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Metamorphosis is the vital biological and morphologic process in economic amphibian bullfrog Aquarana catesbeiana, and is usually quantified by larval period in actual seeding production. As a key growth trait, the short larval period in bullfrogs is profitable for commercial aquaculture and trade, but lack of research on the perspective of genetic breeding. In our study, we identified 37 candidate SNPs related to the larval period using genome-wide association studies (GWAS) from the results of restriction-site associated DNA sequencing (RAD-seq) in 40 individuals (containing 20 juvenile frogs and 20 tadpoles), and genotyped SNPs above in 576 individuals with different phenotypes of larval period accurately using genotyping-in-thousands by sequencing technology (GT-seq), and finally validated nine SNPs (containing five loci with strictly higher level confidence) significantly associated with larval period. More importantly, these data suggest that the genes surrounding nine candidate SNPs could be involved in the biological processes associated with tissue-specific occurrences of cell proliferation, cell death, and changes in cell differentiation during metamorphosis. This study fills a research gap in the larval period of bullfrog breeding work and lays a preliminary foundation for further selective breeding. [ABSTRACT FROM AUTHOR]

The bullfrog Aquarana catesbeiana is one of the main farmed frog species in China, with a low overall survival of farmed bullfrogs from hatching to harvest since bullfrog tadpoles are fragile during the metamorphosis period. The intestinal bacterial community can play crucial roles in animal development; however, little is known about the alteration of the gut microbial community of A. catesbeiana during metamorphosis. The present study used 16S rRNA amplicon sequencing to investigate the intestinal bacterial community in A. catesbeiana at four distinct developmental stages. Moreover, we determined the bullfrog's body morphological parameters and the intestine histology at different developmental stages. The results showed a reduction in the total length and snout–vent length of A. catesbeiana during metamorphosis. The intestinal microbial composition of A. catesbeiana exhibited variation throughout the process of metamorphosis. The terrestrial stage showed shifts in the bacterial composition compared to the aquatic stages, including a reduction in Bacteroidetes and an increase in Firmicutes. Furthermore, the presence of Prevotella, Bifidobacterium, Leucobacter, Corynebacterium, Bulleidia, Dorea, Robinsoniella, and Clostridium in A. catesbeiana metamorphosis appears to be mainly related to the host's epithelial cells' height and total body mass. The results indicated that the intestinal microbial composition changed with the bullfrog–tadpole metamorphosis. The genera of Prevotella, Bifidobacterium, Leucobacter, Corynebacterium, Bulleidia, Dorea, Robinsoniella, and Clostridium might be potential probiotics. [ABSTRACT FROM AUTHOR]

The northern leopard frog (Lithobates pipiens) has undergone dramatic declines in population size and range over recent decades in western Canada and the United States. In British Columbia, only a single population remains at the Creston Valley Wildlife Management Area. Yet, the continuing viability of this population is uncertain. In this paper, the current genetic structure of northern leopard frog populations in western Canada was assessed using microsatellite markers. Historical samples from the extinct population of Fort Steele in British Columbia were compared with the Creston Valley population to understand changes in population genetic parameters over time. Genotypic data from four populations (Creston Valley, Drain K, Prince Spring, and Cypress Hill) sampled in 2004 and 2019 were compared. To evaluate changes in the genetic diversity of the Creston Valley population over time, allelic richness and expected heterozygosity of the population were compared at three time points using genotypes from 2000, 2004, and 2019. Northern leopard frog populations in western Canada showed high genetic differentiation, with genetic diversity decreasing from east to west. Although there weren't notable changes in genetic parameters between 2004 and 2019, there was evidence of a decline in diversity between 2000 and 2019. The extinct population of Fort Steele had private alleles, while the current Creston Valley population did not, suggesting a genetic bottleneck in the Creston Valley population. Therefore, genetic rescue, specifically for the endangered Creston Valley population, can be considered as an action to support recovery. Additionally, continued genetic monitoring will help in the effective management of the species by providing information on the success of conservation actions. [ABSTRACT FROM AUTHOR]

Located east of the Antarctic Peninsula, Cockburn Island is a small island in the James Ross Archipelago. Studies of mosses on the island are scarce. The oldest studies date from the first half of the nineteenth century to the most recent in 1993. The number of records of mosses is very small due to the difficulty of accessing the area. Here, we report an updated composition of the moss flora of the plateau, in which four new records have been found: Bryoerythrophyllum antarcticum , Ceratodon purpureus , Pohlia wilsonii and Schistidium lewis-smithii. The occurrence of these species on the plateau shows that the ranges of these species have expanded from the Antarctic Peninsula to the east. This collection highlights the need for further research into the dynamics of moss flora in the context of climate change. [ABSTRACT FROM AUTHOR]

Metamorphosis is a crucial process in the life cycle of Rana (Aquarana) catesbeiana. R. catesbeiana tadpoles, in their short larval period, possess a high survival rate and also a highly competitive ability in the amphibious stage. In actual seed production, the economic traits of larval period and metamorphosis rate are used as quantifiable indicators of quality for individuals and populations, respectively. However, studies of these economic traits in larval cultivation and production are still lacking. In this study, we constructed 40 full-sib families of R. catesbeiana and measured the weight and metamorphosis rate of tadpoles at different developmental stages. Subsequently, we calculated the phenotypic and genetic association between weight and metamorphosis rate in tadpoles and assessed the heritability of these two traits. The heritabilities of weight at three developmental stages were all higher than 0.40 and decreased with advancement of the developmental stage; the heritability of the metamorphosis rate was 0.18 ± 0.20, a moderate level. Correlation analysis of weight and metamorphosis rate at each developmental stage in each tadpole family showed that weight at stages 25-I, 25-II, and 25-III was significantly correlated at the phenotypic level but non-significantly at the genetic level. The metamorphosis rate was only moderately associated with stage 25-III weight (0.38, p < 0.05). The results of this study confirm the importance and transportability of tadpole weight in actual seed production and provide basic data and a potentially optimized direction for the selective breeding of high-metamorphosis-rate bullfrogs. [ABSTRACT FROM AUTHOR]

The application of herbicides is one of the leading causes of the decline of amphibians in the world. Atrazine is widely used to control herbaceous weeds in crops. In Mexico, it is not regulated and widely applied. More information regarding the effects of atrazine in aquatic systems and on amphibians in this country is therefore needed. Amphibians have a smooth skin coated with excretions that protect them from harmful environmental influences, yet still facilitates the exchange of gases, ions, and thermoregulation, but is especially susceptible to absorbing toxic substances, including atrazine. A few studies have revealed that atrazine modifies the thickness of the epithelial layer in fish, but there are few studies to that effect in frogs. No studies have investigated whether atrazine exposure affects mucopolysaccharides or glucans, which are essential for hydrating the skin. We hypothesized and found confirmed that the herbicide atrazine reduces the thickness of the dorsal epithelium and promotes a greater presence of mucopolysaccharides in the dorsal epithelium and glands in Lithobates spectabilis. Our findings suggest that this frog is likely more vulnerable to dehydration, ultraviolet radiation, and will suffer impaired wound healing when exposed to atrazine. [ABSTRACT FROM AUTHOR]

Chalcone synthase (CHS), a key enzyme in plant flavonoid synthesis, is essential for plant tolerance to abiotic stress. However, little research on CHS from the earliest terrestrial plants, such as mosses, has been reported. Here, the biological function of a CHS gene from Antarctic moss Pohlia nutans (PnCHS1) was studied. PnCHS1 had a 32.8–53.7% similarity to CHS from other species, however it still had highly conserved motifs of CHS such as Catalytic site (Asn366, His333) and Co-A binding site (Ser146). Subcellular localization analysis showed that PnCHS1 was distributed in the cell membrane and in the membranes of endothelial organelles. Heterologous expression of PnCHS1 increased flavonoid content in 5-day-old Arabidopsis grown with 24 h light and 17-day-old Arabidopsis cultured with sucrose, as well as anthocyanin content in the latter. PnCHS1 heterologous expression in Arabidopsis increased plant tolerance to salt stress, including a high germination rate and a long taproot. Heterologous expression of PnCHS1 boosted tolerance to oxidative stress while decreasing the sensitivity to ABA. Under H2O2 or ABA stress, the expression pattern of PnCHS1, ROS scavenging enzyme gene (FeSOD1, FeSOD2, Cu-Zn-SOD2, and Cu-Zn-SOD3) and three genes of ABA signal pathway (RAB18, RD29B, and NCED3) were considerably up-regulated by real-time quantitative analysis. It indicates that PnCHS1 could enhance plant tolerance to NaCl and oxidative stresses, and may play a role in the adaptation of Antarctic moss to extreme environments. [ABSTRACT FROM AUTHOR]

Simple Summary: The production of artificially farmed bullfrogs in China is limited by the low metamorphosis rate of tadpoles. This study investigated the effects of different doses (0 g/kg, 1.5 g/kg, 3 g/kg, 4.5 g/kg, and 6 g/kg) of thyroid powder added to the diets on the metamorphosis and growth of bullfrog tadpoles. The results showed that 4.5 g/kg of thyroid powder could significantly increase the metamorphosis rate and weight gain rate of tadpoles, while adding 6 g/kg of thyroid powder could increase the average weight of tadpoles during metamorphosis. In addition, both doses of thyroid powder could promote the fat breakdown metabolism of tadpoles and alter the intestinal microbiota composition (increasing the abundance of beneficial bacteria, especially Akkermansia). In summary, appropriate doses of thyroid powder could promote the metamorphosis and growth of tadpoles, and might be used to solve the problem of the low metamorphosis rate of bullfrogs. A low metamorphosis rate of amphibian larvae, commonly known as tadpoles, limits the farming production of bullfrogs (Lithobates catesbeiana). This study aimed to examine the effects of processed thyroid powder as a feed additive on tadpole metamorphosis, lipid metabolism, and gut microbiota. Five groups of tadpoles were fed with diets containing 0 g/kg (TH0), 1.5 g/kg (TH1.5), 3 g/kg (TH3), 4.5 g/kg (TH4.5), and 6 g/kg (TH6) thyroid powder for 70 days. The results showed that TH increased the average weight of tadpoles during metamorphosis, with the TH6 group having the highest values. The TH4.5 group had the highest metamorphosis rate (p < 0.05). Biochemical tests and Oil Red O staining showed that the lipid (triglyceride) content in the liver decreased after TH supplementation, especially at doses higher than 1.5 g/kg. RT-qPCR revealed that TH at doses higher than 4.5 g/kg significantly up-regulated the transcriptional expression of the pparα, accb, fas, fadd6, acadl, and lcat genes, which are related to lipid metabolism (p < 0.05). These results showed that TH seems to simultaneously promote the synthesis and decomposition of lipid and fatty acids, but ultimately show a decrease in lipids. As for the gut microbiota, it is noteworthy that Verrucomicrobia increased significantly in the TH4.5 and TH6 groups, and the Akkermansia (classified as Verrucomicrobia) was the corresponding genus, which is related to lipid metabolism. Specifically, the metabolic pathways of the gut microbiota were mainly enriched in metabolic-related functions (such as lipid metabolism), and there were significant differences in metabolic and immune pathways between the TH4.5 and TH0 groups (p < 0.05). In summary, TH may enhance lipid metabolism by modulating the gut microbiota (especially Akkermansia), thereby promoting the growth of tadpoles. Consequently, a supplementation of 4.5 g/kg or 6 g/kg of TH is recommended for promoting the metamorphosis and growth of tadpoles. [ABSTRACT FROM AUTHOR]

The development of balanced, healthy, ready-to-consume, and easy-to-prepare products has led to the development of new food technologies. Despite their high commercial value, bullfrog (Aquarana catesbeiana) carcasses result in low yields, with the thighs being the most marketed in comparison to other carcass portions. In this sense, liver pâté is a traditional food consumed worldwide, mainly in European countries, and may be prepared by incorporating bullfrog meat by-products and certain viscera. In this context, the aim of the present study was to develop a pâté product based on a mixture comprising 50% grounded bullfrog torso meat and 50% liver paste, with each treatment incorporating 10% liver paste increments, totaling five final mixtures. The nutritional compositions and physicochemical, microbiological, and toxicological characteristics of each mixture were assessed. The dry matter percentage of the prepared product was determined to be 27.00%, while mineral content was 1.45%, lipid content was 4.00%, and total protein content was 20.00%. Finally, microbiological counts were in agreement with current food safety regulations. The developed pâté serves as a standard, recycling underused industrial materials, adding value to the production chain at low operational costs, creating a more accessible market, and promoting the popularization of this type of meat. [ABSTRACT FROM AUTHOR]

Sexually dimorphic body colouration can serve to signal quality in vertebrates, but less is known about its importance in amphibians when compared to some other groups. The green frog (Lithobates clamitans) is a common anuran of aquatic habitats in eastern North America. In adults of both sexes, the dorsal abdomen is green or brown, and the ventral abdomen usually white. In contrast, throat colouration is sexually dimorphic; adult male throats are usually bright yellow in colour, whereas females and some males express white throats. We assessed body colouration in males and females from a population in Georgia, USA using spectrophotometry to quantify variation in these features and determine if hidden dimorphism was present. We then asked whether this spectral variation correlated with aspects of phenotype linked to fitness in anurans. Male throats were higher in Green-Yellow Chroma and lower in UV Chroma than those of females, but the sexes did not differ in ventral or dorsal abdominal colour. Male SVL was related to ventral abdominal colouration; larger males tended to have ventral abdomens with longer-wavelength Hue and reduced Green-Yellow Chroma compared to smaller males. However, throat or dorsal abdominal colouration was unrelated to any morphometric trait examined in either sex. Overall, variation in male throat and abdominal colour was only weakly related to indices of male quality; instead, we hypothesize that the persistence of white-throated males in populations throughout the range of green frogs is related to the presence of sex-reversed males and intersex individuals recently described from other populations. [ABSTRACT FROM AUTHOR]

Elizabethkingia miricola is an emerging opportunistic pathogen that is highly pathogenic in both immunocompromised humans and animals. Once the disease occurs, treatment can be very difficult. Therefore, a deep understanding of the pathological mechanism of Elizabethkingia miricola is the key to the prevention and control of the disease. In this study, we isolated the pathogenic bacteria from bullfrogs with dark skin color, weak limbs, wryneck, and cataracts. Via subsequent morphological observations and a 16S rRNA gene sequence analysis, the pathogen was identified as Elizabethkingia miricola. The histopathological and transmission electron microscopy analysis revealed that the brain was the main target organ. Therefore, brain samples from diseased and healthy bullfrogs were used for the RNA-Seq analysis. The comparative transcriptome analysis revealed that the diseased bullfrog brain was characterized by the immune activation and inflammatory response, which were mediated by the "NOD-like receptor signaling pathway" and the "Toll-like receptor signaling pathway". We also performed qRT-PCR to examine the expression profile of inflammation-related genes, which further verified the reliability of our transcriptome data. Based on the above results, it was concluded that the NOD/Toll-like receptor-related networks that dominate the immune activation and inflammatory response were activated in the brain of Elizabethkingia miricola-infected bullfrogs. This study contributes to the search for therapeutic targets for bullfrog meningitis and provides basic information for establishing effective measures to prevent and control bullfrog meningitis. [ABSTRACT FROM AUTHOR]

The effects of allicin and antioxidant of bamboo leaves (AOB) on the quality of bullfrogs (Lithobates catesbeiana) during refrigerated storage (4 °C) were investigated. The quality changes in samples treated with deionized water (CK), allicin solution (All), antioxidant of bamboo leaves (AOB), and allicin solution combined with AOB solution (AA) in microbiological, physicochemical, and sensory evaluation were analyzed, respectively. The results demonstrated that combination treatment inhibited the increase in total viable counts, delayed the decrease in amino acid content, and retarded the sensory deterioration. Preservative treatment has an inhibitory effect on the early storage of PBC, which can reduce PBC by about 1.0 log CFU/g. The reduction in thiobarbituric acid (TBA) content and total volatile basic nitrogen (TVB-N) content indicated that combination treatment could better restrain the lipid oxidation and degradation of protein than the CK group and single-treatment group. In addition, the TVB-N content in the AA group still did not exceed the threshold on the 14th day. As a consequence, combination treatment prolonged the shelf life of bullfrogs for another six days. Therefore, allicin and AOB with excellent antioxidant and antimicrobial activity could be an effective approach to delay the biochemical reaction of refrigerated bullfrogs. This study has provided a potential approach for increasing the shelf life of bullfrogs and preserving their quality during refrigerated storage. [ABSTRACT FROM AUTHOR]

Environmental DNA analysis of water samples has recently emerged as a powerful tool for studying the distribution, ecology, and conservation of many amphibian species. Validating efficacy through comparison with established methods of detection is important for any new method. We used multi‐method and single‐method occupancy models to explore the effectiveness of 3 techniques for detecting northern leopard frogs (Lithobates pipiens) and boreal chorus frogs (Pseudacris maculata). We conducted surveys using automated recording units, environmental DNA sampling, and visual encounter surveys in spring (30 Apr–3 Jun) and summer (23 Jul–27 Aug) of 2014 at 68 sites in southern Alberta, Canada. The multi‐method analysis incorporated data from all 3 survey methods while accounting for the lack of independence of detections within a sampling occasion, and we compared this to single‐method analyses to explore occupancy biases associated with each method and differences in method‐specific detection probability. Occupancy and detection probabilities estimated from environmental DNA analyses were biased for northern leopard frogs, overestimating probability of detection and underestimating occupancy. We could not assess bias for boreal chorus frogs because of overdispersion present in in the models. Although no single covariate explained this bias, it was ameliorated (albeit by reducing precision) by including a raw visual count of individuals as a proxy for abundance during the breeding but not the post‐metamorphic season. These results emphasize the need for careful consideration of temporal and spatial aspects of sampling design, conducting pilot studies, and external validation of eDNA‐only occupancy monitoring schemes prior to widespread implementation. [ABSTRACT FROM AUTHOR]

The limb bones of vertebrates have a critical role in supporting the weight of the body and transmitting forces that power locomotion. The loads that limb bones experience can vary in association with a range of factors, including locomotor environment or developmental stage. Limbed vertebrates that are habitually found in environments with low locomotor loads (e.g. water) might be predicted to also exhibit limb bones with less elevated mechanical properties, such as yield stiffness and yield stress. Frogs provide a distinctive case, in which these ideas can be tested as they experience changes in both locomotor style and habitat as they develop. However, while many frog taxa shift from aquatic to terrestrial habitats as they metamorphose, some lineages, such as pipids, maintain an aquatic lifestyle even after metamorphosis, providing a comparative framework for the effects of habitat shifts on developing limbs in vertebrates. This study compares the material composition and mechanical properties of the femur between frog species that are aquatic specialists (Xenopus laevis) vs generalists that spend considerable time both on land and in water (Lithobates catesbeianus) as they transition from metamorphic tadpoles to fully grown adults. MicroCT scanning was used to determine changes in bone density related to developmental stage and hindlimb use during swimming. Microindentation was then used to collect hardness values from the cortical bone of each femur, which was used to evaluate bone material properties. We found that aquatic frogs had less overall bone mineral density (BMD) than terrestrial frogs and that BMD was more elevated in the cortical region of the diaphysis than trabeculae and distal and proximal epiphyses. Despite its less elevated BMD, bone mechanical properties were not significantly different in aquatic specialist X. laevis than in more terrestrial L. catesbeianus. Our results suggest that the limb bones of aquatic frogs may experience compensatory effects through development to offset their lower BMD. Furthermore, changes in bone density and material properties across development may help to explain some of the differences in locomotor performance found between aquatic and terrestrial metamorphic frogs, providing insight into how environmental factors might correlate with bone ossification. [ABSTRACT FROM AUTHOR]

The environment in Antarctica is characterized by low temperature, intense UVB and few vegetation types. The Pohlia nutans M211 are bryophytes, which are the primary plants in Antarctica and can thrive well in the Antarctic harsh environment. The transcriptional profiling of Pohlia nutans M211 under low temperature and high UVB conditions was analyzed to explore their polar adaptation mechanism in the extreme Antarctic environment by third-generation sequencing and second-generation sequencing. In comparison to earlier second-generation sequencing techniques, a total of 43,101 non-redundant transcripts and 10,532 lncRNA transcripts were obtained, which were longer and more accurate. The analysis results of GO, KEGG, AS (alternative splicing), and WGCNA (weighted gene co-expression network analysis) of DEGs (differentially expressed genes), combined with the biochemical kits revealed that antioxidant, secondary metabolites pathways and photosynthesis were the key adaptive pathways for Pohlia nutans M211 to the Antarctic extreme environment. Furthermore, the low temperature and strong UVB are closely linked for the first time by the gene HY5 (hlongated hypocotyl 5) to form a protein interaction network through the PPI (protein–protein interaction networks) analysis method. The UVR8 module, photosynthetic module, secondary metabolites synthesis module, and temperature response module were the key components of the PPI network. In conclusion, this study will help to further explore the polar adaptation mechanism of Antarctic plants represented by bryophytes and to enrich the polar gene resources. [ABSTRACT FROM AUTHOR]

Artificial light at night (ALAN) and noise pollution have been shown to affect urban wildlife everywhere, but little is known about the effects of these variables on urban frogs. Our objective was to model the effects of ALAN and noise pollution (as well as a suite of other habitat variables) on site occupancy of gray treefrogs (Hyla versicolor) and green frogs (Lithobates clamitans) in the city of Syracuse, New York, USA. We conducted frog call surveys at a total of 43 sites during the breeding seasons of 2018–2020 throughout the Syracuse metropolitan area. Estimated gray treefrog occupancy (with 95% confidence intervals in parentheses) ranged from 40% (24–72%) to 66% (43–81%) and was highest at sites with minimal ALAN, low noise pollution levels, and high tree coverage. Green frog occupancy rates ranged from 24% (17–30%) to 64% (35–85%) and was highest at sites near standing water but was not as affected by ALAN or noise pollution as was gray treefrog occupancy. Ultimately, frog occupancy was negatively related to ALAN and noise pollution and thus conservation plans for urban frogs should address both of these variables. [ABSTRACT FROM AUTHOR]

The Dobročský prales National Nature Reserve, situated in the Veporské vrchy Mts in Central Slovakia, represents a valuable preserved fragment of original primeval fir-beech forest within the Western Carpathians. A preliminary survey of the bryophyte flora of the reserve has already been carried out in the past and altogether 84 taxa have been reported from this area. Here, we publish a total of 103 bryophyte species (25 liverworts and 78 mosses), out of which 40 are reported as new for the reserve. Additionally, out of the recorded bryophytes, one species is considered as critically endangered (CR) in Slovakia (Orthotrichum scanicum), two as endangered (EN) (Dicranum viride, Ulota drummondii), two as vulnerable (VU) (Neckera pennata, N. pumila), five as near threatened (NT) (Buxbaumia viridis, Lewinskya striata, Orthotrichum patens, Rhynchostegium confertum, Ulota bruchii), and one species is data deficient (DD) (Pohlia lutescens). [ABSTRACT FROM AUTHOR]

As resource extraction moves north across the globe, wetland ecosystems in Canada are increasingly degraded because of disturbances associated with anthropic activities, including timber harvesting, hydroelectric development, and mining. These activities may particularly affect amphibian species that depend on certain wetland types for breeding, such as peatland and beaver ponds. We assessed the influence of pond and landscape-level characteristics on amphibian use of 50 ponds in northern Quebec, Canada in 2018 and 2019. Using acoustic recorders and visual counts, we estimated occupancy of calling males and abundance of metamorphosed individuals and egg masses of three amphibian species: Wood Frogs (Lithobates sylvaticus), Mink Frogs (Lithobates septentrionalis), and Spring Peepers (Pseudacris crucifer). We quantified the influence of variables such as pond type, area, fish presence, acidity, and landscape features on occupancy and abundance. We found no effect of explanatory variables on the probability of occupancy of calling males of the three species. Detection probability of Spring Peeper choruses increased with air temperature. The abundance of Mink Frog metamorphosed individuals decreased with increasing pond area and increased with water pH. Wood Frog reproductive effort, quantified as egg mass abundance, was more than four times greater in beaver ponds than in peatland ponds. Our survey results provide a reference to guide management decisions regarding conservation of amphibian assemblages in increasingly disturbed wetlands of northern Canada. [ABSTRACT FROM AUTHOR]

In Mexico, atrazine is one of the herbicides most widely authorized and used in different irrigation districts. Atrazine is a herbicide that contaminates aquatic systems. Previous studies have shown that atrazine causes damage to red blood cells and liver tissue in different aquatic species, including abnormalities in melanomacrophages. However, more information on amphibians is needed, since most of these studies have been done on fish. Furthermore, no study has determined the effect of atrazine on species native to Mexico. Therefore, in this study, we asked what the effects of atrazine are on the erythrocytes and melanomacrophages of the liver in the male frog (Lithobates spectabilis). In the present study, we analyzed (1) the cytotoxicity of atrazine using the micronucleus test, (2) the area of melanomacrophage centers and the presence of melanin, and (3) the characterization of liver damage using histological techniques. Our results show that atrazine is cytotoxic to erythrocytes, increases the area of and melanin presence in melanomacrophage centers, and causes liver damage in male L. spectabilis. Therefore, hepatotoxicity and cytotoxicity are indicators of environmental stress. We suggest monitoring Mexico's aquatic systems and further analyzing atrazine effects and other pollutants on native species. [ABSTRACT FROM AUTHOR]

Antarctic organisms are consistently suffering from multiple environmental pressures, especially the strong UV radiation caused by the loss of the ozone layer. The mosses and lichens dominate the vegetation of the Antarctic continent, which grow and propagate in these harsh environments. However, the molecular mechanisms and related regulatory networks of these Antarctic plants against UV-B radiation are largely unknown. Here, we used an integrated multi-omics approach to study the regulatory mechanism of long non-coding RNAs (lncRNAs) of an Antarctic moss (Pohlia nutans) in response to UV-B radiation. We identified a total of 5729 lncRNA sequences by transcriptome sequencing, including 1459 differentially expressed lncRNAs (DELs). Through functional annotation, we found that the target genes of DELs were significantly enriched in plant-pathogen interaction and the flavonoid synthesis pathway. In addition, a total of 451 metabolites were detected by metabonomic analysis, and 97 differentially change metabolites (DCMs) were found. Flavonoids account for 20% of the total significantly up-regulated metabolites. In addition, the comprehensive transcriptome and metabolome analyses revealed the co-expression pattern of DELs and DCMs of flavonoids. Our results provide insights into the regulatory network of lncRNA under UV-B radiation and the adaptation of Antarctic moss to the polar environments. [ABSTRACT FROM AUTHOR]

A review of 60 Virginia Herpetological Society biodiversity surveys conducted between 1991 and 2022 found that geographic, seasonal, habitat, and climate factors are impacting the prevalence of anurans found during surveys. Of 28 anuran species inhabiting Virginia, 25 were documented in surveys with three, Anaxyrus quercicus, Hyla gratiosa, and Pseudacris nigrita not being found at any survey, even when surveys occurred in locations within these species' ranges. Lithobates clamitans was the most commonly found frog, at 54 of 60 surveys (it was found in 90% of surveys occurring in its known range). Eighteen species of anurans were found in 50% or less of the surveys conducted in their known ranges. As a group, chorus frogs (genus Pseudacris), excluding Pseudacris crucifer, were among the least reported anurans during surveys, even when surveys were conducted within their known ranges. Surveys were conducted from March until September, with the majority occurring in May (46%). By conducting a pre-site survey in March and a post-site survey in June, many more species of anurans could be included in the final species tally for a given location. [ABSTRACT FROM AUTHOR]

Objectives: Antibiotic resistance is a rising global threat to human health and is prompting researchers to seek effective alternatives to conventional antibiotics, which include antimicrobial peptides (AMPs). Recently, we have reported AMPlify, an attentive deep learning model for predicting AMPs in databases of peptide sequences. In our tests, AMPlify outperformed the state-of-the-art. We have illustrated its use on data describing the American bullfrog (Rana [Lithobates] catesbeiana) genome. Here we present the model files and training/test data sets we used in that study. The original model (the balanced model) was trained on a balanced set of AMP and non-AMP sequences curated from public databases. In this data note, we additionally provide a model trained on an imbalanced set, in which non-AMP sequences far outnumber AMP sequences. We note that the balanced and imbalanced models would serve different use cases, and both would serve the research community, facilitating the discovery and development of novel AMPs. Data description: This data note provides two sets of models, as well as two AMP and four non-AMP sequence sets for training and testing the balanced and imbalanced models. Each model set includes five single sub-models that form an ensemble model. The first model set corresponds to the original model trained on a balanced training set that has been described in the original AMPlify manuscript, while the second model set was trained on an imbalanced training set. [ABSTRACT FROM AUTHOR]

New distributional data are presented for 12 species of moss collected from the Graham Coast and Danco Coast together with their offshore islands on the west side of the Antarctic Peninsula. Pohlia wahlenbergii (F.Weber & D.Mohr) A.L.Andrews is new to the Antarctic Peninsula and the Graham Coast and it is the southernmost station of the species, whereas Warnstorfia sarmentosa (Wahlenb.) Hedenäs is new to the Danco Coast. Schizymenium pusillum (Hook. & Wilson) A.J.Shaw is recorded for the first time on the Antarctic Peninsula mainland, and Schistidium rivulare (Brid.) Podp. is found at its southernmost locality on Cape Pérez on the mainland Graham Coast. Andreaea regularis Müll.Hal., Kiaeria pumila (Mitt.) Ochyra, Bucklandiella sudetica (Funck) Bedn.-Ochyra & Ochyra, Warnstorfia fontinaliopsis (Müll.Hal.) Ochyra and Pohlia nutans (Hedw.) Lindb. are new for Hovgaard Island in the Wilhelm Archipelago, and the latter is additionally recorded for the first time from Point Rasmussen on the mainland Graham Coast. Bryum pallescens Schleich. ex Schwägr. is new to Darboux Island, while Polytrichum juniperinum Hedw. and Brachythecium austroglareosum (Müll. Hal.) Kindb. are new to Lahille Island in the Grandidier Channel. Updated distribution maps for all species in the study areas of the Danco and Graham Coasts and the northern Antarctic Peninsula are presented. The moss floras of the Graham and Danco Coast regions consist currently of 51 and 47 species, respectively. [ABSTRACT FROM AUTHOR]

Mexico possesses a large diversity of amphibians partly due to its complex topography and transitional position between the Nearctic and Neotropical biogeographical regions. However, its helminth parasite fauna has been relatively poorly studied. Specimens of the Vaillant's frog, Lithobates vaillanti (Brocchi) were sampled in the tropical rain forest of Nahá, in the Chiapas Highlands, and examined for parasites. Two trematode species were collected from their hosts; morphologically, specimens were allocated to the genera Langeronia Caballero and Bravo-Hollis, 1949 and Haematoloechus Looss, 1899, respectively. Individuals were sequenced for two molecular markers (the mitochondrial cytochrome c oxidase gene, and the ribosomal gene 28S), and processed for morphological analyses, including scanning electron microscopy. The new evidence was not enough to accomplish the identification at species level of Langeronia sp. due to the lack of sequence data from the type localities of Langeronia parva Christian, 1970 and Langeronia macrocirra Caballero and Bravo-Hollis, 1949. Likewise, the newly generated data were useful to properly identify the adult specimens of lung flukes as Haematoloechus complexus Seely, 1906. [ABSTRACT FROM AUTHOR]

Through collections in 61 localities, the bryophytic flora of the Genal Valley is studied. A total of 154 taxa form the bryophytic diversity of the studied territory, 131 are mosses, 21 liverworts and 2 hornworts. Cephaloziella calyculata (Durieu & Mont.) Müll. Frib. and Geheebia erosa (J.A. Jiménez & J. Guerra) J.A. Jiménez & M.J. Cano are cited for the first time in Andalusia. Acaulon mediterraneum Limpr. and Pohlia annotina (Hedw.) Lindb. are new records for the Malaga province. Taking into account their ecological behavior and habitats, the main bryophyte communities of the territory are described. [ABSTRACT FROM AUTHOR]

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Wetland communities are increasingly threatened by multiple stressors simultaneously, such as pesticides and salinization. We examined the effects of ecologically-relevant exposures to broad-spectrum insecticides and salinization on amphibian neurodevelopment, which is strongly linked to how organisms respond behaviorally to environmental change. Prior research showed that exposure to trace concentrations of an organophosphate pesticide (chlorpyrifos) altered the brain shape and behavior of larval and metamorphic amphibians. It is unknown whether brain shape is altered by additional pesticides and road salt. Using outdoor mesocosms, we tested whether salt (NaCl) and representatives from three pesticide families (organophosphates, pyrethroids, and neonicotinoids) altered tadpole (Lithobates pipiens) brain shape. Of the two organophosphates, chlorpyrifos induced relatively longer telencephalon lengths relative to body mass, consistent with previous studies, but malathion had no effect on brain shape. Of the two pyrethroids, permethrin, but not cypermethrin, increased telencephalon length. For the neonicotinoids, there were marginally significant effects of imidacloprid and thiamethoxam on telencephalon length. Thus, the impacts of pesticides on brain shape was not dictated by pesticide family. Exposure to relatively high concentrations of salt resulted in brains that were less wide but had longer optic tecta. Although we failed to find strong interactive effect of salt with pesticides, there was some weak, nonsignificant, evidence that exposure to salt masked responses to pesticides. Together, our results indicate that environmentally realistic levels of pesticides and salinization can alter larval brain shape. Our study highlights the importance of studying the impacts of naturally-occurring levels of pesticides and salinization on vertebrate neural development. [Display omitted] • Trace levels of agrochemicals and salinization impact vertebrate neural development. • Naturally-occurring levels of pesticides changed tadpole brain shape. • Pesticide type did not predict impacts on tadpole brain shape. • Naturally-occurring levels of road salt changed tadpole brain shape. [ABSTRACT FROM AUTHOR]

This experiment investigated the dietary phosphorus (P) requirement of bullfrogs Aquarana catesbeiana. Six diets containing available P (AP) levels of 0.29% (the control group), 0.47%, 0.65%, 0.88%, 1.06% and 1.24% were formulated and fed to bullfrogs for 56 days. As dietary AP level increased from 0.29% to 1.24%, weight gain rate increased and then decreased, reaching the highest at the AP level of 0.88% (P < 0.05). Compared to the control group, content of crude protein in the whole-body was significantly increased in bullfrogs fed the 0.88% AP diet (P < 0.05). Content of crude lipid in the whole-body was significantly decreased in bullfrogs fed the 0.65%, 0.88%, 1.06% and 1.24% AP diets compared to those fed the 0.29% and 0.47% AP diets (P < 0.05). Bullfrogs fed the 0.65%, 0.88%, 1.06%, and 1.24% AP diets had higher content of serum P than those fed the 0.29% and 0.47% AP diets (P < 0.05). Activity of glutamic pyruvic transaminase in the serum was significantly decreased in bullfrogs fed the 0.88%, 1.06% and 1.24% AP diets compared to those fed the 0.29% and 0.47% AP diets (P < 0.05). Bullfrogs fed the 0.65%, 0.88%, 1.06% and 1.24% AP diets had lower contents of total cholesterol in the liver and triglycerides in the serum than the control group (P < 0.05). Meanwhile, bullfrogs fed the 0.47%, 0.65%, 0.88% and 1.06% AP diets had higher total antioxidant capacity in the serum than the control group (P < 0.05). Compared to the control group, contents of P and calcium in the whole-body were significantly increased in bullfrogs fed the 0.65%, 0.88%, 1.06% and 1.24% AP diets (P < 0.05). Compared to the control group, bullfrogs fed the 0.88%, 1.06% and 1.24% AP diets had lower expression of sodium-dependent phosphate transporter in the intestine and kidney, and higher expression of hormone-sensitive triglyceride lipase in the liver (P < 0.05). Bullfrogs fed the 0.88% and 1.06% AP diets had higher the mucosal fold height than those fed the 0.29% and 1.24% AP diets (P < 0.05). Compared to those fed the 0.29% and 1.24% AP diets, the abundance of potentially pathogenic bacteria Serratia and Acinetobacter in the intestine was decreased in bullfrogs fed the 0.88% AP diet. Using the weight gain rate, feed efficiency, whole-body and serum P content as evaluation indicators, the AP requirements of bullfrogs was 0.82% to 0.89%. • Appropriate levels of available phosphorus in the feed could increased nutrient utilization and promote bullfrog growth. • Appropriate levels of available phosphorus in the feed could improve intestinal health. • Appropriate levels of available phosphorus in the feed could promote lipolysis and reduce liver fat deposition. • Using the weight gain rate, feed efficiency, whole body and serum P content as evaluation indicators, the AP requirements of bullfrogs was 0.82% to 0.89%. [ABSTRACT FROM AUTHOR]

The chronic toxicity of short chain perfluoroalkyl sulfonic acids (PFSAs), such as perfluorobutanesulfonic acid (PFBS) and perfluorohexanesulfonic acid (PFHxS), are relatively understudied despite the increasing detection of these compounds in the environment. We investigated the chronic toxicity and bioconcentration of PFBS and PFHxS using northern leopard frog (Rana [Lithobates] pipiens) tadpoles. We exposed Gosner stage (GS) 25 tadpoles to either PFBS or PFHxS at nominal concentrations of 0.1, 1, 10, 100, and 1000 μg/L until metamorphosis (GS42). We then assessed tadpole growth, development, stress, and immune metrics, and measured fatty acid (FA) composition and PFSA concentrations in liver and whole-body tissues. Tadpole growth and development measures were relatively unaffected by PFSA exposure. However, tadpoles exposed to 1000 μg/L PFBS or PFHxS had significantly increased hepatosomatic indexes (HSI) relative to controls. Further, tadpoles from the 1000 μg/L PFHxS treatment had altered FA profiles relative to controls, with increased total FAs, saturated FAs, monounsaturated FAs, and omega-6 polyunsaturated FAs. In addition, tadpoles from the 1000 μg/L PFHxS treatment had a higher probability of waterborne corticosterone detection. These results suggest that PFBS and PFHxS influence the hepatic health of tadpoles, and that PFHxS may alter lipid metabolism in tadpoles. We also observed a higher probability of tadpoles being phenotypically female after exposure to an environmentally relevant concentration (0.1 μg/L) of PFHxS, suggesting that PFHxS may exert endocrine disrupting effects on tadpoles during early development. The measured bioconcentration factors (BCFs) for both compounds were ≤10 L kg−1 wet weight, suggesting low bioconcentration potential for PFBS and PFHxS in tadpoles. Many of the significant effects observed in this study occurred at concentrations several orders of magnitude above those measured in the environment; however, our work shows effects of PFSAs exposure on amphibians and provides essential information for ecological risk assessments of these compounds. [Display omitted] • Perfluoroalkyl sulfonic acid (PFSA) toxicity studies using amphibians are limited. • Exposure to PFSAs increases tadpole hepatosomatic index. • PFHxS disrupts tadpole liver fatty acid composition. • Exposure to PFHxS alters tadpole sex ratios at low concentrations. • PFBS and PFHxS have low bioconcentration potential in tadpoles. [ABSTRACT FROM AUTHOR]

Environmental variation favors the evolution of phenotypic plasticity. For many species, we understand the costs and benefits of different phenotypes, but we lack a broad understanding of how plastic traits evolve across large clades. Using identical experiments conducted across North America, we examined prey responses to predator cues. We quantified five life-history traits and the magnitude of their plasticity for 23 amphibian species/populations (spanning three families and five genera) when exposed to no cues, crushed-egg cues, and predatory crayfish cues. Embryonic responses varied considerably among species and phylogenetic signal was common among the traits, whereas phylogenetic signal was rare for trait plasticities. Among trait-evolution models, the Ornstein-Uhlenbeck (OU) model provided the best fit or was essentially tied with Brownian motion. Using the best fitting model, evolutionary rates for plasticities were higher than traits for three life-history traits and lower for two. These data suggest that the evolution of life-history traits in amphibian embryos is more constrained by a species' position in the phylogeny than is the evolution of life history plasticities. The fact that an OU model of trait evolution was often a good fit to patterns of trait variation may indicate adaptive optima for traits and their plasticities.

The article focuses on the observation of larval aggregations in Rana sylvatica (Wood Frog) tadpoles in multiple woodland ponds, challenging the previous notion that they are solitary and suggesting that this behavior may not be as uncommon as previously thought.

The Atlantic and Amazon rainforests have a shared but unclear past, with intermittent connections resulting from historical climate change. We investigate these connections by studying the phylogeography and climatic niche of the disjunct distributed frog Lithobates palmipes. We sequenced two fragments of mitochondrial DNA from Atlantic Forest (AtF) and Amazonia (AmF) individuals and evaluated how genetic diversity is distributed in space and whether past demographic changes occurred. Also, we evaluated the existence of past suitable connections between biomes for L. palmipes through ecological niche models (ENM) and tested for niche divergence. The AtF group is nested within the AmF group and closely related to individuals from eastern Amazonia, a pattern recovered in many species that used northeast connection routes. We found evidence of recurrent use of connections in different directions and time during the Pleistocene, resulting in genetic structure between biomes, with no signal of demographic change and evidence of niche divergence across both genetic groups. ENMs indicated suitable areas connecting forests throughout northeastern Brazil during the Pleistocene. Mitochondrial lineages do not match biomes exactly. One lineage is composed of AtF populations and eastern Amazonia individuals. The other is composed of western Amazonia individuals, suggesting an effect of past climatic heterogeneity within the Amazonia forest. This is the first evidence that this route drove genetic and ecological diversity for amphibians recently, a group with habits and ecological requirements different from other vertebrates that have been shown to use this putative corridor. [ABSTRACT FROM AUTHOR]

Native predators may ignore or avoid non‐native prey because they do not recognize the novel organisms as food, or the invasive prey may bring antipredatory defences against which the native predators have not co‐evolved a sufficient attack. Non‐native ants successfully invade novel habitats worldwide and, in eastern North America, several invasive ant species bring venomous stings in quantities that far exceed that of native ant species. Ants make up a considerable portion of anuran diets, and we investigated how several native anurans reacted to the invasion of the non‐native European fire ant (Myrmica rubra). Myrmica rubra has a venomous sting, and it occurs in aggressive swarms that can deliver multiple stings. Despite these defences, based on field observations, we expected that leopard frogs (Lithobates pipiens) might consume the abundant ants. We also predicted that habitat niche differences from the moisture‐dependent ants would limit consumption by the more terrestrial American toads (Anaxyrus americanus) and more aquatic green frogs (Lithobates clamitans). Our results suggested that none of the anuran species make use of the M. rubra swarms. The anurans, particularly A. americanus, consumed ample native ants in the field, but not M. rubra ants. In the laboratory, A. americanus ate several M. rubra ants, and L. pipiens a few, but experienced anuran individuals collected from M. rubra‐invaded habitat were less likely to eat the ants in laboratory. Hence, at best, M. rubra invasion appears to supplant rather than supplement anuran food resources. [ABSTRACT FROM AUTHOR]

12-oxo-phytodienoic acid (OPDA) is a biosynthetic precursor of jasmonic acid and triggers multiple biological processes from plant development to stress responses. However, the OPDA signaling and relevant regulatory networks were largely unknown in basal land plants. Using an integrated multi-omics technique, we investigated the global features in metabolites and transcriptional profiles of an Antarctic moss (Pohlia nutans) in response to OPDA treatment. We detected 676 metabolites based on the widely targeted metabolomics approach. A total of 82 significantly changed metabolites were observed, including fatty acids, flavonoids, phenolic acids, amino acids and derivatives, and alkaloids. In addition, the transcriptome sequencing was conducted to uncover the global transcriptional profiles. The representative differentially expressed genes were summarized into functions including Ca2+ signaling, abscisic acid signaling, jasmonate signaling, lipid and fatty acid biosynthesis, transcription factors, antioxidant enzymes, and detoxification proteins. The integrated multi-omics analysis revealed that the pathways of jasmonate and ABA signaling, lipid and fatty acid biosynthesis, and flavonoid biosynthesis might dominate the molecular responses to OPDA. Taken together, these observations provide insights into the molecular evolution of jasmonate signaling and the adaptation mechanisms of Antarctic moss to terrestrial habitats. [ABSTRACT FROM AUTHOR]

Many amphibian species possess male-specific secretory breeding glands. In anurans, such specialized glands are often present as nuptial pads at the first digit of the hand, which are pressed against the female during amplexus. However, the role of nuptial pad secretions remains largely unknown. Here, we investigate the inner morphology as well as the RNA expression patterns of the nuptial pads of several Central American Lithobates species (Ranidae). As shown for the breeding glands of other amphibian species, the Lithobates nuptial pads are composed of large specialized mucus glands, excreting proteinaceous content to the surface. Whole-transcriptome sequencing revealed that for one of the species the most highly expressed transcripts encoding secretory proteins in the nuptial pads are sodefrin precursor-like factor (SPF) proteins, known to have a pheromone function in multiple amphibian species. The other two species, however, lack high expression of SPF transcripts but express other secretory proteins, whose roles in amphibian breeding glands remain unknown. Several of these proteins are highly expressed in all samples, suggesting a direct role during courtship or for the maintenance/development of the glands. [ABSTRACT FROM AUTHOR]

A new propaguliferous moss species, Pohlia tibetana X.R.Wang & X.M.Shao (Mielichhoferiaceae), from Tibet, southwest China, is described. The new species differs most saliently from other species of Pohlia by its combination of slender plants, loosely attached leaves and axillary solitary, and dark red and flowerlike gemmae. In this paper, the line drawings, photographs, habit of the new species are provided and a morphological comparison of it with the similar species is made. [ABSTRACT FROM AUTHOR]

Antarctica is the coldest, driest, and most windy continent on earth. The major terrestrial vegetation consists of cryptogams (mosses and lichens) and two vascular plant species. However, the molecular mechanism of cold tolerance and relevant regulatory networks were largely unknown in these Antarctic plants. Here, we investigated the global alterations in metabolites and regulatory pathways of an Antarctic moss (Pohlia nutans) under cold stress using an integrated multi-omics approach. We found that proline content and several antioxidant enzyme activities were significantly increased in P. nutans under cold stress, but the contents of chlorophyll and total flavonoids were markedly decreased. A total of 559 metabolites were detected using ultra high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). We observed 39 and 71 differentially changed metabolites (DCMs) after 24 h and 60 h cold stress, indicating that several major pathways were differentially activated for producing fatty acids, alkaloids, flavonoids, terpenoids, and phenolic acids. In addition, the quantitative transcriptome sequencing was conducted to uncover the global transcriptional profiles of P. nutans under cold stress. The representative differentially expressed genes (DEGs) were identified and summarized to the function including Ca2+ signaling, ABA signaling, jasmonate signaling, fatty acids biosynthesis, flavonoid biosynthesis, and other biological processes. The integrated dataset analyses of metabolome and transcriptome revealed that jasmonate signaling, auxin signaling, very-long-chain fatty acids and flavonoid biosynthesis pathways might contribute to P. nutans acclimating to cold stress. Overall, these observations provide insight into Antarctic moss adaptations to polar habitats and the impact of global climate change on Antarctic plants. [ABSTRACT FROM AUTHOR]

Translocation is increasingly used to move animals of conservation concern away from sites where habitat will be destroyed (mitigation translocation), but outcomes have rarely been adequately monitored, particularly for amphibians. We used radiotelemetry monitoring to assess survival and movement of 23 experimentally translocated, adult Gopher Frogs (Lithobates capito) at a recipient site in north-central Florida, USA. Although posttranslocation monitoring was our primary goal, we also compared our results with those of 24 nontranslocated frogs that were monitored in three previous efforts, conducted at different locations and times. For both translocated and nontranslocated frogs, movement was the most important predictor of mortality, with translocated frogs having a significantly higher probability of movement and higher mortality during the first month following release. However, there was no effect of translocation on survival after controlling for probability of movement because movement was dangerous for both translocated and nontranslocated frogs. Movement by translocated frogs was likely a behavioral response to the translocation experience, whereas movement by nontranslocated frogs was associated with breeding pond visitation, which was not observed within the translocated group. Survival was high for both groups once they settled into underground refugia and movement declined. Despite the comparatively high mortality of translocated frogs immediately following release, more than half survived to the end of monitoring and remained in the vicinity of the release site, meeting an early benchmark of translocation success. [ABSTRACT FROM AUTHOR]

Most regions of the Antarctic continent are experiencing increased dryness due to global climate change. Mosses and lichens are the dominant vegetation of the ice-free areas of Antarctica. However, the molecular mechanisms of these Antarctic plants adapting to drought stress are less documented. Here, transcriptome and metabolome analyses were employed to reveal the responses of an Antarctic moss (Pohlia nutans subsp. LIU) to drought stress. We found that drought stress made the gametophytes turn yellow and curled, and enhanced the contents of malondialdehyde and proline, and the activities of antioxidant enzymes. Totally, 2,451 differentially expressed genes (DEGs) were uncovered under drought treatment. The representative DEGs are mainly involved in ROS-scavenging and detoxification, flavonoid metabolism pathway, plant hormone signaling pathway, lipids metabolism pathway, transcription factors and signal-related genes. Meanwhile, a total of 354 differentially changed metabolites (DCMs) were detected in the metabolome analysis. Flavonoids and lipids were the most abundant metabolites and they accounted for 41.53% of the significantly changed metabolites. In addition, integrated transcriptome and metabolome analyses revealed co-expression patterns of flavonoid and long-chain fatty acid biosynthesis genes and their metabolites. Finally, qPCR analysis demonstrated that the expression levels of stress-related genes were significantly increased. These genes included those involved in ABA signaling pathway (NCED3, PP2C, PYL, and SnAK2), jasmonate signaling pathway (AOC, AOS, JAZ, and OPR), flavonoid pathway (CHS, F3',5'H, F3H, FLS, FNS, and UFGT), antioxidant and detoxifying functions (POD, GSHPx, Prx and DTX), and transcription factors (ERF and DREB). In summary, we speculated that P. nutans were highly dependent on ABA and jasmonate signaling pathways, ROS scavenging, flavonoids and fatty acid metabolism in response to drought stress. These findings present an important knowledge for assessing the impact of coastal climate change on Antarctic basal plants. [ABSTRACT FROM AUTHOR]

Purpose: Soil diaspore banks of bryophytes are poorly known in tundra grasslands, yet can be important for the maintenance of local bryophyte assemblages. We examined the effects of fertilization and grazing exclusion on above-ground bryophyte assemblages and soil diaspore banks in a tundra grassland. Methods: We collected soil diaspore samples and recorded the cover of above-ground bryophytes from a full-factorial experiment with NPK fertilization and grazing exclusion treatments (a Nutrient Network site in NW Finland). Soil diaspore samples were germinated on trays in a greenhouse. We analyzed the compositions of diaspore bank assemblages and of above-ground assemblages and assessed their responses to the experimental treatments. Results: The diaspore bank contained c. 50% of taxa found in above-ground assemblages; 26 bryophyte taxa germinated from the diaspore bank, while 40 taxa were found in the above-ground assemblages. These communities had distinct species compositions: the diaspore bank was dominated by Pohlia nutans, while above-ground assemblages were dominated by several species. NPK fertilization and grazing exclusion had negative effects on bryophyte richness and cover in above-ground assemblages, and weaker effects on these responses in the diaspore bank. Conclusion: Soil diaspore banks comprise about half of the bryophyte taxa encountered in above-ground assemblages. Bryophyte diaspore banks are more buffered against nutrient enrichment and grazing exclusion than above-ground assemblages, suggesting that diaspore banks may enhance persistence and recovery of local bryophyte assemblages from environmental changes. [ABSTRACT FROM AUTHOR]

Aquaculture water eutrophication is primarily driven by nitrogen (N) and phosphorus (P), partly derived from animal excretions. Understanding the N and P metabolism is crucial for mitigating environmental pollution caused by aquaculture. This study investigated N and P budgets in bullfrogs (Aquarana catesbeiana) of varying body weights: 52.63 ± 0.33 (50 g), 98.64 ± 0.55 (100 g), 159.97 ± 0.58 (150 g) and 250.01 ± 2.61 (250 g). Our findings highlighted the significant influence of body size on N and P budgets in bullfrogs. As body weight increased, feed intake rate, N and P intake rates, growth rate, N and P growth rates, N and P metabolism rates, feces rate, while the N and P feces rates all decreased. The relationship between each index and body weight was expressed as a power function (Y = aWb). The N and P budget equations for bullfrogs were established as follows: 100 Intake N (I N) = 30.75 Growth N (G N) + 62.48 Metabolism N (M N) + 2.10 Feces N (F N) + 4.67 Others (O N), and 100 P Intake P (I P) = 74.16 Growth P (G P) + 4.18 Metabolism P (M P) + 7.92 Feces P (F P) + 13.75 Others (O P). In conclusion, daily feeding per body weight of bullfrog should be reduced as their body weight increased. Consequently, the dietary protein should be progressively lowered to minimize nitrogen waste, while bullfrogs demonstrated effective utilization of P in the soybean meal diet. • The nitrogen and phosphorus budgets of bullfrogs in different body weights were obtained. • The relationship between each parameter in the N budget equation and bullfrog body weight was obtained. • The relationship between each parameter in the P budget equation and bullfrog body weight was obtained. [ABSTRACT FROM AUTHOR]

High proportions of soybean meal in aquafeed have been confirmed to induce various intestinal pathologies. This study aims to investigate the regulatory effects of rosmarinic acid (RA), an antioxidant with anti-inflammatory and antimicrobial properties, when added to high soybean meal feeds in different doses, (0, 0.5, 1, and 4 g/kg). During the 56-day feeding trial, results indicated that, compared to the control group without RA (0 g/kg), the 1 g/kg and 4 g/kg RA groups increased bullfrog survival rates and total weight gain while reducing feed coefficient. Additionally, these doses markedly suppressed the expression of key intestinal inflammatory markers (tlr5 , myd88 , tnfα , il1β , cxcl8 , cxcl12) and the activity and content of intestinal antioxidants (CAT, MDA, GSH, GPX). Concurrently, RA significantly downregulated the transcription levels of antioxidant-related genes (cat , gpx5 , cyba , cybb , mgst , gclc , gsta , gstp), suggesting RA's potential to alleviate intestinal inflammation and oxidative stress induced by high soybean meal and to help downregulate and restore normal expression of antioxidant enzyme genes. However, the 0.5 g/kg RA group did not show a significant improvement in survival rates; instead, it upregulated the transcription of some antioxidant genes (cat , gpx5 , cyba , cybb), revealing the complexity and dose-dependency of RA's antioxidant action. Furthermore, RA supplementation significantly reshaped the intestinal microbial community structure and relative abundance in bullfrogs, particularly affecting the genera Hafnia , Phascolarctobacterium , and Lactococcus. Notably, high doses of RA (1 g/kg, 4 g/kg) were able to downregulate pathways associated with the enrichment of gut microbiota in diseases such as Parkinson's, Staphylococcus aureus infection, and Systemic lupus erythematosus, suggesting its potential in anti-inflammatory action and health maintenance to prevent potential diseases. • RA supplementation at 1 g/kg and 4 g/kg significantly enhanced survival rates of bullfrogs. • These doses effectively suppressed key inflammation markers and reduced the activity of oxidative stress-related enzymes. • High RA dosages restructured the gut microbiota and inhibited pathways linked to disease, underscoring its preventative potential against inflammation-related conditions. • The study underscored the importance of RA dosage, with 0.5 g/kg showing limited benefits, highlighting the complexity of RA's effects. [ABSTRACT FROM AUTHOR]

The Antarctic continent has extreme natural environment and fragile ecosystem. Mosses are one of the dominant floras in the Antarctic continent. However, their genomic features and adaptation processes to extreme environments remain poorly understood. Here, we assembled the high-quality genome sequence of the Antarctic moss (Pohlia nutans) with 698.20 Mb and 22 chromosomes. We found that the high proportion of repeat sequences and a recent whole-genome duplication (WGD) contribute to the large size genome of P. nutans when compared to other bryophytes. The genome of P. nutans harbors the signatures of massive segmental gene duplications and large expansions of gene families, likely facilitating neofunctionalization. Genomic characteristics that may support the Antarctic lifestyle of this moss comprise expanded gene families involved in phenylpropanoid biosynthesis, unsaturated fatty acid biosynthesis, and plant hormone signal transduction. Additional contributions include the significant expansion and upregulation of several genes encoding DNA photolyase, antioxidant enzymes, flavonoid biosynthesis enzymes, possibly reflecting diverse adaptive strategies. Notably, integrated multi-omic analyses elucidate flavonoid biosynthesis may function as the reactive oxygen species detoxification under UV-B radiation. Our studies provide insight into the unique features of the Antarctic moss genome and their molecular responses to extreme terrestrial environments. [ABSTRACT FROM AUTHOR]

Animal movement is a key process that connects and maintains populations on the landscape, yet for most species, we do not understand how intrinsic and extrinsic factors interact to influence individual movement behavior.Land‐use/land‐cover changes highlight that connectivity among populations will depend upon an individual's ability to traverse habitats, which may vary as a result of habitat permeability, individual condition, or a combination of these factors.We examined the effects of intrinsic (body size) and extrinsic (habitat type) factors on desiccation tolerance, movement, and orientation in three anuran species (American toads, Anaxyrus americanus; northern leopard frogs, Lithobates pipiens; and Blanchard's cricket frogs, Acris blanchardi) using laboratory and field studies to connect the effects of susceptibility to desiccation, size, and movement behavior in single‐habitat types and at habitat edges.Smaller anurans were more vulnerable to desiccation, particularly for species that metamorphose at relatively small sizes. Habitat type had the strongest effect on movement, while body size had more situational and species‐specific effects on movement. We found that individuals moved the farthest in habitat types that, when given the choice, they oriented away from, suggesting that these habitats are less favorable and could represent barriers to movement.Overall, our work demonstrated that differences in habitat type had strong impacts on individual movement behavior and influenced choices at habitat edges. By integrating intrinsic and extrinsic factors into our study, we provided evidence that population connectivity may be influenced not only by the habitat matrix but also by the condition of the individuals leaving the habitat patch. [ABSTRACT FROM AUTHOR]

Flavonoids are the important secondary metabolites. They are thought to play an important role in plant adaptation to terrestrial environment. However, the downstream branching pathway of flavonoids in bryophytes, which are the most ancient of terrestrial plants, remains unclear. Here, we cloned a flavonoid 3′‐hydroxylase gene (PnF3′H) from the Antarctic moss Pohlia nutans and studied its function in plant stress tolerance. The Arabidopsis with overexpressing PnF3′H (AtOE) were constructed. The AtOE plants had more lateral roots and higher activities of antioxidant enzymes than the wild‐type plants under oxidative stress. Meanwhile, the gene expression levels of reactive oxygen species (ROS) scavengers (i.e., AtCAT3, AtFeSOD1, and AtCu‐ZnSOD3) were upregulated in the AtOE plants, and the transcription levels of ROS producing enzyme genes were significantly downregulated. The AtOE plans showed increased sensitivity to NaCl stress or abscisic acid (ABA) treatment during seed germination and early root development. Furthermore, several stress‐resistant genes in the ABA signaling pathway were also downregulated in the AtOE plants when compared with the wild‐type plants. These results suggested that PnF3′H participates in regulating the oxidative tolerance and ABA sensitivity to enable P. nutans to adapt to polar environments. [ABSTRACT FROM AUTHOR]

Lithobates areolatus (Crawfish Frog) is an imperiled amphibian, unique among ranid frogs due to its obligate use of crayfish burrows, highly terrestrial behavior, and reliance on open-canopy habitats within the central USA. Currently listed as near-threatened by the IUCN, and as state endangered, threatened, or of greatest conservation need in every state where it occurs, L. areolatus could potentially serve as an umbrella species for biodiversity conservation in the region. However, few studies have sought to identify site characteristics most strongly associated with the occupancy of L. areolatus or rigorously assessed the status of populations across core areas of the species’ range in Arkansas, Oklahoma, and Kansas. Within northwest Arkansas, we used an occupancy-modeling framework to 1) determine landscape characteristics that could serve as predictors of the occupancy of L. areolatus and 2) assess the status of current and historical populations. We completed 405 time-constrained auditory surveys across 81 potential and historical breeding wetlands of L. areolatus over two breeding seasons (March–April 2016 and 2017). Estimated occupancy and detection were 0.26 and 0.32, respectively. We did not detect L. areolatus at 37.5% (6/16) of historic breeding wetlands during our study, indicating these populations are likely extirpated. Occupancy probability was strongly related to density of prairie mounds within 1 km of breeding wetlands and was weakly related to clay and chert/gravel loam soil. Our results suggest that: 1) L. areolatus is widespread throughout northwest Arkansas but is threatened by the expanding human population, 2) detection probability is high under optimal conditions (cool temperatures [9–128C] and recent rain [within 24 hr]), and 3) prairie mound density is a useful proxy for upland habitat quality, likely reflecting minimal soil disturbance and presence of crayfish burrows. [ABSTRACT FROM AUTHOR]

The Nordic Bryological Society held its Annual meeting and excursion from 5 to 9 August 2019 in Sodankylä, Kittilä and Kolari in northern Finland. The excursion was attended by twenty-one participants. Special emphasis was given to boreal aapa mires and their Sphagnum species. A multitude of Sphagnum species typical to the area was encountered. Also, Red Listed species of meso- and eutrophic flark fens were discovered, e.g. Hamatocaulis vernicosus, H. lapponicus, Meesia longiseta, Schistochilopsis grandiretis and Moerckia flotoviana. Sphagnum annulatum, S. flexuosum, S. divinum, Heterogemma laxa and Scapania umbrosa were collected for the first time from Kittilän Lappi biogeographical province. Sphagnum annulatum, S. divinum, Campylium laxifolium, Pohlia sphagnicola, Gymnocolea borealis and Heterogemma laxa were collected for the first time from Sompion Lappi biogeographical province. In total, 54 records of Red Listed species were made. [ABSTRACT FROM AUTHOR]

Amphibian populations are decreasing worldwide, and pollution is a contributing factor. Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants known to exert immunotoxicity. To assess impacts of PCBs on frogs, we exposed Lithobates pipiens tadpoles to a diet of PCB‐126 (0–5 ng PCB‐126/g wet food) through metamorphic climax. Postmetamorphic frogs were immunized with keyhole limpet hemocyanin (KLH); then production of KLH‐specific IgY, as well as total IgY and IgM, was measured (Trial I). A second larval study (0 and 7.3 ng PCB‐126/g wet food) was performed to investigate whether PCB altered antigenic responses in prometamorphic tadpoles (Gosner Stage 36–39), and to measure the innate immune response of postmetamorphic frogs (Trial II). After larval PCB‐126 exposure, both KLH‐specific IgY levels and complement activity were reduced. Because postmetamorphic frogs carried a body burden of PCB‐126 (2.4 ng/g or less), we wanted to determine whether the effect on immune response was due to larval exposure or to the resulting body burden as frogs. To test this, we reared tadpoles under control conditions (no PCB), and limited PCB exposure to postmetamorphosis only by injecting 2‐week‐old frogs with 10 ng PCB‐126/g (Trial III). The resulting body burden (3.4 ng/g) was similar to that of frogs in Trial I, but we no longer detected suppression of KLH‐specific IgY or hemolytic activity. These results suggest life‐stage–specific immune responses; however, because we administered PCB‐126 differently between trials, it is premature to conclude that these differences are intrinsically life stage dependent, and further study is warranted. Regardless, our study demonstrated a long‐lasting effect of larval PCB‐126 exposure that persisted through metamorphosis and suppressed frog immunity. Environ Toxicol Chem 2022;41:81–94. © 2021 SETAC [ABSTRACT FROM AUTHOR]

The increasing use of agrochemicals, alone and in combination, has been implicated as a potential causative factor in the decline of amphibians worldwide. Fertilizers and pesticides are frequently combined into single‐use tank mixtures for agricultural applications to decrease costs while meeting the food demands of a growing human population. Limited data are available on the effects of increased nitrogen levels in nontarget species, such as amphibians, and therefore investigating alterations in the nitrogen cycle and its impacts on amphibians needs to be considered in best management practices going forward. The objective of the present study was to elucidate the impact of fertilizer (urea) and herbicide (atrazine and/or alachlor) tank mixtures on the hepatic metabolome of juvenile leopard frogs as well as to investigate alterations in oxidative stress by relating these changes to glutathione (GSH) levels. Herbicide exposure only moderately increased this parameter in amphibians, however, urea alone and in combination with either atrazine or alachlor statistically elevated GSH levels. Interestingly, urea also inhibited pesticide uptake: calculated bioconcentration factors were greatly decreased for atrazine and alachlor when urea was present in the exposure mixture. Metabolomic profiling identified fluxes in hepatic metabolites that are involved in GSH and carbohydrate metabolic processes as well as altered intermediates in the urea cycle. Ultimately, understanding the biological impacts of nitrogenous fertilizers alone and in combination with pesticide exposure will inform best management practices to conserve declining amphibian populations worldwide. Environ Toxicol Chem 2022;41:122–133. © 2021 SETAC [ABSTRACT FROM AUTHOR]

In order to reveal the bryophyte diversity of the Anzer valley and its surroundings, bryophyte samples were collected from 33 stations in the research area between June and July 2019. As a result of the examination of the samples, a total of 338 bryophyte taxa belonging to 135 genera and 69 families were identified and from those 286 were mosses and 52 liverworts. Among the identified, Scapania obscura (Arn. & Jens.) Schiffn., Sphagnum fimbriatum Wilson, Sphagnum papillosum Lindb., Dicranella staphylina H. Whitehouse, and Pohlia lescuriana (Sull.) Ochi, are reported for the second time from Turkey. In addition, a total of 88 bryophyte taxa (9 liverworts and 79 mosses) are new to for Rize province. As a result of this study, with the addition of 88 new taxa for Rize province, the number of bryophyte taxa determined from Rize province is 424. [ABSTRACT FROM AUTHOR]