Small Frogs Research Articles

Variation of the quantity of lymph in the subcutaneous sinuses in the Common frog (<i>Rana temporaria</i>)

Seasonal variation in the amount of fluid in the subcutaneous lymphatic sinuses of the common frog (Rana temporaria) and differences in the dynamics of its mass in adult males and females from autumn to spring are shown. The hypothesis that enlarged lymphatic sinuses (one of the elements of the “nuptial attire” of R. temporaria) can be used by small frogs to gain competitive advantages in assortative pair selection during reproduction is tested.

Diet, sexual dimorphism, and fertility aspects of Melanophryniscus fulvoguttatus (Mertens, 1937) from Central-East Brazil

Melanophryniscus fulvoguttatus is a small toad that inhabits the Cerrado, Atlantic Forest, and humid Chaco of South America. Due to its aposematic coloration and behavior, it is a species that may present chemical defenses such as alkaloids and a restricted diet similar to other species of the genus. Although it was described in the early 20th century, there is still little information on its natural history and ecology. Here, we described the diet, tested the sexual dimorphism, and calculated the fertility index of M. fulvoguttatus based on a sample of eight males and 21 females from a population within the Cerrado. Sexual dimorphism was assessed using 15 morphometric measures; diet was calculated as an index of relative importance by prey item and tested for sex differences; fertility was tested for relations between body size and the number of eggs; and we also estimated the reproductive investment. Our results demonstrate that this population’s diet consisted mostly of ant species, with Pheidole radoszkowskii being the most important, followed by Crematogaster sp. and Cyphomyrmex transversus. Regarding sexual dimorphism, we observed that females were significantly larger than males, with a positive relationship between female size and the number of eggs. We did not find significant differences in the diets of males and females. Although the diet and reproductive aspects of M. fulvoguttatus are similar to those of its congeneric species, further studies are needed in order to address the relationship between the species diet and its chemical defenses.

Small Paa Frog and Marbled Cascade Frog are not endemic to Nepal: a response to Tachamo-Shah et al. 2023

Response to ‘Wetland biodiversity of Ramaroshan Lake complex: a need for conservation’ on JoTT Vol 16 issue 12 <https://doi.org/10.11609/jott.7918.15.12.24299-24320>. Many information in the article promising, highlighting the additional attention the area should receive for conservation. However, there are some aspects, particularly that are related to conservation status and endemism of amphibian species which is misleading, making me to realize to write this response.

Teacher toads: Buffering apex predators from toxic invaders in a remote tropical landscape

AbstractEven after research identifies new approaches for wildlife management, translating those methods for delivery can be logistically challenging. In tropical Australia, invasive cane toads (Rhinella marina) fatally poison many anuran‐eating native predators. Small‐scale trials show that vulnerable predators exposed to small (nonlethal) toads can learn to delete toads from their diets, increasing survival of those predators after toads invade. We deployed this method in the remote Kimberley region of tropical Australia, with >200,000 eggs, tadpoles, or metamorph toads released in advance of the expanding toad invasion front. Remote camera surveys before and after “teacher toad” deployment showed that large monitor lizards (Varanus panoptes) were almost extirpated from control plots but remained abundant in treatment plots, indicating broad‐scale success of this novel intervention.

Green, charismatic, microendemic, and threatened: breeding biology of the leaf frog Pithecopus rusticus (Anura: Hylidae: Phyllomedusinae)

ABSTRACT Pithecopus rusticus is a small and charismatic leaf frog species known only from the type locality, in the Brazilian Subtropical Highland Grasslands of the Atlantic Forest, southern Brazil. In this study, we describe aspects of the reproductive biology and populational size of P. rusticus, encompassing the characterization of breeding season, microhabitat use for vocalization and spawning, the variation in body size of males and females and operational sex ratio, as well as explore the influence of climate variables on the abundance of individuals. We collected information from 2015 to 2021, mainly in the breeding seasons of 2015/16 and 2017/18. We recorded 91 individuals of P. rusticus, with a recapture rate of 61% in the 2015/16 breeding season and 57% in the 2017/18 breeding season. The estimated population size was 28.9 individuals for the 2015/16 breeding season and 21 individuals for the 2017/18 breeding season. The temporal reproductive pattern was intermediate, being concentrated in spring to early summer months (October to January), and the male calling activity differed throughout the night, increasing from 9pm onwards. The abundance of P. rusticus was significantly related with relative air humidity. We found sexual size dimorphism, with females larger than males, and a male-skewed operational sex ratio. Males and females used Poaceae and Cyperaceae leaves located close to water. Spawns contained 43 ± 5 eggs, with a diameter of 3.26 ± 0.45 mm, and were deposited on leaves of Senecio (Asteraceae) and Eriocaulon (Eriocaulaceae). Information on natural history is essential to support the implementation and success of in situ and ex situ conservation strategies for this endangered species.

Larger Common River Frogs (Amietia delalandii) have Fewer and Shorter Tissue Microplastic Fibres than Smaller Frogs

Little is known about microplastics (MPs) in adult frogs. We investigated MPs in adult Common River Frogs (Amietia delalandii) from Potchefstroom, South Africa. Five kinds of samples were analysed: natural water, water used to rinse the skin, skin, intestine, and the remainder of the body (corpus). Tissues were digested. Microplastics occurred in all frogs and sample types (1128 MPs counted). Fibres were the most prevalent MP. Fibre lengths were between 28 and 4300 μm, either polyester or polyvinyl alcohol. MPs in skin were likely derived from the ambient, and MPs in the corpus from translocation via the skin. Fibres in tissues were significantly shorter in larger frogs, a phenomenon we provisionally assign to in situ biodegradation. Microplastics in frogs can potentially be transferred through the food web to higher trophic levels. This study provides the first evidence of MPs in adult frog tissues and avenues for further investigations.Graphical

Frog Olympics

Groups of three students make a small, medium, and large frog, using Cricut Design Space to size correctly and personalize their frogs. Once the frogs are folded, they are entered into five Olympic events: Long jump, same-side flipper, backwards flipper, high jump, and fastest faller. Students keep track of their measurements. During each event, the student can make three attempts and keep the best measurement. After each team member has completed all the events, students will calculate the mean, median, and mode for the three frogs for each event. As a class, they will put all the data on the board and decide if the mean, median, or mode best represent the data fairly to decide which team will get first place.

Multiple contact zones and karyotypic evolution in a neotropical frog species complex

Previous studies of DNA sequence and karyotypic data have revealed high genetic diversity in the Physalaemus cuvieri – Physalaemus ephippifer species complex—a group of small leptodactylid frogs in South America. To date, seven major genetic lineages have been recognized in this group, with species delimitation tests supporting four to seven of them as valid species. Among these, only P. ephippifer shows heteromorphic sex chromosomes, but the implications of cytogenetic divergence for the evolution of this group are unknown. We analyzed karyotypic, mitochondrial DNA, and 3RAD genomic data to characterize a putative contact zone between P. ephippifer and P. cuvieri Lineage 1, finding evidence for admixture and karyotypic evolution. We also describe preliminary evidence for admixture between two other members of this species complex—Lineage 1 and Lineage 3 of P. cuvieri. Our study sheds new light on evolutionary relationships in the P. cuvieri – P. ephippifer species complex, suggesting an important role of karyotypic divergence in its evolutionary history and underscoring the importance of hybridization as a mechanism of sex chromosome evolution in amphibians.

Quantifying the effects of Anthropocene activities on Mexican endemic amphibians

AbstractIn order to make robust and feasible conservation plans, assessments of species' vulnerability or risk of extinction are ideally needed. However, there are wide differences in the criteria used to assess species vulnerability. Recently, a growing approach seeks to understand the patterns of biodiversity loss using life history traits because these traits show differential responses to environmental disturbances. In order to generate a functional vulnerability assessment for Mexican endemic amphibians, we integrated information from species distribution modeling, functional traits, and spatially explicit threats weighted differentially for each functional group. We obtained 124 distribution models evaluated by species, nine functional groups that represent the differential risk of species against anthropic threats, and 124 layers of spatial vulnerability. We found a generalized presence of threats to amphibians throughout the Mexican territory, highlighting the center of the country as the most affected area, while the southeast and north had a lower level of anthropic activity. We found differential vulnerability values in the distributions of Mexican endemic amphibians. In general, the anthropogenic impact on the distribution of Mexican endemic amphibians is high, and the percentage of habitat loss ranges from 51 to 97%, with an average of 83% lost to anthropogenic pressures. The functional group with the greatest loss of distributional area was found in the salamander genus Ambystoma, while functional groups 2 (frogs with arboreal habits, small size, and reproduction and development in bodies of water) and 4 (small or medium size frogs occupying terrestrial or riparian habitats with oviposition and development occurring in bodies of water or phytotelms) maintain the largest remaining suitable area after considering the threats. We present a replicable methodology that can be implemented anywhere, providing a new tool to generate specific layers that represent threats to functional groups. This allows for updated assessments of species distribution models that can be used in conservation planning, offering more robust data to make conservation planning decisions.

Two new Poyntonophrynus species (Anura: Bufonidae) highlight the importance of Angolan centers of endemism

Abstract The pygmy toad genus Poyntonophrynus is endemic to southern Africa. The morphology of these small toads is conserved. They are usually dully colored, and are predominately adapted to arid conditions. During recent surveys in Angola we found Poyntonophrynus specimens that were not assignable to known species. Using an integrative approach, based on mitochondrial and nuclear DNA, morphology, osteology, biogeography and ecology, we identified three new lineages, and describe two of them as new species. All three lineages are closely related to P. pachnodes, an Angolan endemic species, but they are geographically isolated from it. The new species are morphologically distinguishable, and are associated with two of the most important Angolan centers of endemism: the western escarpment and the central highlands. In order to get a more comprehensive understanding of the osteology of the genus, we also provide an osteological characterization of P. dombensis, which was not available to date. Our findings i) increase the number of earless species in the genus Poyntonophrynus, ii) emphasize southwestern Africa as the cradle of diversification in this genus, iii) report the occurrence of Poyntonophrynus in humid environments, thus showing that these toads are ecologically more variable than previously thought, and iv) underline the importance of further biodiversity studies in Angolan centers of endemism.

Jumping between narrow banks: social spacing of the stream-dwelling montane frog, Crossodactylus trachystomus (Hylodidae)

Spacing patterns among individuals can reveal many ecological and behavioral features, such as responses to resource availability and social organization. The study of the amphibian movements still constitutes a gap in the knowledge of the animal ecology, and the general issues of the patterns of home range are poorly known to date. Herein, we evaluated the social spacing of a small stream-dwelling frog (Crossodactylus trachystomus), an endemic species from the Espinhaço mountain range in southeastern Brazil. We found that C. trachystomus shows one of the smallest home ranges among anurans, indicating a high philopatry level. We also showed that the home range size did not differ between females and males, neither was influenced by individual body size, which reveals a possible limitation for the use of larger home ranges in riparian systems. The distribution of home ranges showed high overlap among adult males, suggesting a weak territorial behavior or a possible “dear enemy effect” for this species. Beyond expanding the knowledge about the spatial ecology and behavior of the genus Crossodactylus, our outcomes contributed to the understanding of space use and the social organization of frogs, revealing spatial patterns that can be expected for other stream-dwelling frog species.

An initial molecular resolution of the mantellid frogs of the Guibemantis liber complex reveals three new species from northern Madagascar

The small arboreal frog Guibemantis liber (Anura: Mantellidae) has served as an example for the existence of deep conspecific lineages that differ by a substantial amount in mitochondrial DNA but are similar in morphology and bioacoustics and thus are assigned to the same nominal species. During fieldwork in northern Madagascar, we identified additional such lineages and surprisingly, observed close syntopy of two of these at various sites. In-depth study based on DNA sequences of the mitochondrial cytochrome b gene from 338 specimens of G. liber sensu lato from across its range, sequences of four nuclear-encoded markers for 154‒257 of these specimens, a phylogenomic dataset obtained by the FrogCap target capture approach, and additional mitochondrial genes for representatives of most mitochondrial lineages, as well as bioacoustic and morphological comparisons, revealed concordant differentiation among several lineages of the G. liber complex. We identify nine lineages differing by 5.3‒15.5% in cytochrome b and 2.4‒10.1% in the 16S rRNA gene, and find that several of these lack or have only limited allele sharing in the nuclear-encoded genes. Based on sympatric or parapatric occurrence without genetic admixture, combined with differences in bioacoustic and morphological characters, we scientifically name three lineages from northern Madagascar as new species: G. razokysp. nov., G. razandrysp. nov., and G. fotsitendasp. nov. Of these new species, G. razokysp. nov. and G. razandrysp. nov. show widespread syntopy across northern Madagascar and differ in body size and advertisement calls. Guibemantis fotsitendasp. nov. is sister to G. razandrysp. nov., but appears to occur at lower elevations, including in close geographic proximity on the Marojejy Massif. We also detected subtle differences in advertisement calls among various other mitochondrial lineages distributed in the Northern Central East and Southern Central East of Madagascar, but the status and nomenclatural identity of these lineages require further morphological and bioacoustic study of reliably genotyped individuals, and assignment of the three available names in the complex: Rhacophorus liber Peracca, 1893, Gephyromantis albogularis Guibé, 1947, and Gephyromantis variabilis Millot and Guibé, 1951. We discuss the identity and type material of these three nomina, designate a lectotype for Gephyromantis variabilis from Itremo, and flag the collection of new material from their type localities, Andrangoloaka and Itremo, as paramount for a comprehensive revision of the G. liber complex.

A new species of Gracixalus (Anura, Rhacophoridae) from northwestern Vietnam.

A new species of small tree frog is described from northwestern Vietnam based on morphological differences and molecular divergence. Gracixalustruongisp. nov. is distinguishable from its congeners and other small rhacophorid species on the basis of a combination of the following characters: size relatively small, SVL 32.2-33.1 mm in males, 37.6-39.3 mm in females; head slightly wider than long; vomerine teeth absent; snout round and long RL/SVL 0.17-0.19 in males, 0.16-0.17 in females; spines on upper eyelid absent; supratympanic fold distinct; tympanum distinct; dorsal skin smooth; throat smooth and venter granular; tibiotarsal projection absent; webbing of fingers rudimentary, toes with moderately developed webbing; dorsum moss-green, with an inverse Y-shaped dark green marking extended from interorbital region to posterior region of dorsum; external vocal sac absent in males; males with a nuptial pad on finger I. In the molecular analyses, the new species has no clear sister taxon and is at least 4.5% divergent from other congeners based on a fragment of the mitochondrial 16S rRNA gene.

Dodecaploid Xenopus longipes provides insight into the emergence of size scaling relationships during development

Genome and cell size are strongly correlated across species1,2,3,4,5,6 and influence physiological traits like developmental rate.7,8,9,10,11,12 Although size scaling features such as the nuclear-cytoplasmic (N/C) ratio are precisely maintained in adult tissues,13 it is unclear when during embryonic development size scaling relationships are established. Frogs of the genus Xenopus provide a model to investigate this question, since 29 extant Xenopus species vary in ploidy from 2 to 12 copies (N)of the ancestral frog genome, ranging from 20 to 108 chromosomes.14,15 The most widely studied species, X.laevis (4N= 36) and X.tropicalis (2N= 20), scale at all levels, from body size to cellular and subcellular levels.16 Paradoxically, the rare, critically endangered dodecaploid (12N= 108) Xenopus longipes (X.longipes) is a small frog.15,17 We observed that despite some morphological differences, X.longipes and X.laevis embryogenesis occurred with similar timing, with genome to cell size scaling emerging at the swimming tadpole stage. Across the three species, cell size was determined primarily by egg size, whereas nuclear size correlated with genome size during embryogenesis, resulting in different N/C ratios in blastulae prior to gastrulation. At the subcellular level, nuclear size correlated more strongly with genome size, whereas mitotic spindle size scaled with cell size. Our cross-species study indicates that scaling of cell size to ploidy is not due to abrupt changes in cell division timing, that different size scaling regimes occur during embryogenesis, and that the developmental program of Xenopus is remarkably consistent across a wide range of genome and egg sizes.

A molecular perspective on the systematics and distribution of Loxopholis lizards in South and Central America, with advances on the biogeography of the tribe Ecpleopodini (Gymnophthalmidae: Squamata)

Knowledge about the biological diversification of vertebrates in the Amazonia has previously relied on taxa that diversified in relatively recent timeframes (i.e. Plio-Pleistocene). Dating of evolutionary events in small lizards and frogs, on the other hand, has progressively demonstrated that the major phylogenetic events in these organisms occurred earlier in time, from the Eocene to the Miocene, opening a window to reveal the Amazonia’s landscape dynamics throughout ancient periods. Here we investigate the phylogenetic relationships, diversification times, and biogeography of Loxopholis, a diverse genus of small leaf-litter ecpleopodin lizards endemic to the Amazonia. In order to place Loxopholis diversity into a larger taxonomic perspective, we used statistical biogeographic methods (BioGeoBEARS) to reconstruct the biogeography of the Ecpleopodini tribe. We found that the evolution of the Ecpleopodini occurred mostly in the Amazonia’s north region. Additionally, we found evidence that contacts between the Amazonia and the Atlantic Forest took place multiple times during the Cenozoic (earlier than previously proposed) and that these events influenced species colonization of open environments in South America via the Vanishing Refuge model. Our hypothesis on the evolution of Loxopholis, in contrast, suggests that multiple processes acted on the current species distribution, including three main dispersal events: the emergence of Lake Pebas, the rising of the Iquitos arch, the Andean orogeny and the emergence of the Panama Isthmus.

Trans in the Chapel: Attending Church as a Newly Out Transgender Woman

The ratchet tightened in my chest pulling into the parking lot. Four of our five children in tow and one serving a mission. Fifteen minutes early in the hopes that we could settle in before anyone noticed. My children insist we sit in our usual pew to the right side, six rows back on the bleached knotty pine and speckled blue-green padded benches that were clean of goldfish and Cheerios. Dressed in a freshly pressed Foxcroft white oxford women's button-up blouse and black pleated polyester women's dress slacks, I slid into the bench and practiced my breathing exercises while trying to look away from anyone who might look over. My eyelashes were subtly coated in matte black mascara, on my cheeks a light dusting of dusty rose-colored blush powder, just enough that I could feel comfortable and almost myself.“Nice to see you back where you belong, Brother English.”Look down, don't make eye contact, and breathe.“Thank you.”Breathe in and hold for three seconds, breathe out and hold for three seconds. Breathe in and hold for three seconds, and again, breathe out and hold for three seconds.“Well, hello, young man . . . nice to see you, it has been a while. Are you sticking around for priesthood this time?”It will be okay. Three, two, one . . . let the breath out.“Hello, it has been a while.”I forced a smile then looked back down at the polished, almond-shaped tips of my shiny black Naturalizer flats, remembering that my toes were painted the color of lilacs somewhere underneath. I hoped I didn't scuff them on the way in.I watched peripherally as the Relief Society president came in the room and moved from sister to sister, greeting them as they came in with their families. Her navy, floor-length chevron maxi dress moved gracefully with her from Sister Tanner to Sister Johnston to Sister Brown. A stiff and highly appropriate handshake with the second counselor, then on to Sister Hansen. As she came toward the English family pew, she sat down beside me and softly took my hand.“I'm so glad you made the extra effort to be here. You look beautiful and full of grace.”I took a deep breath, and we wept together until the meeting was about to start.She moved her family over to sit in front of my little family, pulling a small pack of tissues out of her purse and handing them to me with a subtle look of reassurance.Forty-seven minutes of breathing exercises and making small origami frogs out of the program to distract myself from the anxiety of the meeting. Someone said a closing prayer. The Relief Society president returned to my side, held my hand again, tears again.“Would it be okay if I stay here with you for a minute?”“No, thank you, I need to go outside if I am going to be okay.”“Okay, is it okay if I check on you?”“Yes, I will be out in the car until the kids are done with their meetings.”Standing up, adjusting the blouse, careful to not scuff my toes. Taking a breath as two hands extend in front of me.“Nice to see you, Brother English. Glad you are back where you belong.”Breathe, correct my posture after the aggressive grab and shake of my clamped-down left shoulder.“Would you consider coming early to help the young men pass the sacrament next week?”“Maybe.”Moving to the car, I reach into my pocket, pull out one of the tissues, dab the corner of my eye, careful to not disturb the long black lashes. Grateful to have worn waterproof mascara this time.

Emergent properties of species-habitat networks in an insular forest landscape.

Deforestation and fragmentation are pervasive drivers of biodiversity loss, but how they scale up to entire landscapes remains poorly understood. Here, we apply species-habitat networks based on species co-occurrences to test the effects of insular fragmentation on multiple taxa—medium-large mammals, small nonvolant mammals, lizards, understory birds, frogs, dung beetles, orchid bees, and trees—across 22 forest islands and three continuous forest sites within a river-damming quasi-experimental landscape in Central Amazonia. Widespread, nonrandom local species extinctions were translated into highly nested networks of low connectance and modularity. Networks’ robustness considering the sequential removal of large-to-small sites was generally low; between 5% (dung beetles) and 50% (orchid bees) of species persisted when retaining only <10 ha of islands. In turn, larger sites and body size were the main attributes structuring the networks. Our results raise the prospects that insular forest fragmentation results in simplified species-habitat networks, with distinct taxa persistence to habitat loss.

A Comparison of Growth Patterns between Large- and Small-sized Rana tagoi (Amphibia: Ranidae) from Kitayama, Kyoto, Japan

In the Kitayama-region of Kyoto city, two types of the brown frog Rana tagoi occur syntopically. They are populations of small and large frogs that do not overlap in adult body size and proved to be heterospecific genetically. In order to clarify the cause and significance of this body size difference, we studied the growth pattern in the two populations. For comparison, we also examined an allopatric population of R. tagoi from Shishiga-tani, Kyoto, which is genetically very close to the large type, and occurs without co-inhabiting different sized individuals. We examined sections of periosteal bones, and counted the number of LAGs in the bone to determine ages of individuals. We used logistic model and estimated instantaneous growth rate and asymptotic size, to describe growth pattern. Each of the two types from Kitayama exhibited unique growth pattern, and the Shishiga-tani population showed a growth pattern intermediate between those of the two types in asymptotic size. Difference in size of two types is discussed with relation to the character displacement.

SIGNIFICANCE OF A SMALL REGURGITALITE CONTAINING LISSAMPHIBIAN BONES, FROM THE MORRISON FORMATION (UPPER JURASSIC), WITHIN A DIVERSE PLANT LOCALITY DEPOSIT IN SOUTHEASTERN UTAH, USA

Abstract A new specimen from a plant locality in the Morrison Formation of southeastern Utah exhibits characters suggestive of a small bromalite, possibly from a fish or semi-aquatic mammal. The specimen consists of a cluster of small bones, most referable to lissamphibians, including elements of at least one small frog (possibly a tadpole) and possibly the smallest reported salamander specimen from the formation. Chemical and taphonomic characters suggest that the specimen is a regurgitalite, the first from both the Morrison Formation and the Jurassic of North America. The lissamphibian material in the bromalite represents the southernmost likely occurrence of frogs and salamanders in the formation. The possible salamander material may represent a rare juvenile rather than a new taxon, and it is morphologically more similar to Valdotriton and Comonecturoides than it is to Iridotriton. The frog material is similarly unidentifiable to specific taxon.

First Report of Culturable Skin Bacteria in Melanophryniscus admirabilis (Admirable Redbelly Toad).

Melanophryniscus admirabilis is a small toad, critically endangered with a microendemic distribution in the Atlantic Forest in southern Brazil. The amphibian skin microbiome is considered one of the first lines of defense against pathogenic infections, such as Batrachochytrium dendrobatidis (Bd). The knowledge of skin amphibian microbiomes is important to numerous fields, including species conservation, detection, and quantification of environmental changes and stressors. In the present study, we investigated, for the first time, cultivable bacteria in the skin of wild M. admirabilis, and detected Bd fungus by nested polymerase chain reaction (PCR) technique. Skin swab samples were collected from 15 wild M. admirabilis, and the isolation of bacteria was performed by means of different culture strategies. A total of 62 bacterial isolates being Bacillus (n = 22; 34.48%), Citrobacter (n = 10; 16.13%), and Serratia (n = 12; 19.35%) were more frequently isolated genera. Interestingly, all skin samples tested were Bd negative. Some bacterial genera identified in our study might be acting in a synergic relationship and protecting them against the Bd fungus. In addition, these bacteria may play an essential role in maintaining this species in an environment modulated by anthropic actions. This first report of skin cultivable bacteria from M. admirabilis natural population improves our knowledge of skin amphibian microbiomes, contributing to a better understanding of their ecology and how this species has survived in an environment modulated by anthropic action.