Search Results (266)

Understanding how habitat conditions drive morphological adaptations in animals is critical in ecology, yet amphibian studies remain limited. This study investigated intraspecific variation in ecomorphological traits of three montane stream-dwelling frogs (Quasipaa boulengeri, Amolops sinensis, and Odorrana margaratae) across elevation gradients in Tianping Mountain, China. Using morphological measurements and environmental variables collected from ten transects, we analyzed functional traits related to feeding and locomotion and assessed their associations with microhabitat variables. Significant trait differences between low- and high-elevation groups were detected only in Q. boulengeri, with high-elevation individuals exhibiting greater body mass and shorter hindlimbs. Redundancy analysis demonstrated that microhabitat variables, particularly air humidity, flow rate, and rock coverage, were linked to trait variations. For example, air humidity and flow rate significantly influenced Q. boulengeri’s body and limb proportions, while flow rate affected A. sinensis’s snout and limb morphology. In addition, sex and seasonal effects were also associated with trait variations. These results underscore amphibians’ phenotypic plasticity in response to the environment and highlight the role of microhabitat complexity in shaping traits. By linking habitat heterogeneity to eco-morphology, this study advocates for conservation strategies that preserve varied stream environments to support amphibian resilience amid environmental changes. Full article

Mycoplasmas are known respiratory pathogens in tortoises, but few studies exist in snakes. To better understand the correlation with clinical signs and co-infections, samples from mycoplasma-positive snakes with and without clinical respiratory disease were analyzed. Oral swabs from 15 snakes (pythons n = 12, boas n = 3) were examined using polymerase chain reaction (PCR) and third-generation sequencing (TGS). Additionally, mycoplasma isolation assays were performed. Pathogens detected by PCR included Mycoplasmas (15/15, 100%), serpentoviruses (9/15, 60%), and Chlamydia sp. (2/15, 13%); those detected by TGS included Mycoplasmas (14/15, 93%), serpentoviruses (10/15, 67%), Chlamydia sp. (1/15, 7%), and 15 different bacterial species. Sequencing of the mycoplasma PCR products revealed a close genetic relationship to Mycoplasmopsis agassizii. TGS identified genetically distinct mycoplasmas and three different serpentoviruses. While mycoplasmas could not be successfully propagated, Brucella intermedia comb. nov. was identified in eight cultures. Respiratory disease in snakes is often multifactorial, involving various pathogens and environmental influences. This study demonstrates that comprehensive diagnostics are essential for understanding disease processes in snakes and improving the detection of diverse pathogens. Further research is needed to improve laboratory diagnostics for infectious diseases in reptiles and to better understand the roles of various pathogens in respiratory diseases in snakes. Full article

Emerging infectious diseases such as chytridiomycosis and ranavirosis, caused by Batrachochytrium dendrobatidis (Bd) and ranavirus (RV), respectively, are major contributors to global amphibian declines. Despite their significance, comprehensive data on the spatial epidemiology of these pathogens in South Korea remain limited. This study aimed to assess the nationwide co-occurrence and prevalence of Bd and RV across four anuran species in five administrative regions. Infection rates were analyzed in relation to host species, sex, and life history stage. Results indicated distinct prevalence patterns driven by ecological traits. Bd was predominantly detected in mountainous and coastal habitats, whereas RV was more common in flat inland areas. Both pathogens exhibited peak occurrence in central regions, likely reflecting seasonal transmission dynamics rather than stable endemic hotspots. The observed spatial heterogeneity appears to be influenced by pathogen-specific thermal tolerance and host ecology. These findings underscore the importance of understanding host–pathogen–environment interactions for effective disease surveillance and management. Continuous monitoring and integrative ecological approaches are essential to mitigate pathogen-induced biodiversity loss and to inform amphibian conservation strategies in East Asia. Full article

Sexual dimorphism is prevalent among animals, influencing both functional morphological traits and behavioral performances. In this study, we investigated the sexual differences in the morphological parameters of Kaloula borealis (Anura, Microhylidae) during the breeding season using 48 specimens. Our results reveal that among the 16 external morphological traits, females had significantly larger snout-vent length and eye diameter than males. The former presumably contributes to enhancing fertility, while the latter is associated with larger body size. Males exhibited significantly greater head width and thigh width than females, which may be related to accessing a wider range of food sources and enhancing their locomotor ability, respectively. Among the 32 appendicular muscles, 10 displayed significant sexual dimorphism in dry mass, suggesting divergent reproductive strategies between the sexes. Among the eight internal organs analyzed, males possessed significantly heavier hearts and lungs than females, which is likely an adaptation to higher metabolic demands and calling behavior. Collectively, our findings demonstrate that sex-specific differences in external morphology, muscle mass, and internal organ mass reflect distinct ecological and reproductive adaptations between males and females and contribute to the phenotypic diversities in Anura. Full article

Rana dybowskii, widely distributed and extensively farmed in northeast China, holds significant economic value, particularly for its fallopian tubes, which are used as a traditional Chinese medicinal tonic known as “Oviductus Ranae.” As the light spectrum is a cost-effective regulatory factor in aquaculture, understanding its effects on the tadpole stage of R. dybowskii is critical for optimizing cultivation practices. This study investigated the effects of five light colors (white, red, yellow, blue, and green) on steroid hormone levels and gut microbiota composition in R. dybowskii tadpoles. Steroid hormone levels were measured on days 15, 30, 45, and 60 using high-performance liquid chromatography (HPLC), while gut microbial communities were analyzed through high-throughput 16S rRNA sequencing. Results showed that the testosterone (T) level of frogs in green light (group G) peaked on day 60 (2.62 ± 3.70 ng/g). The estradiol (E2) level in blue light (group B) also peaked on day 60 (2.87 ± 0.71 ng/g). Importantly, sex ratio analysis revealed that the proportion of females was highest under blue light, reaching 61.11%. Meanwhile, the richness and diversity of the gut bacterial community of the tadpoles was highest under yellow light, followed by blue light. These data suggest that hormone levels fluctuated and the composition of the gut flora of R. dybowskii changed under different light colors. Our results advance R. dybowskii physiological knowledge and support aquaculture practices. Full article

The spatial orientation of mammals and birds has been intensively studied for many years, but the cognitive mechanism of spatial orientation and memory used by squamates remains poorly understood. Our study evaluated the learning and memory abilities of leopard geckos (Eublepharis macularius) in an adapted Morris water maze. The animals learned during the training phase consisted of 20 trials. To assess long-term memory, we retested geckos twice after several months. The geckos remembered the learned information in a short re-test after two months, but after four months, they required retraining to find the platform. We hypothesise that the duration of memory corresponds with short-term changes in semi-desert environments within one season, while disruption of memory performance after a six-month gap may simulate the more extensive seasonal change in spatial relationships in their natural environment. Moreover, during the winter period, geckos exhibit low activity, which can be connected with decreased frequency of foraging trips. Therefore, the memory loss after four months may reflect the low level of memory jogging. The motivation during the experiment was the crucial parameter of learning and memory processes. In later phases, geckos were less motivated to perform the task. Finally, they relearned the spatial orientation task, but they moved more slowly as the experiment progressed. Full article

The intestinal microbiota regulates host metabolic homeostasis through production of bioactive microbial metabolites. These microorganisms facilitate digestion, enhance immune function, maintain osmoregulation, and support physiological balance via these bioactive compounds, thereby enhancing environmental adaptation. Our study investigated intestinal microbiota–liver metabolic interactions in Leptobrachium liui using 16S rRNA gene sequencing and non-targeted liquid chromatography–tandem mass spectrometry metabolomics. Key findings include (1) comparable alpha diversity but distinct microbial community structures between the small intestine (SI) and large intestine (LI), with the SI dominated by Enterobacteriaceae (72.14%) and the LI by Chitinophagaceae (55.16%); (2) segment-specific microbe–metabolite correlations, with predominantly positive correlations in the SI and complex patterns in the LI involving fatty acids, amino acids, and energy metabolites; and (3) significant correlations between specific bacterial families (Aeromonadaceae, Enterobacteriaceae, Chitinophagaceae) and hepatic metabolites related to fatty acid metabolism, amino acid synthesis, and energy pathways, indicating potential gut–liver axis associations. These findings provide insights into amphibian intestinal microbiota–hepatic metabolite associations and may inform future studies of host–microbe interactions. Full article

Edge populations can harbor unique genetic diversity shaped by historical isolation and play a key role in species’ resilience and range expansion under ongoing climate warming. The Aesculapian snake (Zamenis longissimus) reaches the northern limit of its range in Central Europe, where isolated populations may provide key insights into the species’ evolutionary potential and conservation priorities. In Bohemia (the western Czech Republic), only one reproducing population, in the vicinity of Stráž nad Ohří (SO), had previously been confirmed north of the species’ continuous distribution. Here, we report two additional reproducing populations recently discovered through long-term monitoring: one at the Želinský meander (ZM) and another in Central Bohemia (CB). The ZM population is autochthonous, viable, and genetically remarkable, harboring two divergent mitochondrial haplotypes: the widespread Eastern phylogeographical clade haplotype E1 and a novel haplotype, W10, belonging to the Western clade. This represents the first confirmed record of a Western clade haplotype in the Czech Republic, and only the second known locality within the species’ entire range where both clades coexist. In contrast, the CB population—founded by human-mediated translocation from SO—is expanding dynamically and is represented solely by E1, the only haplotype previously recorded in the country. Our study highlights the importance of incorporating genetic data into conservation planning and understanding species’ evolutionary potential. The mitochondrial diversity uncovered at the ZM exemplifies how historical processes, isolation, and lineage mixing shape contemporary genetic structure. Preserving such populations, which retain unique evolutionary diversity, will be critical for maintaining the resilience of Z. longissimus in Central Europe. More broadly, disjunct northern populations may serve as reservoirs of genetic diversity, enhancing adaptive potential and supporting future range expansion under climate change. Recognizing and conserving this diversity is essential not only for local persistence but also for species-level resilience in a rapidly changing environment. Full article

The global increase in temperature has directly impacted the environment and reproduction of ectothermic organisms, leading to defects in processes that intervene in sperm quality and maturation. The present study evaluates the effect of temperature on sperm quality of the lizard Lepidophyma gaigeae in the surroundings of Landa de Matamoros, Querétaro, México. As a species under special protection, only 12 male individuals were captured in December 2020 with 4 exposed at (1) preferred temperature (Tpref) at 24 °C; (2) low temperature (LT) at 21 °C; (3) either individuals without treatment (Control) with fluctuating temperature of the habituation site, to compare the effect on the viability, concentration, and integrity of DNA, as well as the presence of the cytoplasmic droplet (CD). Sperm viability decreased by approximately 50% in organisms exposed to Tpref, accompanied by a significant reduction in concentration. Likewise, the CD evaluation showed a retention percentage of 30% at the cauda level, while the LT and Control groups showed 5% in this terminal area of the epididymis. The percentage of sperm with intact DNA was also decreased in the Tpref group compared to the LT and control groups. These findings highlight how thermal environments impact reptilian reproduction, reinforcing not only what has already been found in these species in recent years, but also the repercussions that it presents in the medium- or long-term exposure in these organisms at an ecological level, as well as the consequences with the potential damage and even infertility, in case of prolonged exposition to preferred temperatures. Full article

The intestinal microbiota is vital for host immunity and metabolism, and its changes are associated with the development stage of hosts. However, little is known regarding how growth and development of anurans affect the diversity of their microbiota, which has a complex life cycle. The Tibetan toad (Bufo tibetanus) is a wild population in the high-altitude area of southwest China, which has special adaptability to the environment. Here, the microbial community of the Tibetan toad at six developmental stages (from the tadpole at Gosner stage 18 to the 8-year-old adult) was assessed using high-throughput 16S rRNA sequencing. The alpha diversity index analysis showed that the Chao, Ace, and Shannon indices were highest at Gosner stage 32 and decreased as development progressed, and their alpha diversity remained unchanged over time in adult stages. Beta diversity revealed that the gut microbiota structure differed significantly from Gosner stages 18 to 31, and it became similar to adult toads from Gosner stages 45 to 46 and in juvenile groups. At the phylum level, Firmicutes, Proteobacteria, and Actinobacteria were dominant phyla in tadpoles and adults. The relative abundance of Firmicutes and Proteobacteria in the adult group was significantly higher and lower than that of tadpoles, respectively. The linear discriminant analysis effect size (LEfSe) analysis identified seven phyla exhibiting significant differences during life stages: Verrucomicrobiota, Bacteroidota, and Proteobacteria (Gosner 18 to 31), Cyanobateria and Chloroflexi (Gosner 32 to 41), Actinobacteriota (Gosner 45 to 46), Desulfobacterota (juvenile group), and Firmicutes (adult group). A pathway enrichment analysis revealed that the metabolism and biosynthesis of secondary metabolites were significantly enriched across all developmental stages. This research unveiled variations in the intestinal microbiota composition during development in anurans. Factors such as developmental stage, habitat type and feeding habit jointly affected the gut microbial diversity and community composition in the Tibetan toad. The findings of this study can provide information for understanding the influence of historical developments on the intestinal microbiota and provide protection information for anurans. Full article

In recent decades, the keeping of exotic animals has gained popularity among enthusiasts worldwide. However, alongside the development of exotic animal husbandry, issues related to health status and adequate veterinary care are coming to the forefront. The introduction of new snakes into a collection and shared enclosures should always be preceded by an assessment of their parasitic status. In our study, we present an overview of the screening for the presence of Cryptosporidium spp. in individuals captured in regions of Indonesia and Suriname, intended for further trade. Out of 40 tested fecal samples, the presence of cryptosporidial oocysts was confirmed in 6 samples. Detection was performed by molecular methods, namely Nested PCR targeting the GP60 gene region (60 kDa glycoprotein). By sequencing, we confirmed the presence of C. parvum in Oligodon octolineatus (n = 1) and Trimeresurus insularis (n = 1), C. tyzzeri in Corallus spp. (n = 2), and C. hominis in Boiga dendrophila spp. gemmicincta (n = 2), which is the very first time that this species has been detected in snakes in captivity. Although the presence of Cryptosporidium species, typical for snakes, was not detected, the identified species may pose a health risk to humans, especially workers who come into direct contact with animals. Full article

The global decline of amphibians is linked to habitat loss, with urbanization and roads as major threats. Roads fragment habitats and introduce stressors like pollution, temperature changes, and non-native predators. Despite growing awareness, studies in Latin America are scarce. In this study, we examined life-history traits of Rhinella arenarum from four sites in central Argentina that differ in urbanization intensity near roads. We analyzed snout–vent length (SVL), age, growth, size at maturity, and longevity in reproductive individuals. Sexual size dimorphism was present across sites, with females consistently larger than males. Moderate variation in SVL and age structure was observed among populations, with smaller and generally younger individuals in sites with medium-to-high urbanization. In contrast, individuals from the least disturbed site tended to show broader age ranges and greater longevity. Growth rates were also slower in the most urbanized site. While differences were moderate and sample sizes limited, these patterns suggest that urban-associated factors may influence demographic traits in R. arenarum. These findings contribute to our understanding of how human-altered environments might affect amphibian populations and highlight the need to distinguish between natural geographic variation and anthropogenic impacts on amphibian populations. Full article

Understanding reproductive biology and associated disorders is crucial for the clinical management of chelonians, particularly those maintained in captivity. This literature review presents an overview of the main pathological conditions affecting the female reproductive tract of these animals. For each condition, practical and effective diagnostic and therapeutic procedures are detailed. Commonly observed disorders include dystocia, ectopic eggs, follicular stasis, infertility, oophoritis, salpingitis, cloacitis, cloacal or oviductal prolapse, neoplasms, and ovarian torsion. The fundamental approach to these conditions always involves a thorough clinical examination, which requires extensive knowledge of the species, a clinical history, and management practices. Diagnostic procedures include physical exams, imaging techniques (ultrasound, radiography, CT, endoscopy), and surgical interventions. A shared feature of many pathologies is the influence of management errors and the presence of non-specific clinical signs. Full article

An analysis of the age structure of three water frog species (P. lessonae, P. ridibundus, P. esculentus) in the Middle Volga region of Russia was conducted. The skeletochronological method determined their maximum lifespans to be 7, 6, and 4 years, respectively. This study revealed specific characteristics of the age structure of Pelophylax frogs in relation to their taxonomic composition when cohabiting (population system type) and the degree of habitat transformation. Differences in body size and lifespan were observed among cryptic forms exhibiting mitochondrial DNA replacement and the presence of various types of heterozygous and homozygous alleles. Water frogs of the genus Pelophylax have a complex taxonomic structure, including hybrid species and morphologically cryptic forms, as well as massive mitochondrial DNA introgression. The aim of our paper was to analyze the age structure of three species of water frogs (P. lessonae, P. ridibundus, and P. esculentus) in the Middle Volga River region (European Russia). Based on the skeletochronological method, we determined their maximum lifespans of seven, six, and four years, respectively. The onset of sexual maturity in the marsh frogs occurred after two and four winterings in males and females (respectively), in the pond frog—one to two years, and in the edible frog—one to three years. This study revealed specific characteristics of the age structure of Pelophylax frogs in relation to their taxonomic composition when cohabiting (population system type) and the degree of habitat transformation. Differences in body size and lifespan were observed among cryptic forms exhibiting mitochondrial DNA replacement and the presence of various types of heterozygous and homozygous alleles. Full article

Es Colomer Island is occupied by a melanistic population of the Lilford’s Wall lizard, Podarcis lilfordi. Adult males are larger than females, with longer tails, and higher values of body mass, pileus length, head heigh, head width, hindleg length and number of dorsal scales. Adult sex ratio is balanced or slightly skewed towards males. At the summit of the islet, body condition was found to be significantly better than in almost vertical slopes. We found a higher proportion of digit amputations in adult males, probably due to frequent male–male interactions, promoted by high lizard density. During a 2024 survey, we recorded the highest known density of the Lilford’s Wall lizard. The prevalence of mites and blood parasites was 100%. The frequent intraspecific interactions, shown by the proportion of males with digit amputations, could be the source of the higher prevalence and susceptibility to blood parasite infections. The diet of lizards from Colomer is omnivorous, including several prey groups, as well as carcass remains from birds and mammals, and even conspecifics. Lizards from Colomer are an excellent example of the effects of extreme environmental conditions, with high population densities, strong intraspecific competition, the widespread presence of external and blood parasites, the extensive use of the scarce resources, and the opportunistic use of unpredictable resources in masting years, such as the fruits of the joint pine. Full article