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Since the partition of the traditional genus Triturus RAFINESQUE, 1820 by GARCIA PARIS et al. (2004), the Al-pine Newt, formerly Triturus alpestris (LAURENTI, 1768), was first assigned to Mesotriton BOLKAY, 1927. This allocation was challenged by SCHMIDTLER (2004, 2009) who had unearthed and revived the older but almost never used name Ichthyosaura SONNINI & LATREILLE, 1802, a potential nomen oblitum which was based on the flawed drawing of a larva figured by LAURENTI (1768) as Proteus tritonius, bearing the type locality "in alpe Etscher". Because of this locality, the otherwise unidentifiably drawn larva was interpreted as belonging to the Alpine Newt and was considered as the "iconotype" of Ichthyo-saura alpestris n. comb. sensu SCHMIDTLER (2009). This proposal has been controversially discussed, and eventually the supporters of this nomenclatural innovation gained the upper hand. We show that the argumentation of the advocates of replacing Mesotriton by Ichthyosaura overlooked some important aspects in LAURENTI'S work concerning the type locali-ties of both the nomina Proteus tritonius and Triton alpestris. Also, details of the illustrated larva and LAURENTI'S description of its collecting site and circumstances do not support the view that this "iconotype" could unambiguously be referred to the Alpine Newt. Moreover, LAURENTI himself expressly denied the identity of these two nomina. Therefore, according to Article 12.2.5. ICZN, Ichthyosaura must be regarded as a nomen dubium. To resolve this uncertainty, we designate a topotypic larva of Salamandra salamandra (LINNAEUS, 1758) as the neotype for Proteus tritonius LAURENTI, 1768, rendering LAURENTI's name synonymous with the Fire Salamander. Consequently, the Alpine Newt must be named again Mesotriton alpestris (BOLKAY, 1927). [ABSTRACT FROM AUTHOR]

Background: The blood–brain barrier (BBB) is a semipermeable interface that prevents the non-selective transport into the central nervous system. It controls the delivery of macromolecules fueling the brain metabolism and the immunological surveillance. The BBB permeability is locally regulated depending on the physiological requirements, maintaining the tissue homeostasis and influencing pathological conditions. Given its relevance in vertebrate CNS, it is surprising that little is known about the BBB in Amphibians, some of which are capable of adult CNS regeneration. Results: The BBB size threshold of the anuran Xenopus laevis (African clawed toad), as well as two urodele species, Ambystoma mexicanum (axolotl) and Pleurodeles waltl (Iberian ribbed newt), was evaluated under physiological conditions through the use of synthetic tracers. We detected important differences between the analyzed species. Xenopus exhibited a BBB with characteristics more similar to those observed in mammals, whereas the BBB of axolotl was found to be permeable to the 1 kDa tracer. The permeability of the 1 kDa tracer measured in Pleurodeles showed values in between axolotl and Xenopus vesseks. We confirmed that these differences are species-specific and not related to metamorphosis. In line with these results, the tight junction protein Claudin-5 was absent in axolotl, intermediate in Pleurodeles and showed full-coverage in Xenopus vessels. Interestingly, electron microscopy analysis and the retention pattern of the larger tracers (3 and 70 kDa) demonstrated that axolotl endothelial cells exhibit higher rates of macropinocytosis, a non-regulated type of transcellular transport. Conclusions: Our study demonstrated that, under physiological conditions, the blood–brain barrier exhibited species-specific variations, including permeability threshold, blood vessel coverage, and macropinocytosis rate. Future studies are needed to test whether the higher permeability observed in salamanders could have metabolic and immunological consequences contributing to their remarkable regenerative capacity. [ABSTRACT FROM AUTHOR]

\nHIGHLIGHTSAt the end of the summer of 2023, in September, an intense water discolouration (red tide) accompanied by fish mortality was observed in the Gulf of Tadjoura. This discolouration of the seawater was caused by a potentially toxic dinoflagellate, Pyrodinium bahamense. The proliferation, located near the coast between the Moucha/Maskali islands and the city of Tadjoura, was significant enough to be detected by satellite imagery. P. bahamense had formed an almost monospecific bloom (90%), with a density of 1.8 × 106 cells l‒1 (22 September 2023). Other dinoflagellates such as Dinophysis miles, Dinophysis caudata, Tripos furca, Lingulaulax sp. (formerly Lingulodinium), Balechina sp. and Protoperidinium sp. were detected at very low concentrations. This study characterises P. bahamense through an integrated approach, combining detailed morphological analysis with molecular phylogenetic analyses based on the internal transcribed spacer (ITS) region and the D1–D3 regions of large subunit ribosomal (LSU rDNA). For the first time, we have molecularly identified the toxic ribotype from the Indo-Pacific in the Gulf of Aden region. This discovery highlights an emerging risk of this toxic ribotype in the eastern Mediterranean basin. This region, already facing various environmental challenges, may see its vulnerability heightened with the emergence of new risks. A red tide was formed in September 2023 by Pyrodinium bahamense.First morpho-molecular identification of P. bahamense in the Gulf of Aden.The genotype corresponded to the toxic ribotype and the Indo-Pacific ribotype.A red tide was formed in September 2023 by Pyrodinium bahamense.First morpho-molecular identification of P. bahamense in the Gulf of Aden.The genotype corresponded to the toxic ribotype and the Indo-Pacific ribotype. [ABSTRACT FROM AUTHOR]

The main aim of this research is to increase a low water flow rate of 1 l/m up to a minimum of 6 l/m using a TapBoost pump. This pump will be used to support poor domestic flow rates in the UK & ROI. TapBoost was developed without the need for mechanical seals by using wet rotor technology making it the most efficient water boosting pump in Salamander's pump range. The various stages of design, testing and development of the TapBoost pump are reported in this paper. TapBoost is an inexpensive solution to improve the water flow rate given from a trickling single outlet anywhere in a domestic setting. TapBoost has been specially designed to be easily installed onto any existing or new water mains pipework. The main conclusions are as follows: i) the TapBoost was successfully designed, manufactured, tested and launched in March 2022, meeting the specification requirements given by Salamander Pumps to develop and launch this new product, ii) The results showed that the pump delivers a boosted water flow rate of 6.75 l/m compared to the original water flow rate, without the use of the pump, of just 1 l/m, iii) The performance of the TapBoost is better than the leading competitor in the market. [ABSTRACT FROM AUTHOR]

This study introduces a novel neuromechanical model employing a detailed spiking neural network to explore the role of axial proprioceptive sensory feedback, namely stretch feedback, in salamander locomotion. Unlike previous studies that often oversimplified the dynamics of the locomotor networks, our model includes detailed simulations of the classes of neurons that are considered responsible for generating movement patterns. The locomotor circuits, modeled as a spiking neural network of adaptive leaky integrate-and-fire neurons, are coupled to a three-dimensional mechanical model of a salamander with realistic physical parameters and simulated muscles. In open-loop simulations (i.e., without sensory feedback), the model replicates locomotor patterns observed in-vitro and in-vivo for swimming and trotting gaits. Additionally, a modular descending reticulospinal drive to the central pattern generation network allows to accurately control the activation, frequency and phase relationship of the different sections of the limb and axial circuits. In closed-loop swimming simulations (i.e. including axial stretch feedback), systematic evaluations reveal that intermediate values of feedback strength increase the tail beat frequency and reduce the intersegmental phase lag, contributing to a more coordinated, faster and energy-efficient locomotion. Interestingly, the result is conserved across different feedback topologies (ascending or descending, excitatory or inhibitory), suggesting that it may be an inherent property of axial proprioception. Moreover, intermediate feedback strengths expand the stability region of the network, enhancing its tolerance to a wider range of descending drives, internal parameters' modifications and noise levels. Conversely, high values of feedback strength lead to a loss of controllability of the network and a degradation of its locomotor performance. Overall, this study highlights the beneficial role of proprioception in generating, modulating and stabilizing locomotion patterns, provided that it does not excessively override centrally-generated locomotor rhythms. This work also underscores the critical role of detailed, biologically-realistic neural networks to improve our understanding of vertebrate locomotion. Author summary: In this paper, we developed a computational model to investigate how salamanders move, both while swimming and walking. Unlike previous studies that often oversimplified the dynamics of these complex neural networks, our model includes detailed simulations of the classes of neurons that are considered responsible for generating movement patterns. The locomotor circuits, modeled as a spiking neural network, are coupled to a three-dimensional mechanical model of a salamander with realistic physical parameters and simulated muscles. The neural model integrates axial proprioceptive sensory feedback from the body's movements to modulate the locomotor gaits. Our simulations suggest that this sensory feedback plays a major role in controlling the rhythm and coordination of movements. This has implications for understanding not only how salamanders move but also provides insights into the evolution of locomotion in vertebrates. By investigating how central and sensory mechanisms interact to produce efficient and adaptable movement, our work contributes to the broader field of neuroscience and robotics, offering potential strategies for designing more effective biomimetic robots. [ABSTRACT FROM AUTHOR]

Morphological abnormalities in amphibians are commonly associated with anthropogenic activity, although little baseline information on the prevalence of abnormalities in uncontaminated environments exist. Here, we leverage a 12-year study of spotted salamanders (Ambystoma maculatum (Shaw, 1802)) in an uncontaminated ecosystem in Algonquin Provincial Park, Canada, to estimate abnormality rates and explore how abnormalities affect fitness-related traits. Annual abnormality rates estimated from drift fence data ranged from 4.3% to 5.8% of individuals sampled. Abnormality rates from aquatic trapping between 2008 and 2019 varied from 1.2% to 16.7%, where temporal increases in abnormality rates were observed. We also performed a targeted, systematic literature survey and found that Caudata exhibited a slightly higher abnormality prevalence than Anura, and that the baseline frequency of abnormalities described at our drift fence site is slightly lower than rates reported in the literature (8.1%, 95% CI, 4.76%–13.3%). Salamanders with abnormalities exhibited a slightly, but not significantly, higher body condition and a significantly earlier arrival date at the breeding site, both of which are traits typically associated with high-fitness individuals. Our study suggests that abnormalities have detectable phenotypic consequences, and underlines the need for temporal sampling efforts to provide ranges of baseline abnormality rates, rather than a point estimate. [ABSTRACT FROM AUTHOR]

Reticulation between radiating lineages is a common feature of diversification. We examine these phenomena in the Pisgah clade of Desmognathus salamanders from the southern Appalachian Mountains of the eastern United States. The group contains 4–7 species exhibiting 2 discrete phenotypes, aquatic "shovel-nosed" and semi-aquatic "black-bellied" forms. These ecomorphologies are ancient and have apparently been transmitted repeatedly between lineages through introgression. Geographically proximate populations of both phenotypes exhibit admixture, and at least 2 black-bellied lineages have been produced via reticulations between shovel-nosed parentals, suggesting potential hybrid speciation dynamics. However, computational constraints currently limit our ability to reconstruct network radiations from gene-tree data. Available methods are limited to level-1 networks wherein reticulations do not share edges, and higher-level networks may be non-identifiable in many cases. We present a heuristic approach to recover information from higher-level networks across a range of potentially identifiable empirical scenarios, supported by theory and simulation. When extrinsic information indicates the location and direction of reticulations, our method can successfully estimate a reduced possible set of nonlevel-1 networks. Phylogenomic data support a single backbone topology with up to 5 overlapping hybrid edges in the Pisgah clade. These results suggest an unusual mechanism of ecomorphological hybrid speciation, wherein a binary threshold trait causes some hybrid populations to shift between microhabitat niches, promoting ecological divergence between sympatric hybrids and parentals. This contrasts with other well-known systems in which hybrids exhibit intermediate, novel, or transgressive phenotypes. The genetic basis of these phenotypes is unclear and further data are needed to clarify the evolutionary basis of morphological changes with ecological consequences. [ABSTRACT FROM AUTHOR]

Remotely-sensed risk assessments of emerging, invasive pathogens are key to targeted surveillance and outbreak responses. The recent emergence and spread of the fungal pathogen, Batrachochytrium salamandrivorans (Bsal), in Europe has negatively impacted multiple salamander species. Scholars and practitioners are increasingly concerned about the potential consequences of this lethal pathogen in the Americas, where salamander biodiversity is higher than anywhere else in the world. Although Bsal has not yet been detected in the Americas, certain countries have already proactively implemented monitoring and detection plans in order to identify areas of greatest concern and enable efficient contingency planning in the event of pathogen detection. To predict areas in Costa Rica with a high Bsal transmission risk, we employed ecological niche modeling combined with biodiversity and tourist visitation data to ascertain the specific risk to a country with world renowned biodiversity. Our findings indicate that approximately 23% of Costa Rica's landmass provides suitable conditions for Bsal, posing a threat to 37 salamander species. The Central and Talamanca mountain ranges, in particular, have habitats predicted to be highly suitable for the pathogen. To facilitate monitoring and mitigation efforts, we identified eight specific protected areas that we believe are at the greatest risk due to a combination of high biodiversity, tourist visitation, and suitable habitat for Bsal. We advise regular monitoring utilizing remotely-sensed data and ecological niche modeling to effectively target in-situ surveillance and as places begin implementing educational efforts. [ABSTRACT FROM AUTHOR]

Amphibian skull development is a traditional model system for evo-devo study. Based on morphological and experimental data, tissue and hormonal inductions were revealed as main regulatory mechanisms involved in craniogeny. In salamander "nasal complex" (cartilaginous nasal capsule and associated dermal bones), the earliest developmental events are regulated by tissue interactions, while later events become hormonally induced. Similar increase of hormonal induction is displayed in urodelan evolution from basal to advanced taxa. This evolutionary shift in dominating regulatory mechanisms results in progressive divergence of larval and adult morphologies, thus providing grounds for diversification of ontogenetic strategies and life history evolution. [ABSTRACT FROM AUTHOR]

SUMMARY: As tertiary gene pools of wheat, Aegilops comosa and Ae. caudata contain many excellent genes/traits and gradually become important and noteworthy wild resources for wheat improvement worldwide. However, the lack of molecular markers and cytological probes with good specificity and high sensitivity limits the development and utilization of Triticum aestivum–Ae. comosa (Ta. Aeco)/Ae. caudata (Ta. Aeca) introgression lines. Using specific‐locus amplified fragment sequencing, two Ae. comosa and one Ae. caudata accessions, Chinese Spring, and three Ta. Aeco and Ta. Aeca introgression lines each were sequenced to develop new molecular markers and cytological probes. After strict sequence comparison and verification in different materials, a total of 39 molecular markers specific to three chromosomes in Ae. comosa (nine, seven, and 10 markers for 1M, 2M, and 7M, respectively) and Ae. caudata (two, six, and five markers for 3C, 4C, and 5C, respectively) and 21 fluorescence in situ hybridization (FISH) probes (one centromeric probe with signals specific to the M chromosomes, two centromeric probes with signals in all the tested genomes, and six, eight, and four FISH probes specific to the M, C, and M, C, and U chromosomes, respectively) were successfully exploited. The newly developed molecular markers and cytological probes could be used in karyotype studies, centromere evolutionary analyses of Aegilops, and had the ability to detect the fusion centromeres and small‐fragment translocations in introgression lines. Significance Statement: Specific molecular markers and FISH probes can serve as sensitive tools for screening Ae. comosa and Ae. caudata introgressions in wheat. [ABSTRACT FROM AUTHOR]

The Atıf's Lycian Salamander, Lyciasalamandra atifi is recorded from Kuz Cave (Sütçüler District, Isparta Province), in the Mediterranean Region of Türkiye. This record is the first case showing the locality of this endemic salamander species except from Antalya Province. The morphometric characters and color-pattern features of the specimens were compared with specimens from the known Turkish localities according to the literature. We observed that the specimens of the Kuz Cave population were similar in some characters to the specimens of L. a. veithi reported in the literature. [ABSTRACT FROM AUTHOR]

Water striders (Hemiptera: Gerridae) are sucking predators that inhabit freshwater and marine environments. They prey mainly on insects that fall on the water surface, but they are also known to feed on amphibian eggs. Here, we report on the predation of egg sacs of Hynobius nigrescens (Caudata: Hynobiidae) by Gerris (Macrogerris) insularis. We observed predation on egg sacs of H. nigrescens by G. insularis at a pond in a mountainous area of Nagano City, Nagano Prefecture, Japan. We also found egg sacs with predation marks probably made by water striders at a pond in the mountainous area of Nishimeya Village, Aomori Prefecture, Japan. Five water striders collected around the preyed egg sacs were identified as G. insularis. We filled three tanks with water and an egg sac, and three water striders that were collected at the site in Nishimeya Village were placed together in each tank. In two tanks, the jelly layer of the egg sac was partially cut in a horizontal manner, while in another tank, the jelly layer was removed on the part of the egg sac exposed on the water surface. Notably, the water striders exhibited predatory behavior only when the jelly layers were removed. Considering the results of the rearing experiment and the predation marks observed in the field, G. insularis is also likely to prey on egg sacs at the site in Nishimeya Village. Our study suggested that predation by G. insularis occurs when eggs are accidentally exposed due to disturbance of the jelly layer. [ABSTRACT FROM AUTHOR]

Biting is a common male–male combat tactic across jawed vertebrates, in which teeth or bony beaks serve as weapons. Because biting can cause severe injuries in some species, bite scars provide critical information about the degrees and patterns of fights.Amphibians have a remarkable diversity in tooth morphology and arrangement. However, the functional ecology of amphibian teeth is poorly studied. For example, unlike aquatic suction‐feeding frogs that lost teeth, aquatic salamanders that suction‐feed prey retain numerous sharp teeth, suggesting that teeth as weapons may partially explain their retention.Here, we analysed long‐term injury records of one of the fully aquatic, suction‐feeding salamanders (Japanese Giant Salamander, Andrias japonicus) to examine the previously unexplored potential of amphibian teeth as weapons for male–male combat. The majority of the injuries were missing toes and limbs, which most likely occurred during intra‐specific combat. We explored associations between injuries and independent variables such as sex, body size, body condition and stream sections. We also investigated possible injury‐pattern biases along the lateral (i.e. right vs. left) and longitudinal (i.e. anterior vs. posterior) axes, which could reveal how these animals fight.We found that males had more injuries, larger individuals had more injuries, and males with poorer conditions had more injuries. There was no association between injuries and stream sections. In addition, we found that salamanders had more injuries on the right and posterior sides of the body. The lateral asymmetry in injuries is likely associated with turning asymmetry during combat.Our results revealed the intense male–male combats of giant salamanders, providing evidence of the use of teeth as weapons. Combats via biting in amphibians may be much more common and severe than currently known. Our research suggests the function of amphibian teeth as weapons, which is likely to be a vital selective agent shaping its remarkable diversity. [ABSTRACT FROM AUTHOR]

Megalobatrachonema nipponicum Yamaguti, 1941 (Nematoda: Cosmocercoidea: Kathlaniidae), the type species of the genus Megalobatrachonema, had been only once reported from the Japanese giant salamander, Andrias japonicus (Temminck, 1836) (Amphibia: Cryptobranchidae), in the last 80 years. Herein, we reported the present species from A. japonicus and hybrids (A. japonicus × Andrias davidianus (Blanchard, 1871)) following the original description. The examined specimens were morphologically identical to the original description. We showed the phylogenetic position of M. nipponicum among cosmocercoid species as well as among congeneric species, which suggested the polyphyly of the genus. In addition, the phylogenetic analysis did not support the subgenera in this genus. Thus, we considered the presence or absence of an esophageal bulb valve as a key morph to identify species, not subgenus, of Megalobatrachonema. [ABSTRACT FROM AUTHOR]

According to the Host Manipulation Hypothesis, parasites modify the phenotype of their host to enhance host–host transmission and thereby increase fitness. Metacercarial infection of some amphibians changes host behavior, including locomotion, and thereby enhances predation by the definitive host. To further test this hypothesis, it is first necessary to determine whether a parasite actually modifies a host's phenotype. In the southern Appalachian Mountains of the US, metacercariae of the trematode Metagonimoides oregonensis (Price, 1931) encyst in the musculature of its second intermediate host, the salamander Desmognathus amphileucus Bishop, 1941. Metacercarial infections of musculature in fish negatively affect host swimming performance. Therefore, we tested the hypothesis that infection by M. oregonensis affects walking in the aquatic larvae of D. amphileucus. We compared this mode of locomotion between infected and uninfected larvae by placing them in 1 m troughs of water and allowing them to wander freely until they stopped. Non-parametric (Kaplan–Meier) survival analysis determined that infected salamanders stopped significantly sooner than uninfected ones. Because infected salamanders move less, the presence of this parasite may contribute to genetic divergence in these salamanders by slowing dispersal and concomitant gene flow. Our results suggest that macroparasites can potentially modify a host's behavior with biological consequences beyond enhancement of parasite transmission. [ABSTRACT FROM AUTHOR]

Making timely management decisions is often hindered by uncertainty. Monitoring reduces two key types of uncertainty. First, it serves to reduce structural uncertainty of how the system works and provides support for expectations of how a system works. Second, it serves to reduce parametric uncertainty of the drivers of system dynamics. By combining monitoring data and quantitative models, we can reduce structural and parametric uncertainty. To demonstrate this, we focus on the Shenandoah salamander (Plethodon shenandoah), a United States Federally Endangered Species. Early work suggested that P. shenandoah extinction risk results from competition with a conspecific (Plethodon cinereus). However, more recent work has found equivocal support for this claim, instead suggesting that abiotic factors, such as moisture and temperature, drive P. shenandoah persistence. Using long-term monitoring data, we find that while competition may play a part in P. shenandoah extinction risk, measures of surface moisture are better predictors of occupancy dynamics. Further, we find decreased detection rates of P. shenandoah when P. cinereus is present, suggesting a conflation of detection probability with actual competition, which cautions against making inference from unadjusted observations of occurrence. Using multiple lines of inquiry allows for more robust understanding of system drivers in the face of high uncertainty, increasing opportunities to manage extinction risk. [ABSTRACT FROM AUTHOR]

Sirtuins are a family of lysine deacetylases that regulate cellular homeostasis and energy sensing. Regeneration is the process that restores structural and functional homeostasis at the cellular, tissue, organ, and appendage levels. Several cellular processes, such as epithelial–mesenchymal transition (EMT), proliferation, migration, and differentiation, contribute to restoration after an injury. This review highlights the role of sirtuins in tissue, organ, and anatomical structure regeneration, showing how sirtuins modulate signalling pathways by deacetylating targets such as transcription factors. Furthermore, understanding the role of this protein family could help elucidate the molecular and cellular mechanisms underlying tissue regeneration, which may hold significant potential for fields such as regenerative medicine. The review compiles evidence suggesting that sirtuins are emerging factors in the regeneration of various organs (e.g., skin, liver, heart) and tissues (e.g., bone, muscle, cornea, spinal cord). [ABSTRACT FROM AUTHOR]

The age, content and inter-order relationships of crown Lissamphibia remain a debated topic in vertebrate systematics. Recent phylogenetic analyses of fossil amphibians were used to propose an extended Lissamphibia, with Anura and Caudata nested in Dissorophoidea and with Gymnophiona nested in Stereospondyli, but this hypothesis was not supported by subsequent studies on updated matrices. In a parsimony context, the extended Lissamphibia hypothesis was shown to result from the effects of large island bias on the majority-rule consensus, which masked the presence of topologies supporting the restricted Lissamphibia hypothesis, with all extant orders nested in Dissorophoidea or in Stereospondyli. Re-analysing this dataset, taking into account the presence of inapplicable and polymorphic character states and revising the scores for logically non-independent characters, shows that the phylogenies inferred from the morphological data matrix used to propose the extended Lissamphibia hypothesis are not robust to changes in analytical parameters and that great care should be taken when analysing fossil amphibian datasets. With the set of most parsimonious trees inferred from the unrevised matrix used to propose the extended Lissamphibia hypothesis, I also demonstrate that the phenomenon of large island bias extends to phylogenetic networks, but not to topology-based tests of taxonomic instability that do not rely on split-frequencies. [ABSTRACT FROM AUTHOR]

Amphibians are among the most threatened vertebrates globally, and their conservation status continues to decline. In the updated Global Amphibian Assessment (GAA2), the use of IUCN Criterion E, which projects extinction risks through quantitative models, highlighted southern Europe as a hotspot for salamander extinction risk due to the risk of invasion by the fungal pathogen Batrachochytrium salamandrivorans (Bsal). In particular, for five Italian salamander species, risk categories were elevated significantly based on Criterion E, from Vulnerable or lower to Endangered or Critically Endangered. This increased reliance on Criterion E raises concerns regarding its treatment of uncertainty, as these projections depend heavily on assumptions about Bsal spread, environmental suitability, and host dynamics. Limited exploration of alternative scenarios and reliance on extreme parameter values may result in inflated extinction risk estimates. We emphasize the need for improved documentation of uncertainty and integration of diverse expert opinions in extinction risk assessments, to balance proactive conservation planning with robust scientific methodology. [ABSTRACT FROM AUTHOR]

The trematode currently recognized as Metagonimoides oregonesis primarily utilizes the Southern Black-bellied Salamander, Desmognathus amphileucus, as a second intermediate host in southern Appalachian streams. We investigated seasonal variation in relative intensity within larvae of this salamander species in the Broad River system of northeastern Georgia by counting metacercariae visible through the ventral body wall in February, May, August, and November of 2023. Summer hatching and metamorphosis by salamander larvae coupled with likely summer shedding time of trematode cercariae from the snail host explain much of the variation, which showed a peak relative intensity in November. However, this peak remained even after the effect of salamander size (and presumably age) had been removed. The seasonal pattern we observed may be subject to interannual variation. [ABSTRACT FROM AUTHOR]

Although the Great crested newt (Triturus cristatus) is considered a generalist predator, there are few studies on its prey preferences across its wide range. Data on its feeding are virtually lacking for its southernmost populations; this study aims to fill this gap by analyzing the aquatic food spectrum and prey availability from three ponds in Stara Planina Mts., NW Bulgaria. Ponds were simultaneously sampled once per month; consumed prey items were collected using stomach flushing of captured newts, and hydrobiological samples were taken from each pond to establish potential prey diversity. Remains of ingested prey were found in 109 out of the 141 sampled adult newts (71 male and 70 female). Applying the widely used approach of "operational taxonomic units" (OTUs), prey items from stomach flushing were assigned to 27 OTUs (incl. plants and inorganic matter, and for females only - shed skin), while material from the hydrobiological samples - to 28 (20 of them were also found in the stomach content of the newts). The most frequent prey for both sexes were larvae from the family Chironomidae (found in 21% of the studied newts) and the most abundant superorder Cladocera (60% of the identified prey items). Male newts were more likely than females not to have eaten during the summer when the frequency of empty stomachs was higher compared to spring. For both sexes, prey diversity from stomach content was higher in the spring compared to the summer (Simpson's index values were respectively 0.76 vs. 0.12 for the males and 0.72 vs. 0.54 for the females), and females consumed more diverse prey during the summer, possibly as a result of their breeding behavior. [ABSTRACT FROM AUTHOR]

Bryophilous fungi are an understudied group with unknown biodiversity in tropical regions, and are often underestimated worldwide. In Brazil, research on this ecological group has primarily focused on the southern and southeastern regions. During a survey of bryophilous fungi in the northeastern region, specifically in Bahia State, two novel species, Brachydesmiella bahiensis and Dendryphiosphaera longispora, were discovered. Brachydesmiella bahiensis resembles B. biseptata and B. caudata, but exhibits conidial distal cell morphology between these two species. Dendryphiosphaera longispora has longer conidia than other species within the genus. Also, the uncommon microfungus Dwibeeja sundara was reported for the second time globally. Detailed descriptions and illustrations of each species are provided. [ABSTRACT FROM AUTHOR]

The ability to detect threats quickly is crucial for survival. Primates, including humans, have been shown to identify snakes quickly and accurately due to their evolutionary history. However, it is unclear which visual features humans and primates detect as threat targets. Several studies have suggested that snake scales possess potent visual features. My previous study demonstrated that removing snake scales through digital image processing reduces attention directed toward snakes. Here, I conducted a visual search task using luminance- and contrast-adjusted photographs of snakes and salamanders in monkeys that had never seen these real reptiles and amphibians. This study demonstrates that the presence or absence of snake scales is responsible for the rapid detection of target animals. The monkeys quickly detected one snake photograph from the eight salamander photographs than vice versa. However, when the same salamanders were clothed with snake scales using image processing, the difference in detection speed between snakes and salamanders disappeared. These results are consistent with the snake-detection theory that snakes were a strong selective pressure favoring modifications in the primate visual system that allow them to detect snakes more quickly or reliably. This strongly suggests that primates' snake detection depends on the snake-scale shapes, which are both snake-specific and common to all snakes. [ABSTRACT FROM AUTHOR]

Polyphenisms occur when phenotypic plasticity produces morphologically distinct phenotypes from the same genotype. Plasticity is maintained through fitness trade‐offs which are conferred to different phenotypes under specific environmental contexts. Predicting the impacts of contemporary climate change on phenotypic plasticity is critical for climate‐sensitive animals like amphibians, but elucidating the selective pressures maintaining polyphenisms requires a framework to control for all mechanistic drivers of plasticity.Using a 32‐year dataset documenting the larval and adult histories of 717 Arizona tiger salamanders (Ambystoma mavortium nebulosum), we determined how annual variation in climate and density dependence explained the maintenance of two distinct morphs (terrestrial metamorph vs. aquatic paedomorph) in a high‐elevation polyphenism. The effects of climate and conspecific density on morph development were evaluated with piecewise structural equation models (SEM) to tease apart the direct and indirect pathways by which these two mechanisms affect phenotypic plasticity.Climate had a direct effect on morph outcome whereby longer growing seasons favoured metamorphic outcomes. Also, climate had indirect effects on morph outcome as mediated through density‐dependent effects, such as long overwintering coldspells corresponding to high cannibal densities and light snowpacks corresponding to high larval densities, both of which promoted paedomorphic outcomes.Both climate and density dependence serve as important proxies for growth and resource limitation, which are important underlying drivers of the phenotypic plasticity in animal polyphenisms. Our findings motivate new studies to determine how contemporary climate change will alter the selective pressures maintaining phenotypic plasticity and polyphenisms. [ABSTRACT FROM AUTHOR]

Ecological niche differentiation is a process that accompanies lineage diversification and community assembly. Traditionally, the degree of niche differentiation is estimated by contrasting niche hypervolumes of two taxa, reconstructed using ecologically relevant variables. These methods disregard the fact that niches can shift in different ways and directions. Without means of discriminating between different types of niche differentiation, important evolutionary and ecological patterns may go unrecognized. Herein, we introduce a new conceptual and methodological framework that allows quantification and classification of niche differentiation and divergence between taxa along single niche axis. This new method, the Niche Divergence Plane, is based on species' responses to an underlying environmental gradient, from which we derive a two‐dimensional plane defined by two indices, niche exclusivity and niche dissimilarity. These two indices identify the proportion of the environmental gradient that is unique to each species, that is, how much of the environmental gradient species do not share (niche breadth exclusivity) and how different the species' responses are along the environmental gradient (niche dissimilarity). Thus, the latter can also be seen as a measure of the differences in niche preference or importance, even when there is significant overlap in niche breadth (i.e., low niche exclusivity). Based on the position of the two indices on the divergence plane, we can distinguish niche conservatism from four other general types of niche divergence: hard, soft, weighted, and nested. We demonstrate that the Niche Divergence Plane complements traditional measures of niche similarity (e.g., Schoener's D or Hellinger's I). Additionally, we show an empirical comparison using the Niche Divergence Plane framework on two Ambystoma salamanders. Overall, we demonstrate that the Niche Divergence Plane is a versatile tool that can be used to complement and expand previous methods of ecological niche comparisons and the study of ecological niche divergence. [ABSTRACT FROM AUTHOR]

Behavioral adaptation is one of the first responses put in play by individuals to buffer environmental variations and to maintain homeostatic equilibrium with their environment. Microhabitat selection is pivotal for maximizing fitness, survival and reproduction, but how individuals process and exploit information acquired from the environment to make future microhabitat choice is yet understudied. In this study, we used outdoor mesocosms in which we introduced Strinati's cave salamanders (Speleomantes strinatii), to assess their behavioral patterns of shelter site fidelity. In each mesocosm three microhabitats were available to the salamanders: the leaf litter, a log and a rock. A total of 22 salamanders were tested over an 8-day period, 11 in autumn and 11 in spring. Salamanders shelter site fidelity was driven by both microhabitat humidity and previous experience obtained in the mesocosm. In our experiment, the time spent in the mesocosm was the main factor influencing shelter site fidelity, suggesting that previous experience and familiarity are important in salamanders' behavioral adaptation. Therefore, cave salamanders are capable of learning from experience when selecting their shelters, a behavior that could also be relevant during migration, colonization of new environments and adaptation to climate change. Highlights: How individuals exploit information gained from experience to select a microhabitat is understudied We found that plethodontid salamanders are capable of exploiting information on their environment to select the most suitable microhabiat [ABSTRACT FROM AUTHOR]

Transposable elements (TEs) compose a substantial proportion of the largest eukaryotic genomes. TE diversity has been hypothesized to be negatively correlated with genome size, yet empirical demonstrations of such a relationship in a phylogenetic context are largely lacking. Furthermore, the most abundant type of TEs in genomes varies across groups, and it is not clear if there are patterns of TE activity consistent with genome size among different taxa with large genome sizes. We use low-coverage sequencing of 16 species of Neotropical salamanders, which vary ∼7-fold in genome size, to estimate TE relative abundance and diversity for each species. We also compare the divergence of copies of each TE superfamily to estimate patterns of TE activity in each species. We find a negative relationship between TE diversity and genome size, which is consistent with the hypothesis that either competition among TEs or reduced selection against ectopic recombination may result in lower diversity in the largest genomes. We also find divergent activity patterns in the largest versus the smallest genomes, suggesting that the history of TE activity may explain differences in genome size. Our results suggest that both TE diversity and relative abundance may be predictable, at least within taxonomic groups. [ABSTRACT FROM AUTHOR]

This study aimed to examine the complete mitogenome sequence of Sicista caudata Thomas, 1907. A circular double-stranded structure made up the mitochondrial genome of S. caudata. The complete length of the mitochondrial genome was 16,629 bp. The mitochondrial genome of S. caudata included 13 protein-coding genes, one control region, 22 tRNA genes, two rRNA genes, and one origin of L-strand replication. S. caudata was supported by bootstrap values of 100%. This study verified the evolutionary status of S. caudata in the Superfamily Dipodoidea at the molecular level. [ABSTRACT FROM AUTHOR]

The geographic distribution of genetic variation within a species reveals information about its evolutionary history, including responses to historical climate change and dispersal ability across various habitat types. We combine genetic data from salamander species with geographic, climatic, and life history data collected from open-source online repositories to develop a machine learning model designed to identify the traits that are most predictive of unrecognized genetic lineages. We find evidence of hidden diversity distributed throughout the clade Caudata that is largely the result of variation in climatic variables. We highlight some of the difficulties in using machine-learning models on open-source data that are often messy and potentially taxonomically and geographically biased. [ABSTRACT FROM AUTHOR]

Simple Summary: The Anji salamander (Hynobius amjiensis) is an endangered amphibian native primarily to China. Artificial breeding is crucial for its population growth, yet research on its reproduction remains limited. This study identified 25 early embryo stages and observed that these embryos contain less yolk compared to those of other salamanders or frogs. The Anji salamander employs a "mass escape" reproductive strategy, producing fewer but higher-quality offspring due to intense competition within its restricted breeding habitats. This research offers new insights into these salamnders' breeding biology and proposes methods to enhance breeding practices for conservation. Hynobius amjiensis, also known as the Anji salamander, is an amphibian species currently categorized as endangered due to its limited geographical distribution, primarily in China. To address the critical conservation status of this species, artificial breeding is essential for population expansion. However, progress in artificial breeding efforts has been hindered by the scarcity of research on the reproductive biology of the Anji salamander. In this study, we identified 25 distinct early stages of embryo development. Additionally, we observed that Anji salamander embryos contain a lesser amount of yolk compared to other salamanders or frogs. We further discovered that the Anji salamander employs a highly competitive reproductive strategy, producing a smaller number of high-quality offspring. This strategy aims to generate adaptive individuals through intense intraspecific competition, driven by three factors: extremely confined breeding habitats, a substantial number of eggs, and a reduced yolk content. We introduce the term "mass escape" to describe this strategy, which provides a novel perspective on cannibalization, focusing on the consumption of specific body parts rather than a single-individual activity. This study offers valuable insights into artificial breeding techniques designed to mitigate inherent intraspecific competitive pressure, thereby improving metamorphosis and survival rates. Additionally, it provides a comprehensive table detailing the pre-embryonic developmental stages of the Anji salamander. [ABSTRACT FROM AUTHOR]

Amphibians are increasingly threatened, leading to growing concern about their key role in natural ecosystems globally as predators and essential consumers in food webs. Effective conservation plans are linked to up‐to‐date distributional and ecological information, but dietary knowledge is often underrepresented. This information is essential for understanding ecological requirements, changes in the species and populations, impacts of habitat modification, and developing conservation strategies. Here, we present the current knowledge on amphibian diets in Colombia, to determine (a) the number of species studied and their distribution across families and genera; (b) the temporal and regional patterns in number of articles on amphibian diets; and (c) the trends in topics studied associated with amphibian diets; and to offer (d) a qualitative description of amphibian diets and the methods used for stomach contents collection. We found 70 published studies on the diet of Colombian amphibians between the years 1914 and 2022, including 100 species (11.6% of Colombian species). The Andean region is the best represented, and the Amazon and Orinoco the least. The topics most frequently studied were prey items consumed and ontogeny, followed by systematics and taxonomy, and land‐use change impacts. Forty‐one prey items were consumed, where Coleoptera and Hymenoptera were the most common prey items. While the development of information on amphibian diets has recently increased, knowledge remains limited, with a significant information gap for many Colombian species in different regions. Conducting studies in little‐explored areas of the country, especially the Amazon, Orinoco, and Pacific regions, should have high priority. Investigations should be focused on Caudata and Gymnophiona, plus the anurans of the Hemiphractidae and Pipidae families that do not have diet records in Colombia. Indeed, we evidence the necessity to perform trophic network analysis to understand better the energy flow between species and the associated spatial, temporal, or functional trait changes. [ABSTRACT FROM AUTHOR]

Amphibians are among the most endangered taxa worldwide, but little is known about how their disappearance can alter the functioning and structure of freshwater ecosystems, where they live as larval stages. This is particularly true for urodeles, which often are key predators in these ecosystems. The fire salamander (Salamandra salamandra) is a common predator in European fresh waters, but the species is declining due to habitat loss and the infection by fungal pathogens. We studied the consequences of fire salamander loss from three montane streams, by comparing two key ecosystem processes (periphyton accrual and leaf litter decomposition) and the structure of three communities (periphytic algae, aquatic hyphomycetes and invertebrates) using stream enclosures with and without salamander larvae. Salamander loss did not cause changes in invertebrate abundance or community structure, except for one stream where abundance increased in the absence of salamander larvae. However, salamander loss led to lower periphyton accrual, changes in algal community structure and slower leaf litter decomposition, with no associated changes in fungal communities or microbial decomposition. The changes observed may have been caused by release of salamander predatory pressure on invertebrates, which could have promoted their grazing on periphyton, in contrast to their preference for leaf shredding in the presence of salamander. Our study demonstrates an important role of salamander larvae in montane streams through top‐down control of lower trophic levels and thus in regulating key stream ecosystem processes. Our results highlight the need for improving protection measures for amphibians to prevent these alterations on ecosystem structure and function. [ABSTRACT FROM AUTHOR]

The production of glucocorticoids by the hypothalamic-pituitary-interrenal axis of amphibians and reptiles allows individuals to respond to acute stressors, but chronic elevation can have negative fitness consequences. Amphibians offer a unique opportunity to study the potential effects of elevated glucocorticoids, such as corticosterone (CORT), as lipid-soluble glucocorticoids readily pass through the skin and into the bloodstream. Interestingly, glucocorticoids are also secreted and excreted by amphibians to such an extent that relative rates of CORT release have been used to assess the relative 'health' of populations. Given that CORT has the potential to be both absorbed and secreted through the skin of amphibians and may have a negative impact on fitness, I attempted to assess the degree to which salamanders could identify 'stressed' conspecifics whose CORT levels were experimentally elevated through the use of a dermal patch. Plethodontid salamanders provide a convenient opportunity to evaluate the discrimination of 'stress' levels in amphibians because they utilize well-developed vomeronasal organs to facilitate a range of behavior, and their plasma CORT levels are readily manipulated via transdermal delivery. I tested the ability of Desmognathus ochrophaeus to detect and avoid substrates sullied by conspecifics with elevated CORT. The test was conducted via a simple choice experiment in which male and female test subjects were exposed to substrates sullied by an individual with baseline levels of CORT or the same individual with experimentally elevated CORT. Overall, I found that females did not differentially respond to substrates sullied by 'high-stress' females or males. Males did not avoid substrates sullied by high-stress males but did spend less time than expected on substrates from high-stress females. The differential response by males toward stimuli from high-stress females was replicated in a second study conducted approximately seven months after the first. These findings suggest that male D. ochrophaeus are capable of discerning among females, but not males, in 'high-stress' and 'low-stress' states. Female salamanders did not respond differently to substrates based on the stress level of stimulus donors. [ABSTRACT FROM AUTHOR]

Simple Summary: Age and size variation in widespread amphibians are often related to latitudinal or altitudinal temperature gradients. Species with toxic skin secretions, such as the fire salamander Salamandra salamandra, are an exception to the rule because their survival rates are relatively unaffected by predation, the major source of amphibian mortality. In contrast, average adult size varies greatly among populations, but variation is unrelated to geographical gradients. This study on four neighboring fire salamander populations inhabiting the catchments of low-order streams in the upper middle Rhine Valley (Koblenz, Germany) focuses on the identification of local environmental drivers of variation in age and body size distributions. I collected 192 individuals at two localities per stream, snout–vent length measured, clipped a toe for posterior skeletochronological age determination, and released salamanders in situ again. As expected, demographic parameters were in the range of other populations with an age at maturity of 2–3 years and a maximum lifespan of 17 years, but terrestrial habitat quality accounted for 3.6% of variation among populations. Variation in adult size resulted mainly from a carry-over effect of heavy metal contamination on juvenile growth rates. In conclusion, the average adult body size is a sensitive indicator of local habitat quality. Conspecific amphibian populations may vary widely in local demography and average body size throughout their geographical range. The environmental drivers of variation may reflect geographical gradients or local habitat quality. Among fire salamander populations (Salamandra salamandra), local demography shows a limited range of variation because high concentrations of skin toxins reduce mortality from predation to a minimum, whereas average adult body size varies significantly over a wide range. This study on four neighboring populations inhabiting the catchments of low-order streams in the upper middle Rhine Valley (Koblenz, Germany) focuses on the identification of local environmental drivers of variation in age and body size. I collected 192 individuals at two localities per stream, measured snout–vent length, clipped a toe for posterior skeletochronological age determination, and released salamanders in situ again. Populations were similar in age distribution. Local habitat quality accounted for a significant proportion of demographic variability, mediated by the impact of landscape-induced mortality risk, including roads and agriculture. Still, the main effect of variation in habitat quality was on adult body size, the result of growth rates of aquatic larvae and terrestrial juveniles. Larvae exposed to non-lethal heavy metal contamination in streams developed into smaller juveniles and adults than clean-water larvae, providing evidence for carry-over effects from one stage to another. The generally small average adult size in the Rhine Valley populations compared to those in other parts of the distribution range indicates the action of a still unidentified environmental driver. [ABSTRACT FROM AUTHOR]

Urodele amphibians possess remarkable regenerative abilities, allowing them to rebuild lost body parts. Contrary to lizards, salamanders can fully restore their tails, including the neural spine and components of the vertebral column. The axolotl (Ambystoma mexicanum) is the vertebrate model organism for regeneration research due to its ease of breeding in captivity. However, axolotls are paedomorphic, retaining larval somatic features throughout adulthood and do not naturally undergo metamorphosis, a transition phase from aquatic larvae to terrestrial adults with profound morphological and physiological changes. We investigate the influence of metamorphosis on salamander tail regeneration after conspecific biting in the metamorphosing sister taxon Ambystoma tigrinum using histological analysis to answer two key questions: (1) Does regeneration continue during metamorphosis, or is it halted? (2) How does regeneration differ histologically among larval, metamorphosing and postmetamorphic individuals? Our findings demonstrate that regeneration continues even during metamorphic climax, indicating the simultaneous coordination of metamorphosis and regeneration. Additionally, notable distinctions were observed between developmental stages concerning the speed of regeneration and structural differences in the formation of an apical epithelial cap (AEC). While the approach taken in this study necessarily restricts sample size, it offers valuable insights into regeneration in a metamorphosing species under natural conditions. [ABSTRACT FROM AUTHOR]

The most effective drug, doxorubicin (DOX), is widely used worldwide for clinical application as an anticancer drug. DOX‐induced cytotoxicity is characterized by mitochondrial dysfunction. There is no alternative treatment against DOX‐induced cardiac damage despite intensive research in the present decades. Ohwia caudata has emerged as a potential herbal remedy that prevents from DOX‐induced cytotoxicity owing to its pharmacological action of sustaining mitochondrial dynamics by attenuating oxidative stress and inducing cellular longevity. However, its underlying mechanisms are unknown. The novel treatment provided here depends on new evidence from DOX‐treated H9c2 cells, which significantly enhanced insulin‐like growth factor (IGF) II receptor (IGF‐IIR) pathways that activated calcineurin and phosphorylated dynamin‐related protein 1 (p‐Drp1) at ser616 (p‐Drp1[ser616]); cells undergo apoptosis due to these factors, which translocate to mitochondria and disrupt their function and integrity, and in terms of herbal medicine treatment, which significantly blocked these phenomena. Thus, our findings indicate that maintaining integrity of mitochondria is an essential element in lowering DOX‐induced cytotoxicity, which further emphasizes that our herbal medicine can successfully block IGF‐IIR pathways and could potentially act as an alternative mechanism in terms of cardioprotective against doxorubicin. [ABSTRACT FROM AUTHOR]

Amphibians are well-known for their ability to produce and secrete a mixture of bioactive substances in specialized skin glands for the purpose of antibiotic self-protection and defense against predators. Some of these secretions contain various small molecules, such as the highly toxic batrachotoxin, tetrodotoxin, and samandarine. For some time, the presence of peptides in amphibian skin secretions has attracted researchers, consisting of a diverse collection of – to the current state of knowledge – three to 104 amino acid long sequences. From these more than 2000 peptides many are known to exert antimicrobial effects. In addition, there are some reports on amphibian skin peptides that can promote wound healing, regulate immunoreactions, and may serve as antiparasitic and antioxidative substances. So far, the focus has mainly been on skin peptides from frogs and toads (Anura), eclipsing the research on skin peptides of the ca. 700 salamanders and newts (Caudata). Just recently, several novel observations dealing with caudate peptides and their structure-function relationships were reported. This review focuses on the chemistry and bioactivity of caudate amphibian skin peptides and their potential as novel agents for clinical applications. [ABSTRACT FROM AUTHOR]

Amphibians have the least studied life histories among vertebrates, although they have unique and the most diverse life histories within this group. We compiled a new dataset on adult body mass and 16 other life history traits of 2069 amphibian species across three orders (1796 frogs, 236 salamanders, 37 caecilians). These traits characterise fecundity, offspring development from egg deposition to metamorphosis and adult life. We established allometric models on traits for all amphibians and each of the three orders to assess a potential scaling of traits to body mass and then checked whether allometric slopes were consistent with two different metabolic scaling exponents. Further, we examined a possible fast‐slow continuum in all amphibians, as well as in each of the two orders frogs and salamanders by applying principal component analysis (PCA) to five traits. Our allometric models indicated a positive scaling to body mass for 11 traits across all amphibians, 12 in frogs, and 10 in salamanders, and for five out of eight traits analysed in caecilians. Allometric slopes on most traits characterising offspring development were not significant. All slopes did not support a three‐quarter metabolic scaling exponent, whereas slopes on age at maturity and maximum longevity were consistent with an amphibian metabolic scaling exponent of 0.88. As in fishes, reptiles, birds, and mammals, the first axes of our PCAs indicated a body mass‐dependent fast‐slow continuum in amphibians. Amphibian species of slow life histories have larger body masses, later sexual maturities and longer lifespans and lay more and larger eggs than species of fast life histories, a pattern also known from reptiles. The second axes indicated a trade‐off between egg size and number. As this trade‐off was nearly independent of body mass, we hypothesise that amphibians have occupied a broad range of ecological niches without evolutionary changes in body mass. [ABSTRACT FROM AUTHOR]

Identifying and quantifying the main factors that are jeopardizing amphibian communities worldwide is essential for planning effective amphibian conservation. We collected data on the presence/absence of salamanders and newts (Caudata) and frogs and toads (Anura) in >3600 water points from a large region (30,000 km2) in NW Spain during a 10‐year period (2004–2013). We contrasted a large set of hypotheses explaining presence/absence as a function of anthropogenic factors across the regional elevation gradient (1–2036 m). Logistic regression modeling revealed that salamanders and newts were mainly influenced by pollution and by land use changes, and that the effect of these factors changed with elevation. However, frogs and toads were affected by a larger set of factors acting synergistically, although not including land use changes, and their effect operated at all elevation ranges, except in the case of biological factors (invasive species and wild boar abundance) with higher effects at low elevation. Changes in land use was the most common factor at any elevation and included the abandonment of rural areas, which favors shrub and tree encroachment on former open land, and loss of water points. The most resilient species at any elevation were two frogs, Pelophylax perezi and Rana parvipalmata. The least resilient species were two salamanders, Chioglossa lusitanica and Lissotriton helveticus, followed closely by two toads, Alytes obstetricans and Pelobates cultripes. Unoccupied sites had higher frequencies of biological effects and of changes in land use in the first 5 years of study and lower frequencies of direct human influence factors in the second period. Overall, our results showed that the studied amphibian metacommunity was negatively influenced both by direct and indirect anthropogenic factors, but also that many amphibian species were not only capable of occupying sites which had been altered by human action, but were even favored by land uses generating open habitat, a habitat type that is increasingly uncommon in the region, in the entire Iberian Peninsula and in Europe. [ABSTRACT FROM AUTHOR]

This paper describes the morphology and histological structure of the femora of salamanders of the genus Kiyatriton K. krasnolutskii from the Middle Jurassic (Bathonian) Berezovsk Quarry locality in Krasnoyarsk krai and K. leshchinskiyi from the Lower Cretaceous (Aptian) Shestakovo 1 locality in the Kemerovo Region. The femora of Kiyatriton are characterized by the presence of a large spur-like trochanter, a developed high trochanteric crest, a large ventral fossa (fossa trochanterica), and a bean-shaped proximal end in cross-section. The histological structure is characterized by the presence of a thick, almost avascular cortex formed by both the primary periosteal bone and secondary endosteal bone; a thick periosteal cortex, which consists of a parallel-fibred bone matrix and bears cyclical growth marks (annuli and LAGs), including double LAGs; a thick endosteal cortex consisting of a lamellar bone matrix; the presence of a small medullary cavity; the presence of the Katschenko's line; and the absence of a calcified cartilage and bone remodeling (erosion bays, secondary osteons, and resorption of the walls of the medullary cavity). The similarities in the morphological and histological structure of the femora of Kiyatriton and small-sized modern metamorphosing salamanders (large spur-like trochanter of the femur, deep ventral fossa, rounded proximal end of the femur, avascular periosteal cortex with growth marks, thick layer of endosteal bone forming the inner part of the cortex, and small medullary cavity) indicate that members of the genus Kiyatriton were metamorphosing salamanders with a terrestrial adult stage. The similarity in the structure of the femora of different-aged Middle Jurassic and Early Cretaceous representatives of Kiyatriton indicates that the biological features (growth pattern and the presence of metamorphosis) have not changed for about 40 million years. [ABSTRACT FROM AUTHOR]

Bycatch is one of the leading threats facing aquatic organisms, worldwide. Pesticide bycatch can occur when nontarget species are incidentally killed during chemical application targeting noxious species. The common mudpuppy (Necturus maculosus) is a river‐dwelling salamander that is susceptible to bycatch from 3‐trifluoromethyl‐4‐nitrophenol (TFM) applications. However, the long‐term consequences of TFM bycatch on mudpuppy populations are not well understood. We used population viability analysis to reveal potential impacts of TFM application on a mudpuppy population in Ohio's Grand River under plausible bycatch scenarios. We found that the population was more sensitive to increased juvenile mortality and rapid declines occurred when both adults and juveniles were impacted at high bycatch rates (≥5% of the population) or more frequent TFM intervals (≥5 years). Our results suggest that continued use of TFM could pose a risk to mudpuppy population persistence if bycatch occurs at moderate to high levels and affects both juveniles and adults. Future TFM use and management decisions should be directed with these potential nontarget impacts in mind. [ABSTRACT FROM AUTHOR]

Microplastics (MPs), tiny plastic particles less than 5 mm in size, have emerged as a common and worrying pollutant in marine, freshwater, and terrestrial environments worldwide. In this study, we revealed the microplastic exposure of two endemic newt species for Türkiye. We found that polyethylene terephthalate (PET) was the predominant microplastic polymer type in both species, with the blue fiber shape in particular. We also found that there was a negative correlation between microplastic size and gastrointestinal tract (GIT) weight, but there was no significant difference between body length and GIT weight of both species. Our findings might be surprising as the studied species live in natural spring waters in remote, high-altitude areas. However, the detection of water bottles in their habitats appears to be the reason for their exposure to microplastic pollution. Therefore, reducing the use of single-use plastics is predicted to contribute to the conservation of these endemic newts. [ABSTRACT FROM AUTHOR]

Declines in amphibian populations have led to greater research and monitoring of species of interest, including terrestrial salamanders. Several methods have been used to study salamanders, including artificial cover objects (ACOs). Artificial cover objects are easy to install and use, limit destruction to habitats, are easily reproducible both across and within studies, and can reduce variability between observers and sites by not relying on observer search time or effort, or on natural cover. However, different ACO designs and spacing may yield different capture rates, and thus different estimates of population densities. We examined the influence of ACO wood type, size, shape, and spacing arrays on the number of individually marked red‐backed salamanders (Plethodon cinereus) captured under ACOs. White pine (Pinus strobus) ACOs yielded the most (average of 14 across 3 replicates) individuals, while white ash (Fraxinus americana) ACOs had the least (average of 7 across 3 replicates). Larger ACOs had similar capture rates compared to equal sampled areas of smaller ACOs, but a single smaller ACO tended to have fewer individual salamander captures than a single large ACO. Our results suggested that high‐density ACO spacing arrays may increase capture probability but reduce the area uniquely sampled by each ACO. In contrast, low‐density ACO arrays may produce population estimates more comparable to other arrays. Future studies should consider monitoring goals and available sampling effort when choosing a spacing array. As ACO study design impacts salamander capture rates, a clear understanding of the effects of each element of ACO design is important when drawing inferences or making comparisons among studies. [ABSTRACT FROM AUTHOR]

The study of colour, including physical properties and patterns, is an essential step in comprehensively understanding the role, evolution and diversification of this trait involved in functions like survival, performance, reproductive success and communication. While quantitative studies on colour have primarily focused on colour attributes, such as hue or brightness, the quantitative assessment of how colours are distributed across an organism's body (i.e. pattern) has received less attention despite its high functionality irrespective and together with colour. This gap is particularly noticeable in amphibians, especially in highly polymorphic, continuously variable species. In this study, we use the urodele Salamandra salamandra as a study model to apply an analytical approach for extracting and quantifying colour proportions and patterns variation using the recently developed R packages patternize and recolorize to precisely describe and compare colour distribution at both taxonomic and habitat levels. We first assessed the potential application of this workflow in taxonomic studies by examining its accuracy and sensitivity in differentiating morphs, using S. s. bernardezi and S. s. gallaica subspecies. Subsequently, we applied the same analytical approach to compare colour and colour pattern shifts among population of S. s. bernardezi within an urban–forest system. Our results demonstrated that this methodological workflow effectively detects differences in colour patterns at the taxonomic and habitat levels, confirming its utility in different fields, from systematics to eco‐evolutionary studies. Furthermore, our results revealed an increased prevalence of melanistic colouration and a less homogeneous colour pattern within urban settings, contributing to the limited number of studies about amphibian colouration in anthropic habitats. We outline and discuss alternative hypotheses to explain these patterns, although further investigation is necessary to address several new questions that arise from our results. [ABSTRACT FROM AUTHOR]

The campus of Patrick & Henry Community College in Henry County, Virginia, was surveyed from April 2016 to April 2024. During this period, a total of 38 species were found, including 10 anurans, 7 salamanders, 6 turtles, 3 lizards, and 12 snakes. Seven new records for Henry County were observed and here reported. [ABSTRACT FROM AUTHOR]

Extant salamanders are used as modern analogs of early digit-bearing tetrapods due to general similarities in morphology and ecology, but the study species have been primarily terrestrial and relatively smaller when the earliest digit-bearing tetrapods were aquatic and an order of magnitude larger. Thus, we created a 3D computational model of underwater walking in extant Japanese giant salamanders (Andrias japonicus) using 3D photogrammetry and open-access graphics software (Blender) to broaden the range of testable hypotheses about the incipient stages of terrestrial locomotion. Our 3D model and software protocol represent the initial stages of an open-access pipeline that could serve as a "one-stop-shop" for studying locomotor function, from creating 3D models to analyzing the mechanics of locomotor gaits. While other pipelines generally require multiple software programs to accomplish the different steps in creating and analyzing computational models of locomotion, our protocol is built entirely within Blender and fully customizable with its Python scripting so users can devote more time to creating and analyzing models instead of navigating the learning curves of several software programs. The main value of our approach is that key kinematic variables (e.g. speed, stride length, and elbow flexion) can be easily altered on the 3D model, allowing scientists to test hypotheses about locomotor function and conduct manipulative experiments (e.g. lengthening bones) that are difficult to perform in vivo. The accurate 3D meshes (and animations) generated through photogrammetry also provide exciting opportunities to expand the abundance and diversity of 3D digital animals available for researchers, educators, artists, conservation biologists, etc. to maximize societal impacts. [ABSTRACT FROM AUTHOR]

In this work, the Hypselotriton populations distributed in eastern Guangdong, China are studied in detail to clarify their taxonomic status. Based on morphological comparison and phylogenetic analysis, H. glaucus syn. nov. is synonymised with H. orphicus. Hypselotriton (Cynotriton) oolong sp. nov. from Mt Fenghuang in Chaozhou which used to be misidentified as H. orphicus, is revealed to be an independent lineage of subgenus Cynotriton and can be distinguished from all known congeners in morphology. By contrast, H. orphicus did not cluster within Cynotriton, but gathered with H. jiaoren comb. nov. to form a distinct unnamed clade within the genus. We therefore re-delimitate the intrageneric classification of the genus and a new subgenus Hakkatriton subgen. nov. is erected, corresponding to this unnamed clade. The Chinese Fire-bellied Newt genus Hypselotriton currently contains three subgenera and about ten known species. Identified keys to the subgenera and related congeners of genus Hypselotriton are further provided. [ABSTRACT FROM AUTHOR]

Members of the Iridoviridae family, genus Ranavirus, represent a group of globally emerging pathogens of ecological and economic importance. In 2017, an amphibian die-off of wood frogs (Rana sylvatica) and boreal chorus frogs (Pseudacris maculata) was reported in Wood Buffalo National Park, Canada. Isolation and complete genomic sequencing of the tissues of a wood frog revealed the presence of a frog virus 3 (FV3)-like isolate, Rana sylvatica ranavirus (RSR), with a genome size of 105,895 base pairs, 97 predicted open reading frames (ORFs) bearing sequence similarity to FV3 (99.98%) and a FV3-like isolate from a spotted salamander in Maine (SSME; 99.64%). Despite high sequence similarity, RSR had a unique genomic composition containing ORFs specific to either FV3 or SSME. In addition, RSR had a unique 13 amino acid insertion in ORF 49/50L. No differences were found in the in vitro growth kinetics of FV3, SSME, and RSR; however, genomic differences between these isolates were in non-core genes, implicated in nucleic acid metabolism and immune evasion. This study highlights the importance of viral isolation and complete genomic analysis as these not only provide information on ranavirus spatial distribution but may elucidate genomic factors contributing to host tropism and pathogenicity. [ABSTRACT FROM AUTHOR]

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