs; fold-like tarsal tubercles. With this new species, the number of Pristimantis assigned to the P. myersi Group raises to 16, of which, 12 are in Ecuador. We provide notes on morphology and color variation, advertisement call, and natural history of the new species.

A new Philautus (Anura: Rhacophoridae) from northern Laos allied to P. abditus Inger, Orlov & Darevsky, 1999.

The small rhacophorid frog Philautus abditus is geographically restricted to central Vietnam and adjacent Cambodia. Our fieldwork in northern Laos resulted in the discovery of a Philautus species that very closely resembles P. abditus, but is at least 330 km from the nearest known locality of that species. The Laos population differs from P. abditus in mitochondrial DNA and coloration, and is described here as a new species. Philautus nianeae sp. nov. is distinguished from its congeners by having the combination of a hidden tympanum; no nuptial pads; smooth skin; large black spots on the hidden surfaces of the hind limbs; light venter with dark spotting; and a bronze iris. A second species of Philautus from northern Laos, P. petilus, is transferred on the basis of morphology to the genus Theloderma.

Raorchestes ghatei, a new species of shrub frog (Anura: Rhacophoridae) from the Western Ghats of Maharashtra, India

A new species of shrub frog Raorchestes ghatei is described from the Western Ghats of Maharashtra. The species differs from its congeners based on a combination of characters including small to medium-sized adult males, snout mucronate in dorsal view, canthus rostralis angular and sharp, snout slightly projecting beyond mouth ventrally, tympanum indistinct and one third of the eye diameter, tongue without papilla but with a lingual pit, nuptial pad rudimentary to absent, a bony tubercle on humerus at the end of deltoid ridge present in males and absent in females, skin finely granulated or smooth dorsally, lateral side marbled with white blotches on brown to black background. Molecular phylogeny based on 16S rRNA gene sequence suggests that the new species is genetically distinct and forms a monophyletic clade within Raorchestes. The species exhibits sexual dimorphism with males having single sub-gular vocal sac and a tubercle on the humerus while females lack them. The species shows direct development. The species is widely distributed in the Western Ghats of Maharashtra.

Two new charismatic Pristimantis species (Anura: Craugastoridae) from the tepuis of the "Lost World" (Pantepui region, South America)

Two new colourful species of direct-developing frogs of the genus Pristimantis are described from the summit of two isolated tepuis (sandstone table mountains) in the Eastern Pantepui District of the Guiana Shield highlands. Pristimantis jamescameroni sp. nov. is described from the summit of Aprada-tepui from 2557-2571 m elevation, and P. imthurni sp. nov. is described from the summit of Ptari-tepui at 2471 m elevation. Both species share the absence of a differentiated tympanic membrane and external tympanic annulus (but presence of tiny pharyngeal ostia), the presence of nuptial pads in males, and the presence of lateral fringes on fingers and toes, a combination of characters that immediately distinguishes them from all other known Pantepui congeners. The two new species are morphologically similar to each other and are phylogenetically closely related, but they can be distinguished based on colour pattern and morphological characters such as head proportions, dorsal skin texture, and condition of the supratympanic fold. The IUCN conservation status of the new species is considered as Endangered (EN) owing to their apparent very restricted ranges. The number of described Pristimantis species occurring exclusively on tepui (and faunistically related granitic mountains) summits and upper slopes now reaches eleven.

A New Species ofHyloscirtus(Anura: Hylidae) from Colombia, with a Rediagnosis ofHyloscirtus larinopygion(Duellman, 1973)

Abstract: Hyloscirtus larinopygion is rediagnosed, and a new species formerly confused with that species is described from the highlands of the Central Cordillera in the Andes Mountains of Colombia. The new species differs from the other species of the H. larinopygion group by its color pattern, iris coloration, and presence of a nuptial pad with dark-brown epidermal projections. We discuss variation and diversity of nuptial pads, the calcar tubercle, and some aspects related to the swollen cloacal region in the H. larinopygion group. Finally, we discuss reproductive biology and problems involving the definition of a putative synapomorphy of Hyloscirtus.

Terraranans of the Lost World: a new species of Pristimantis (Amphibia, Craugastoridae) from Abakapá-tepui in the Chimantá massif, Venezuelan Guayana, and additions to the knowledge of P. muchimuk.

A new frog of the genus Pristimantis is named and described from the summit of Abakapá-tepui in the Chimantd massif, south-eastern Venezuela. The new species is known from two adult specimens and is the second craugastorid species described from this massif. It can be readily distinguished from all congeners inhabiting the highlands of the Guiana Shield by the unique combination of the following characters: dorsal skin shagreen and ventral skin coarsely areolate, tympanum small and ill-defined, vocal slits absent in males, finger I shorter than II, thumbs with two whitish and non-spinous nuptial pads in adult males, fingers and toes with broad lateral fringes, basal webbing between all toes, throat and chest nacreous white in life. Also, based on five specimens of Pristimantis muchimuk recently collected from Churi-tepui, we provide new information on this little known species, including an amended diagnosis, notes on morphology, color variation, advertisement calls, and natural history.

Structure and Functional Significance of the Nuptial Thumb Pads in Rana esculenta and R. perezi

The nuptial thumb pads of Rana esculenta and R. perezi are cutaneous specialisations including rows of glands, defined nuptial glands, embedded in the pad dermis. The pads are covered by a black, strongly keratinised epidermis, where high papillae alternate with gland pores. The mucous nature of the above glands is confirmed both under light and transmission electron microscopes. The nuptial pads function in promoting male’s ability to retain the female during amplexus. The nuptial glands release their product onto the keratinised pads, which indicates an adhesive function of the secretion. Such performance is synergic with the complex ridge apparatus of the pad surface, capable of working like a multi-lamellar sucker. Secretions of these glands may also prevent sexual interference by rival males.

A new species of the Scinax catharinae group (Anura, Hylidae) from Serra da Canastra, southwestern state of Minas Gerais, Brazil

We describe Scinax pombali sp. n. a new species of treefrog of the Scinax catharinae group from Serra da Canastra, municipality of Capitólio (20°36'03''S, 46°17'34.9''W, 987 m a.s.l.), located in the Cerrado domains of the State of Minas Gerais, Southeastern Brazil. The new species is characterized by its small size, blotches and color pattern on dorsal surface and hidden regions of flanks and thighs, canthus rostralis lightly concave and well marked, absent nuptial pad, and lack of externally differentiated inguinal gland. Additionally, we describe the tadpole of this new species, which is characterized by the large-sized oral disc and presence of a large number of marginal papillae (two to three rows on its dorsal portion and some rows in unorganized arrangement on its lateroventral portion).

Frog nuptial pads secrete mating season-specific proteins related to salamander pheromones

Males of many frog species develop spiny nuptial pads with underlying glands on their thumbs during the mating period. We used 3D visualization on the European common frog Rana temporaria to show that the morphology of these glands allows the channelling of secreted molecules to the pad's surface during amplexus. Combined transcriptome and proteome analyses show that proteins of the Ly-6/uPAR family, here termed amplexins, are highly expressed in the nuptial glands during the mating season, but are totally absent outside that period. The function of amplexins remains unknown, but it is interesting to note that they share structural similarities with plethodontid modulating factors, proteins that influence courtship duration in salamanders.

An Extraordinary New Species ofMelanophryniscus(Anura, Bufonidae) from Southeastern Brazil

We describe a new species of bufonid from a lowland, sandy soil, restinga habitat in the state of Espírito Santo, southeastern Brazil. Based on the shared occurrence of putative morphological synapomorphies of Melanophryniscus and the results of a phylogenetic analysis of DNA sequences of a broad sample of bufonids, and other anurans, we assign the new species to Melanophryniscus. The new species possesses several peculiar character states that distinguish it from all other Melanophryniscus including, but not limited to: fingers II, III, and V much reduced; nuptial pad with few enlarged, brown-colored spines on medial margin of finger II; seven presacral vertebrae, the last fused with the sacrum; and ventral humeral crest prominent, forming a spinelike projection.

Trenbolone causes mortality and altered sexual differentiation in Xenopus tropicalis during larval development

Trenbolone is an androgen agonist used in cattle production and has been measured in aquatic systems associated with concentrated animal-feeding operations. In this study, the authors characterized the effects of aqueous exposure to 17β-trenbolone during larval Xenopus tropicalis development. Trenbolone exposure resulted in increased mortality of post-Nieuwkoop-Faber stage 58 tadpoles at concentrations ≥100 ng/L. Morphological observations and the timing of this mortality are consistent with hypertrophy of the larynx. Development of nuptial pads, a male secondary sex characteristic, was induced in tadpoles of both sexes at 100 ng/L. Effects on time to complete metamorphosis or body sizes were not observed; however, grow-outs placed in clean media for six weeks were significantly smaller in body size at 78 ng/L. Effects on sex ratios were equivocal, with the first experiment showing a significant shift in sex ratio toward males at 78 ng/L. In the second experiment, no significant effects were observed up to 100 ng/L, although overall sex ratios were similar. Histological assessment of gonads at metamorphosis showed half with normal male phenotypes and half that possessed a mixed-sex phenotype at 100 ng/L. Hypertrophy of the Wolffian ducts was also observed at this concentration. These results indicate that larval 17β-trenbolone exposure results in effects down to 78 ng/L, illustrating potential effects from exposure to androgenic compounds in anurans.

A new small Phrynobatrachus (Amphibia: Anura: Phrynobatrachidae) from southern Cameroon

We describe a new small Phrynobatrachus species from southern Cameroon. The new species exhibits a combination ofunique morphological characters and a distinctive colour pattern consisting of a black lateral face mask, a black throat inmales, a white throat with uniform black lower mandibles in females and a white belly in both sexes. Morphologically itis characterized by small size, absence of an eyelid cornicle, presence of black spines on anterior part of vocal sac in males,spines on flanks, presence of discs on toe and finger tips, distinct webbing, absence of nuptial pads on male thumbs andscapular ridges converging in a straight line. Analysis of mitochondrial 16S rRNA revealed that the new species differsfrom 34 other West and Central African species of the genus by a minimum distance of 4.5% and is most similar to severalPhrynobatrachus species which are almost all endemic to the Cameroon volcanic line or parts of it, i.e. P. chukuchuku(4.9%), P. werneri (5.1%), P. steindachneri (5.2%), P. schioetzi (5.6%), P. batesii (5.9%), P. cricogaster (5.5%), P. danko(6.1%), and P. manengoubensis (6.1%), respectively. The new species is most similar to P. batesii, which was describedfrom forests close to the type locality of the new species. Morphologically the new species differs from P. batesii by muchsmaller size (< 20 mm vs. 25-31 mm), shape of scapular ridges, belly colour, shorter shanks, absence of nuptial pads and presence of gular spines in breeding males.

New insights into sexually dimorphic skin glands of anurans: The structure and ultrastructure of the mental and lateral glands in Hypsiboas punctatus (Amphibia: Anura: Hylidae)

Many anuran species are characterized by sexually dimorphic skin glands. These glands often are concentrated on specific areas, such as the mental region, flanks, or the nuptial pads. We studied the histology and histochemistry of mental and lateral glands in Hypsiboas punctatus, and compared them to skin from other body regions. We describe four types of dermal glands, two types of mucous and two types of serous glands. The mucous glands are formed by a single layered epithelium. The mucocytes surrounding a central lumen are filled with polyhedral granules. Ordinary mucous glands are small sized glands with cubical epithelium, mucoid content, and small granules. Specialized mucous glands are characterized by a larger size, a columnar epithelium, a proteinaceous content and larger granules. Both types of serous glands are syncytial and share some structural features including size, shape, and morphology of secretory granules. However, ordinary and specialized serous glands differ in their histochemical properties, size and appearance of secretory granules, and glandular outlets. The specialized type of mucous glands in H. punctatus resembles most SDSGs described in anurans, whereas the presence of specialized serous glands that are sexually dimorphic is less common. Both specialized glands occur only in mental and lateral regions of males, whereas ordinary mucous and ordinary serous glands occur in males and females.

A scanning electron microscopic study of the surface morphology of nuptial pads in male amphibians (Genus: Bombina , Pelophylax , Rana )

The fine structure of nuptial pad surface of the anuran amphibians Bombina variegata , Pelophylax epeiroticus , Pelophylax ridibundus and Rana dalmatina , was examined by scanning electron microscopy. Nuptial pads are cutaneous secondary sexual characters of males that appear during the breeding season and disappear afterwards following an annual cycle. In males of P. epeiroticus , P. ridibundus and R. dalmatina , nuptial pads were observed on the ventrolateral aspect of the first digit (the thumb) as darkish and remarkably keratinized papillae. In males of B. variegata nuptial pads were almost black and very visible on the thumb, the second and the third digit of the front legs. They also extended on the ventral surface of the forearms. Under scanning electron microscope numerous small papillae were observed rising above pad’s surface. In P. epeiroticus , P. ridibundus and R. dalmatina , these papillae were almost rounded at the base while at the dome shaped top they had many microprocesses organised in groups, thus assuming the shape of a “flower” which differed slightly among these three ranid species. In B. variegata the protuberances were conical with heavily keratinized hooks without microprocesses. Our results show that surface morphology of nuptial pads is unique for each species and could be considered as a species-specific character.

A new species of Pristimantis (Anura: Strabomantidae) from the Brazilian Cerrado

A new species of Pristimantis (Anura: Strabomantidae) from the Pristimantis conspicillatus group is described from theCerrado biome in central Brazil. Pristimantis ventrigranulosus sp. nov. is found in riparian forests associated with a par-ticular palm tree called “babaçú” (Attalea speciosa: Aracaceae) in northwestern Goiás state of Brazil. The new species isonly known from the type locality: Fazenda Macaúba (16°35’23” S; 51°47’43” W, approximately 400 m above sea level),Piranhas Municipality in the state of Goiás. The new species differs from the other species in the P. conspicillatus groupmainly by having, an homogeneously granular belly, Finger I > Finger II, dorsal skin coarsely shagreen, toe and fingerfringes weakly developed or absent, presence of basal webbing and tarsal fold, single nuptial pad on thumb, moderatelydeveloped and round discs on Fingers III and IV, and higher dominant frequency than other Pristimantis with similar calls(ranging 3451.8−4334.8 Hz). The new species shows an advertisement call equal in structure to the calls of P. dundeei, P. fenestratus, P. koehleri and P. vilarsi. Pristimantis dundeei is transferred to the P. conspicillatus group.