Looking at anything that is green when hearing "frog": how object surface colour and stored object colour knowledge influence language-mediated overt attention.

PubMed

Huettig, Falk; Altmann, Gerry T M

2011-01-01

Three eye-tracking experiments investigated the influence of stored colour knowledge, perceived surface colour, and conceptual category of visual objects on language-mediated overt attention. Participants heard spoken target words whose concepts are associated with a diagnostic colour (e.g., "spinach"; spinach is typically green) while their eye movements were monitored to (a) objects associated with a diagnostic colour but presented in black and white (e.g., a black-and-white line drawing of a frog), (b) objects associated with a diagnostic colour but presented in an appropriate but atypical colour (e.g., a colour photograph of a yellow frog), and (c) objects not associated with a diagnostic colour but presented in the diagnostic colour of the target concept (e.g., a green blouse; blouses are not typically green). We observed that colour-mediated shifts in overt attention are primarily due to the perceived surface attributes of the visual objects rather than stored knowledge about the typical colour of the object. In addition our data reveal that conceptual category information is the primary determinant of overt attention if both conceptual category and surface colour competitors are copresent in the visual environment.

Diseases of frogs and toads

USGS Publications Warehouse

Green, D.E.; Converse, K.A.; Majumdar, S.K.; Huffman, J.E.; Brenner, F.J.; Panah, A.I.

2005-01-01

This chapter presents information on infectious diseases of free-living frogs and toads that have completed metamorphosis. The diseases discussed in this chapter pertain principally to sub-adult and adult frogs and toads that are at least 60-90 days removed from completion of metamorphosis. The main emphasis of this chapter is the diseases found in amphibians of Canada and the United States. Diseases of recent metamorphs, larvae and amphibian eggs are presented in the chapters Diseases of Amphibian Eggs and Embryos and Diseases of Tadpoles. The smallest disease agents (viruses and bacteria) are presented first, followed by fungi, protozoa, helminths and ectoparasites. Diseases presented in this chapter are Ranaviral (iridovirus) infection Lucke frog herpesvirus (kidney cancer) Frog erythrocytic virus West Nile virus Red-leg disease (bacterial septicemia) Salmonellosis Chytrid fungal infection Basidiobolus fungi Dermosporidiosis Ichthyophoniasis Dermocystidium & Dermomycoides Myxozoa Ribeiroia flukes and Amphibian malformations Clinostomum metacercaria Aspects of each disease are presented to assist the biologist with recognition of diseases in the field. Hence, the major emphases for identification of diseases are the epizootiological aspects (host species, life stage, casualty numbers, etc) and gross findings ('lesions'). Descriptions of the microscopical, ultrastructural and cultural characteristics of each infectious agent were considered beyond the scope of this text. Detailed cultural and microscopical features of these disease agents are available in other reviews (Taylor et al., 2001; Green, 2001). Some diseases, while common in captive and zoo amphibians, are exceptionally rare in free-living frogs and toads, and therefore are omitted from this review. Among the diseases not presented are infections by chlamydia and mycobacteria, which occur principally in captive colonies of African clawed frogs (Xenopus, Hymenochirus, et al.) and northern leopard frogs

Museum material reveals a frog parasite emergence after the invasion of the cane toad in Australia

PubMed Central

2010-01-01

Background A parasite morphologically indistinguishable from Myxidium immersum (Myxozoa: Myxosporea) found in gallbladders of the invasive cane toad (Bufo marinus) was identified in Australian frogs. Because no written record exists for such a parasite in Australian endemic frogs in 19th and early 20th century, it was assumed that the cane toad introduced this parasite. While we cannot go back in time ourselves, we investigated whether material at the museum of natural history could be used to retrieve parasites, and whether they were infected at the time of their collection (specifically prior to and after the cane toad translocation to Australia in 1935). Results Using the herpetological collection at the Australian Museum we showed that no myxospores were found in any animals (n = 115) prior to the cane toad invasion (1879-1935). The green and golden bell frog (Litoria aurea), the Peron's tree frog (Litoria peronii), the green tree frog (Litoria caerulea) and the striped marsh frog (Limnodynastes peronii) were all negative for the presence of the parasite using microscopy of the gallbladder content and its histology. These results were sufficient to conclude that the population was free from this disease (at the expected minimum prevalence of 5%) at 99.7% confidence level using the 115 voucher specimens in the Australian Museum. Similarly, museum specimens (n = 29) of the green and golden bell frog from New Caledonia, where it was introduced in 19th century, did not show the presence of myxospores. The earliest specimen positive for myxospores in a gallbladder was a green tree frog from 1966. Myxospores were found in eight (7.1%, n = 112) frogs in the post cane toad introduction period. Conclusion Australian wildlife is increasingly under threat, and amphibian decline is one of the most dramatic examples. The museum material proved essential to directly support the evidence of parasite emergence in Australian native frogs. This parasite can be considered one of

Fitting a Structured Juvenile-Adult Model for Green Tree Frogs to Population Estimates from Capture-Mark-Recapture Field Data

USGS Publications Warehouse

Ackleh, A.S.; Carter, J.; Deng, K.; Huang, Q.; Pal, N.; Yang, X.

2012-01-01

We derive point and interval estimates for an urban population of green tree frogs (Hyla cinerea) from capture-mark-recapture field data obtained during the years 2006-2009. We present an infinite-dimensional least-squares approach which compares a mathematical population model to the statistical population estimates obtained from the field data. The model is composed of nonlinear first-order hyperbolic equations describing the dynamics of the amphibian population where individuals are divided into juveniles (tadpoles) and adults (frogs). To solve the least-squares problem, an explicit finite difference approximation is developed. Convergence results for the computed parameters are presented. Parameter estimates for the vital rates of juveniles and adults are obtained, and standard deviations for these estimates are computed. Numerical results for the model sensitivity with respect to these parameters are given. Finally, the above-mentioned parameter estimates are used to illustrate the long-time behavior of the population under investigation. ?? 2011 Society for Mathematical Biology.

Frog decline, frog malformations, and a comparison of frog and human health.

PubMed

Cohen, M M

2001-11-22

The decline in frog populations and the increase in the frequency of frog malformations are discussed. Topics considered for analysis include chytridiomycosis, retinoids, UV-B radiation, chemical contaminants, environmental threats, introduced invasive species and predation, unsustainable use, and enigmatic decline. Care must be taken to distinguish between hypotheses, laboratory experiments, and the findings in feral frog populations. Clearly, the causes of population decline and malformations are heterogeneous. The subject of frogs and humans is addressed under three subheadings: the importance of frogs to human societies, medical implications of frog studies, and a comparison of frog and human disease factors. Copyright 2001 Wiley-Liss, Inc.

Frog eat frog: exploring variables influencing anurophagy.

PubMed

Measey, G John; Vimercati, Giovanni; de Villiers, F André; Mokhatla, Mohlamatsane M; Davies, Sarah J; Edwards, Shelley; Altwegg, Res

2015-01-01

Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested. Methods. We reviewed the literature on frog diet in order to test the size hypothesis and determine whether there are other putative explanations for anurans in the diet of post-metamorphic frogs. In addition to size, we recorded the habitat, the number of other sympatric anuran species, and whether or not the population was invasive. We controlled for taxonomic bias by including the superfamily in our analysis. Results. Around one fifth of the 355 records included anurans as dietary items of populations studied, suggesting that frogs eating anurans is not unusual. Our data showed a clear taxonomic bias with ranids and pipids having a higher proportion of anuran prey than other superfamilies. Accounting for this taxonomic bias, we found that size in addition to being invasive, local anuran diversity, and habitat produced a model that best fitted our data. Large invasive frogs that live in forests with high anuran diversity are most likely to have a higher proportion of anurans in their diet. Conclusions. We confirm the validity of the size hypothesis for anurophagy, but show that there are additional significant variables. The circumstances under which frogs eat frogs are likely to be complex, but our data may help to alert conservationists to the possible dangers of invading frogs entering areas with threatened anuran species.

Frog eat frog: exploring variables influencing anurophagy

PubMed Central

Vimercati, Giovanni; de Villiers, F. André; Mokhatla, Mohlamatsane M.; Davies, Sarah J.; Edwards, Shelley; Altwegg, Res

2015-01-01

Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested. Methods. We reviewed the literature on frog diet in order to test the size hypothesis and determine whether there are other putative explanations for anurans in the diet of post-metamorphic frogs. In addition to size, we recorded the habitat, the number of other sympatric anuran species, and whether or not the population was invasive. We controlled for taxonomic bias by including the superfamily in our analysis. Results. Around one fifth of the 355 records included anurans as dietary items of populations studied, suggesting that frogs eating anurans is not unusual. Our data showed a clear taxonomic bias with ranids and pipids having a higher proportion of anuran prey than other superfamilies. Accounting for this taxonomic bias, we found that size in addition to being invasive, local anuran diversity, and habitat produced a model that best fitted our data. Large invasive frogs that live in forests with high anuran diversity are most likely to have a higher proportion of anurans in their diet. Conclusions. We confirm the validity of the size hypothesis for anurophagy, but show that there are additional significant variables. The circumstances under which frogs eat frogs are likely to be complex, but our data may help to alert conservationists to the possible dangers of invading frogs entering areas with threatened anuran species. PMID:26336644

Pre-cure freezing effect on physicochemical, texture and sensory characteristics of Iberian ham.

PubMed

Pérez-Palacios, T; Ruiz, J; Martín, D; Barat, J M; Antequera, T

2011-04-01

The aim of this work was to investigate the effect of pre-cure freezing on the physicochemical, texture and sensory characteristics of raw and dry-cured hams. Both, refrigerated (R) and pre-cure frozen (F) hams showed the same weight losses during the processing. At the green stage F Iberian hams had lower moisture content, higher values of a* and chroma, lower hardness and chewiness and higher adhesiveness and springiness than R ones. However, at the end of the processing R and F Iberian hams only were different in salt content, F hams showing lower values than R ones. Sensory analysis of Iberian dry-cured ham did not show differences in salty taste. Panelist detected a higher fat hardness and lean pastiness in F than in R hams. The overall acceptability for both groups of dry-cured hams was between average and good.

Multiple sublethal chemicals negatively affect tadpoles of the green frog, Rana clamitans

USGS Publications Warehouse

Boone, Michelle D.; Bridges, Christine M.; Fairchild, James F.; Little, Edward E.

2005-01-01

Many habitats may be exposed to multiple chemical contaminants, particularly in agricultural areas where fertilizer and pesticide use are common; however, the singular and interactive effects of contaminants are not well understood. The objective of our study was to examine how realistic, sublethal environmental levels of ammonium nitrate fertilizer (0, 10, 20 mg/L and ammonium chloride control) and the common insecticide carbaryl (0 or 2.5 mg/L) individually and interactively affect the development, size, and survival of green frog (Rana clamitans) tadpoles. We reared tadpoles for 95 d in outdoor 1,000-L polyethylene ponds. We found that the combination of carbaryl and nitrate had a negative effect on development and mass of tadpoles compared to the positive effect that either contaminant had alone. Presence of carbaryl was generally associated with short-term increases in algal resources, including ponds exposed to both carbaryl and nitrate. However, with exposure to nitrate and carbaryl, tadpole mass and development were not positively affected as with one chemical stressor alone. The combination of these sublethal contaminants may reduce the ability of amphibians to benefit from food-rich environments or have metabolic costs. Our study demonstrates the importance of considering multiple stressors when evaluating population-level responses.

Influence of pre-cure freezing of Iberian ham on proteolytic changes throughout the ripening process.

PubMed

Pérez-Palacios, Trinidad; Ruiz, Jorge; Barat, Jose Manuel; Aristoy, María Concepción; Antequera, Teresa

2010-05-01

This work aimed to investigate the effect of pre-cure freezing Iberian hams on proteolysis phenomena throughout the ripening process. Non-protein nitrogen (NPN), peptide nitrogen (PN) and amino acid nitrogen (AN) as well as amino acid and dipeptide evolution followed the same trend in both refrigerated (R) and pre-cure frozen (F) Iberian hams during processing. At the different stages of ripening, there were no differences in the content of NPN and AN while F dry-cured hams had higher levels of PN than R hams at the final step. This seemed to be more related to the salt content (lower in F than in R hams) than to the pre-cure freezing treatment. Most amino acids and dipeptides detected showed higher concentrations in F than in R Iberian hams at the green stage, being rather similar at the intermediate phases. At the final stage, the effects of pre-cure freezing of Iberian hams were not well defined, higher levels of some amino acids and dipeptides were found in R than in F Iberian hams whereas other amino acids were lower in R than in F hams. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

A Comparison of V-Frog[C] to Physical Frog Dissection

ERIC Educational Resources Information Center

Lalley, James P.; Piotrowski, Phillip S.; Battaglia, Barbara; Brophy, Keith; Chugh, Kevin

2010-01-01

The purpose of the present study was to examine and compare the effectiveness of virtual frog dissection using V-Frog[C] and physical frog dissection on learning, retention, and affect. Subjects were secondary students enrolled in year-long life science classes in a suburban high school (N=102). Virtual dissections were done with V-Frog[C], a…

Enzyme activity in the aestivating green-striped burrowing frog (Cyclorana alboguttata).

PubMed

Mantle, Beth L; Guderley, Helga; Hudson, Nicholas J; Franklin, Craig E

2010-10-01

Green-striped burrowing frogs (Cyclorana alboguttata) can depress their resting metabolism by more than 80% during aestivation. Previous studies have shown that this species is able to withstand long periods of immobilisation during aestivation while apparently maintaining whole muscle mass and contractile performance. The aim of this study was to determine the effect of prolonged aestivation on the levels of metabolic enzymes (CCO, LDH and CS) in functionally distinct skeletal muscles (cruralis, gastrocnemius, sartorius, iliofibularis and rectus abdominus) and liver of C. alboguttata. CS activity was significantly reduced in all tissues except for the cruralis, gastrocnemius and the liver. LDH activity was significantly reduced in the sartorius and rectus abdominus, but remained at control (active) levels in the other tissues. CCO activity was significantly reduced in the gastrocnemius and rectus abdominus, and unchanged in the remaining tissues. Muscle protein was significantly reduced in the sartorius and iliofibularis during aestivation, and unchanged in the remaining muscles. The results suggest that the energy pathways involved in the production and consumption of ATP are remodelled during prolonged aestivation but selective. Remodelling and subsequent down-regulation of metabolic activity seem to target the smaller non-jumping muscles, while the jumping muscles retain enzyme activities at control levels during aestivation. These results suggest a mechanism by which aestivating C. alboguttata are able to maintain metabolic depression while ensuring that the functional capacity of critical muscles is not compromised upon emergence from aestivation.

What are carotenoids signaling? Immunostimulatory effects of dietary vitamin E, but not of carotenoids, in Iberian green lizards.

PubMed

Kopena, Renata; López, Pilar; Martín, José

2014-12-01

In spite that carotenoid-based sexual ornaments are one of the most popular research topics in sexual selection of animals, the antioxidant and immunostimulatory role of carotenoids, presumably signaled by these colorful ornaments, is still controversial. It has been suggested that the function of carotenoids might not be as an antioxidant per se, but that colorful carotenoids may indirectly reflect the levels of nonpigmentary antioxidants, such as melatonin or vitamin E. We experimentally fed male Iberian green lizards (Lacerta schreiberi) additional carotenoids or vitamin E alone, or a combination of carotenoids and vitamin E dissolved in soybean oil, whereas a control group only received soybean oil. We examined the effects of the dietary supplementations on phytohaemagglutinin (PHA)-induced skin-swelling immune response and body condition. Lizards that were supplemented with vitamin E alone or a combination of vitamin E and carotenoids had greater immune responses than control lizards, but animals supplemented with carotenoids alone had lower immune responses than lizards supplemented with vitamin E and did not differ from control lizards. These results support the hypothesis that carotenoids in green lizards are not effective as immunostimulants, but that they may be visually signaling the immunostimulatory effects of non-pigmentary vitamin E. In contrast, lizards supplemented with carotenoids alone have higher body condition gains than lizards in the other experimental groups, suggesting that carotenoids may be still important to improve condition.

What are carotenoids signaling? Immunostimulatory effects of dietary vitamin E, but not of carotenoids, in Iberian green lizards

NASA Astrophysics Data System (ADS)

Kopena, Renata; López, Pilar; Martín, José

2014-12-01

In spite that carotenoid-based sexual ornaments are one of the most popular research topics in sexual selection of animals, the antioxidant and immunostimulatory role of carotenoids, presumably signaled by these colorful ornaments, is still controversial. It has been suggested that the function of carotenoids might not be as an antioxidant per se, but that colorful carotenoids may indirectly reflect the levels of nonpigmentary antioxidants, such as melatonin or vitamin E. We experimentally fed male Iberian green lizards ( Lacerta schreiberi) additional carotenoids or vitamin E alone, or a combination of carotenoids and vitamin E dissolved in soybean oil, whereas a control group only received soybean oil. We examined the effects of the dietary supplementations on phytohaemagglutinin (PHA)-induced skin-swelling immune response and body condition. Lizards that were supplemented with vitamin E alone or a combination of vitamin E and carotenoids had greater immune responses than control lizards, but animals supplemented with carotenoids alone had lower immune responses than lizards supplemented with vitamin E and did not differ from control lizards. These results support the hypothesis that carotenoids in green lizards are not effective as immunostimulants, but that they may be visually signaling the immunostimulatory effects of non-pigmentary vitamin E. In contrast, lizards supplemented with carotenoids alone have higher body condition gains than lizards in the other experimental groups, suggesting that carotenoids may be still important to improve condition.

Bioaccumulation of polychlorinated biphenyls in ranid frogs and northern water snakes from a hazardous waste site and a contaminated watershed.

PubMed

Fontenot, L W; Noble, G P; Akins, J M; Stephens, M D; Cobb, G P

2000-04-01

Livers of bullfrogs (Rana catesbeiana) from a polychlorinated biphenyl (PCB) contaminated watershed and hazardous waste site located in Pickens County, South Carolina, contained significantly higher concentrations of PCBs (2.33 and 2.26 ppm, respectively) than those from a reference site (0.05 ppm). Green frogs (R. clamitans) from the two contaminated sites also accumulated higher levels of PCBs (2.37 and 3.88 ppm, respectively) than those from the reference site (0.02 ppm). No temporal variation was observed in PCB concentrations of bullfrogs or green frogs from the contaminated sites between 1992 and 1993. Levels of PCBs in the livers of northern water snakes (Nerodia sipedon) were significantly higher in snakes from the contaminated watershed (13.70 ppm) than in those from the waste site (2.29 ppm) and two reference sites (2.50 and 1.23 ppm). When compared to frogs, significantly higher bioaccumulation occurred in water snakes from the contaminated watershed. No significant differences in PCB levels were found with respect to sex or body size (snout-vent length (SVL) or body mass) for frogs or snakes. PCBs were detected also in eggs of both frogs and snakes. Results of this study provide baseline data and document the bioaccumulation of PCB residues in frog and snake tissues; however, the significance of these tissue residues to reproduction, survival, growth/development, and population dynamics in contaminated habitats is unknown.

Decreased hydrogen peroxide production and mitochondrial respiration in skeletal muscle but not cardiac muscle of the green-striped burrowing frog, a natural model of muscle disuse.

PubMed

Reilly, Beau D; Hickey, Anthony J R; Cramp, Rebecca L; Franklin, Craig E

2014-04-01

Suppression of disuse-induced muscle atrophy has been associated with altered mitochondrial reactive oxygen species (ROS) production in mammals. However, despite extended hindlimb immobility, aestivating animals exhibit little skeletal muscle atrophy compared with artificially immobilised mammalian models. Therefore, we studied mitochondrial respiration and ROS (H2O2) production in permeabilised muscle fibres of the green-striped burrowing frog, Cyclorana alboguttata. Mitochondrial respiration within saponin-permeabilised skeletal and cardiac muscle fibres was measured concurrently with ROS production using high-resolution respirometry coupled to custom-made fluorometers. After 4 months of aestivation, C. alboguttata had significantly depressed whole-body metabolism by ~70% relative to control (active) frogs, and mitochondrial respiration in saponin-permeabilised skeletal muscle fibres decreased by almost 50% both in the absence of ADP and during oxidative phosphorylation. Mitochondrial ROS production showed up to an 88% depression in aestivating skeletal muscle when malate, succinate and pyruvate were present at concentrations likely to reflect those in vivo. The percentage ROS released per O2 molecule consumed was also ~94% less at these concentrations, indicating an intrinsic difference in ROS production capacities during aestivation. We also examined mitochondrial respiration and ROS production in permeabilised cardiac muscle fibres and found that aestivating frogs maintained respiratory flux and ROS production at control levels. These results show that aestivating C. alboguttata has the capacity to independently regulate mitochondrial function in skeletal and cardiac muscles. Furthermore, this work indicates that ROS production can be suppressed in the disused skeletal muscle of aestivating frogs, which may in turn protect against potential oxidative damage and preserve skeletal muscle structure during aestivation and following arousal.

Failure of tetracycline as a biomarker in batch-marking juvenile frogs

USGS Publications Warehouse

Hatfield, Jeffrey S.; Henry, Paula F.P.; Olsen, Glenn H.; Paul, M.M.; Hammerschlag, Richard S.

2001-01-01

Recent widespread amphibian declines call for better techniques to assess population dynamics. Tetracycline as a biomarker in capture-recapture studies is one technique used successfully in fish, reptiles, and mammals. A two-phase experimental study was conducted to evaluate tetracycline as a biomarker in green frogs (Rana clamitans) and pickerel frogs (Rana palustris). In the first experimental phase tadpoles were exposed to water containing either 250 mg/l or 500 mg/l tetracycline for a period of 24 hr. During the second phase, juvenile frogs were exposed to tetracycline in water at 500 mg/l or given injections of tetracycline at the dose rate of 100 mg/kg body weight. At selected times several weeks later, under tricaine methanesulfonate anesthesia, a toe was surgically excised from each animal, sectioned and viewed under an ultraviolet microscope. No significant differences were found between the various treatments and control animals (untreated). Therefore, the use of tetracycline as a biomarker in anurans using these techniques is not recommended.

Comparative Pathology and Ecological Implications of Two Myxosporean Parasites in Native Australian Frogs and the Invasive Cane Toad

PubMed Central

Hartigan, Ashlie; Dhand, Navneet K.; Rose, Karrie; Šlapeta, Jan; Phalen, David N.

2012-01-01

Myxosporean parasites Cystodiscus axonis and C. australis are pathogens of native and exotic Australian frog species. The pathology and ecological outcomes of infection with these parasites were investigated in this study. Gliosis was correlated to Cystodiscus axonis plasmodia in the brains of (9/60) tadpoles and (3/9) adult endangered Green and golden bell frogs using ordinal regression. Severe host reactions to C. axonis (haemorrhage, necrosis, and vasulitis) were observed in the brains of threatened Southern bell frogs (8/8), critically endangered Booroolong frogs (15/44) and Yellow spotted bell frogs (3/3). Severe brain lesions were associated with behavioural changes, neurological dysfunction, and spontaneous death. Both C. axonis and C. australis develop in the bile ducts of tadpoles, the plasmodia were significantly associated with biliary hyperplasia, inflammation and the loss of hepatocytes in (34/72) Green and golden bell frog tadpoles using ordinal regression. These lesions were so severe that in some cases 70% of the total liver was diseased. Normal liver function in tadpoles is necessary for metamorphosis, metabolism, and immune function. We postulate that this extensive liver damage would have significant host health impacts. Severe hepatic myxosporidiosis was more prevalent in tadpoles examined in autumn and winter (overwintered), suggestive of delayed metamorphosis in infected tadpoles, which would have serious flow-on effects in small populations. We compared the sensitivity of histopathology and species-specific PCR in the detection of C. australis and C. axonis. PCR was determined to be the most sensitive method (detection limit 1 myxospore equivalent of ribosomal DNA). Histology, however, had the advantage of assessing the impact of the parasite on the host. It was concluded that these parasites have the potential for significant ecological impacts, because of their high prevalence of infection and their ability to cause disease in some frogs

The genetics of the pre-Roman Iberian Peninsula: a mtDNA study of ancient Iberians.

PubMed

Sampietro, M L; Caramelli, D; Lao, O; Calafell, F; Comas, D; Lari, M; Agustí, B; Bertranpetit, J; Lalueza-Fox, C

2005-09-01

The Iberians developed a surprisingly sophisticated culture in the Mediterranean coast of the Iberian Peninsula from the 6th century BC until their conquest by the Romans in the 2nd century BC. They spoke and wrote a non-Indo-European language that still cannot be understood; their origins and relationships with other non-Indo-European peoples, like the Etruscans, are unclear, since their funerary practices were based on the cremation of bodies, and therefore anthropology has been unable to approach the study of this people. We have retrieved mitochondrial DNA (mtDNA) from a few of the scarce skeletal remains that have been preserved, some of them belonging to ritualistically executed individuals. The most stringent authentication criteria proposed for ancient DNA, such as independent replication, amino-acid analysis, quantitation of template molecules, multiple extractions and cloning of PCR products, have been followed to obtain reliable sequences from the mtDNA hypervariable region 1 (HVR1), as well as some haplogroup diagnostic SNPs. Phylogeographic analyses show that the haplogroup composition of the ancient Iberians was very similar to that found in modern Iberian Peninsula populations, suggesting a long-term genetic continuity since pre-Roman times. Nonetheless, there is less genetic diversity in the ancient Iberians than is found among modern populations, a fact that could reflect the small population size at the origin of the population sampled, and the heterogenic tribal structure of the Iberian society. Moreover, the Iberians were not especially closely related to the Etruscans, which points to considerable genetic heterogeneity in Pre-Roman Western Europe.

To Be or Not to Be...a Frog: The Frog Prince and Shifting Paradigms.

ERIC Educational Resources Information Center

Crane, Lisa Marie

1997-01-01

Discusses three modern variations of the classic "Frog Prince" folk tale: "Pondlarker" (Fred Gwynne); "The Frog Prince Continued" (Jon Scieszka); and "The Prince of the Pond" (Donna Jo Napoli). Notes that these variants create a world in which frogs can have values, wisdom, and emotion, and in which frogs can influence the ways of humanity. (RS)

A regional survey of malformed frogs in Minnesota (USA) (Minnesota malformed frogs).

PubMed

Vandenlangenberg, Susan M; Canfield, Jeffrey T; Magner, Joseph A

2003-02-01

In late 1995, school children discovered malformed frogs in a south central Minnesota pond. Press coverage resulted in numerous citizen reports of frog malformation across Minnesota in 1996. After some initial site investigation, 3 affected frog sites and 4 nearby reference sites were selected for more detailed evaluation. Field biologists made 89 visits to study sites beginning spring 1997 through fall 1999 to examine the number and type of frog malformations. Over 5,100 Leopard frogs (Rana pipiens) were captured and examined at all study sites. Water elevations and associated littoral inundation were recorded from 1997-2000. Results indicate that malformation occurred at all study sites above historical background levels. Rana pipiens malformation across all sites over three seasons averaged 7.9% and ranged from 0 to 7% at reference sites and 4 to 23% at affected sites. At one northern Minnesota site, mink frog (Rana septentrionalis) malformation was 75% in 1998. A site characteristic common to the most affected sites was an elastic zone of littoral inundation. Climate driven hydrologic variation likely influenced water depth and associated breeding locations.

Frog Statistics

Science.gov Websites

Whole Frog Project and Virtual Frog Dissection Statistics wwwstats output for January 1 through duplicate or extraneous accesses. For example, in these statistics, while a POST requesting an image is as well. Note that this under-represents the bytes requested. Starting date for following statistics

Landscape associations of frog and toad species in Iowa and Wisconsin, U.S.A

USGS Publications Warehouse

Knutson, M.G.; Sauer, J.R.; Olsen, D.A.; Mossman, M.J.; Hemesath, L.M.; Lannoo, M.J.; Kaiser, Hinrich; Casper, Gary S.; Bernstein, Neil P.

2000-01-01

Landscape habitat associations of frogs and toads in Iowa and Wisconsin were tested to determine whether they support or refute previous general habitat classifications. We examined which Midwestern species shared similar habitats to see if these associations were consistent across large geographic areas (states). Rana sylvatica (wood frog), Hyla versicolor (eastern gray treefrog), Pseudacris crucifer (spring peeper), and Acris crepitans (cricket frog) were identified as forest species, P. triseriata (chorus frog), H. chrysoscelis (Cope's gray treefrog), R. pipiens (leopard frog), and Bufo americanus (American toad) as grassland species, and R. catesbeiana (bullfrog), R. clamitans (green frog), R. palustris (pickerel frog), and R. septentrionalis (mink frog) as lake or stream species. The best candidates to serve as bioindicators of habitat quality were the forest species R. sylvatica, H. versicolor, and P. crucifer, the grassland species R. pipiens and P. triseriata, and a cold water wetland species, R. palustris. Declines of P. crucifer, R. pipiens, and R. palustris populations in one or both states may reflect changes in habitat quality. Habitat and community associations of some species differed between states, indicating that these relationships may change across the range of a species. Acris crepitans may have shifted its habitat affinities from open habitats, recorded historically, to the more forested habitat associations we recorded. We suggest contaminants deserve more investigation regarding the abrupt and widespread declines of this species. Interspersion of different habitat types was positively associated with several species. A larger number of wetland patches may increase breeding opportunities and increase the probability of at least one site being suitable. We noted consistently negative associations between anuran species and urban development. Given the current trend of urban growth and increasing density of the human population, declines of

Trypanosome transmission by Corethrella wirthi (Diptera: Chaoboridae) to the green treefrog, Hyla cinerea (Anura: Hylidae).

PubMed

Johnson, R N; Young, D G; Butler, J F

1993-09-01

Seventy-two percent of 215 male green tree frog, Hyla cinerea (Schneider), captured in Alachua and Levy counties, FL, between April and mid-September 1978 and 1979 were infected with an undescribed Trypanosoma sp. None of the 31 female frogs captured concurrently was infected. Periodic sampling of the peripheral blood from the infected male frogs showed that the trypanosomes were present in high numbers only at night. Conspecific trypanosomes also were found in the mid and hind guts of female Corethrella wirthi Stone flies collected on or near male frogs in the field. Transmission of the parasite to uninfected frogs was demonstrated by exposure of male and female frogs to naturally infected flies and to parasites injected subdermally. This is the first report of parasite transmission by a species of Corethrella.

Jan Swammerdam's frogs

PubMed Central

Sleigh, Charlotte

2012-01-01

Having discussed insect metamorphosis at length, Jan Swammerdam's Bybel der Natuure (1679/1737) reached its climax with a substantial description of the generation and muscular activity of frogs. This paper explores the rhetorical role of frogs in Swammerdam's ‘great work’, showing how they were the Archimedean point from which he aimed to reorder all of creation—from insects to humans—within one glorious, God-ordained natural history and philosophy. Swammerdam linked insects to frogs through a demonstration that all underwent epigenesis; and frogs were then linked to humans through a demonstration of their identical muscular activity. The success of Swammerdam's strategy required a theological reconstruction of the frog, traditionally an ungodly creature, such that trustworthy knowledge could be obtained from its body. Perhaps surprisingly, this act of theological cleansing is shown to be somewhat prefigured in the distinctly non-experimental natural history of Edward Topsell (1608). The paper also examines Swammerdam's interactions with the mystic Antoinette Bourignon, and his challenges in reconciling a spirituality of meletetics with a material epistemology in natural philosophy. Differences are revealed between the natural analogies given by Swammerdam in his published and unpublished writings, undermining to a certain extent the triumphal insect–frog–human rhetorical structure of the Bybel.

Virtual Frog Dissection Kit Version 2.2

Science.gov Websites

Virtual Frog Dissection Kit This award-winning interactive program is part of the "Whole Frog " project. You can interactively dissect a (digitized) frog named Fluffy, and play the Virtual Frog animals other than the frog that have a computer-graphics based virtual dissection page. We get frequent

49 CFR 213.137 - Frogs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... than 10 m.p.h. (c) If the tread portion of a frog casting is worn down more than three-eighths inch below the original contour, operating speed over that frog shall not be more than 10 m.p.h. (d) Where... 49 Transportation 4 2011-10-01 2011-10-01 false Frogs. 213.137 Section 213.137 Transportation...

Geomorphology of the Iberian Continental Margin

NASA Astrophysics Data System (ADS)

Maestro, Adolfo; López-Martínez, Jerónimo; Llave, Estefanía; Bohoyo, Fernando; Acosta, Juan; Hernández-Molina, F. Javier; Muñoz, Araceli; Jané, Gloria

2013-08-01

The submarine features and processes around the Iberian Peninsula are the result of a complex and diverse geological and oceanographical setting. This paper presents an overview of the seafloor geomorphology of the Iberian Continental Margin and the adjacent abyssal plains. The study covers an area of approximately 2.3 million km2, including a 50 to 400 km wide band adjacent to the coastline. The main morphological characteristics of the seafloor features on the Iberian continental shelf, continental slope, continental rise and the surrounding abyssal plains are described. Individual seafloor features existing on the Iberian Margin have been classified into three main groups according to their origin: tectonic and/or volcanic, depositional and erosional. Major depositional and erosional features around the Iberian Margin developed in late Pleistocene-Holocene times and have been controlled by tectonic movements and eustatic fluctuations. The distribution of the geomorphological features is discussed in relation to their genetic processes and the evolution of the margin. The prevalence of one or several specific processes in certain areas reflects the dominant morphotectonic and oceanographic controlling factors. Sedimentary processes and the resulting depositional products are dominant on the Valencia-Catalán Margin and in the northern part of the Balearic Promontory. Strong tectonic control is observed in the geomorphology of the Betic and the Gulf of Cádiz margins. The role of bottom currents is especially evident throughout the Iberian Margin. The Galicia, Portuguese and Cantabrian margins show a predominance of erosional features and tectonically-controlled linear features related to faults.

Yet More Frogs

ERIC Educational Resources Information Center

Shutler, Paul M. E.

2011-01-01

Extending a recent paper by Derek Holton, we show how to represent the algorithm for the Frog Problem diagrammatically. This diagrammatic representation suggests a simpler proof of the symmetrical case (equal numbers of frogs of each colour) by allowing the even and odd cases to be treated together. It also provides a proof in the asymmetrical…

Ancient DNA evidence of Iberian lynx palaeoendemism

NASA Astrophysics Data System (ADS)

Rodríguez-Varela, Ricardo; Tagliacozzo, Antonio; Ureña, Irene; García, Nuria; Crégut-Bonnoure, Evelyne; Mannino, Marcello A.; Arsuaga, Juan Luis; Valdiosera, Cristina

2015-03-01

The Iberian lynx, endemic to the Iberian Peninsula, is the most threatened carnivore in Europe and the most endangered felid in the world. Widely distributed throughout Iberia during the Pleistocene and Holocene it is now confined to two small populations in southern Spain. Lynx species differentiation, based solely on morphological analysis from skeletal traits, is a difficult task and can potentially lead to misidentification. In order to verify whether Iberian lynx had a wider geographical distribution in the past, we successfully sequenced 152 base pairs (bp) of the cytochrome b gene and 183 bp of the mitochondrial control region in 20 Late Pleistocene and Holocene fossil remains of Lynx sp. from southern Europe. Our results confirm the presence of Iberian lynx outside the Iberian Peninsula demonstrating that this is a palaeoendemic species that had a wider distribution range in southern Europe during the Holocene and the Late Pleistocene. In addition, we documented the presence of both Palaearctic extant lynx species in the Arene Candide (north Italy) site during the Last Glacial Maximum.

Do all frogs swim alike? The effect of ecological specialization on swimming kinematics in frogs.

PubMed

Robovska-Havelkova, Pavla; Aerts, Peter; Rocek, Zbynek; Prikryl, Tomas; Fabre, Anne-Claire; Herrel, Anthony

2014-10-15

Frog locomotion has attracted wide scientific interest because of the unusual and derived morphology of the frog pelvic girdle and hind limb. Previous authors have suggested that the design of the frog locomotor system evolved towards a specialized jumping morphology early in the radiation of the group. However, data on locomotion in frogs are biased towards a few groups and most of the ecological and functional diversity remains unexplored. Here, we examine the kinematics of swimming in eight species of frog with different ecologies. We use cineradiography to quantify movements of skeletal elements from the entire appendicular skeleton. Our results show that species with different ecologies do differ in the kinematics of swimming, with the speed of limb extension and especially the kinematics of the midfoot being different. Our results moreover suggest that this is not a phylogenetic effect because species from different clades with similar ecologies converge on the same swimming kinematics. We conclude that it is important to analyze frog locomotion in a broader ecological and evolutionary context if one is to understand the evolutionary origins of this behavior. © 2014. Published by The Company of Biologists Ltd.

Mosquito repellents in frog skin

PubMed Central

Williams, C.R; Smith, B.P.C; Best, S.M; Tyler, M.J

2006-01-01

The search for novel insect repellents has been driven by health concerns over established synthetic compounds such as diethyl-m-toluamide (DEET). Given the diversity of compounds known from frog skin and records of mosquito bite and ectoparasite infestation, the presence of mosquito repellents in frogs seemed plausible. We investigated frog skin secretions to confirm the existence of mosquito repellent properties. Litoria caerulea secretions were assessed for mosquito repellency by topical application on mice. The secretions provided protection against host-seeking Culex annulirostris mosquitoes. Olfactometer tests using aqueous washes of skin secretions from L. caerulea and four other frog species were conducted to determine whether volatile components were responsible for repellency. Volatiles from Litoria rubella and Uperoleia mjobergi secretions were repellent to C. annulirostris, albeit not as repellent as a DEET control. The demonstration of endogenous insect repellents in amphibians is novel, and demonstrates that many aspects of frog chemical ecology remain unexplored. PMID:17148373

Development of the pseudothumb in frogs

PubMed Central

Tokita, Masayoshi; Iwai, Noriko

2010-01-01

Frogs have highly conserved hand and foot morphology, possessing four fingers and five toes. As an exception, two Japanese ranid frog species, the Otton frog Babina subaspera and the dagger frog Babina holsti, possess a unique thumb-like structure (the pseudothumb) in the forelimb, giving an appearance of a total of five fingers on the hand. To obtain insights into the developmental mechanisms that generate this novel character, we investigated the hand morphogenesis of the Otton frog. The unique morphological pattern of the pseudothumb was already established in juveniles. Surprisingly, the bud-like structure, which is similar to the area of inductive activity (e.g. feather buds in birds and the carapacial ridge in turtles), was detected over the site where the future prepollex develops in larvae. By contrast, this bud-like structure was not found in larvae of other ranid species. We discuss possible scenarios that would favour the evolution of this very unusual trait in frogs. PMID:20147308

PYCNOIB: Biodiversity and Biogeography of Iberian Pycnogonids

PubMed Central

Soler-Membrives, Anna; Munilla, Tomás

2015-01-01

Biodiversity and biogeographic studies comparing the distribution patterns of benthic marine organisms across the Iberian Atlantic and Mediterranean waters are scarce. The Pycnogonida (sea spiders) are a clear example of both endemicity and diversity, and are considered a key taxon to study and monitor biogeographic and biodiversity patterns. This is the first review that compiles data about abundance and diversity of Iberian pycnogonids and examines their biogeographic patterns and bathymetric constraints using GIS tools. A total of 17762 pycnogonid records from 343 localities were analyzed and were found to contain 65 species, 21 genera and 12 families. Achelia echinata and Ammothella longipes (family Acheliidae) were the most abundant comprising ~80% of the total records. The Acheliidae is also the most speciose in Iberian waters with 15 species. In contrast, the family Nymphonidae has 7 species but is significantly less abundant (<1% of the total records) than Acheliidae. Species accumulation curves indicate that further sampling would increase the number of Iberian species records. Current sampling effort suggests that the pycnogonid fauna of the Mediterranean region may be richer than that of the Atlantic. The Strait of Gibraltar and the Alboran Sea are recognized as species-rich areas that act as buffer zones between the Atlantic and Mediterranean boundaries. The deep waters surrounding the Iberian Peninsula are poorly surveyed, with only 15% of the sampling sites located below 1000 m. Further deep-water sampling is needed mainly on the Iberian Mediterranean side. PMID:25781483

Analysis of transient receptor potential ankyrin 1 (TRPA1) in frogs and lizards illuminates both nociceptive heat and chemical sensitivities and coexpression with TRP vanilloid 1 (TRPV1) in ancestral vertebrates.

PubMed

Saito, Shigeru; Nakatsuka, Kazumasa; Takahashi, Kenji; Fukuta, Naomi; Imagawa, Toshiaki; Ohta, Toshio; Tominaga, Makoto

2012-08-31

Transient receptor potential ankyrin 1 (TRPA1) and TRP vanilloid 1 (V1) perceive noxious temperatures and chemical stimuli and are involved in pain sensation in mammals. Thus, these two channels provide a model for understanding how different genes with similar biological roles may influence the function of one another during the course of evolution. However, the temperature sensitivity of TRPA1 in ancestral vertebrates and its evolutionary path are unknown as its temperature sensitivities vary among different vertebrate species. To elucidate the functional evolution of TRPA1, TRPA1s of the western clawed (WC) frogs and green anole lizards were characterized. WC frog TRPA1 was activated by heat and noxious chemicals that activate mammalian TRPA1. These stimuli also activated native sensory neurons and elicited nocifensive behaviors in WC frogs. Similar to mammals, TRPA1 was functionally co-expressed with TRPV1, another heat- and chemical-sensitive nociceptive receptor, in native sensory neurons of the WC frog. Green anole TRPA1 was also activated by heat and noxious chemical stimulation. These results suggest that TRPA1 was likely a noxious heat and chemical receptor and co-expressed with TRPV1 in the nociceptive sensory neurons of ancestral vertebrates. Conservation of TRPV1 heat sensitivity throughout vertebrate evolution could have changed functional constraints on TRPA1 and influenced the functional evolution of TRPA1 regarding temperature sensitivity, whereas conserving its noxious chemical sensitivity. In addition, our results also demonstrated that two mammalian TRPA1 inhibitors elicited different effect on the TRPA1s of WC frogs and green anoles, which can be utilized to clarify the structural bases for inhibition of TRPA1.

Analysis of Transient Receptor Potential Ankyrin 1 (TRPA1) in Frogs and Lizards Illuminates Both Nociceptive Heat and Chemical Sensitivities and Coexpression with TRP Vanilloid 1 (TRPV1) in Ancestral Vertebrates*

PubMed Central

Saito, Shigeru; Nakatsuka, Kazumasa; Takahashi, Kenji; Fukuta, Naomi; Imagawa, Toshiaki; Ohta, Toshio; Tominaga, Makoto

2012-01-01

Transient receptor potential ankyrin 1 (TRPA1) and TRP vanilloid 1 (V1) perceive noxious temperatures and chemical stimuli and are involved in pain sensation in mammals. Thus, these two channels provide a model for understanding how different genes with similar biological roles may influence the function of one another during the course of evolution. However, the temperature sensitivity of TRPA1 in ancestral vertebrates and its evolutionary path are unknown as its temperature sensitivities vary among different vertebrate species. To elucidate the functional evolution of TRPA1, TRPA1s of the western clawed (WC) frogs and green anole lizards were characterized. WC frog TRPA1 was activated by heat and noxious chemicals that activate mammalian TRPA1. These stimuli also activated native sensory neurons and elicited nocifensive behaviors in WC frogs. Similar to mammals, TRPA1 was functionally co-expressed with TRPV1, another heat- and chemical-sensitive nociceptive receptor, in native sensory neurons of the WC frog. Green anole TRPA1 was also activated by heat and noxious chemical stimulation. These results suggest that TRPA1 was likely a noxious heat and chemical receptor and co-expressed with TRPV1 in the nociceptive sensory neurons of ancestral vertebrates. Conservation of TRPV1 heat sensitivity throughout vertebrate evolution could have changed functional constraints on TRPA1 and influenced the functional evolution of TRPA1 regarding temperature sensitivity, whereas conserving its noxious chemical sensitivity. In addition, our results also demonstrated that two mammalian TRPA1 inhibitors elicited different effect on the TRPA1s of WC frogs and green anoles, which can be utilized to clarify the structural bases for inhibition of TRPA1. PMID:22791718

Honors for the Virtual Frog Dissection Kit

Science.gov Websites

Honors for the Virtual Frog Dissection Kit Study Web The dissection kit received a StudyWeb award Frog Project | Virtual Frog Page last modified: 01/23/05 Contacts: Bill Johnston, David Robertson

Crustal parameters in the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Banda, E.

1988-06-01

The structure of the crust in the Iberian Peninsula has been investigated for the last 15 years by Spanish and Portuguese groups in close collaboration with other European institutions. The first experiments were carried out in Portugal (Mueller et al., 1973) with the aim of investigating the crustal structure of the Hercynian belt in the southwest corner of the Iberian peninsula. Other experiments have been subsequently realized to study different aspects of the crust in various regions of Portugal. In Spain the main effort has been focused in Alpine areas, with the first experiments in the Alboran Sea and the Betic Cordilleras (Working Group for Deep Seismic Sounding in Spain, 1974-1975, 1977; Working Group for Deep Seismic Sounding in the Alboran Sea, 1974-1975, 1978). Follow-up experiments until 1981 completed the work in the Betic Cordillera. Extensive experiments were carried out in the Pyrenees in 1978. Further surveys covered the Balearic Islands in 1976, the Valencia Trough in 1976 and 1983, and the Celtiberian Chain (or Iberic system) in 1981. The Hercynian belt has only been studied in detail in the northwest corner of Spain in 1982, with smaller studies in the central Iberian Massif in 1976 and 1986. Mostaanpour (1984) has compiled some crustal parameters (crustal thickness, average crustal velocity and Pn velocity) for western Europe. Meanwhile, more complete data are available for the Iberian Peninsula. The results presented here were derived from a large number of seismic refraction experiments which have been carried out mostly along or close to coastal areas of the Iberian Peninsula. Offshore explosions of various sizes were used as the energy source in most cases, in addition to some quarry blasts. Unfortunately this leaves most of the inner part of the Iberian Peninsula unsurveyed. Our purpose is to summarize some of the crustal parameters obtained so far and to detail the appropriate literature for the interested reader.

Ultrasonic monitoring of Iberian fat crystallization during cold storage

NASA Astrophysics Data System (ADS)

Corona, E.; García-Pérez, J. V.; Santacatalina, J. V.; Peña, R.; Benedito, J.

2012-12-01

The aim of this work was to evaluate the use of ultrasonic measurements to characterize the crystallization process and to assess the textural changes of Iberian fat and Iberian ham during cold storage. The ultrasonic velocity was measured in two types of Iberian fats (Montanera and Cebo) during cold storage (0, 2, 5, 7 and 10 °C) and in vacuum packaged Iberian ham stored at 6°C for 120 days. The fatty acid profile, thermal behaviour and textural properties of fat were determined. The ultrasonic velocity and textural measurements showed a two step increase during cold storage, which was related with the separate crystallization of two fractions of triglycerides. It was observed that the harder the fat, the higher the ultrasonic velocity. Likewise, Cebo fat resulted harder than Montanera due to a higher content of saturated triglycerides. The ultrasonic velocity in Iberian ham showed an average increase of 55 m/s after 120 days of cold storage due to fat crystallization. Thus, non-destructive ultrasonic technique could be a reliable method to follow the crystallization of fats and to monitor the changes in the textural properties of Iberian ham during cold storage.

Complete Genome Sequence of Frog virus 3, Isolated from a Strawberry Poison Frog (Oophaga pumilio) Imported from Nicaragua into the Netherlands

PubMed Central

Hughes, Joseph; van Beurden, Steven J.; Suárez, Nicolás M.; Haenen, Olga L. M.; Voorbergen-Laarman, Michal; Gröne, Andrea; Kik, Marja J. L.

2017-01-01

ABSTRACT Frog virus 3 was isolated from a strawberry poison frog (Oophaga pumilio) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op/2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the reference Frog virus 3 isolate. PMID:28860243

Complete Genome Sequence of Frog virus 3, Isolated from a Strawberry Poison Frog (Oophaga pumilio) Imported from Nicaragua into the Netherlands.

PubMed

Saucedo, Bernardo; Hughes, Joseph; van Beurden, Steven J; Suárez, Nicolás M; Haenen, Olga L M; Voorbergen-Laarman, Michal; Gröne, Andrea; Kik, Marja J L

2017-08-31

Frog virus 3 was isolated from a strawberry poison frog ( Oophaga pumilio ) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op /2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the reference Frog virus 3 isolate. Copyright © 2017 Saucedo et al.

Modelling the growth of the brown frog (Rana dybowskii)

PubMed Central

Du, Xiao-peng; Hu, Zong-fu; Cui, Li-yong

2018-01-01

Well-controlled development leads to uniform body size and a better growth rate; therefore, the ability to determine the growth rate of frogs and their period of sexual maturity is essential for producing healthy, high-quality descendant frogs. To establish a working model that can best predict the growth performance of frogs, the present study examined the growth of one-year-old and two-year-old brown frogs (Rana dybowskii) from metamorphosis to hibernation (18 weeks) and out-hibernation to hibernation (20 weeks) under the same environmental conditions. Brown frog growth was studied and mathematically modelled using various nonlinear, linear, and polynomial functions. The model input values were statistically evaluated using parameters such as the Akaike’s information criterion. The body weight/size ratio (Kwl) and Fulton’s condition factor (K) were used to compare the weight and size of groups of frogs during the growth period. The results showed that the third- and fourth-order polynomial models provided the most consistent predictions of body weight for age 1 and age 2 brown frogs, respectively. Both the Gompertz and third-order polynomial models yielded similarly adequate results for the body size of age 1 brown frogs, while the Janoschek model produced a similarly adequate result for the body size of age 2 brown frogs. The Brody and Janoschek models yielded the highest and lowest estimates of asymptotic weight, respectively, for the body weights of all frogs. The Kwl value of all frogs increased from 0.40 to 3.18. The K value of age 1 frogs decreased from 23.81 to 9.45 in the first four weeks. The K value of age 2 frogs remained close to 10. Graphically, a sigmoidal trend was observed for body weight and body size with increasing age. The results of this study will be useful not only for amphibian research but also for frog farming management strategies and decisions.

Drought variability and change across the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Coll, Joan Ramon; Aguilar, Enric

2015-04-01

Drought variability and change is assessed in this study across the Iberian Peninsula along the 20th century and the first decade of the 21st century using state of the art drought indices: the Sc-PDSI, the SPI and the SPEI. Daily temperature and precipitation data from 24 time-series regularly spread over Iberian Peninsula are quality controlled and also homogenized in a monthly scale to create the Monthly Iberian Temperature and Precipitation Series (MITPS) for the period 1906-2010. The Sc-PDSI, the 12-month SPI and 12-month SPEI are computed on a monthly basis using the newly MITPS dataset to identify dry and wet conditions across time. Precipitation data is only required to compute SPI, but potential evapotranspiration (PET) is also needed to perform the Sc-PDSI and SPEI, which is estimated using the Tornthwaite's method. The analysis conducted in this study confirms that drought conditions are worsening for most of the Iberian Peninsula across time strongly induced by global warming especially during the last three decades. All drought indices have found a drying trend in the Pyrenees, Ebro basin, central Iberia and in the south and south-eastern area while a wetting trend is identified in the western and in the north-western region. Future projections also indicate a clear increase in hydrological drought conditions along the 21st century, thus, water saving and the application of effective water management strategies will be crucial to minimize the impact of hydrological droughts over the Iberian Peninsula into the near future. KEY WORDS: Drought, climate change, Iberian Peninsula, drought indices.

Drought variability and change across the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Coll, J. R.; Aguilar, E.; Ashcroft, L.

2017-11-01

Drought variability and change was assessed across the Iberian Peninsula over more than 100 years expanding through the twentieth century and the first decade of the twenty-first century. Daily temperature and precipitation data from 24 Iberian time series were quality controlled and homogenized to create the Monthly Iberian Temperature and Precipitation Series (MITPS) for the period 1906-2010. The Standardized Precipitation Index (SPI), driven only by precipitation, and the Standardized Precipitation Evapotranspiration Index (SPEI), based on the difference between the precipitation and the reference evapotranspiration (ET0), were computed at annual and seasonal scale to describe the evolution of droughts across time. The results confirmed that a clear temperature increase has occurred over the entire Iberian Peninsula at the annual and seasonal scale, but no significant changes in precipitation accumulated amounts were found. Similar drought variability was provided by the SPI and SPEI, although the SPEI showed greater drought severity and larger surface area affected by drought than SPI from 1980s to 2010 due to the increase in atmospheric evaporative demand caused by increased temperatures. Moreover, a clear drying trend was found by the SPEI for most of the Iberian Peninsula at annual scale and also for spring and summer, although the SPI did not experience significant changes in drought conditions. From the drying trend identified for most of the Iberian Peninsula along the twentieth century, an increase in drought conditions can also be expected for this region in the twenty-first century according to future climate change projections and scenarios.

Teams Explore the Whole Frog

ERIC Educational Resources Information Center

Cessna, Clair E.

1973-01-01

Describes the content and organization of a laboratory session in which student teams work on the organs, tissues, and parasites of a pithed frog. The procedure maximizes participation by every student, makes possible the fullest use of each frog, and permits a rather broad study in a limited time. (JR)

The Classroom Animal: The Leopard Frog.

ERIC Educational Resources Information Center

Science and Children, 1985

1985-01-01

Describes the natural history of the leopard frog and factors which make it appropriate for short-term study in the classroom. Information on the frog's habits, life cycle, housing, care, and health is included. (DH)

Frog Swarms: Earthquake Precursors or False Alarms?

PubMed Central

Grant, Rachel A.; Conlan, Hilary

2013-01-01

Simple Summary Media reports linking unusual animal behaviour with earthquakes can potentially create false alarms and unnecessary anxiety among people that live in earthquake risk zones. Recently large frog swarms in China and elsewhere have been reported as earthquake precursors in the media. By examining international media reports of frog swarms since 1850 in comparison to earthquake data, it was concluded that frog swarms are naturally occurring dispersal behaviour of juveniles and are not associated with earthquakes. However, the media in seismic risk areas may be more likely to report frog swarms, and more likely to disseminate reports on frog swarms after earthquakes have occurred, leading to an apparent link between frog swarms and earthquakes. Abstract In short-term earthquake risk forecasting, the avoidance of false alarms is of utmost importance to preclude the possibility of unnecessary panic among populations in seismic hazard areas. Unusual animal behaviour prior to earthquakes has been reported for millennia but has rarely been scientifically documented. Recently large migrations or unusual behaviour of amphibians have been linked to large earthquakes, and media reports of large frog and toad migrations in areas of high seismic risk such as Greece and China have led to fears of a subsequent large earthquake. However, at certain times of year large migrations are part of the normal behavioural repertoire of amphibians. News reports of “frog swarms” from 1850 to the present day were examined for evidence that this behaviour is a precursor to large earthquakes. It was found that only two of 28 reported frog swarms preceded large earthquakes (Sichuan province, China in 2008 and 2010). All of the reported mass migrations of amphibians occurred in late spring, summer and autumn and appeared to relate to small juvenile anurans (frogs and toads). It was concluded that most reported “frog swarms” are actually normal behaviour, probably caused by

"RED-LEG"—AN INFECTIOUS DISEASE OF FROGS

PubMed Central

Emerson, Haven; Norris, Charles

1905-01-01

The epidemics we have observed, were due to the presence and growth in the frogs of Bacillus hydrophilus fuscus. This was proved by recovering the bacillus in pure culture from the body fluids of frogs sick or dead of the disease, and the inoculation of healthy frogs with an emulsion of the pure culture, and by obtaining the same clinical picture and pathological findings as in the original diseased frogs; and, finally, by recovering the bacillus in pure culture from frogs inoculated and sick or dying as a result of the inoculation. The disease is widely distributed throughout North America and Europe, and in this country and Canada is known as "red-leg." It has been observed by us chiefly in the warm weather of September and October. The disease is characterized by congestion of the ventral surfaces of the body, with more or less ulceration in, and hæmorrhage beneath, the skin, bloating due to serous exudation into the lymph sacs, gradual failure to respond to stimuli, which symptoms are followed by coma and death, the last being occasionally preceded by tetanic seizures. After death hæmorrhages into the muscles and degenerative changes in the muscles, spleen, liver, and, to a slight degree, in the intestinal tract, are found. The blood shows an advanced degree of anæmia and leucocytosis. Predisposing causes of the disease are lesions of the skin, which seem to be the usual portal of entry of the infection, and lowered resistance from heat and from anæmia. By a series of controlled experiments with inoculated frogs we have shown that, while temperatures a little above freezing have no harmful effect upon the frogs, they completely control all manifestations of the disease in inoculated or diseased frogs, if the frogs are left in the cold for a period as long as seven days; and, further, that even short periods in the cold chamber will bring about a delay of the fatal results in diseased or inoculated frogs. The anæmia so often found in apparently healthy

Mitochondrial haplotype variation and phylogeography of Iberian brown trout populations.

PubMed

MacHordom, A; Suárez, J; Almodóvar, A; Bautista, J M

2000-09-01

The biogeographical distribution of brown trout mitochondrial DNA haplotypes throughout the Iberian Peninsula was established by polymerase chain reaction-restriction fragment polymorphism analysis. The study of 507 specimens from 58 localities representing eight widely separated Atlantic-slope (north and west Iberian coasts) and six Mediterranean drainage systems served to identify five main groups of mitochondrial haplotypes: (i) haplotypes corresponding to non-native, hatchery-reared brown trout that were widely distributed but also found in wild populations of northern Spain (Cantabrian slope); (ii) a widespread Atlantic haplotype group; (iii) a haplotype restricted to the Duero Basin; (iv) a haplotype shown by southern Iberian populations; and (v) a Mediterranean haplotype. The Iberian distribution of these haplotypes reflects both the current fishery management policy of introducing non-native brown trout, and Messinian palaeobiogeography. Our findings complement and extend previous allozyme studies on Iberian brown trout and improve present knowledge of glacial refugia and postglacial movement of brown trout lineages.

Theorizing Iberian Studies

ERIC Educational Resources Information Center

Newcomb, Robert Patrick

2015-01-01

A growing number of scholars invested in Iberian Studies are asking how peninsular literary and cultural studies might be reimagined, and reinvigorated, by placing the Spanish and Portuguese canons into critical dialogue with each other, and with Galician, Catalan, Basque/Euskadi, and Latin American and North African immigrant writers, cultural…

Frog tongue surface microstructures: functional and evolutionary patterns

PubMed Central

Gorb, Stanislav N

2016-01-01

Summary Frogs (Lissamphibia: Anura) use adhesive tongues to capture fast moving, elusive prey. For this, the tongues are moved quickly and adhere instantaneously to various prey surfaces. Recently, the functional morphology of frog tongues was discussed in context of their adhesive performance. It was suggested that the interaction between the tongue surface and the mucus coating is important for generating strong pull-off forces. However, despite the general notions about its importance for a successful contact with the prey, little is known about the surface structure of frog tongues. Previous studies focused almost exclusively on species within the Ranidae and Bufonidae, neglecting the wide diversity of frogs. Here we examined the tongue surface in nine different frog species, comprising eight different taxa, i.e., the Alytidae, Bombinatoridae, Megophryidae, Hylidae, Ceratophryidae, Ranidae, Bufonidae, and Dendrobatidae. In all species examined herein, we found fungiform and filiform papillae on the tongue surface. Further, we observed a high degree of variation among tongues in different frogs. These differences can be seen in the size and shape of the papillae, in the fine-structures on the papillae, as well as in the three-dimensional organization of subsurface tissues. Notably, the fine-structures on the filiform papillae in frogs comprise hair-like protrusions (Megophryidae and Ranidae), microridges (Bufonidae and Dendrobatidae), or can be irregularly shaped or absent as observed in the remaining taxa examined herein. Some of this variation might be related to different degrees of adhesive performance and may point to differences in the spectra of prey items between frog taxa. PMID:27547606

Prototype next generation frog foundation - preliminary evaluation : research results.

DOT National Transportation Integrated Search

2016-06-01

Conventional wisdom suggests that a solid or rigid one-piece frog is preferred because it is easy to maintain. However, testing and subsequent modeling demonstrated that a flexible frog (i.e., a two-piece frog split in the flangeway) produced signifi...

Efficacy of ivermectin as an anthelmintic in leopard frogs.

PubMed

Letcher, J; Glade, M

1992-02-15

Ivermectin administered cutaneously at dosages of 2 mg/kg of body weight eliminated nematode infections in leopard frogs. Three clinical trials were conducted. In the first trial, 5 groups of 11 frogs were given ivermectin IM at dosages of 0, 0.2, 0.4, 2, or 20 mg/kg. All frogs given ivermectin IM at dosages of 2.0 mg/kg or greater died. In trial 2, 44 frogs, allotted to 5 groups, were given ivermectin cutaneously at 0, 0.2, 2, or 20 mg/kg. Cutaneously administered ivermectin was not toxic at dosages up to 20 mg/kg. In trial 3, nematode infections were eliminated in all 10 frogs treated cutaneously with ivermectin at 2.0 mg/kg.

Immunogenetic and population genetic analyses of Iberian cattle.

PubMed

Kidd, K K; Stone, W H; Crimella, C; Carenzi, C; Casati, M; Rognoni, G

1980-01-01

Blood samples were collected from more than 100 animals in each of 2 Spanish cattle breeds (Retinto and De Lidia), 2 Portuguese breeds (Alentejana and Mertolenga), and American Longhorn cattle. All samples for the 4 Iberian breeds were tested for 20 polymorphic systems; American Longhorn were tested for 19 of the 20. For each breed an average inbreeding coefficient was estimated by a comparison of the observed and expected heterozygosity at 7 or 8 codominant systems tested. All breeds had positive values but only 3 breeds had estimates of inbreeding that were statistically significantly different from 0: De Lidia with f = 0.17, Retinto with f = 0.08 and Mertolenga with f = 0.05. The De Lidia breed especially may be suffering from inbreeding depression since this high value is greater than expected if all of the animals were progeny of half-sib matings. Genetic distances were calculated from the gene frequency data on these 5 breeds plus 9 other European breeds. Analyses of these distances show a closely related group of the 4 Iberian breeds and American Longhorn, confirming the close relationships among the Iberian breeds and the Iberian, probably Portuguese, origin of American Longhorn cattle.

Semi-automated identification of leopard frogs

USGS Publications Warehouse

Petrovska-Delacrétaz, Dijana; Edwards, Aaron; Chiasson, John; Chollet, Gérard; Pilliod, David S.

2014-01-01

Principal component analysis is used to implement a semi-automatic recognition system to identify recaptured northern leopard frogs (Lithobates pipiens). Results of both open set and closed set experiments are given. The presented algorithm is shown to provide accurate identification of 209 individual leopard frogs from a total set of 1386 images.

CARE AND FEEDING OF FROGS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Margaret; Chiang, Eugene, E-mail: mpan@astro.berkeley.edu

2012-01-15

'Propellers' are features in Saturn's A ring associated with moonlets that open partial gaps. They exhibit non-Keplerian motion (Tiscareno et al.); the longitude residuals of the best-observed propeller, 'Bleriot', appear consistent with a sinusoid of period {approx}4 years. Pan and Chiang proposed that propeller moonlets librate in 'frog resonances' with co-orbiting ring material. By analogy with the restricted three-body problem, they treated the co-orbital material as stationary in the rotating frame and neglected non-co-orbital material. Here we use simple numerical experiments to extend the frog model, including feedback due to the gap's motion, and drag associated with the Lindblad diskmore » torques that cause Type I migration. Because the moonlet creates the gap, we expect the gap centroid to track the moonlet, but only after a time delay t{sub delay}, the time for a ring particle to travel from conjunction with the moonlet to the end of the gap. We find that frog librations can persist only if t{sub delay} exceeds the frog libration period P{sub lib}, and if damping from Lindblad torques balances driving from co-orbital torques. If t{sub delay} << Pl{sub ib}, then the libration amplitude damps to zero. In the case of Bleriot, the frog resonance model can reproduce the observed libration period P{sub lib} {approx_equal} 4 yr. However, our simple feedback prescription suggests that Bleriot's t{sub delay} {approx} 0.01P{sub lib}, which is inconsistent with the observed libration amplitude of 260 km. We urge more accurate treatments of feedback to test the assumptions of our toy models.« less

FROGS (Friends of Granites) report

NASA Astrophysics Data System (ADS)

Miller, Calvin

This VGP News, which is devoted to petrology, is a good one for noting the existence of FROGS. FROGS is, as the name suggests, an informal organization of people whose research relates in one way or another to granitic rocks. Its purpose has been to promote communication among geoscientists with different perspectives and concerns about felsic plutonism. Initially, a major focus was experimental petrology and integration of field-oriented and lab-oriented viewpoints; now that there is the opportunity to communicate with the Eos readership, an obvious additional goal will be to bring together volcanic and plutonic views of felsic magmatism.FROGS first gathered in late 1982 under the guidance of E-an Zen and Pete Toulmin (both at U.S. Geological Survey (USGS), Reston, Va.), who saw a need for greater interaction among those interested in granites and for renewed, focused experimental investigations. They produced two newsletters (which were sent out by direct mail) and organized an informal meeting at the Geological Society of America meeting at Indianapolis, Ind., and then turned over the FROG reins to Sue Kieffer (USGS, Flagstaff, Ariz.) and John Clemens (Arizona State University, Tempe). They generated another newsletter, which was directly mailed to a readership that had grown beyond 200.

Divergence among barking frogs (Eleutherodactylus augusti) in the southwestern United States

USGS Publications Warehouse

Goldberg, Caren S.; Sullivan, Brian K.; Malone, John H.; Schwalbe, Cecil R.

2004-01-01

Barking frogs (Eleutherodactylus augusti) are distributed from southern Mexico along the Sierra Madre Occidental into Arizona and the Sierra Madre Oriental into Texas and New Mexico. Barking frogs in Arizona and most of Texas live in rocky areas in oak woodland, while those in New Mexico and far western Texas live in rodent burrows in desertscrub. Barking frogs in each of the three states have distinct coloration and differ in sexually dimorphic characters, female vocalization, and skin toxicity. We analyzed advertisement call variation and conducted a phylogenetic analysis using mitochondrial DNA sequences (ND2 and tRNA regions) for barking frogs from these three states. Advertisement calls of frogs from Arizona were significantly longer in duration, higher in frequency, and had longer duration pulses than those of frogs from either New Mexico or Texas; frogs from these latter two sites were indistinguishable in these call variables. Phylogenetic analysis showed deep divisions among barking frogs from the three states. Differences in call structure, coloration, and mitochondrial DNA sequences strongly suggest that barking frogs in Arizona are reproductively isolated from those in New Mexico and Texas. Our results indicate that either northern populations are connected via gene flow through southern Mexico (i.e., they are subspecies as currently recognized), or represent independent lineages as originally described (i.e., western barking frogs, E. cactorum in AZ, and the eastern barking frogs, E. latrans in NM, TX).

Parathion accumulation in cricket frogs and its effect on American kestrels

USGS Publications Warehouse

Fleming, W.J.; de Chacin, H.; Pattee, O.H.; Lamont, T.G.

1982-01-01

Adult cricket frogs (Acris crepitans) were held individually for 96 h in static systems containing initial concentrations of either 0, 0.1, 1.0, or 10 ppm parathion in 10 ml water. Mortality of cricket frogs was directly related to the parathion concentration in the water. Frogs from the 1.0- and 10-ppm groups accumulated 0.08 and 4.6 ppm parathion, respectively. One of four American kestrels (Falco sparverius) fed frogs from the 10-ppm group died from organophosphate poisoning less than 3 h after consuming five frogs. Mortality did not occur in kestrels fed frogs from the other treatment groups, which represented more environmentally realistic levels of exposure.

Characterization of the Iberian Y chromosome haplogroup R-DF27 in Northern Spain.

PubMed

Villaescusa, Patricia; Illescas, María José; Valverde, Laura; Baeta, Miriam; Nuñez, Carolina; Martínez-Jarreta, Begoña; Zarrabeitia, Maria Teresa; Calafell, Francesc; de Pancorbo, Marian M

2017-03-01

The European paternal lineage R-DF27 has been proposed as a haplogroup of Iberian origin due to its maximum frequencies in the Iberian Peninsula. In this study, the distribution and structure of DF27 were characterized in 591 unrelated male individuals from four key populations of the north area of the Iberian Peninsula through the analysis of 12 Y-SNPs that define DF27 main sublineages. Additionally, Y-SNP allele frequencies were also gathered from the reference populations in the 1000 Genomes Project to compare and obtain a better landscape of the distribution of DF27. Our results reveal frequencies over 35% of DF27 haplogroup in the four North Iberian populations analyzed and high frequencies for its subhaplogroups. Considering the low frequency of DF27 and its sublineages in most populations outside of the Iberian Peninsula, this haplogroup seems to have geographical significance; thus, indicating a possible Iberian patrilineal origin of vestiges bearing this haplogroup. The dataset presented here contributes with new data to better understand the complex genetic variability of the Y chromosome in the Iberian Peninsula, that can be applied in Forensic Genetics. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Seroprevalence of Toxoplasma gondii in Iberian pig sows.

PubMed

Pablos-Tanarro, Alba; Ortega-Mora, Luis Miguel; Palomo, Antonio; Casasola, Francisco; Ferre, Ignacio

2018-05-01

The objective of the present study was to investigate the seroprevalence of Toxoplasma gondii infection in Iberian sows reared in extensive and intensive management conditions and to compare two serologic techniques used for diagnosis. In addition, some possible risk factors associated with the presence of serum antibodies to T. gondii were also studied. Serum samples were collected from 2492 Iberian sows on 14 pig farms. Three types of management systems were included, traditional extensive outdoor farms (five farms), intensive farms with outdoor access (n = 4), and conventional intensive indoor farms (n = 5). The presence of serum antibodies to T. gondii was evaluated by two commercially available tests: an indirect enzyme-linked immunosorbent assay (ELISA) and a direct agglutination test (DAT). Serum antibodies against T. gondii were detected in 237 sows (9.5%) by at least one of the techniques used. The mean seroprevalence of toxoplasmosis in Iberian sows was 5.8% by ELISA and 8.9% by DAT. An agreement kappa-value of 0.68 (95%, CI = 0.63-0.74) was found between both tests. The results from this study suggest that the prevalence of T. gondii antibodies among Iberian sows seems to be moderate-low. The presence of serum antibodies against T. gondii in Iberian sows was associated to an extensive management system and low-level facilities of the farm, sow number (> 1000 animals), presence of cats, absence of rodent control and bird-proof nets in windows, well-water source, feed sources and storage (from the same farm and not stored in silo), absence of fences, and low farm worker qualification.

Ovarian dysgerminomas in two mountain chicken frogs (Leptodactylus fallax).

PubMed

Fitzgerald, Scott D; Duncan, Ann E; Tabaka, Chris; Garner, Michael M; Dieter, April; Kiupel, Matti

2007-03-01

This report describes the gross, histologic, and immunohistochemical features of ovarian dysgerminomas in two adult female mountain chicken frogs (Leptodactylusfallax) from the same zoological institution. One frog was found dead, and the other frog had been ill for several days with a bloated abdomen and lethargy. On necropsy, large, pale multilobulated masses replaced the left ovary in both frogs, and one frog also had numerous smaller nodules scattered throughout the coelomic viscera. Histologically, these masses were composed of sheets and cords of polyhedral discrete germ cells consistent with the diagnosis of dysgerminoma. Neoplastic cells stained positive with immunohistochemistry for Oct4, which has been reported to detect stem cells including germ cells in a variety of species, including humans. Ovarian tumors are uncommonly encountered in both reptiles and amphibians, and this report is the first report of dysgerminoma in any amphibian species.

Albumin Evolution in Frogs: A Test of the Evolutionary Clock Hypothesis

PubMed Central

Wallace, Donald G.; Maxson, Linda R.; Wilson, Allan C.

1971-01-01

Frogs are an ancient group compared to placental mammals. Yet, although there are about as many species of frogs as there are of mammals, zoologists consider that frogs have undergone only limited morphological divergence, while placental mammals have diversified greatly in morphology and way of life. The serum albumins of numerous frog species were compared by the quantitative microcomplement fixation technique. Frogs that are morphologically similar enough to merit taxonomic distinction at only the species level often exhibit differences in the serological properties of their albumins larger than those usually seen between mammals placed in distinct families or suborders. Thus, there seems to be a contrast between albumin evolution and evolution at the organismal level. The large differences between albumins among frogs can be explained by the hypothesis that albumin evolution has proceeded at the same rate in frogs as in mammals. PMID:5002283

FROGS: Find, Rapidly, OTUs with Galaxy Solution.

PubMed

Escudié, Frédéric; Auer, Lucas; Bernard, Maria; Mariadassou, Mahendra; Cauquil, Laurent; Vidal, Katia; Maman, Sarah; Hernandez-Raquet, Guillermina; Combes, Sylvie; Pascal, Géraldine

2018-04-15

Metagenomics leads to major advances in microbial ecology and biologists need user friendly tools to analyze their data on their own. This Galaxy-supported pipeline, called FROGS, is designed to analyze large sets of amplicon sequences and produce abundance tables of Operational Taxonomic Units (OTUs) and their taxonomic affiliation. The clustering uses Swarm. The chimera removal uses VSEARCH, combined with original cross-sample validation. The taxonomic affiliation returns an innovative multi-affiliation output to highlight databases conflicts and uncertainties. Statistical results and numerous graphical illustrations are produced along the way to monitor the pipeline. FROGS was tested for the detection and quantification of OTUs on real and in silico datasets and proved to be rapid, robust and highly sensitive. It compares favorably with the widespread mothur, UPARSE and QIIME. Source code and instructions for installation: https://github.com/geraldinepascal/FROGS.git. A companion website: http://frogs.toulouse.inra.fr. geraldine.pascal@inra.fr. Supplementary data are available at Bioinformatics online.

49 CFR 213.355 - Frog guard rails and guard faces; gage.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face, measured...

49 CFR 213.355 - Frog guard rails and guard faces; gage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face, measured...

49 CFR 213.355 - Frog guard rails and guard faces; gage.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face, measured...

49 CFR 213.355 - Frog guard rails and guard faces; gage.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face, measured...

49 CFR 213.355 - Frog guard rails and guard faces; gage.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face, measured...

A New Species of Haplophyllum A. Juss. (Rutaceae) from the Iberian Peninsula: Evidence from Morphological, Karyological and Molecular Analyses

PubMed Central

NAVARRO, F. B.; SUÁREZ-SANTIAGO, V. N.; BLANCA, G.

2004-01-01

• Background and Aims The discovery of a new species, Haplophyllum bastetanum F.B. Navarro, V.N. Suárez-Santiago & Blanca sp. nov., in the south-east of Spain has prompted the comparative study of species of the Iberian Peninsula, and others related, through morphological, cytogenetic, molecular, distributional and ecological characterization. • Methods The morphological study involved a quantitative analysis of the species present in the Iberian Peninsula and a comparative analysis of the morphological characteristics between H. bastetanum and other related species. Mitotic analyses were made with root meristems taken from germinating seeds. Phylogenetic analyses of the internal transcribed spacer sequences of nuclear ribosomal DNA were performed using neighbour-joining (NJ) and maximum-parsimony methods. • Key Results Haplophyllum bastetanum is a diploid species (2n = 18) distinguished primarily for its non-trifoliate glabrous leaves, lanceolate sepals, dark-green petals with a dorsal band of hairs, and a highly hairy ovary with round-apex locules. The other two Iberian species (H. linifolium and H. rosmarinifolium) are tetraploid (2n = 36) and have yellow petals. Both phylogenetic methods generated a well-supported clade grouping H. linifolium with H. rosmarinifolium. In the NJ tree, the H. linifolium–H. rosmarinifolium clade is a sister group to H. bastetanum, while in the parsimony analysis this occurred only when the gaps were coded as a fifth base and the characters were reweighted according to the rescaled consistency index. This latter group is supported by the sequence divergence among taxa. • Conclusions The phylogenies established from DNA sequences together with morphological and cytogenetic analyses support the separation of H. bastetanum as a new species. The results suggest that the change in the number of chromosomes may be the key mechanism of speciation of the genus Haplophyllum in the Iberian Peninsula. An evolutionary scheme for them

Condition-dependent reproductive effort in frogs infected by a widespread pathogen

PubMed Central

Roznik, Elizabeth A.; Sapsford, Sarah J.; Pike, David A.; Schwarzkopf, Lin; Alford, Ross A.

2015-01-01

To minimize the negative effects of an infection on fitness, hosts can respond adaptively by altering their reproductive effort or by adjusting their timing of reproduction. We studied effects of the pathogenic fungus Batrachochytrium dendrobatidis on the probability of calling in a stream-breeding rainforest frog (Litoria rheocola). In uninfected frogs, calling probability was relatively constant across seasons and body conditions, but in infected frogs, calling probability differed among seasons (lowest in winter, highest in summer) and was strongly and positively related to body condition. Infected frogs in poor condition were up to 40% less likely to call than uninfected frogs, whereas infected frogs in good condition were up to 30% more likely to call than uninfected frogs. Our results suggest that frogs employed a pre-existing, plastic, life-history strategy in response to infection, which may have complex evolutionary implications. If infected males in good condition reproduce at rates equal to or greater than those of uninfected males, selection on factors affecting disease susceptibility may be minimal. However, because reproductive effort in infected males is positively related to body condition, there may be selection on mechanisms that limit the negative effects of infections on hosts. PMID:26063847

Ancient origin of endemic Iberian earth-boring dung beetles (Geotrupidae).

PubMed

Cunha, Regina L; Verdú, José R; Lobo, Jorge M; Zardoya, Rafael

2011-06-01

The earth-boring dung beetles belong to the family Geotrupidae that includes more than 350 species classified into three subfamilies Geotrupinae, Lethrinae, and Taurocerastinae, mainly distributed across temperate regions. Phylogenetic relationships within the family are based exclusively on morphology and remain controversial. In the Iberian Peninsula there are 33 species, 20 of them endemic, which suggests that these lineages might have experienced a radiation event. The evolution of morphological adaptations to the Iberian semi-arid environments such as the loss of wings (apterism) or the ability to exploit alternative food resources is thought to have promoted diversification. Here, we present a phylogenetic analysis of 31 species of Geotrupidae, 17 endemic to the Iberian Peninsula, and the remaining from southeastern Europe, Morocco, and Austral South America based on partial mitochondrial and nuclear gene sequence data. The reconstructed maximum likelihood and Bayesian inference phylogenies recovered Geotrupinae and Lethrinae as sister groups to the exclusion of Taurocerastinae. Monophyly of the analyzed geotrupid genera was supported but phylogenetic relationships among genera were poorly resolved. Ancestral character-state reconstruction of wing loss evolution, dating, and diversification tests altogether showed neither evidence of a burst of cladogenesis of the Iberian Peninsula group nor an association between apterism and higher diversification rates. Loss of flight did not accelerate speciation rates but it was likely responsible for the high levels of endemism of Iberian geotrupids by preventing their expansion to central Europe. These Iberian flightless beetle lineages are probably paleoendemics that have survived since the Tertiary in this refuge area during Plio-Pleistocene climatic fluctuations by evolving adaptations to arid and semi-arid environments. Copyright © 2011 Elsevier Inc. All rights reserved.

The wood frog (Rana sylvatica): a technical conservation assessment

USGS Publications Warehouse

Muths, E.; Rittmann, S.; Irwin, J.; Keinath, D.; Scherer, R.

2005-01-01

Overall, the wood frog (Rana sylvatica) is ranked G5, secure through most of its range (NatureServe Explorer 2002). However, it is more vulnerable in some states within the USDA Forest Service Region 2: S3 (vulnerable) in Colorado, S2 (imperiled) in Wyoming, and S1 (critically imperiled in South Dakota (NatureServe Explorer 2002); there are no records for wood frogs in Kansas or Nebraska. Primary threats to wood frog populations are habitat fragmentation (loss of area, edge effects, and isolation) and habitat loss due to anthropogenic causes (e.g., wetland draining, grazing) and natural changes as habitat succession occurs. Wood frogs are most conspicuous at breeding sites early in the spring, when snow and ice are often still present at pond margins. They tolerate frezzing and hibernate terrestrially in shallow depressions, under leaf litter, grasses, logs, or rocks (Bagdonas 1968, Bellis 1961a); there are no reports of aquatic hibernation for this species (Licht 1991, Pinder et al. 1992). Wood frogs require semi-permanent and temporary pools of natural origin and adjacent wet meadows, and landscape alterations that shorten the hydroperiod of ponds can result in catastrophic tadpole mortality. Plant communities utilized by wood frogs in the Rocky Mountains are hydric to mesic and include sedge and grass meadows, willow hummocks, aspen groves, lodgepole pine forests, and woodlands with leaf litter and/or herbaceous understory (Maslin 1947, Bellis 1961a, Roberts and Lewin 1979, Haynes and Aird 1981). Wood frogs are likely to disperse into surrounding marsh and woodlands soon after oviposition (Heatwole 1961, Haynes and Aird 1981). In the arly fall, wood frogs begin to seek hibernacula at or just below the ground surface, generally in upland forest habitat (Regosin et al. 2003). Licht (1991) demonstrated shelter-seeking behavior at 1.5 [degrees] C. Once they have concealed themselves for hibernation, wood frogs are very difficult to detecta?|

Southern dispersal and Palaeoecological implications of woolly rhinoceros ( Coelodonta antiquitatis): review of the Iberian occurrences

NASA Astrophysics Data System (ADS)

Álvarez-Lao, Diego J.; García, Nuria

2011-07-01

Cold-adapted large mammal populations spread southward during the coldest and driest phases of the Late Pleistocene reaching the Iberian Peninsula. Presence of woolly rhinoceros ( Coelodonta antiquitatis) can be identified from 23 Iberian sites, which is compiled and analyzed herein, and the fossil specimens from seven of these sites are described here for first time. Morphological and biometrical analyses demonstrate that the Iberian woolly rhinoceros did not significantly differ from individuals of other European populations, but represent the westernmost part of a continuous Eurasian belt of distribution. The first presence of woolly rhino in the Iberian Peninsula has been identified during the late Middle Pleistocene and early Late Pleistocene. However, the highest abundance of this species is recorded during MIS 3 and 2. The latest Iberian occurrences can be dated around 20 ka BP. The presence of woolly rhinoceros in the Iberian Peninsula correlates with periods of extreme dry and cold climatic conditions documented in Iberian terrestrial and marine sediment sequences. From a palaeobiogeographic point of view, the maximum southern spread of C. antiquitatis on the Iberian Peninsula was registered during the late Middle Pleistocene or early Late Pleistocene, reaching the latitude of Madrid (about 40°N). Subsequently, during MIS 3 and 2, all Iberian finds were restricted to the Northern regions of Iberia (Cantabrian area and Catalonia). The southern expansion of C. antiquitatis during the Late Pleistocene in the Iberian Peninsula reached similar latitudes to other Eurasian regions. The ecological composition of fossil assemblages with presence of woolly rhinoceros was statistically analyzed. Results show that temperate ungulate species are predominant at Iberian assemblages, resulting in a particular mixture of temperate and cold elements different of the typical Eurasian cold-adapted faunal associations. This particular situation suggests two possible

FROG - Fingerprinting Genomic Variation Ontology

PubMed Central

Bhardwaj, Anshu

2015-01-01

Genetic variations play a crucial role in differential phenotypic outcomes. Given the complexity in establishing this correlation and the enormous data available today, it is imperative to design machine-readable, efficient methods to store, label, search and analyze this data. A semantic approach, FROG: “FingeRprinting Ontology of Genomic variations” is implemented to label variation data, based on its location, function and interactions. FROG has six levels to describe the variation annotation, namely, chromosome, DNA, RNA, protein, variations and interactions. Each level is a conceptual aggregation of logically connected attributes each of which comprises of various properties for the variant. For example, in chromosome level, one of the attributes is location of variation and which has two properties, allosomes or autosomes. Another attribute is variation kind which has four properties, namely, indel, deletion, insertion, substitution. Likewise, there are 48 attributes and 278 properties to capture the variation annotation across six levels. Each property is then assigned a bit score which in turn leads to generation of a binary fingerprint based on the combination of these properties (mostly taken from existing variation ontologies). FROG is a novel and unique method designed for the purpose of labeling the entire variation data generated till date for efficient storage, search and analysis. A web-based platform is designed as a test case for users to navigate sample datasets and generate fingerprints. The platform is available at http://ab-openlab.csir.res.in/frog. PMID:26244889

Seismic Reflection Transect across the Central Iberian Zone (Iberian Massif): The ALCUDIA project

NASA Astrophysics Data System (ADS)

Carbonell, R.; Simancas, F.; Martinez-Poyatos, D.; Ayarza, P.; Gonzalez, P.; Tejero, R.; Martín-Parra, L.; Matas, J.; Gonzalez-Lodeiro, F.; Pérez-Estaún, A.; García-Lobon, J.; Mansilla, L.; Palomeras, I.

2007-12-01

The lithosphere of the Central Iberian Zone (CIZ) differs from that of the southwestern Iberian Massif. They are limited by a suture zone. The seismic reflection profile IBERSEIS suggested that the activity of a Carboniferous mantle plume resulted in abundant intrusions of mafic magmas in the mid-to-lower crust which resulted in a singular crustal evolution. The current knowledge of the area based mostly in surface geological mapping suggests that basic magmatism continues further towards the north, indicating that the mantle plume may have affected a bigger area up to the Tajo depression. Furthermore, the existence of the Almadén mine, one of the largest mercury mine in the world within the CIZ, favour that the crust in this area is the result of anomalous lithospheric processes. Accordingly, the ALCUDIA project has been lauched aiming to study the structure and nature of the lithosphere of the CIZ. It includes the acquisition of a deep high resolution seismic reflection transect, detailed geological mapping, kinematic, petrologic and geochemical studies, and other geophysical studies (potential field methods). This new profile extends the previous IBERSEIS Transect towards the northeast, completing almost 600 km of deep seismic profiles, crossing the southern half of the Iberian Variscides. The transect crosses some important structures, such as the Toledo fault, Santa Elena Fault, Alcudia anticline, Almadén syncline, and some major magnetic anomalies. The preliminary results reveal that the crust is 30 km thick in average, with a horizontal Moho, a highly reflective mid-to-lower crust with a few mantle reflectors and well defined features in the upper crust with the indication of detachments zones that might link to the mid- crustal reflective zone.

49 CFR 213.139 - Spring rail frogs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of each...

49 CFR 213.139 - Spring rail frogs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of each...

49 CFR 213.139 - Spring rail frogs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of each...

49 CFR 213.139 - Spring rail frogs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of each...

49 CFR 213.139 - Spring rail frogs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of each...

Description of the tadpoles of two endemic frogs: the Phu Luang cascade frog Odorrana aureola (Anura: Ranidae) and the Isan big-headed frog Limnonectes isanensis (Anura: Dicroglossidae) from northeastern Thailand.

PubMed

Ampai, Natee; Rujirawan, Attapol; Arkajag, Jirachai; Mcleod, David S; Aowphol, Anchalee

2015-07-07

We describe the external morphology of the tadpoles of two frogs endemic to Thailand: the Phu Luang cascade frog    (Odorrana aureola) and the Isan big-headed frog (Limnonectes isanensis) from the type localities in the Phu Luang Wildlife Sanctuary, Loei Province, northeastern Thailand. Morphological and genetic characters (16S rRNA) were used to identify specimen and match tadpoles to the adults. Detailed descriptions of external morphology and coloration in life are provided for both species. We provide a brief discussion of the ecology of these tadpoles and a comparison to previously published data from tadpoles of closely related taxa. Additionally, we provide evidence for the utility of larval morphology in resolving the taxonomic puzzles presented by cryptic species complexes.

Body wiping behaviors associated with cutaneous lipids in hylid tree frogs of Florida.

PubMed

Barbeau, Tamatha R; Lillywhite, Harvey B

2005-06-01

Body wiping behavior, integumentary secretions and rates of evaporative water loss (EWL) were examined in six species of Florida tree frogs (Anura: Hylidae). Additionally, morphology of the integument and dermal glands were compared among these and one other Florida tree frog (Hyla andersonii), an arid-adapted tree frog (Phyllomedusa hypochondrialis), and a highly aquatic frog (Rana utricularia). An extra-epidermal layer of lipid and mucus, presumably secreted from dermal granular glands, was detected on the skin of all Florida hylid frogs examined. Distinct body wiping behaviors were observed in the hylid frogs, but these were less complex than those described previously in phyllomedusine frogs, which occupy arid habitats, secrete lipids onto their skin, and are regarded as relatively 'waterproof'. Florida hylids occupy seasonally arid habitats and appear to have reduced rates of EWL. The suite of traits we observed in these frogs have been previously documented in a rhacophorid tree frog from seasonally arid regions of India and likely represent an evolutionary convergent response to periodic dehydration stress. The presence of lipids that are spread by simple wiping behaviors to form an extra-epidermal water barrier may represent an early stage of the more advanced adaptations described in more waterproof arboreal frogs.

Evolution and genome specialization of Brucella suis biovar 2 Iberian lineages.

PubMed

Ferreira, Ana Cristina; Tenreiro, Rogério; de Sá, Maria Inácia Corrêa; Dias, Ricardo

2017-09-12

Swine brucellosis caused by B. suis biovar 2 is an emergent disease in domestic pigs in Europe. The emergence of this pathogen has been linked to the increase of extensive pig farms and the high density of infected wild boars (Sus scrofa). In Portugal and Spain, the majority of strains share specific molecular characteristics, which allowed establishing an Iberian clonal lineage. However, several strains isolated from wild boars in the North-East region of Spain are similar to strains isolated in different Central European countries. Comparative analysis of five newly fully sequenced B. suis biovar 2 strains belonging to the main circulating clones in Iberian Peninsula, with publicly available Brucella spp. genomes, revealed that strains from Iberian clonal lineage share 74% similarity with those reference genomes. Besides the 210 kb translocation event present in all biovar 2 strains, an inversion with 944 kb was presented in chromosome I of strains from the Iberian clone. At left and right crossover points, the inversion disrupted a TRAP dicarboxylate transporter, DctM subunit, and an integral membrane protein TerC. The gene dctM is well conserved in Brucella spp. except in strains from the Iberian clonal lineage. Intraspecies comparative analysis also exposed a number of biovar-, haplotype- and strain-specific insertion-deletion (INDELs) events and single nucleotide polymorphisms (SNPs) that could explain differences in virulence and host specificities. Most discriminative mutations were associated to membrane related molecules (29%) and enzymes involved in catabolism processes (20%). Molecular identification of both B. suis biovar 2 clonal lineages could be easily achieved using the target-PCR procedures established in this work for the evaluated INDELs. Whole-genome analyses supports that the B. suis biovar 2 Iberian clonal lineage evolved from the Central-European lineage and suggests that the genomic specialization of this pathogen in the Iberian Peninsula

Nematode and ciliate nasal infection in captive archey's frogs (Leiopelma archeyi).

PubMed

Shaw, Stephanie; Speare, Richard; Lynn, Denis H; Yeates, Gregor; Zhao, Zeng; Berger, Lee; Jakob-Hoff, Richard

2011-09-01

Archey's frogs (Leiopelma archeyi) are first on the list of evolutionarily distinct and globally endangered (EDGE) amphibians. Captive breeding is an important strategy for protection of the species, but programs are hampered by a lack of information on diseases present in wild and captive populations. Two novel nematodes (Koerneria sp. and Rhabditis sp.) were found separately in four captive Archey's frogs showing clinical signs of hemorrhagic purulent nasal discharge and weight loss. One of these frogs also had a novel protozoal infection (Tetrahymena) in the nasal cavity. Koerneria, Rhabditis, and Tetrahymena have not previously been reported in amphibians in New Zealand. One frog was treated successfully with oral moxidectin at 0.4 mg/kg for the nematode infection and topical metronidazole at 10 mg/kg for the protozoal infection. The clinical signs abated only after both infections were cleared. The second frog died before treatment could be established. The third and fourth frogs were found dead.

Ant and Mite Diversity Drives Toxin Variation in the Little Devil Poison Frog.

PubMed

McGugan, Jenna R; Byrd, Gary D; Roland, Alexandre B; Caty, Stephanie N; Kabir, Nisha; Tapia, Elicio E; Trauger, Sunia A; Coloma, Luis A; O'Connell, Lauren A

2016-06-01

Poison frogs sequester chemical defenses from arthropod prey, although the details of how arthropod diversity contributes to variation in poison frog toxins remains unclear. We characterized skin alkaloid profiles in the Little Devil poison frog, Oophaga sylvatica (Dendrobatidae), across three populations in northwestern Ecuador. Using gas chromatography/mass spectrometry, we identified histrionicotoxins, 3,5- and 5,8-disubstituted indolizidines, decahydroquinolines, and lehmizidines as the primary alkaloid toxins in these O. sylvatica populations. Frog skin alkaloid composition varied along a geographical gradient following population distribution in a principal component analysis. We also characterized diversity in arthropods isolated from frog stomach contents and confirmed that O. sylvatica specialize on ants and mites. To test the hypothesis that poison frog toxin variability reflects species and chemical diversity in arthropod prey, we (1) used sequencing of cytochrome oxidase 1 to identify individual prey specimens, and (2) used liquid chromatography/mass spectrometry to chemically profile consumed ants and mites. We identified 45 ants and 9 mites in frog stomachs, including several undescribed species. We also showed that chemical profiles of consumed ants and mites cluster by frog population, suggesting different frog populations have access to chemically distinct prey. Finally, by comparing chemical profiles of frog skin and isolated prey items, we traced the arthropod source of four poison frog alkaloids, including 3,5- and 5,8-disubstituted indolizidines and a lehmizidine alkaloid. Together, the data show that toxin variability in O. sylvatica reflects chemical diversity in arthropod prey.

Cystic urolithiasis in captive waxy monkey frogs (Phyllomedusa sauvagii).

PubMed

Archibald, Kate E; Minter, Larry J; Dombrowski, Daniel S; O'Brien, Jodi L; Lewbart, Gregory A

2015-03-01

The waxy monkey frog (Phyllomedusa sauvagii) is an arboreal amphibian native to arid regions of South America, and it has developed behavioral and physiologic adaptations to permit survival in dry environments. These adaptations include a uricotelic nitrogen metabolism and unique cutaneous lipid excretions to prevent evaporative water loss. Uroliths are a rare finding in amphibians. Six adult, presumed wild-caught waxy monkey frogs housed in a museum animal collection were diagnosed with cystic urolithiasis over a 7-yr period, and a single animal was diagnosed with four recurrent cases. Six cases were identified incidentally at routine physical or postmortem examination and four cases were identified during veterinary evaluation for coelomic distension, lethargy, anorexia, and increased soaking behavior. Calculi were surgically removed from three frogs via cystotomy, and a single frog underwent three cystotomies and two cloacotomies for recurrent urolithiasis. Two frogs died within the 24-hr postoperative period. Two representative calculi from a single frog were submitted for component analysis and found to consist of 100% ammonium urate. In the present report, cystic calculi are proposed to be the result of a high-protein diet based on a single invertebrate source, coupled with uricotelism, dehydration, increased cutaneous water loss, body temperature fluctuations facilitating supersaturation of urine, and subsequent accumulation and precipitation of urogenous wastes within the urinary bladder. Surgical cystotomy represents a short-term treatment strategy for this condition. Preventative measures, such as supplying a diversified and balanced diet in addition to environmental manipulation aimed at promoting adequate hydration, are anticipated to be more-rewarding management tools for cystic urolithiasis in the waxy monkey frog.

Elastic modulus of tree frog adhesive toe pads.

PubMed

Barnes, W Jon P; Goodwyn, Pablo J Perez; Nokhbatolfoghahai, Mohsen; Gorb, Stanislav N

2011-10-01

Previous work using an atomic force microscope in nanoindenter mode indicated that the outer, 10- to 15-μm thick, keratinised layer of tree frog toe pads has a modulus of elasticity equivalent to silicone rubber (5-15 MPa) (Scholz et al. 2009), but gave no information on the physical properties of deeper structures. In this study, micro-indentation is used to measure the stiffness of whole toe pads of the tree frog, Litoria caerulea. We show here that tree frog toe pads are amongst the softest of biological structures (effective elastic modulus 4-25 kPa), and that they exhibit a gradient of stiffness, being stiffest on the outside. This stiffness gradient results from the presence of a dense network of capillaries lying beneath the pad epidermis, which probably has a shock absorbing function. Additionally, we compare the physical properties (elastic modulus, work of adhesion, pull-off force) of the toe pads of immature and adult frogs.

Frog: The fast & realistic OpenGL event displayer

NASA Astrophysics Data System (ADS)

Quertenmont, Loïc

2010-04-01

FROG [1] [2] is a generic framework dedicated to visualisation of events in high energy physics experiment. It is suitable to any particular physics experiment or detector design. The code is light (< 3 MB) and fast (browsing time ~ 20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OpenGL[3] and Glut [4] libraries. Moreover, Frog does not require installation of heavy third party libraries for the visualisation. This documents describes the features and principles of Frog version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally the application of FROG for physic experiment/environement, such as Gastof, CMS, ILD, Delphes will be presented for illustration.

First report of spontaneous chytridiomycosis in frogs in Asia.

PubMed

Une, Yumi; Kadekaru, Sho; Tamukai, Kenichi; Goka, Kouichi; Kuroki, Toshiro

2008-11-20

This is the first report of amphibian chytridiomycosis in Asia. We discovered a lethal outbreak in Japan, among 45 exotic frogs from 18 species kept for breeding by a private owner. Of these 45 frogs, 16 died and another 7 were found to be infected by chytrid fungus Batrachochytrium dendrobatidis (Bd) but survived after treatment. Bd was detected in frogs from 9 species (Lepidobatrachus laevis, Ceratophrys cornuta, C. cranwelli, C. ornata, C. calcarata, Chacophrys pierotti, Occidozyga lima, Leptodactylus pentadactylus and Plethodontohyla tuberata).

Panamanian frog species host unique skin bacterial communities

PubMed Central

Belden, Lisa K.; Hughey, Myra C.; Rebollar, Eria A.; Umile, Thomas P.; Loftus, Stephen C.; Burzynski, Elizabeth A.; Minbiole, Kevin P. C.; House, Leanna L.; Jensen, Roderick V.; Becker, Matthew H.; Walke, Jenifer B.; Medina, Daniel; Ibáñez, Roberto; Harris, Reid N.

2015-01-01

Vertebrates, including amphibians, host diverse symbiotic microbes that contribute to host disease resistance. Globally, and especially in montane tropical systems, many amphibian species are threatened by a chytrid fungus, Batrachochytrium dendrobatidis (Bd), that causes a lethal skin disease. Bd therefore may be a strong selective agent on the diversity and function of the microbial communities inhabiting amphibian skin. In Panamá, amphibian population declines and the spread of Bd have been tracked. In 2012, we completed a field survey in Panamá to examine frog skin microbiota in the context of Bd infection. We focused on three frog species and collected two skin swabs per frog from a total of 136 frogs across four sites that varied from west to east in the time since Bd arrival. One swab was used to assess bacterial community structure using 16S rRNA amplicon sequencing and to determine Bd infection status, and one was used to assess metabolite diversity, as the bacterial production of anti-fungal metabolites is an important disease resistance function. The skin microbiota of the three Panamanian frog species differed in OTU (operational taxonomic unit, ~bacterial species) community composition and metabolite profiles, although the pattern was less strong for the metabolites. Comparisons between frog skin bacterial communities from Panamá and the US suggest broad similarities at the phylum level, but key differences at lower taxonomic levels. In our field survey in Panamá, across all four sites, only 35 individuals (~26%) were Bd infected. There was no clustering of OTUs or metabolite profiles based on Bd infection status and no clear pattern of west-east changes in OTUs or metabolite profiles across the four sites. Overall, our field survey data suggest that different bacterial communities might be producing broadly similar sets of metabolites across frog hosts and sites. Community structure and function may not be as tightly coupled in these skin symbiont

Coleman Revisited: School Segregation, Peers, and Frog Ponds

ERIC Educational Resources Information Center

Goldsmith, Pat Rubio

2011-01-01

Students from minority segregated schools tend to achieve and attain less than similar students from White segregated schools. This study examines whether peer effects can explain this relationship using normative models and frog-pond models. Normative models (where peers become alike) suggest that minority schoolmates are a liability. Frog-pond…

COMPARATIVE TOXICITY OF DIURON ON SURVIVAL AND GROWTH OF PACIFIC TREEFROG, BULLFROG, RED-LEGGED FROG, AND AFRICAN CLAWED FROG EMBRYOS AND TADPOLES

EPA Science Inventory

The effects of the herbicide diuron on survival and growth of Pacific treefrog (Pseudacris regilla),bullfrog(Rana catesbeiana), red-legged frog(Rana aurora),and African clawed frog(Xenopus laevis)embryos and tadpoles were determined in static-renewal tests. P.regilla and X.laevis...

The response of Rana muscosa, the mountain yellow-legged frog, to short distance translocations.

Treesearch

K. R. Matthews

2003-01-01

ABSTRACT.—To determine the response of Mountain Yellow-Legged Frogs to short distance translocations, I placed transmitters on 20 adult frogs and moved them short distances from 144–630 m and monitored their responses for up to 30 days. Of the 20 translocated frogs, seven frogs returned to their original capture site, four frogs moved in the direction of their capture...

Tourism and the conservation of critically endangered frogs.

PubMed

Morrison, Clare; Simpkins, Clay; Castley, J Guy; Buckley, Ralf C

2012-01-01

Protected areas are critical for the conservation of many threatened species. Despite this, many protected areas are acutely underfunded, which reduces their effectiveness significantly. Tourism is one mechanism to promote and fund conservation in protected areas, but there are few studies analyzing its tangible conservation outcomes for threatened species. This study uses the 415 IUCN critically endangered frog species to evaluate the contribution of protected area tourism revenue to conservation. Contributions were calculated for each species as the proportion of geographic range inside protected areas multiplied by the proportion of protected area revenues derived from tourism. Geographic ranges were determined from IUCN Extent of Occurrence maps. Almost 60% (239) of critically endangered frog species occur in protected areas. Higher proportions of total range are protected in Nearctic, Australasian and Afrotopical regions. Tourism contributions to protected area budgets ranged from 5-100%. These financial contributions are highest for developing countries in the Afrotropical, Indomalayan and Neotropical regions. Data for both geographic range and budget are available for 201 critically endangered frog species with proportional contributions from tourism to species protection ranging from 0.8-99%. Tourism's financial contributions to critically endangered frog species protection are highest in the Afrotropical region. This study uses a coarse measure but at the global scale it demonstrates that tourism has significant potential to contribute to global frog conservation efforts.

Tourism and the Conservation of Critically Endangered Frogs

PubMed Central

Morrison, Clare; Simpkins, Clay; Castley, J. Guy; Buckley, Ralf C.

2012-01-01

Protected areas are critical for the conservation of many threatened species. Despite this, many protected areas are acutely underfunded, which reduces their effectiveness significantly. Tourism is one mechanism to promote and fund conservation in protected areas, but there are few studies analyzing its tangible conservation outcomes for threatened species. This study uses the 415 IUCN critically endangered frog species to evaluate the contribution of protected area tourism revenue to conservation. Contributions were calculated for each species as the proportion of geographic range inside protected areas multiplied by the proportion of protected area revenues derived from tourism. Geographic ranges were determined from IUCN Extent of Occurrence maps. Almost 60% (239) of critically endangered frog species occur in protected areas. Higher proportions of total range are protected in Nearctic, Australasian and Afrotopical regions. Tourism contributions to protected area budgets ranged from 5–100%. These financial contributions are highest for developing countries in the Afrotropical, Indomalayan and Neotropical regions. Data for both geographic range and budget are available for 201 critically endangered frog species with proportional contributions from tourism to species protection ranging from 0.8–99%. Tourism's financial contributions to critically endangered frog species protection are highest in the Afrotropical region. This study uses a coarse measure but at the global scale it demonstrates that tourism has significant potential to contribute to global frog conservation efforts. PMID:22984440

Welcome to Fermilab Frogs!

Science.gov Websites

continent except Antarctica! Endangered! In the Chicago region, volunteers have joined a nationwide effort to count frogs. The Chicago Wilderness organization enlists the help of volunteers to record the

Population estimates of Hyla cinerea (Schneider) (Green Tree frog) in an urban environment

USGS Publications Warehouse

Pham, L.; Boudreaux, S.; Karhbet, S.; Price, B.; Ackleh, A.S.; Carter, J.; Pal, N.

2007-01-01

Hyla cinerea (Green Treefrog) is a common wetlands species in the southeastern US. To better understand its population dynamics, we followed a relatively isolated population of Green Treefrogs from June 2004 through October 2004 at a federal office complex in Lafayette, LA. Weekly, Green Treefrogs were caught, measured, marked with VIE tags, and released. The data were used to estimate population size. The time frame was split into two periods: before and after August 17, 2004. Before August 17, 2004, the average estimated population size was 143, and after August 24, 2005, this value jumped to 446, an increase possibly due to tadpoles metamorphosing into adults.

Foothill yellow-legged frog conservation assessment in California

Treesearch

Marc P. Hayes; Clara A. Wheeler; Amy J. Lind; Gregory A. Green; Diane C. Macfarlane

2016-01-01

The foothill yellow-legged frog (Rana boylii) is a stream-breeding amphibian that has experienced significant population declines over a large portion of its historical range. This frog is nearing extirpation in much of the Sierra Nevada region where existing populations are sparse. Water development and diversions are likely to be the primary...

North Atlantic Oscillation influence on the stramflows of the Iberian Rivers

NASA Astrophysics Data System (ADS)

Lorenzo-Lacruz, J.; González-Hidalgo, J. C.; Vicente-Serrano, S. M.; López-Moreno, J. I.

2010-09-01

"NORTH ATLANTIC OSCILLATION INFLUENCE ON THE STREAMFLOWS OF THE IBERIAN RIVERS" LORENZO-LACRUZ, J. ¹, GONZÁLEZ-HIDALGO, J.C.², VICENTE-SERRANO, S.M. ¹, LÓPEZ-MORENO, J.I.¹ ¹Instituto Pirenaico de Ecología, CSIC (Spanish Research Council), Campus de Aula Dei, P.O. Box 202, Zaragoza 50080, Spain ²Departamento de Geografía, Universidad de Zaragoza, Zaragoza, Spain. We analyzed the North Atlantic Oscillation (NAO) influence on the monthly river discharges of Iberian rivers from 1945 to 2005. The study covers most of the Iberian river basins, using 187 monthly discharge series. The aim of this study is to determine the role of the variability of the NAO on the Iberian river discharges. Using the winter NAO we calculated correlations with the monthly river discharge series. We identified the positive and negative phases of the winter NAO for the period 1945-2006, and related to river discharge anomalies. Significant differences in river discharge were found between the positive and negative NAO phases with negative anomalies (dry conditions) during positive NAO periods, and positive anomalies (wet conditions) during negative NAO periods The results show a consistent and strong control of the river discharges by the winter NAO, but some spatial differences are shown, as three different domains were defined: a region under the direct influence of the NAO (central and western part of the Iberian Peninsula), a transition zone (Ebro Valley) and region free from that influence (Eastern part of the Iberian Peninsula). The spatial differences are also identified in the annual pattern of discharge anomalies. The basin characteristics, the location of the gauging stations and the human management are the possible drivers of these differences.

49 CFR 213.143 - Frog guard rails and guard faces; gage.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Frog guard rails and guard faces; gage. 213.143... and guard faces; gage. The guard check and guard face gages in frogs shall be within the limits... frog to the guard line 1 of its guard rail or guarding face, measured across the track at right angles...

49 CFR 213.143 - Frog guard rails and guard faces; gage.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Frog guard rails and guard faces; gage. 213.143... and guard faces; gage. The guard check and guard face gages in frogs shall be within the limits... frog to the guard line 1 of its guard rail or guarding face, measured across the track at right angles...

49 CFR 213.143 - Frog guard rails and guard faces; gage.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Frog guard rails and guard faces; gage. 213.143... and guard faces; gage. The guard check and guard face gages in frogs shall be within the limits... frog to the guard line 1 of its guard rail or guarding face, measured across the track at right angles...

49 CFR 213.143 - Frog guard rails and guard faces; gage.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Frog guard rails and guard faces; gage. 213.143... and guard faces; gage. The guard check and guard face gages in frogs shall be within the limits... frog to the guard line 1 of its guard rail or guarding face, measured across the track at right angles...

49 CFR 213.143 - Frog guard rails and guard faces; gage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Frog guard rails and guard faces; gage. 213.143... and guard faces; gage. The guard check and guard face gages in frogs shall be within the limits... frog to the guard line 1 of its guard rail or guarding face, measured across the track at right angles...

Isolation of Brucella inopinata-Like Bacteria from White's and Denny's Tree Frogs.

PubMed

Kimura, Masanobu; Une, Yumi; Suzuki, Michio; Park, Eun-Sil; Imaoka, Koichi; Morikawa, Shigeru

2017-05-01

Brucella inopinata strain BO1 and B. sp. strain BO2 isolated from human patients, respectively, are genetically different from classical Brucella species. We isolated bacteria of the genus Brucella from two species of wild-caught tropical frogs kept in the facilities in Japan: White's tree frog, which inhabits Oceania, and Denny's tree frog, which inhabits Southeast Asia. Phylogenetic analyses based on 16S rRNA and recA gene sequences and multilocus sequence analysis showed that two isolates of Brucella spp. showed significant similarity to BO1, BO2, and the isolates from other wild-caught frogs. These results suggest that a variety of frog species are susceptible to a novel clade of Brucella bacteria, including B. inopinata.

Hyperspectral analysis of columbia spotted frog habitat

USGS Publications Warehouse

Shive, J.P.; Pilliod, D.S.; Peterson, C.R.

2010-01-01

Wildlife managers increasingly are using remotely sensed imagery to improve habitat delineations and sampling strategies. Advances in remote sensing technology, such as hyperspectral imagery, provide more information than previously was available with multispectral sensors. We evaluated accuracy of high-resolution hyperspectral image classifications to identify wetlands and wetland habitat features important for Columbia spotted frogs (Rana luteiventris) and compared the results to multispectral image classification and United States Geological Survey topographic maps. The study area spanned 3 lake basins in the Salmon River Mountains, Idaho, USA. Hyperspectral data were collected with an airborne sensor on 30 June 2002 and on 8 July 2006. A 12-year comprehensive ground survey of the study area for Columbia spotted frog reproduction served as validation for image classifications. Hyperspectral image classification accuracy of wetlands was high, with a producer's accuracy of 96 (44 wetlands) correctly classified with the 2002 data and 89 (41 wetlands) correctly classified with the 2006 data. We applied habitat-based rules to delineate breeding habitat from other wetlands, and successfully predicted 74 (14 wetlands) of known breeding wetlands for the Columbia spotted frog. Emergent sedge microhabitat classification showed promise for directly predicting Columbia spotted frog egg mass locations within a wetland by correctly identifying 72 (23 of 32) of known locations. Our study indicates hyperspectral imagery can be an effective tool for mapping spotted frog breeding habitat in the selected mountain basins. We conclude that this technique has potential for improving site selection for inventory and monitoring programs conducted across similar wetland habitat and can be a useful tool for delineating wildlife habitats. ?? 2010 The Wildlife Society.

SIFT-MS analysis of Iberian hams from pigs reared under different conditions.

PubMed

Carrapiso, Ana I; Noseda, Bert; García, Carmen; Reina, Raquel; Sánchez Del Pulgar, José; Devlieghere, Frank

2015-06-01

The aim of this study was to investigate the usefulness of a Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS) equipment to tentatively quantify relevant volatile compounds of dry-cured Iberian ham, and to differentiate Iberian hams from pigs reared at four different conditions yielding different commercial grades. The SIFT-MS analysis allowed the rapid quantification of 39 Iberian ham volatile compounds, 16 of them being significantly affected by the rearing conditions of pigs. The full spectra SIFT-MS data allowed the correct classification of 79.2% of hams according to diet, which is a smaller percentage than that obtained using intramuscular fatty acid data (95.8%) obtained by using a gas chromatograph-flame ionization detector after lipid extraction and transesterification. Therefore, the SIFT-MS analysis would be a rapid tool to tentatively quantify some relevant volatile compounds, and also would provide a rapid but rough classification of Iberian ham according to the rearing conditions of pigs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Proposed method for evaluating the effects of PCBs in sediment on egg mass viability and reproductive success in frogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidt, C.S.; Henning, M.H.; Ebert, E.S.

1995-12-31

A proposed study design for evaluating the effect of PCBs in the sediments of a large New England river on reproductive success in frogs is described. Depending on field conditions and species abundance, the study will use either bullfrogs, Rana catesbiana; spring peepers, Hyla pickeringii; or green frogs, Rana claymitans as the study model. A selected number of gravid females will be collected from both the target area and a reference area matched with respect to a number of key variables including, but not limited to, stream flow, temperature, pH, substrate type, depth, surrounding land use, and organic carbon contentmore » of sediments. The gravid frogs will be transferred to a laboratory, where the egg masses will be stripped following induced ovulation, and then fertilized using semen from males collected in the field. Egg masses will be maintained under static renewal conditions for a period up to and including 7 days post hatch, during which mortality and gross morphological appearance will be evaluated. In the event that statistically significant differences in these endpoints are noted, a dose response model will be developed to relate observed effects to previously determined PCB concentrations in egg masses and maternal tissues. The results of this study will be of significant utility in evaluating reproductive toxicity of PCBs in ecological risk assessment.« less

Plasticity of peripheral auditory frequency sensitivity in Emei music frog.

PubMed

Zhang, Dian; Cui, Jianguo; Tang, Yezhong

2012-01-01

In anurans reproductive behavior is strongly seasonal. During the spring, frogs emerge from hibernation and males vocalize for mating or advertising territories. Female frogs have the ability to evaluate the quality of the males' resources on the basis of these vocalizations. Although studies revealed that central single torus semicircularis neurons in frogs exhibit season plasticity, the plasticity of peripheral auditory sensitivity in frog is unknown. In this study the seasonally plasticity of peripheral auditory sensitivity was test in the Emei music frog Babina daunchina, by comparing thresholds and latencies of auditory brainstem responses (ABRs) evoked by tone pips and clicks in the reproductive and non-reproductive seasons. The results show that both ABR thresholds and latency differ significantly between the reproductive and non-reproductive seasons. The thresholds of tone pip evoked ABRs in the non-reproductive season increased significantly about 10 dB than those in the reproductive season for frequencies from 1 KHz to 6 KHz. ABR latencies to waveform valley values for tone pips for the same frequencies using appropriate threshold stimulus levels are longer than those in the reproductive season for frequencies from 1.5 to 6 KHz range, although from 0.2 to 1.5 KHz range it is shorter in the non-reproductive season. These results demonstrated that peripheral auditory frequency sensitivity exhibits seasonal plasticity changes which may be adaptive to seasonal reproductive behavior in frogs.

49 CFR 236.327 - Switch, movable-point frog or split-point derail.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained so...

49 CFR 236.327 - Switch, movable-point frog or split-point derail.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained so...

49 CFR 236.327 - Switch, movable-point frog or split-point derail.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained so...

49 CFR 236.327 - Switch, movable-point frog or split-point derail.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained so...

49 CFR 236.327 - Switch, movable-point frog or split-point derail.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained so...

Clusters of Earthquakes In The Southern of Iberian Peninsula

NASA Astrophysics Data System (ADS)

Posadas, A. M.; Luzón, F.; Vidal, F.

The southern part of the Iberian Peninsula forms part of the western border of Eurasia- Africa plate boundary. This area is characterized by the occurrence of earthquakes of moderate magnitude (the maximum magnitude ranging from 4.5 to 5.5). From the point of view of seismic activity, this region is the most active one in he Iberian Penin- sula. Until earlier 80, only the National Seismic Network belonging to the National Geographic Institute monitores the activity in the south of Iberian Peninsula. From 1983 to the actuality, the Andalusian Seismic Network belonging to the Andalusian Geophysics Institute and Seismic Disaster Prevention, records the microseismicity of the area. Nowadays, the earthquakes catalogue used belongs to the Andalusian Insti- tute of Geophysics and Seismic Disaster Prevention and it counts on more than 20000 events registered from 1985 to 2001. Today, after 20 years of recording seismic ac- tivity, statistics analysis of the catalogue have sense. In this paper we present a first approach to the clustering properties of the seismicity in the south of the Iberian Penin- sula. The analysis carried out starts with the study of clustering properties (temporal and spatial properties) in the Southern of Iberian Peninsula seismicity to demonstrate, by using the Fractal Dimension of the temporal earthquake distribution and the Mor- ishita Index of the spatial distribution of earthquakes, that this seismicity is charac- terized by a tendency to form earthquake clusters, both spatial and temporal clusters. As an example, five seismogenetic areas of the zone are analyzed (Adra-Berja, Agron, Alboran, Antequera and Loja). This particular study of the series find out the b param- eter from the Gutenberg-Richter's Law (which characterizes the energetic relaxation of events), the p parameter from Omori's Law (that characterizes the temporal relax- ation of aftershocks) and the Fractal Dimension of the spatial distribution of earth- quakes (to find the

Poison frog colors are honest signals of toxicity, particularly for bird predators.

PubMed

Maan, Martine E; Cummings, Molly E

2012-01-01

Antipredator defenses and warning signals typically evolve in concert. However, the extensive variation across taxa in both these components of predator deterrence and the relationship between them are poorly understood. Here we test whether there is a predictive relationship between visual conspicuousness and toxicity levels across 10 populations of the color-polymorphic strawberry poison frog, Dendrobates pumilio. Using a mouse-based toxicity assay, we find extreme variation in toxicity between frog populations. This variation is significantly positively correlated with frog coloration brightness, a viewer-independent measure of visual conspicuousness (i.e., total reflectance flux). We also examine conspicuousness from the view of three potential predator taxa, as well as conspecific frogs, using taxon-specific visual detection models and three natural background substrates. We find very strong positive relationships between frog toxicity and conspicuousness for bird-specific perceptual models. Weaker but still positive correlations are found for crab and D. pumilio conspecific visual perception, while frog coloration as viewed by snakes is not related to toxicity. These results suggest that poison frog colors can be honest signals of prey unpalatability to predators and that birds in particular may exert selection on aposematic signal design. © 2011 by The University of Chicago.

Frog species richness, composition and beta-diversity in coastal Brazilian restinga habitats.

PubMed

Rocha, C F D; Hatano, F H; Vrcibradic, D; Van Sluys, M

2008-02-01

We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation) along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí), Espírito Santo (Praia das Neves and Setiba) and Bahia (Prado and Trancoso). We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species), followed by Grussaí and Trancoso (eight species in each). The commonest species in the restingas was Scinax alter (found in eight restingas), followed by Aparasphenodon brunoi (seven areas). Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances) seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13 degrees; p = 0.007). Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical

Diptera of forensic importance in the Iberian Peninsula: larval identification key.

PubMed

Velásquez, Y; Magaña, C; Martínez-Sánchez, A; Rojo, S

2010-09-01

A revision of the species and families of sarcosaprophagous flies (Diptera: Calliphoridae, Sarcophagidae, Muscidae, Fanniidae, Drosophilidae, Phoridae, Piophilidae and Stratiomyidae) suitable for forensic purposes in the Iberian Peninsula is presented. Morphological characteristics that allow the accurate identification of third instars of the species present in the Iberian Peninsula are described and presented in the form of a diagnostic key. For larval Calliphoridae, characteristics such as the spines of the body segments were useful for the genus Calliphora whereas features of the anal segment and the cephalopharyngeal skeleton were useful for larvae of Lucilia. Identification of three Chrysominae species present in the Iberian Peninsula is included. For larval Sarcophagidae, characters such as the arrangement and shape of spiracular openings, structures of the anal segment and the cephalopharyngeal skeleton were used for the first time. A new record of Sarcophaga cultellata Pandellé, from a human corpse, is also included as well as recent incursions into the European cadaveric entomofauna such as Synthesiomyia nudiseta (van der Wulp) and Hermetia illucens (Linnaeus). This work provides useful new information that could be applied to forensic investigations in the Iberian Peninsula and in southern Europe.

Predation by Oregon spotted frogs (Rana pretiosa) on Western toads (Bufo boreas) in Oregon, USA

USGS Publications Warehouse

Pearl, Christopher A.; Hayes, M.P.

2002-01-01

Toads of the genus Bufo co-occur with true frogs (family Ranidae) throughout their North American ranges. Yet, Bufo are rarely reported as prey for ranid frogs, perhaps due to dermal toxins that afford them protection from some predators. We report field observations from four different localities demonstrating that Oregon spotted frogs (Rana pretiosa) readily consume juvenile western toads (Bufo boreas) at breeding sites in Oregon. Unpalatability thought to deter predators of selected taxa and feeding mode may not protect juvenile stages of western toads from adult Oregon spotted frogs. Activity of juvenile western toads can elicit ambush behavior by Oregon spotted frog adults. Our review of published literature suggests that regular consumption of toadlets sets Oregon spotted frogs apart from most North American ranid frogs. Importance of the trophic context of juvenile western toads as a seasonally important resource to Oregon spotted frogs needs critical investigation.

Unfertilized frog eggs die by apoptosis following meiotic exit

PubMed Central

2011-01-01

Background A characteristic feature of frog reproduction is external fertilization accomplished outside the female's body. Mature fertilization-competent frog eggs are arrested at the meiotic metaphase II with high activity of the key meiotic regulators, maturation promoting factor (MPF) and cytostatic factor (CSF), awaiting fertilization. If the eggs are not fertilized within several hours of ovulation, they deteriorate and ultimately die by as yet unknown mechanism. Results Here, we report that the vast majority of naturally laid unfertilized eggs of the African clawed frog Xenopus laevis spontaneously exit metaphase arrest under various environmental conditions and degrade by a well-defined apoptotic process within 48 hours after ovulation. The main features of this process include cytochrome c release, caspase activation, ATP depletion, increase of ADP/ATP ratio, apoptotic nuclear morphology, progressive intracellular acidification, and egg swelling. Meiotic exit seems to be a prerequisite for execution of the apoptotic program, since (i) it precedes apoptosis, (ii) apoptotic events cannot be observed in the eggs maintaining high activity of MPF and CSF, and (iii) apoptosis in unfertilized frog eggs is accelerated upon early meiotic exit. The apoptotic features cannot be observed in the immature prophase-arrested oocytes, however, the maturation-inducing hormone progesterone renders oocytes susceptible to apoptosis. Conclusions The study reveals that naturally laid intact frog eggs die by apoptosis if they are not fertilized. A maternal apoptotic program is evoked in frog oocytes upon maturation and executed after meiotic exit in unfertilized eggs. The meiotic exit is required for execution of the apoptotic program in eggs. The emerging anti-apoptotic role of meiotic metaphase arrest needs further investigation. PMID:22195698

Clinical signs, pathology and dose-dependent survival of adult wood frogs, Rana sylvatica, inoculated orally with frog virus 3 Ranavirus sp., Iridoviridae.

PubMed

Forzn, Mara J; Jones, Kathleen M; Vanderstichel, Raphal V; Wood, John; Kibenge, Frederick S B; Kuiken, Thijs; Wirth, Wytamma; Ariel, Ellen; Daoust, Pierre-Yves

2015-05-01

Amphibian populations suffer massive mortalities from infection with frog virus 3 FV3, genus Ranavirus, family Iridoviridae, a pathogen also involved in mortalities of fish and reptiles. Experimental oral infection with FV3 in captive-raised adult wood frogs, Rana sylvatica Lithobates sylvaticus, was performed as the first step in establishing a native North American animal model of ranaviral disease to study pathogenesis and host response. Oral dosing was successful LD50 was 10(2.93 2.423.44) p.f.u. for frogs averaging 35mm in length. Onset of clinical signs occurred 614days post-infection p.i. median 11 days p.i. and time to death was 1014 days p.i. median 12 days p.i.. Each tenfold increase in virus dose increased the odds of dying by 23-fold and accelerated onset of clinical signs and death by approximately 15. Ranavirus DNA was demonstrated in skin and liver of all frogs that died or were euthanized because of severe clinical signs. Shedding of virus occurred in faeces 710 days p.i. 34.5days before death and skin sheds 10 days p.i. 01.5days before death of some frogs dead from infection. Most common lesions were dermal erosion and haemorrhages haematopoietic necrosis in bone marrow, kidney, spleen and liver and necrosis in renal glomeruli, tongue, gastrointestinal tract and urinary bladder mucosa. Presence of ranavirus in lesions was confirmed by immunohistochemistry. Intracytoplasmic inclusion bodies probably viral were present in the bone marrow and the epithelia of the oral cavity, gastrointestinal tract, renal tubules and urinary bladder. Our work describes a ranaviruswood frog model and provides estimates that can be incorporated into ranavirus disease ecology models. © 2015 The Authors.

Take time to smell the frogs: vocal sac glands of reed frogs (Anura: Hyperoliidae) contain species-specific chemical cocktails

PubMed Central

Starnberger, Iris; Poth, Dennis; Peram, Pardha Saradhi; Schulz, Stefan; Vences, Miguel; Knudsen, Jette; Barej, Michael F; Rödel, Mark-Oliver; Walzl, Manfred; Hödl, Walter

2013-01-01

Males of all reed frog species (Anura: Hyperoliidae) have a prominent, often colourful, gular patch on their vocal sac, which is particularly conspicuous once the vocal sac is inflated. Although the presence, shape, and form of the gular patch are well-known diagnostic characters for these frogs, its function remains unknown. By integrating biochemical and histological methods, we found strong evidence that the gular patch is a gland producing volatile compounds, which might be emitted while calling. Volatile compounds were confirmed by gas chromatography–mass spectrometry in the gular glands in 11 species of the hyperoliid genera Afrixalus, Heterixalus, Hyperolius, and Phlyctimantis. Comparing the gular gland contents of 17 specimens of four sympatric Hyperolius species yielded a large variety of 65 compounds in species-specific combinations. We suggest that reed frogs might use a complex combination of at least acoustic and chemical signals in species recognition and mate choice. PMID:24277973

A Suspected Parasite Spill-Back of Two Novel Myxidium spp. (Myxosporea) Causing Disease in Australian Endemic Frogs Found in the Invasive Cane Toad

PubMed Central

Hartigan, Ashlie; Fiala, Ivan; Dyková, Iva; Jirků, Miloslav; Okimoto, Ben; Rose, Karrie; Phalen, David N.; Šlapeta, Jan

2011-01-01

Infectious diseases are contributing to the decline of endangered amphibians. We identified myxosporean parasites, Myxidium spp. (Myxosporea: Myxozoa), in the brain and liver of declining native frogs, the Green and Golden Bell frog (Litoria aurea) and the Southern Bell frog (Litoria raniformis). We unequivocally identified two Myxidium spp. (both generalist) affecting Australian native frogs and the invasive Cane toad (Bufo marinus, syn. Rhinella marina) and demonstrated their association with disease. Our study tested the identity of Myxidium spp. within native frogs and the invasive Cane toad (brought to Australia in 1935, via Hawaii) to resolve the question whether the Cane toad introduced them to Australia. We showed that the Australian brain and liver Myxidium spp. differed 9%, 7%, 34% and 37% at the small subunit rDNA, large subunit rDNA, internal transcribed spacers 1 and 2, but were distinct from Myxidium cf. immersum from Cane toads in Brazil. Plotting minimum within-group distance against maximum intra-group distance confirmed their independent evolutionary trajectory. Transmission electron microscopy revealed that the brain stages localize inside axons. Myxospores were morphologically indistinguishable, therefore genetic characterisation was necessary to recognise these cryptic species. It is unlikely that the Cane toad brought the myxosporean parasites to Australia, because the parasites were not found in 261 Hawaiian Cane toads. Instead, these data support the enemy-release hypothesis predicting that not all parasites are translocated with their hosts and suggest that the Cane toad may have played an important spill-back role in their emergence and facilitated their dissemination. This work emphasizes the importance of accurate species identification of pathogens relevant to wildlife management and disease control. In our case it is paving the road for the spill-back role of the Cane toad and the parasite emergence. PMID:21541340

Modeling potential river management conflicts between frogs and salmonids

Treesearch

Steven F. Railsback; Bret C. Harvey; Sarah J. Kupferberg; Margaret M. Lang; Scott McBain; Hart H. Welsh

2016-01-01

Management of regulated rivers for yellow-legged frogs (Rana boylii) and salmonids exemplifies potential conflicts among species adapted to different parts of the natural flow and temperature regimes. Yellow-legged frogs oviposit in rivers in spring and depend on declining flows and warming temperatures for egg and tadpole survival and growth,...

Frog sound identification using extended k-nearest neighbor classifier

NASA Astrophysics Data System (ADS)

Mukahar, Nordiana; Affendi Rosdi, Bakhtiar; Athiar Ramli, Dzati; Jaafar, Haryati

2017-09-01

Frog sound identification based on the vocalization becomes important for biological research and environmental monitoring. As a result, different types of feature extractions and classifiers have been employed to evaluate the accuracy of frog sound identification. This paper presents a frog sound identification with Extended k-Nearest Neighbor (EKNN) classifier. The EKNN classifier integrates the nearest neighbors and mutual sharing of neighborhood concepts, with the aims of improving the classification performance. It makes a prediction based on who are the nearest neighbors of the testing sample and who consider the testing sample as their nearest neighbors. In order to evaluate the classification performance in frog sound identification, the EKNN classifier is compared with competing classifier, k -Nearest Neighbor (KNN), Fuzzy k -Nearest Neighbor (FKNN) k - General Nearest Neighbor (KGNN)and Mutual k -Nearest Neighbor (MKNN) on the recorded sounds of 15 frog species obtained in Malaysia forest. The recorded sounds have been segmented using Short Time Energy and Short Time Average Zero Crossing Rate (STE+STAZCR), sinusoidal modeling (SM), manual and the combination of Energy (E) and Zero Crossing Rate (ZCR) (E+ZCR) while the features are extracted by Mel Frequency Cepstrum Coefficient (MFCC). The experimental results have shown that the EKNCN classifier exhibits the best performance in terms of accuracy compared to the competing classifiers, KNN, FKNN, GKNN and MKNN for all cases.

The recent (upper Miocene to Quaternary) and present tectonic stress distributions in the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Herraiz, M.; de Vicente, G.; Lindo-Ñaupari, R.; Giner, J.; Simón, J. L.; GonzáLez-Casado, J. M.; Vadillo, O.; RodríGuez-Pascua, M. A.; CicuéNdez, J. I.; Casas, A.; CabañAs, L.; Rincón, P.; CortéS, A. L.; RamíRez, M.; Lucini, M.

2000-08-01

A general synthesis of the recent and present stress situation and evolution in the Iberian Peninsula was obtained from microstructural and seismological analysis. The stress evolution was deduced from (1) fault population analysis (FPA) from 409 sites distributed throughout the Iberian Peninsula, (2) paleostress indicators given by 324 stations taken from the bibliography, and (3) seismic data corresponding to 161 focal mechanisms evenly spread in the studied region. The application of FPA together with the determination of stress tensors and focal mechanisms for the whole Iberian microplate has provided two main results: (1) the Iberian Peninsula is undergoing a NW-SE oriented compression, except for the northeastern part (Pyrenees, Ebro Basin, and Iberian Chain), where it is N-S to NE-SW, and the Gulf of Cádiz, where it seems to be E-W, and (2) the main trends of the stress field have remained almost constant since the upper Miocene. The analysis performed by zones suggests the presence of local heterogeneities in the stress field.

Parasites of the mink frog (rana septentrionalis) from Minnesota, U.S.A.

USGS Publications Warehouse

Schotthoefer, Anna M.; Bolek, M.G.; Cole, Rebecca A.; Beasley, Val R.

2009-01-01

Twenty-two mink frogs, Rana septentrionalis, collected from two locations in Minnesota, United States, were examined for helminth and protozoan blood parasites in July 1999. A total of 16 parasite taxa were recovered including 5 larval digenean trematodes, 7 adult digenean trematodes, 3 nematodes, and I Trypanosorna species. Infracommunities were dominated by the digeneans in terms of richness and abundance. In particular, echinostomatid metacercariae in the kidneys of frogs were the most common parasites found, infecting 100% of the frogs and consisting of about 90% of all helminth individuals recovered. Gorgodera amplicava, Gorgoderina multilohata, Haernaroloechus pan'iplexus, Haernatoloechus breviplexus, Cosnwcercoides dukae, and Oswaldocruzia pipiens represent new host records. The survey presented here represents the second known helminth survey of mink frogs conducted in North America. A summary of metazoan parasites reported from mink frogs is included.

Surveys for presence of Oregon spotted frog (Rana pretiosa): background information and field methods

USGS Publications Warehouse

Pearl, Christopher A.; Clayton, David; Turner, Lauri

2010-01-01

The Oregon spotted frog (Rana pretiosa) is the most aquatic of the native frogs in the Pacific Northwest. The common name derives from the pattern of black, ragged-edged spots set against a brown or red ground color on the dorsum of adult frogs. Oregon spotted frogs are generally associated with wetland complexes that have several aquatic habitat types and sizeable coverage of emergent vegetation. Like other ranid frogs native to the Northwest, Oregon spotted frogs breed in spring, larvae transform in summer of their breeding year, and adults tend to be relatively short lived (3-5 yrs). Each life stage (egg, tadpole, juvenile and adult) has characteristics that present challenges for detection. Breeding can be explosive and completed within 1-2 weeks. Egg masses are laid in aggregations, often in a few locations in large areas of potential habitat. Egg masses can develop, hatch, and disintegrate in <2 weeks during warm weather. Tadpoles can be difficult to identify, have low survival, and spend most of their 3-4 months hidden in vegetation or flocculant substrates. Juveniles and adults are often difficult to capture and can spend summers away from breeding areas. Moreover, a substantial portion of extant populations are of limited size (<100 breeding adults), and field densities of all life stages are often low. An understanding of the biology of the species and use of multiple visits are thus important for assessing presence of Oregon spotted frogs. This report is meant to be a resource for USDA Region 6 Forest Service (FS) and OR/WA Bureau of Land Management (BLM) personnel tasked with surveying for the presence of Oregon spotted frogs. Our objective was to summarize information to improve the efficiency of field surveys and increase chances of detection if frogs are present. We include overviews of historical and extant ranges of Oregon spotted frog. We briefly summarize what is known of Oregon spotted frog habitat associations and review aspects of behavior and

Prehistoric contacts over the Straits of Gibraltar indicated by genetic analysis of Iberian Bronze Age cattle

PubMed Central

Anderung, Cecilia; Bouwman, Abigail; Persson, Per; Carretero, José Miguel; Ortega, Ana Isabel; Elburg, Rengert; Smith, Colin; Arsuaga, Juan Luis; Ellegren, Hans; Götherström, Anders

2005-01-01

The geographic situation of the Iberian Peninsula makes it a natural link between Europe and North Africa. However, it is a matter of debate to what extent African influences via the Straits Gibraltar have affected Iberia's prehistoric development. Because early African pastoralist communities were dedicated to cattle breeding, a possible means to detect prehistoric African–Iberian contacts might be to analyze the origin of cattle breeds on the Iberian Peninsula. Some contemporary Iberian cattle breeds show a mtDNA haplotype, T1, that is characteristic to African breeds, generally explained as being the result of the Muslim expansion of the 8th century A.D., and of modern imports. To test a possible earlier African influence, we analyzed mtDNA of Bronze Age cattle from the Portalón cave at the Atapuerca site in northern Spain. Although the majority of samples showed the haplotype T3 that dominates among European breeds of today, the T1 haplotype was found in one specimen radiocarbon dated 1800 calibrated years B.C. Accepting T1 as being of African origin, this result indicates prehistoric African–Iberian contacts and lends support to archaeological finds linking early African and Iberian cultures. We also found a wild ox haplotype in the Iberian Bronze Age sample, reflecting local hybridization or backcrossing or that aurochs were hunted by these farming cultures. PMID:15941827

Test development and use in five Iberian Latin American countries.

PubMed

Wechsler, Solange M; Oakland, Thomas; León, Carmem; Vivas, Eleonora; de Almeida, Leandro; Franco, Amanda; Pérez-Solís, María; Contini, Norma

2014-08-01

The abundance of scholarship on test development and use generally is higher in English-speaking than in Iberian Latin American countries. The purpose of this article is to help overcome this imbalance by describing and identifying similarities and differences in test development and use in two Iberian (Portugal and Spain) and three of the largest Latin American (Argentina, Brazil, and Venezuela) countries. The stages of test development in each country, roles of professional associations, presence of standards for test use, professionals' educational training, commonly used tests, together with prominent challenges to continued progress are discussed. Test development and use in these five countries are transitioning from a dependence on the use of translated tests to greater reliance on adapted and finally nationally constructed tests. Continued growth requires adherence to international standards guiding test development and use. Stronger alliance among professional associations in the Iberian Latin American countries could serve as a catalyst to promote test development in these regions. © 2014 International Union of Psychological Science.

Assessment of radiocesium contamination in frogs 18 months after the Fukushima Daiichi nuclear disaster

PubMed Central

Matsushima, Noe; Ihara, Sadao; Takase, Minoru; Horiguchi, Toshihiro

2015-01-01

We investigated the accumulation of radionuclides in frogs inhabiting radioactively contaminated areas around Fukushima Daiichi Nuclear Power Plant (FDNPP) to search for possible adverse effects due to radionuclides. We collected 5 frog species and soil samples in areas within and outside a 20-km radius from FDNPP in August and September 2012 and determined their radiocesium concentrations (134Cs and 137Cs). There was a positive correlation between radiocesium concentrations in the soil samples and frogs, and the highest concentration in frogs was 47,278.53 Bq/kg-wet. Although we conducted a histological examination of frog ovaries and testes by light microscopy to detect possible effects of radionuclides on the morphology of germ cells, there were no clear abnormalities in the gonadal tissues of frogs collected from sites with different contamination levels. PMID:25857262

Assessment of radiocesium contamination in frogs 18 months after the Fukushima Daiichi nuclear disaster

NASA Astrophysics Data System (ADS)

Matsushima, Noe; Ihara, Sadao; Takase, Minoru; Horiguchi, Toshihiro

2015-04-01

We investigated the accumulation of radionuclides in frogs inhabiting radioactively contaminated areas around Fukushima Daiichi Nuclear Power Plant (FDNPP) to search for possible adverse effects due to radionuclides. We collected 5 frog species and soil samples in areas within and outside a 20-km radius from FDNPP in August and September 2012 and determined their radiocesium concentrations (134Cs and 137Cs). There was a positive correlation between radiocesium concentrations in the soil samples and frogs, and the highest concentration in frogs was 47,278.53 Bq/kg-wet. Although we conducted a histological examination of frog ovaries and testes by light microscopy to detect possible effects of radionuclides on the morphology of germ cells, there were no clear abnormalities in the gonadal tissues of frogs collected from sites with different contamination levels.

Assessment of radiocesium contamination in frogs 18 months after the Fukushima Daiichi nuclear disaster.

PubMed

Matsushima, Noe; Ihara, Sadao; Takase, Minoru; Horiguchi, Toshihiro

2015-04-10

We investigated the accumulation of radionuclides in frogs inhabiting radioactively contaminated areas around Fukushima Daiichi Nuclear Power Plant (FDNPP) to search for possible adverse effects due to radionuclides. We collected 5 frog species and soil samples in areas within and outside a 20-km radius from FDNPP in August and September 2012 and determined their radiocesium concentrations ((134)Cs and (137)Cs). There was a positive correlation between radiocesium concentrations in the soil samples and frogs, and the highest concentration in frogs was 47,278.53 Bq/kg-wet. Although we conducted a histological examination of frog ovaries and testes by light microscopy to detect possible effects of radionuclides on the morphology of germ cells, there were no clear abnormalities in the gonadal tissues of frogs collected from sites with different contamination levels.

Habitat use and spatial structure of a barking frog (Eleutherodactylus augusti) population in southeastern Arizona

USGS Publications Warehouse

Goldberg, C.S.; Schwalbe, C.R.

2004-01-01

Barking Frogs (Eleutherodactylus augusti) are the northernmost ranging member of the large tropical family Leptodactylidae. We investigated the ecology of this saxicolous species at the northern edge of its range in a canyon in southern Arizona. We captured 54 frogs on discontinuous rock outcrops; eight of nine females and 39 of 45 males were on limestone outcrops. The remaining frogs were closer to limestone outcrops by more than 200 m than would be expected if they were distributed randomly with respect to limestone formations. Seven of 10 frogs radio-tracked had core home ranges (50% fixed kernel) from 94 to 100% on limestone; the other three frogs did not have any part of their home range on limestone outcrops. During five years of mark-recapture efforts, no frogs were found on a different outcrop from the one where they were originally captured; no radio-tracked frogs moved between outcrops during the breeding season. We estimated that four to 20 Barking Frogs occupied each outcrop; these groups probably are connected primarily by juvenile dispersal. As an organism living at the edge of its range, Barking Frogs in Arizona may rely heavily on extensive underground areas such as those found in limestone to protect them from a physiologically challenging environment. To manage for the persistence of Barking Frogs in southern Arizona, we must identify and protect habitat patches and movement pathways among them.

Antimicrobial peptides from frog skin: biodiversity and therapeutic promises.

PubMed

Ladram, Ali; Nicolas, Pierre

2016-06-01

More than a thousand antimicrobial peptides (AMPs) have been reported in the last decades arising from the skin secretion of amphibian species. Generally, each frog species can express its own repertoire of AMPs (typically, 10-20 peptides) with differing sequences, sizes, and spectrum of action, which implies very rapid divergence, even between closely related species. Frog skin AMPs are highly potent against antibiotic-resistant bacteria, protozoa, yeasts, and fungi by permeating and destroying their plasma membrane and/or inactivating intracellular targets. These peptides have attracted considerable interest as a therapeutic alternative to conventional anti-infective agents. However, efforts to obtain a new generation of drugs using these peptides are still challenging because of high associated R&D costs due to their large size (up to 46 residues) and cytotoxicity. This review deals with the biodiversity of frog skin AMPs and assesses the therapeutic possibilities of temporins, the shortest AMPs found in the frog skin, with 8-17 residues. Such short sequences are easily amenable to optimization of the structure and to solution-phase synthesis that offer reduced costs over solid-phase chemistry.

Propulsive efficiency of frog swimming with different feet and swimming patterns

PubMed Central

Jizhuang, Fan; Wei, Zhang; Bowen, Yuan; Gangfeng, Liu

2017-01-01

ABSTRACT Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11%) between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58%) fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency. PMID:28302669

ELECTRIC IMPEDANCE OF THE FROG EGG

PubMed Central

Cole, Kenneth S.; Guttman, Rita M.

1942-01-01

Electrical impedance measurements were made upon unfertilized and fertilized eggs of the leopard frog, Rana pipiens, over a frequency range of 0.05 to 10 kc. Average values of 170 ohm cm.2 were obtained for the plasma membrane resistance of the egg, 2.0 µf/cm.2 for the plasma membrane capacity, 86° for the phase angle of the membrane, and 570 ohm cm. for the specific resistance of the interior. These values did not change upon fertilization. No spontaneous rhythmical impedance changes such as have been found by Hubbard and Rothschild in the trout egg were found in frog eggs. PMID:19873312

Dynamics of testis-ova in a wild population of Japanese pond frogs, Rana nigromaculata.

PubMed

Kobayashi, Tohru; Kumakura, Masahiko; Yoshie, Sumio; Sugishima, Tomomi; Horie, Yoshifumi

2015-02-01

Although many studies have reported the occurrence of testis-ova in wild frog populations, the origin and trigger of testis-ova differentiation/development remain unclear. A high frequency of testis-ova has been previously reported for wild populations of the Japanese pond frog, Rana nigromaculata (cf. Iwasawa and Asai, '59). In the present study, we aimed to clarify the dynamics of testis-ova in this frog species, including the origin and artificial induction of testis-ova. Testis-ova were observed in both mature frogs and puberty-stage frogs (i.e., 0- and 1-year-old frogs). However, the early stages of testis-ova (~pachytene stage) were mostly observed in puberty-stage male frogs at the onset of spermatogenesis. The early stages of testis-ova were observed in the cysts of early secondary spermatogonia and the single cysts of the primary spermatogonium. This finding indicates that testis-ova differentiation occurs during spermatogonial proliferation and that it is correlated with the initiation of spermatogenesis. We also examined whether estrogen exposure induced testis-ova differentiation and how it is correlated with the progression of spermatogenesis. When 1-year-old frogs were exposed to estradiol-17β during spring (i.e., when spermatogenesis was initiated), testis-ova differentiation was induced in a dose-dependent manner. However, this phenomenon did not occur in 1-year-old frogs during summer, (i.e., when the transition from spermatogonia to spermatocytes mainly occurs). These results present the first evidence that testis-ova of the Japanese pond frog are derived from primary and early secondary spermatogonia, and that estrogen exposure induces testis-ova differentiation accompanied by the initiation of spermatogenesis. © 2015 Wiley Periodicals, Inc.

Marsh frogs, Pelophylax ridibundus, determine migratory direction by magnetic field.

PubMed

Shakhparonov, Vladimir V; Ogurtsov, Sergei V

2017-01-01

Orientation by magnetic cues appears to be adaptive during animal migrations. Whereas the magnetic orientation in birds, mammals, and urodele amphibians is being investigated intensively, the data about anurans are still scarce. This study tests whether marsh frogs could determine migratory direction between the breeding pond and the wintering site by magnetic cues in the laboratory. Adult frogs (N = 32) were individually tested in the T-maze 127 cm long inside the three-axis Helmholtz coil system (diameter 3 m). The arms of the maze were positioned parallel to the natural migratory route of this population when measured in accordance with magnetic field. The frogs were tested under two-motivational conditions mediated by temperature/light regime: the breeding migratory state and the wintering state. The frogs' choice in a T-maze was evident only when analyzed in accordance with the direction of the magnetic field: they moved along the migratory route to the breeding pond and followed the reversion of the horizontal component of the magnetic field. This preference has been detected in both sexes only in the breeding migratory state. This suggests that adult ranid frogs can obtain directional information from the Earth's magnetic field as was shown earlier in urodeles and anuran larvae.

Stable isotope analyses-A method to distinguish intensively farmed from wild frogs.

PubMed

Dittrich, Carolin; Struck, Ulrich; Rödel, Mark-Oliver

2017-04-01

Consumption of frog legs is increasing worldwide, with potentially dramatic effects for ecosystems. More and more functioning frog farms are reported to exist. However, due to the lack of reliable methods to distinguish farmed from wild-caught individuals, the origin of frogs in the international trade is often uncertain. Here, we present a new methodological approach to this problem. We investigated the isotopic composition of legally traded frog legs from suppliers in Vietnam and Indonesia. Muscle and bone tissue samples were examined for δ 15 N, δ 13 C, and δ 18 O stable isotope compositions, to elucidate the conditions under which the frogs grew up. We used DNA barcoding (16S rRNA) to verify species identities. We identified three traded species ( Hoplobatrachus rugulosus, Fejervarya cancrivora and Limnonectes macrodon ); species identities were partly deviating from package labeling. Isotopic values of δ 15 N and δ 18 O showed significant differences between species and country of origin. Based on low δ 15 N composition and generally little variation in stable isotope values, our results imply that frogs from Vietnam were indeed farmed. In contrast, the frogs from the Indonesian supplier likely grew up under natural conditions, indicated by higher δ 15 N values and stronger variability in the stable isotope composition. Our results indicate that stable isotope analyses seem to be a useful tool to distinguish between naturally growing and intensively farmed frogs. We believe that this method can be used to improve the control in the international trade of frog legs, as well as for other biological products, thus supporting farming activities and decreasing pressure on wild populations. However, we examined different species from different countries and had no access to samples of individuals with confirmed origin and living conditions. Therefore, we suggest improving this method further with individuals of known origin and history, preferably including

Introducing the Forensic Research/Reference on Genetics knowledge base, FROG-kb.

PubMed

Rajeevan, Haseena; Soundararajan, Usha; Pakstis, Andrew J; Kidd, Kenneth K

2012-09-01

Online tools and databases based on multi-allelic short tandem repeat polymorphisms (STRPs) are actively used in forensic teaching, research, and investigations. The Fst value of each CODIS marker tends to be low across the populations of the world and most populations typically have all the common STRP alleles present diminishing the ability of these systems to discriminate ethnicity. Recently, considerable research is being conducted on single nucleotide polymorphisms (SNPs) to be considered for human identification and description. However, online tools and databases that can be used for forensic research and investigation are limited. The back end DBMS (Database Management System) for FROG-kb is Oracle version 10. The front end is implemented with specific code using technologies such as Java, Java Servlet, JSP, JQuery, and GoogleCharts. We present an open access web application, FROG-kb (Forensic Research/Reference on Genetics-knowledge base, http://frog.med.yale.edu), that is useful for teaching and research relevant to forensics and can serve as a tool facilitating forensic practice. The underlying data for FROG-kb are provided by the already extensively used and referenced ALlele FREquency Database, ALFRED (http://alfred.med.yale.edu). In addition to displaying data in an organized manner, computational tools that use the underlying allele frequencies with user-provided data are implemented in FROG-kb. These tools are organized by the different published SNP/marker panels available. This web tool currently has implemented general functions possible for two types of SNP panels, individual identification and ancestry inference, and a prediction function specific to a phenotype informative panel for eye color. The current online version of FROG-kb already provides new and useful functionality. We expect FROG-kb to grow and expand in capabilities and welcome input from the forensic community in identifying datasets and functionalities that will be most helpful

Introducing the Forensic Research/Reference on Genetics knowledge base, FROG-kb

PubMed Central

2012-01-01

Background Online tools and databases based on multi-allelic short tandem repeat polymorphisms (STRPs) are actively used in forensic teaching, research, and investigations. The Fst value of each CODIS marker tends to be low across the populations of the world and most populations typically have all the common STRP alleles present diminishing the ability of these systems to discriminate ethnicity. Recently, considerable research is being conducted on single nucleotide polymorphisms (SNPs) to be considered for human identification and description. However, online tools and databases that can be used for forensic research and investigation are limited. Methods The back end DBMS (Database Management System) for FROG-kb is Oracle version 10. The front end is implemented with specific code using technologies such as Java, Java Servlet, JSP, JQuery, and GoogleCharts. Results We present an open access web application, FROG-kb (Forensic Research/Reference on Genetics-knowledge base, http://frog.med.yale.edu), that is useful for teaching and research relevant to forensics and can serve as a tool facilitating forensic practice. The underlying data for FROG-kb are provided by the already extensively used and referenced ALlele FREquency Database, ALFRED (http://alfred.med.yale.edu). In addition to displaying data in an organized manner, computational tools that use the underlying allele frequencies with user-provided data are implemented in FROG-kb. These tools are organized by the different published SNP/marker panels available. This web tool currently has implemented general functions possible for two types of SNP panels, individual identification and ancestry inference, and a prediction function specific to a phenotype informative panel for eye color. Conclusion The current online version of FROG-kb already provides new and useful functionality. We expect FROG-kb to grow and expand in capabilities and welcome input from the forensic community in identifying datasets and

Root iron uptake efficiency of Ulmus laevis and U. minor and their distribution in soils of the Iberian Peninsula

PubMed Central

Venturas, Martin; Fernández, Victoria; Nadal, Paloma; Guzmán, Paula; Lucena, Juan J.; Gil, Luis

2014-01-01

The calcifuge and calcicole character of wild plants has been related to nutrient availability shortages, including iron (Fe)-deficiency. Surprisingly, just a few studies examined the relation between root Fe uptake and plant distribution in different soil types. We assessed the root Fe acquisition efficiency of two Ulmus species with calcareous (Ulmus minor) and siliceous (U. laevis) soil distribution patterns in the Iberian Peninsula. Seedlings of both elm species were grown hydroponically with different Fe concentrations during 6 weeks. Plant physiological responses to Fe-limiting conditions were evaluated as were the ferric reductase activity and proton (H+) extrusion capacity of the roots. Iron deprived elm seedlings of both species were stunted and suffered severe Fe-chlorosis symptoms. After Fe re-supply leaf chlorophyll concentrations rose according to species-dependent patterns. While U. minor leaves and seedlings re-greened evenly, U. laevis did so along the nerves of new growing leaves. U. minor had a higher root ferric reductase activity and H+-extrusion capability than U. laevis and maintained a better nutrient balance when grown under Fe-limiting conditions. The two elm species were found to have different Fe acquisition efficiencies which may be related to their natural distribution in calcareous and siliceous soils of the Iberian Peninsula. PMID:24723927

A perchlorate sensitive iodide transporter in frogs

PubMed Central

Carr, Deborah L.; Carr, James A.; Willis, Ray E.; Pressley, Thomas A.

2008-01-01

Nucleotide sequence comparisons have identified a gene product in the genome database of African clawed frogs (Xenopus laevis) as a probable member of the solute carrier family of membrane transporters. To confirm its identity as a putative iodide transporter, we examined the function of this sequence after heterologous expression in mammalian cells. A green monkey kidney cell line transfected with the Xenopus nucleotide sequence had significantly greater 125I uptake than sham-transfected control cells. The uptake in carrier-transfected cells was significantly inhibited in the presence of perchlorate, a competitive inhibitor of mammalian Na+/iodide symporter. Tissue distributions of the sequence were also consistent with a role in iodide uptake. The mRNA encoding the carrier was found to be expressed in the thyroid gland, stomach, and kidney of tadpoles from X. laevis, as well as the bullfrog Rana catesbeiana. The ovaries of adult X. laevis also were found to express the carrier. Phylogenetic analysis suggested that the putative X. laevis iodide transporter is orthologous to vertebrate Na+-dependent iodide symporters. We conclude that the amphibian sequence encodes a protein that is indeed a functional Na+/iodide symporter in Xenopus laevis, as well as Rana catesbeiana. PMID:18275962

Natural levels of abnormalities in the trilling frog (neobactrachus centralis) at the Olympic dam mine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Read, J.L.; Tyler, M.J.

1994-07-01

Frogs are more susceptible than most vertebrates to environmental contaminants. Unlike amniotes, the frog egg is not protected by a semi-impervious shell, and hence is readily exposed to pollutants. In addition, tadpoles develop in wetlands to which many noxious substances drain from the surrounding landscape. Coupled with this high exposure rate, frogs are also very sensitive to trace elements, some pesticides, heavy metals especially when coupled with exposure to low pH and ionizing radiation. Frogs commonly exhibit discernible deformities following exposure to teratogenic contaminants, and therefore are valuable indicators of the existence of noxious substances in the environment. The abundancemore » and ease of sampling of frogs, along with their sensitivity to environmental contaminants, makes them ideal organisms for environmental monitoring in the Australian arid zone. The study of abnormalities in frogs has become an integral part of the Environmental Management Programme of the Olympic Dam Operations (ODO) copper-uranium-gold-silver mine in northern South Australia. The Trilling Frog (Neobatrachus centralis) is the only frog species which has been recorded at Olympic Dam. It is likely that these frogs, are relatively sedentary, thus enhancing their value as indicator organisms. A pilot survey in 1989 documented frog deformity levels comparable to those found at undisturbed sites in Australia and in other countries. This paper reports on larger study conducted in February and March 1992 when heavy rains provided another opportunity to survey the frog population. The low levels of abnormalities support the conclusion that N. centralis at Olympic Dam does not appear to be accumulating or being influenced by the very low levels of radionuclides present here.« less

Stictonectes abellani sp. n. (Coleoptera: Dytiscidae: Hydroporinae) from the Iberian Peninsula, with notes on the phylogeny, ecology and distribution of the Iberian species of the genus.

PubMed

Millán, Andrés; Picazo, Félix; Fery, Hans; Moreno, José Luis; Sánchez-Fernández, David

2013-12-09

Stictonectes abellani sp. n. is described from the Iberian Peninsula. On average, the new species is larger and the colouration of the upper surface darker than in most other species of the genus. Seemingly the species has been confounded with others in the past, particularly S. optatus (Seidlitz, 1887). Males can be separated from externally similar species by studying the shape of the parameres. Additionally, the anterior margin of the clypeus is provided with a distinct rim in both sexes, which is absent or only weakly present in other species. The habitus and the male genitalia of the new species are illustrated, and compared with those of S. optatus. External morphological differences from other members of the genus are discussed. According to studies of the molecular phylogeny, based on fragments of four mitochondrial genes, S. abellani sp. n. is clearly separated from previously described species of Stictonectes Brinck, 1943, apparently being relatively basal within the genus. The new species is rather widely distributed in the south-western part of the Iberian Peninsula, inhabiting pools in small temporary siliceous streams. We provide distributional maps for all eight Iberian Stictonectes and estimate the potential distributional areas of the new species and the other two endemic Iberian species S. occidentalis Fresneda & Fery, 1990 and S. rebeccae Bilton, 2011, based on environmental niche modelling. 

Cascades frog conservation assessment

Treesearch

Karen Pope; Catherine Brown; Marc Hayes; Gregory Green; Diane Macfarlane

2014-01-01

The Cascades frog (Rana cascadae) is a montane, lentic-breeding amphibian that has become rare in the southern Cascade Range and remains relatively widespread in the Klamath Mountains of northern California. In the southern Cascades, remaining populations occur primarily in meadow habitats where the fungal disease, chytridiomycosis, and habitat...

Phylogeny and biogeography of South Chinese brown frogs (Ranidae, Anura).

PubMed

Zhou, Yu; Wang, Sirui; Zhu, Hedan; Li, Pipeng; Yang, Baotian; Ma, Jianzhang

2017-01-01

Few studies have explored the role of Cenozoic tectonic evolution in shaping the patterns and processes of extant animal distributions in and around East Asia. In this study, we selected South Chinese brown frogs as a model to examine the phylogenetic and biogeographical consequences of Miocene tectonic events within South China and its margins. We used mitochondrial and nuclear molecular data to reconstruct phylogenetic interrelationships among Chinese brown frogs using Bayesian and maximum likelihood analyses. The phylogeny results show that there are four main clades of Chinese brown frogs. Excepting the three commonly known Chinese brown frog species groups, R. maoershanensis forms an independent clade nearest to the R. japonica group. Phylogeny and P-distance analyses confirmed R. maoershanensis as a valid species. Among South Chinese brown frogs, there are four subclades associated with four geographical areas: (I) R. maoershanensis; (II) R. japonica; (III) R. chaochiaoensis; and (IV) other species of the R. longicrus species group. Divergence times, estimated using mitochondrial sequences, place the vicariance events among the four subclades in the middle to late Miocene epoch. Our results suggest that (1) South Chinese brown frogs originated due to a vicariance event separating them from the R. chensinensis species group at the time of the Geological movement (~18 million years ago, Ma) in southern Tibet and the Himalayan region; (2) the separation and speciation of R. maoershanensis from the R. japonica group occurred due to the dry climate at approximately 16 Ma; (3) South Chinese brown frogs migrated from South China to Japan at the time (~10.8 Ma) that the global sea-level fell and the East China Sea Shelf Basin was swamp facies, when a land gallery may have formed across the sea to connect the two areas; and (4) R. chaochiaoensis separated from other species of the R. longicrus species group during the uplift of the Tibetan Plateau at approximately 9

A novel reproductive mode in frogs: a new species of fanged frog with internal fertilization and birth of tadpoles.

PubMed

Iskandar, Djoko T; Evans, Ben J; McGuire, Jimmy A

2014-01-01

We describe a new species of fanged frog (Limnonectes larvaepartus) that is unique among anurans in having both internal fertilization and birth of tadpoles. The new species is endemic to Sulawesi Island, Indonesia. This is the fourth valid species of Limnonectes described from Sulawesi despite that the radiation includes at least 15 species and possibly many more. Fewer than a dozen of the 6455 species of frogs in the world are known to have internal fertilization, and of these, all but the new species either deposit fertilized eggs or give birth to froglets.

Use of femur bone density to segregate wild from farmed Dybowski's frog (Rana dybowskii).

PubMed

Yang, Shu Hui; Huang, Xiao Ming; Xia, Rui; Xu, Yan Chun; Dahmer, Thomas D

2011-04-15

Wildlife has been utilized by humans throughout history and demand continues to grow today. Farming of wildlife can supplement the supply of wild-harvested wildlife products and, in theory, can reduce pressure on free-ranging populations. However, poached wildlife products frequently enter legal markets where they are fraudulently sold as farmed wildlife products. To effectively close this illegal trade in wild-captured wildlife, there is a need to discriminate wild products from farmed products. Because of the strong market demand for wild-captured frog meat and the resulting strong downward pressure on wild populations, we undertook research to develop a method to discriminate wild from farmed Dybowski's frog (Rana dybowskii) based on femur bone density. We measured femur bone density (D(f)) as the ratio of bone mass to bone volume. D(f) of wild frogs revealed a slightly increasing linear trend with increasing age (R(2)=0.214 in males and R(2)=0.111 in females, p=0.000). Wild males and wild females of age classes from 2 to ≥ 5 years had similar D(f) values. In contrast, 2-year-old farmed frogs showed significantly higher D(f) values (p=0.000) among males (mean D(f)=0.623 ± 0.011 g/ml, n=32) than females (mean D(f)=0.558 ± 0.011 g/ml, n=27). For both sexes, D(f) of wild frogs was significantly higher than that of farmed frogs (p=0.000). Among males, 87.5% (28 of 32 individuals) of farmed frogs were correctly identified as farmed frogs and 86.3% (69 of 80 individuals) of wild frogs were correctly identified as wild frogs. These results suggest that femur bone density is one reliable tool for discriminating between wild and farmed Dybowski's frog. This study also highlights a novel strategy with explicit forensic potential to discriminate wild from captive bred wildlife species. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Antimicrobial peptides from the skins of North American frogs.

PubMed

Conlon, J Michael; Kolodziejek, Jolanta; Nowotny, Norbert

2009-08-01

North America is home to anuran species belonging to the families Bufonidae, Eleutherodactylidae, Hylidae, Leiopelmatidae, Ranidae, and Scaphiopodidae but antimicrobial peptides have been identified only in skin secretions and/or skin extracts of frogs belonging to the Leiopelmatidae ("tailed frogs") and Ranidae ("true frogs"). Eight structurally-related cationic alpha-helical peptides with broad-spectrum antibacterial activity, termed ascaphins, have been isolated from specimens of Ascaphus truei (Leiopelmatidae) occupying a coastal range. Characterization of orthologous antimicrobial peptides from Ascaphus specimens occupying an inland range supports the proposal that this population should be regarded as a separate species A. montanus. Ascaphin-8 shows potential for development into a therapeutically valuable anti-infective agent. Peptides belonging to the brevinin-1, esculentin-1, esculentin-2, palustrin-1, palustrin-2, ranacyclin, ranatuerin-1, ranatuerin-2, and temporin families have been isolated from North American ranids. It is proposed that "ranalexins" represent brevinin-1 peptides that have undergone a four amino acid residue internal deletion. Current taxonomic recommendations divide North American frogs from the family Ranidae into two genera: Lithobates and Rana. Cladistic analysis based upon the amino acid sequences of the brevinin-1 peptides provides strong support for this assignment.

Temperature and evaporative water loss of leaf-sitting frogs: the role of reflection spectra

PubMed Central

Blount, Chris; Dickinson, Mark

2016-01-01

ABSTRACT The near infrared reflection peak in some frogs has been speculated to be either for enhancing crypticity, or to help them with thermoregulation. The theoretical background for the thermoregulatory processes has been established before, but little consideration has been given to the contribution from the frogs' reflection spectra differences. In this investigation, the reflection spectra from a range of different species of frogs were taken and combined with precise surface area measurements of frogs and an approximation to the mass transfer coefficient of agar frog models. These were then used to simulate the temperature and water evaporation in anurans with and without the near infrared reflective peak. We have shown that the presence of the near infrared reflection peak can contribute significantly to the temperature and evaporative water loss of a frog. The significance of the steady-state temperature differences between frogs with and without the near infrared reflection peak is discussed in a realistic and an extreme scenario. Temperature differences of up to 3.2°C were found, and the rehydration period was increased by up to 16.7%, although this does not reduce the number of rehydration events between dawn and dusk. PMID:27793832

Phase Reconstruction from FROG Using Genetic Algorithms[Frequency-Resolved Optical Gating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Omenetto, F.G.; Nicholson, J.W.; Funk, D.J.

1999-04-12

The authors describe a new technique for obtaining the phase and electric field from FROG measurements using genetic algorithms. Frequency-Resolved Optical Gating (FROG) has gained prominence as a technique for characterizing ultrashort pulses. FROG consists of a spectrally resolved autocorrelation of the pulse to be measured. Typically a combination of iterative algorithms is used, applying constraints from experimental data, and alternating between the time and frequency domain, in order to retrieve an optical pulse. The authors have developed a new approach to retrieving the intensity and phase from FROG data using a genetic algorithm (GA). A GA is a generalmore » parallel search technique that operates on a population of potential solutions simultaneously. Operators in a genetic algorithm, such as crossover, selection, and mutation are based on ideas taken from evolution.« less

Pathological Study of Blood Parasites in Rice Field Frogs, Hoplobatrachus rugulosus (Wiegmann, 1834)

PubMed Central

Sailasuta, Achariya; Satetasit, Jetjun; Chutmongkonkul, Malinee

2011-01-01

One hundred and forty adult rice field frogs, Hoplobatrachus rugulosus (Wiegmann, 1834), were collected in Srakaew province, Thailand. For blood parasite examination, thin blood smears were made and routinely stained with Giemsa. The results showed that 70% of the frogs (98/140) were infected with 5 species of blood parasites, including a Trypanosoma rotatorium-like organism, Trypanosoma chattoni, Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima. Pathological examination of the liver, lung, spleen, and kidney of the frogs that were apparently infected with one of these blood parasites were collected and processed by routine histology and subsequently stained with haematoxylin and eosin. Histopathological findings associated with the Trypanosoma rotatorium-like organism and Trypanosoma chattoni-infected frogs showed no pathological lesions. Hepatozoon sp. a and Hepatozoon sp. b-infected frogs developed inflammatory lesions predominantly in the liver, demonstrating granuloma-like lesions with Hepatozoon sp. meronts at the centre. Tissue sections of Lankesterella minima-infected frogs also showed lesions. Liver and spleen showed inflammatory lesions with an accumulation of melanomacrophage centres (MMCs) surrounding the meronts and merozoites. It is suggested that Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima-infections are capable of producing inflammatory lesions in the visceral organs of rice field frogs, and the severity of lesions is tentatively related to levels of parasitemia. PMID:21918731

Sophisticated Communication in the Brazilian Torrent Frog Hylodes japi

PubMed Central

de Sá, Fábio P.; Zina, Juliana; Haddad, Célio F. B.

2016-01-01

Intraspecific communication in frogs plays an important role in the recognition of conspecifics in general and of potential rivals or mates in particular and therefore with relevant consequences for pre-zygotic reproductive isolation. We investigate intraspecific communication in Hylodes japi, an endemic Brazilian torrent frog with territorial males and an elaborate courtship behavior. We describe its repertoire of acoustic signals as well as one of the most complex repertoires of visual displays known in anurans, including five new visual displays. Previously unknown in frogs, we also describe a bimodal inter-sexual communication system where the female stimulates the male to emit a courtship call. As another novelty for frogs, we show that in addition to choosing which limb to signal with, males choose which of their two vocal sacs will be used for visual signaling. We explain how and why this is accomplished. Control of inflation also provides additional evidence that vocal sac movement and color must be important for visual communication, even while producing sound. Through the current knowledge on visual signaling in Neotropical torrent frogs (i.e. hylodids), we discuss and highlight the behavioral diversity in the family Hylodidae. Our findings indicate that communication in species of Hylodes is undoubtedly more sophisticated than we expected and that visual communication in anurans is more widespread than previously thought. This is especially true in tropical regions, most likely due to the higher number of species and phylogenetic groups and/or to ecological factors, such as higher microhabitat diversity. PMID:26760304

Sophisticated Communication in the Brazilian Torrent Frog Hylodes japi.

PubMed

de Sá, Fábio P; Zina, Juliana; Haddad, Célio F B

2016-01-01

Intraspecific communication in frogs plays an important role in the recognition of conspecifics in general and of potential rivals or mates in particular and therefore with relevant consequences for pre-zygotic reproductive isolation. We investigate intraspecific communication in Hylodes japi, an endemic Brazilian torrent frog with territorial males and an elaborate courtship behavior. We describe its repertoire of acoustic signals as well as one of the most complex repertoires of visual displays known in anurans, including five new visual displays. Previously unknown in frogs, we also describe a bimodal inter-sexual communication system where the female stimulates the male to emit a courtship call. As another novelty for frogs, we show that in addition to choosing which limb to signal with, males choose which of their two vocal sacs will be used for visual signaling. We explain how and why this is accomplished. Control of inflation also provides additional evidence that vocal sac movement and color must be important for visual communication, even while producing sound. Through the current knowledge on visual signaling in Neotropical torrent frogs (i.e. hylodids), we discuss and highlight the behavioral diversity in the family Hylodidae. Our findings indicate that communication in species of Hylodes is undoubtedly more sophisticated than we expected and that visual communication in anurans is more widespread than previously thought. This is especially true in tropical regions, most likely due to the higher number of species and phylogenetic groups and/or to ecological factors, such as higher microhabitat diversity.

Field guide to malformations of frogs and toads: with radiographic interpretations

USGS Publications Warehouse

Meteyer, Carol U.

2000-01-01

In 1995, students found numerous malformed frogs on a field trip to a Minnesota pond. Since that time, reports of malformed frogs have increased dramatically. Malformed frogs have now been reported in 44 states in 38 species of frogs, and 19 species of toads. Estimates as high as 60% of the newly metamorphosed frog populations have had malformations at some ponds (NARCAM, ’99). The wide geographic distribution of malformed frogs and the variety of malformations are a concern to resource managers, research scientists and public health officials. The potential for malformations to serve as a signal of ecosystem disruption, and the affect this potential disruption might have on other organisms that share those ecosystems, has not been resolved. Malformations represent an error that occurred early in development. The event that caused the developmental error is temporally distant from the malformation we see in the fully developed animal. Knowledge of normal developmental principles is necessary to design thoughtful investigations that will define the events involved in abnormal development in wild frog populations.Development begins at the time an egg is fertilized and progresses by chemical communication between cells and cell layers. This communication is programmed through gene expression. Malformations represent primary errors in development, errors in chemical communication or translation of genetic information. Deformations arise later in development and usually result from the influence of mechanical factors (such as amputation) that alter shape or anatomy of a structure that has developed normally. The occurrence and the type of malformations are influenced by the type of error or insult as well as the timing of the error (the developmental stage at which the error occurred). The appearance of the malformation can therefore provide clues that suggest when the error may have occurred. If the malformation is an incomplete organ, such as an incomplete limb, the

Using a Phototransduction System to Monitor the Isolated Frog Heart

ERIC Educational Resources Information Center

Stephens, Philip J.

2015-01-01

A simple and inexpensive method of monitoring the movement of an isolated frog heart provides comparable results to those obtained with a force transducer. A commercially available photoresistor is integrated into a Wheatstone bridge circuit, and the output signal is interfaced directly with a recording device. An excised, beating frog heart is…

Sexual differences in prevalence of a new species of trypanosome infecting túngara frogs

PubMed Central

Bernal, Ximena E.; Pinto, C. Miguel

2016-01-01

Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus), a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp.), were examined for trypanosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (<1%). This finding suggests this protozoan parasite may be transmitted by frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylogenetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes. PMID:26977404

Sexual differences in prevalence of a new species of trypanosome infecting túngara frogs.

PubMed

Bernal, Ximena E; Pinto, C Miguel

2016-04-01

Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus), a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp.), were examined for trypanosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (<1%). This finding suggests this protozoan parasite may be transmitted by frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylogenetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes.

Electronic nose for the identification of pig feeding and ripening time in Iberian hams.

PubMed

Santos, J P; García, M; Aleixandre, M; Horrillo, M C; Gutiérrez, J; Sayago, I; Fernández, M J; Arés, L

2004-03-01

An electronic nose system to control the processing of dry-cured Iberian ham is presented. The sensors involved are tin oxide semiconductors thin films. They were prepared by RF sputtering. Some of the sensors were doped with metal catalysts as Pt and Pd, in order to improve the selectivity of the sensors. The multisensor with 16 semiconductor sensors, gave different responses from two types of dry-cured Iberian hams which differ in the feeding and curing time. The data has been analysed using the PCA (principal component analysis) and backpropagation and probabilistic neural networks. The analysis shows that different types of Iberian ham can be discriminated and identified successfully.

Atlas of Iberian water beetles (ESACIB database).

PubMed

Sánchez-Fernández, David; Millán, Andrés; Abellán, Pedro; Picazo, Félix; Carbonell, José A; Ribera, Ignacio

2015-01-01

The ESACIB ('EScarabajos ACuáticos IBéricos') database is provided, including all available distributional data of Iberian and Balearic water beetles from the literature up to 2013, as well as from museum and private collections, PhD theses, and other unpublished sources. The database contains 62,015 records with associated geographic data (10×10 km UTM squares) for 488 species and subspecies of water beetles, 120 of them endemic to the Iberian Peninsula and eight to the Balearic Islands. This database was used for the elaboration of the "Atlas de los Coleópteros Acuáticos de España Peninsular". In this dataset data of 15 additional species has been added: 11 that occur in the Balearic Islands or mainland Portugal but not in peninsular Spain and an other four with mainly terrestrial habits within the genus Helophorus (for taxonomic coherence). The complete dataset is provided in Darwin Core Archive format.

Atlas of Iberian water beetles (ESACIB database)

PubMed Central

Sánchez-Fernández, David; Millán, Andrés; Abellán, Pedro; Picazo, Félix; Carbonell, José A.; Ribera, Ignacio

2015-01-01

Abstract The ESACIB (‘EScarabajos ACuáticos IBéricos’) database is provided, including all available distributional data of Iberian and Balearic water beetles from the literature up to 2013, as well as from museum and private collections, PhD theses, and other unpublished sources. The database contains 62,015 records with associated geographic data (10×10 km UTM squares) for 488 species and subspecies of water beetles, 120 of them endemic to the Iberian Peninsula and eight to the Balearic Islands. This database was used for the elaboration of the “Atlas de los Coleópteros Acuáticos de España Peninsular”. In this dataset data of 15 additional species has been added: 11 that occur in the Balearic Islands or mainland Portugal but not in peninsular Spain and an other four with mainly terrestrial habits within the genus Helophorus (for taxonomic coherence). The complete dataset is provided in Darwin Core Archive format. PMID:26448717

Chemical camouflage--a frog's strategy to co-exist with aggressive ants.

PubMed

Rödel, Mark-Oliver; Brede, Christian; Hirschfeld, Mareike; Schmitt, Thomas; Favreau, Philippe; Stöcklin, Reto; Wunder, Cora; Mebs, Dietrich

2013-01-01

Whereas interspecific associations receive considerable attention in evolutionary, behavioural and ecological literature, the proximate bases for these associations are usually unknown. This in particular applies to associations between vertebrates with invertebrates. The West-African savanna frog Phrynomantis microps lives in the underground nest of ponerine ants (Paltothyreus tarsatus). The ants usually react highly aggressively when disturbed by fiercely stinging, but the frog is not attacked and lives unharmed among the ants. Herein we examined the proximate mechanisms for this unusual association. Experiments with termites and mealworms covered with the skin secretion of the frog revealed that specific chemical compounds seem to prevent the ants from stinging. By HPLC-fractionation of an aqueous solution of the frogs' skin secretion, two peptides of 1,029 and 1,143 Da were isolated and found to inhibit the aggressive behaviour of the ants. By de novo sequencing using tandem mass spectrometry, the amino acid sequence of both peptides consisting of a chain of 9 and 11 residues, respectively, was elucidated. Both peptides were synthesized and tested, and exhibited the same inhibitory properties as the original frog secretions. These novel peptides most likely act as an appeasement allomone and may serve as models for taming insect aggression.

The Population Decline and Extinction of Darwin’s Frogs

PubMed Central

Soto-Azat, Claudio; Valenzuela-Sánchez, Andrés; Collen, Ben; Rowcliffe, J. Marcus; Veloso, Alberto; Cunningham, Andrew A.

2013-01-01

Darwin’s frogs (Rhinoderma darwinii and R. rufum) are two species of mouth-brooding frogs from Chile and Argentina. Here, we present evidence on the extent of declines, current distribution and conservation status of Rhinoderma spp.; including information on abundance, habitat and threats to extant Darwin’s frog populations. All known archived Rhinoderma specimens were examined in museums in North America, Europe and South America. Extensive surveys were carried out throughout the historical ranges of R. rufum and R. darwinii from 2008 to 2012. Literature review and location data of 2,244 archived specimens were used to develop historical distribution maps for Rhinoderma spp. Based on records of sightings, optimal linear estimation was used to estimate whether R. rufum can be considered extinct. No extant R. rufum was found and our modelling inferred that this species became extinct in 1982 (95% CI, 1980–2000). Rhinoderma darwinii was found in 36 sites. All populations were within native forest and abundance was highest in Chiloé Island, when compared with Coast, Andes and South populations. Estimated population size and density (five populations) averaged 33.2 frogs/population (range, 10.2–56.3) and 14.9 frogs/100 m2 (range, 5.3–74.1), respectively. Our results provide further evidence that R. rufum is extinct and indicate that R. darwinii has declined to a much greater degree than previously recognised. Although this species can still be found across a large part of its historical range, remaining populations are small and severely fragmented. Conservation efforts for R. darwinii should be stepped up and the species re-classified as Endangered. PMID:23776705

Naturally occurring fluorescence in frogs

PubMed Central

Taboada, Carlos; Brunetti, Andrés E.; Pedron, Federico N.; Carnevale Neto, Fausto; Estrin, Darío A.; Bari, Sara E.; Chemes, Lucía B.; Peporine Lopes, Norberto; Lagorio, María G.

2017-01-01

Fluorescence, the absorption of short-wavelength electromagnetic radiation reemitted at longer wavelengths, has been suggested to play several biological roles in metazoans. This phenomenon is uncommon in tetrapods, being restricted mostly to parrots and marine turtles. We report fluorescence in amphibians, in the tree frog Hypsiboas punctatus, showing that fluorescence in living frogs is produced by a combination of lymph and glandular emission, with pigmentary cell filtering in the skin. The chemical origin of fluorescence was traced to a class of fluorescent compounds derived from dihydroisoquinolinone, here named hyloins. We show that fluorescence contributes 18−29% of the total emerging light under twilight and nocturnal scenarios, largely enhancing brightness of the individuals and matching the sensitivity of night vision in amphibians. These results introduce an unprecedented source of pigmentation in amphibians and highlight the potential relevance of fluorescence in visual perception in terrestrial environments. PMID:28289227

Juvenile frogs compensate for small metamorph size with terrestrial growth: Overcoming the effects of larval density and insecticide exposure

USGS Publications Warehouse

Boone, M.D.

2005-01-01

I reared four species of anurans (Rana sphenocephala [Southern Leopard Frog], Rana blairi [Plains Leopard Frog], Rana clamitans [Green Frog], and Bufo woodhousii [Woodhouse's Toad]) for seven to 12 months in small, outdoor terrestrial enclosures (1 x 2 m) to examine the consequences of larval competition (via density) and contaminant exposure (via the insecticide carbaryl). I added six Rana clamitans, eight Rana sphenocephala, eight Rana blairi, and 10 Bufo woodhousii to terrestrial enclosures shortly after metamorphosis and recaptured them during the following spring. All anurans from low-density ponds were significantly larger than those from high-density ponds, but these size differences did not significantly affect survival to or size at spring emergence. However, R. sphenocephala, R. blairi, and R. clamitans that survived to spring had been larger at metamorphosis on average than those that did not survive; in contrast, B. woodhousii that survived the winter were smaller at metamorphosis on average than those that did not survive. Carbaryl exposure affected mass at metamorphosis of R. clamitans and B. woodhousii that were added to enclosures, but this difference disappeared or did not increase by spring emergence. Overall, exposure to carbaryl during the larval period did not have any apparent effects on survival or growth during the terrestrial phase. In my study, anurans were able to offset small size at metamorphosis with terrestrial growth, although there was a trend of reduced overwinter survival for ranid species that metamorphosed at a smaller size. Copyright 2005 Society for the Study of Amphibians and Reptiles.

Frankixalus, a New Rhacophorid Genus of Tree Hole Breeding Frogs with Oophagous Tadpoles

PubMed Central

Biju, S. D.; Mahony, Stephen; Kamei, Rachunliu G.; Thomas, Ashish; Shouche, Yogesh; Raxworthy, Christopher J.; Meegaskumbura, Madhava; Bocxlaer, Ines Van

2016-01-01

Despite renewed interest in the biogeography and evolutionary history of Old World tree frogs (Rhacophoridae), this family still includes enigmatic frogs with ambiguous phylogenetic placement. During fieldwork in four northeastern states of India, we discovered several populations of tree hole breeding frogs with oophagous tadpoles. We used molecular data, consisting of two nuclear and three mitochondrial gene fragments for all known rhacophorid genera, to investigate the phylogenetic position of these new frogs. Our analyses identify a previously overlooked, yet distinct evolutionary lineage of frogs that warrants recognition as a new genus and is here described as Frankixalus gen. nov. This genus, which contains the enigmatic ‘Polypedates’ jerdonii described by Günther in 1876, forms the sister group of a clade containing Kurixalus, Pseudophilautus, Raorchestes, Mercurana and Beddomixalus. The distinctiveness of this evolutionary lineage is also corroborated by the external morphology of adults and tadpoles, adult osteology, breeding ecology, and life history features. PMID:26790105

Reduced body condition and enzymatic alterations in frogs inhabiting intensive crop production areas.

PubMed

Brodeur, Julie C; Suarez, Romina P; Natale, Guillermo S; Ronco, Alicia E; Elena Zaccagnini, Maria

2011-07-01

Parameters indicative of general condition and health were compared amongst adult frogs inhabiting uncultivated lands and fields subjected to agricultural practices typical of the humid pampas of Argentina. Whereas no significant differences existed in the parasite load and external malformations prevalence rate of adult frogs from either environments, a reduced condition factor was clearly demonstrated in frogs from agricultural lands. This conclusion was reached for four frog species of different life habits: the terrestrial fossorial Rhinella fernandezae, the terrestrial Leptodactylus latinasus, the semi-aquatic Leptodactylus ocellatus, and the arborescent Hypsiboas pulchellus. A distinct pattern of enzymatic modifications was furthermore observed in L. ocellatus and H. pulchellus from agricultural lands, including elevated hepatic activities of catalase and cholinesterase, and an inhibition of liver GST activity. Further studies should investigate the causes and consequences of the systematically low condition factor observed in frogs from agricultural fields of the humid pampas of Argentina. Copyright © 2011 Elsevier Inc. All rights reserved.

Evaluation of Antimicrobial and Healing Activities of Frog Skin on Guinea Pigs Wounds

PubMed Central

Rezazade Bazaz, Mahere; Mashreghi, Mohammad; Mahdavi Shahri, Nasser; Mashreghi, Mansour; Asoodeh, Ahmad; Behnam Rassouli, Morteza

2015-01-01

Background: Frog skin secretions have potentials against a wide spectrum of bacteria. Also, frog skin compositions have healing properties. Objectives: The aim of this study was to investigate the antibacterial potentials along with healing properties of frog skin Rana ridibunda, a species which thoroughly lives in Iran marshes, as a biological dressing on wounds. Materials and Methods: In this study, excisional wounds, dressed with frog skin, were compared between experimental and control groups of guinea pigs. In the experimental groups, wounds were dressed with the dermal (FS) and epidermal (RFS) sides of fresh frog R. ridibunda skin, while only usual cotton gauze covered the wounds of the control group. Furthermore, microbial samples were taken on different days (0, 3, 5, and 7 days post injury) to count the number of the colony-forming units. Additionally, the microbial penetration test was performed on frog skin and then the progression of wound closure was evaluated. Results: In the microbial studies, the bacterial load considerably declined in the wounds treated with FS and RFS compared with the control wounds. On day 7 post injury, the numbers of the colony-forming units for the FS, RFS, and control groups were 6.75, 105, and 375, respectively. In the penetration test, fresh frog skin showed to be a bacterial resistant dressing. The results revealed that the rate of wound closure in the experimental groups significantly was accelerated in comparison with that in the control group. Conclusions: Our results demonstrated the antimicrobial properties of frog skin as a wound dressing, which has antimicrobial effects per se. This biological dressing shows promise as an effective biological wound dressing insofar as not only is it capable of resisting microbes and accelerating wound healing but also it is cost-effective and easy to use. PMID:26468364

Surprising migration and population size dynamics in ancient Iberian brown bears (Ursus arctos)

PubMed Central

Valdiosera, Cristina E.; García-Garitagoitia, José Luis; Garcia, Nuria; Doadrio, Ignacio; Thomas, Mark G.; Hänni, Catherine; Arsuaga, Juan-Luis; Barnes, Ian; Hofreiter, Michael; Orlando, Ludovic; Götherström, Anders

2008-01-01

The endangered brown bear populations (Ursus arctos) in Iberia have been suggested to be the last fragments of the brown bear population that served as recolonization stock for large parts of Europe during the Pleistocene. Conservation efforts are intense, and results are closely monitored. However, the efforts are based on the assumption that the Iberian bears are a unique unit that has evolved locally for an extended period. We have sequenced mitochondrial DNA (mtDNA) from ancient Iberian bear remains and analyzed them as a serial dataset, monitoring changes in diversity and occurrence of European haplogroups over time. Using these data, we show that the Iberian bear population has experienced a dynamic, recent evolutionary history. Not only has the population undergone mitochondrial gene flow from other European brown bears, but the effective population size also has fluctuated substantially. We conclude that the Iberian bear population has been a fluid evolutionary unit, developed by gene flow from other populations and population bottlenecks, far from being in genetic equilibrium or isolated from other brown bear populations. Thus, the current situation is highly unusual and the population may in fact be isolated for the first time in its history. PMID:18347332

Surprising migration and population size dynamics in ancient Iberian brown bears (Ursus arctos).

PubMed

Valdiosera, Cristina E; García-Garitagoitia, José Luis; Garcia, Nuria; Doadrio, Ignacio; Thomas, Mark G; Hänni, Catherine; Arsuaga, Juan-Luis; Barnes, Ian; Hofreiter, Michael; Orlando, Ludovic; Götherström, Anders

2008-04-01

The endangered brown bear populations (Ursus arctos) in Iberia have been suggested to be the last fragments of the brown bear population that served as recolonization stock for large parts of Europe during the Pleistocene. Conservation efforts are intense, and results are closely monitored. However, the efforts are based on the assumption that the Iberian bears are a unique unit that has evolved locally for an extended period. We have sequenced mitochondrial DNA (mtDNA) from ancient Iberian bear remains and analyzed them as a serial dataset, monitoring changes in diversity and occurrence of European haplogroups over time. Using these data, we show that the Iberian bear population has experienced a dynamic, recent evolutionary history. Not only has the population undergone mitochondrial gene flow from other European brown bears, but the effective population size also has fluctuated substantially. We conclude that the Iberian bear population has been a fluid evolutionary unit, developed by gene flow from other populations and population bottlenecks, far from being in genetic equilibrium or isolated from other brown bear populations. Thus, the current situation is highly unusual and the population may in fact be isolated for the first time in its history.

Distribution and postbreeding environmental relationships of Northern leopard frogs (Rana [Lithobates] pipiens) in Washington

USGS Publications Warehouse

Germaine, S.S.; Hays, D.W.

2009-01-01

Northern leopard frogs (Rana [Lithobates] pipiens) are considered sensitive, threatened, or endangered in all western states and western Canadian provinces. Historically present in eastern Washington in 6 major river drainages, leopard frogs are now only known to occur at 2 localized areas in the Crab Creek drainage in Grant County. During the summers of 2002-2005, we surveyed both areas to document extent of leopard frog distributions and to describe habitat and vertebrate community characteristics associated with leopard frog site occupancy. At Gloyd Seeps, 2 juvenile leopard frogs were observed in a total of 8.2 person-days of searching along a 5-km stream reach. At Potholes Reservoir, we surveyed 243 wetland sites in 7 management units known to have been occupied by leopard frogs during the 1980s. We confirmed leopard frog presence at only 87 sites (36%) in 4 management units. Site occupancy models for individual ponds indicated that, compared to unoccupied sites, occupied sites had slightly greater pond depths, less tall emergent vegetation, more herbaceous vegetative cover, and fewer neighboring ponds containing nonnative predatory fish. Models developed at the 1-km2 scale indicated that occupied areas had greater average midsummer pond depths, fewer ponds occupied by bullfrogs (Rana [Lithobates] catesbeiana) and carp (Cyprinus carpio), and more herbaceous vegetation surrounding ponds. The Gloyd Seeps population now appears defunct, and the Potholes Reservoir population is in sharp decline. Unless management actions are taken to reduce nonnative fish and bullfrogs and to enhance wetland vegetation, leopard frogs may soon be extirpated from both sites and possibly, therefore, from Washington.

California Red-legged Frog - Stipulated Injunction

EPA Pesticide Factsheets

EPA will make effects determinations and initiate consultation with the U.S. Fish and Wildlife Service, regarding the potential effects of 66 pesticide active ingredient registrations on the California red-legged frog.

Hematophagous insects as vectors for frog trypanosomes.

PubMed

Ramos, B; Urdaneta-Morales, S

1977-12-01

Experimental infections of three hematophagous arthropods (Rhodnius prolixus, Aedes aegypti, and Culex pipiens) with a trypanosome of the Trypanosoma rotatorium complex found in the frogs Hyla crepitans and Leptodactylus insularum revealed that A. aegypti is a good host for the flagellate; the course of development in the intestinal tract of the mosquito is described from 15 minutes to 168 hours. C. pipiens showed only low intestinal infections and R. prolixus did not permit development of the parasite. It is postulated that, in addition to the transmission of T. rotatorium by leeches, batrachophilic mosquitoes may transmit the parasite to frogs of more terrestrial habits by being ingested by these anurans.

Capability of MODIS radiance to analyze Iberian turbid plumes

NASA Astrophysics Data System (ADS)

Fernandez-Novoa, Diego; deCastro, Maite; Des, Marisela; Costoya, Xurxo; Mendes, Renato; Gomez-Gesteira, Moncho

2017-04-01

River plumes are formed near river mouths by freshwater and riverine materials. Therefore, the area influenced by freshwater (salinity plume) is usually negatively correlated with the area occupied by suspension and dissolved material (turbid plume). Suspended material results in a strong signal detected by satellite sensors whereas ocean clear waters have negligible contributions. Thus, remote sensing data, such as radiance obtained from Moderate Resolution Imaging Spectroradiometer (MODIS), are a very useful tool to analyze turbid plumes due to the high spatial and time resolution provided. Here, MODIS capability for characterizing similarities and differences among the most important Iberian plumes was assessed under the influence of their main forcing. Daily radiance data from MODIS-Aqua and MODIS-Terra satellite sensors were processed obtaining a resolution of 500 m. Two approaches are usually used for atmospheric correction treatments: Near-Infrared (NIR) bands and a combined algorithm using NIR and Short Wave Infrared (SWIR) bands. In the particular case of Iberian Peninsula plumes both methods offered similar results, although NIR bands present a lower associated error. MODIS allows working with several bands of normalized water-leaving radiances (nLw). Focusing in the resolution provided, nLw555 and 645 were the most appropriate because both provide the best coverage and correlation with river discharge. The nLw645 band was chosen because has a lower water penetration avoiding overestimations of turbidity caused by shallow seafloor areas and/or upwelling blooms. Daily data from both satellites were merged to enhance the robustness and precision of the study by increasing the number of available pixels. Results indicate that differences between radiance data from both satellites are negligible for Iberian plumes, justifying the merging. By last, each turbid limit, to delimit the respective plume from adjacent seawater, was obtained using two alternative

Hidden MHC genetic diversity in the Iberian ibex (Capra pyrenaica).

PubMed

Angelone, Samer; Jowers, Michael J; Molinar Min, Anna Rita; Fandos, Paulino; Prieto, Paloma; Pasquetti, Mario; Cano-Manuel, Francisco Javier; Mentaberre, Gregorio; Olvera, Jorge Ramón López; Ráez-Bravo, Arián; Espinosa, José; Pérez, Jesús M; Soriguer, Ramón C; Rossi, Luca; Granados, José Enrique

2018-05-08

Defining hidden genetic diversity within species is of great significance when attempting to maintain the evolutionary potential of natural populations and conduct appropriate management. Our hypothesis is that isolated (and eventually small) wild animal populations hide unexpected genetic diversity due to their maintenance of ancient polymorphisms or introgressions. We tested this hypothesis using the Iberian ibex (Capra pyrenaica) as an example. Previous studies based on large sample sizes taken from its principal populations have revealed that the Iberian ibex has a remarkably small MHC DRB1 diversity (only six remnant alleles) as a result of recent population bottlenecks and a marked demographic decline that has led to the extinction of two recognized subspecies. Extending on the geographic range to include non-studied isolated Iberian ibex populations, we sequenced a new MHC DRB1 in what seemed three small isolated populations in Southern Spain (n = 132). The findings indicate a higher genetic diversity than previously reported in this important gene. The newly discovered allele, MHC DRB1*7, is identical to one reported in the domestic goat C. aegagrus hircus. Whether or not this is the result of ancient polymorphisms maintained by balancing selection or, alternatively, introgressions from domestic goats through hybridization needs to be clarified in future studies. However, hybridization between Iberian ibex and domestic goats has been reported in Spain and the fact that the newly discovered allele is only present in one of the small isolated populations and not in the others suggests introgression. The new discovered allele is not expected to increase fitness in C. pyrenaica since it generates the same protein as the existing MHC DRB1*6. Analysis of a microsatellite locus (OLADRB1) near the new MHC DRB1*7 gene reveals a linkage disequilibrium between these two loci. The allele OLADRB1, 187 bp in length, was unambiguously linked to the MHC DRB1*7 allele

Formicine ants: An arthropod source for the pumiliotoxin alkaloids of dendrobatid poison frogs

PubMed Central

Saporito, Ralph A.; Garraffo, H. Martin; Donnelly, Maureen A.; Edwards, Adam L.; Longino, John T.; Daly, John W.

2004-01-01

A remarkable diversity of bioactive lipophilic alkaloids is present in the skin of poison frogs and toads worldwide. Originally discovered in neotropical dendrobatid frogs, these alkaloids are now known from mantellid frogs of Madagascar, certain myobatrachid frogs of Australia, and certain bufonid toads of South America. Presumably serving as a passive chemical defense, these alkaloids appear to be sequestered from a variety of alkaloid-containing arthropods. The pumiliotoxins represent a major, widespread, group of alkaloids that are found in virtually all anurans that are chemically defended by the presence of lipophilic alkaloids. Identifying an arthropod source for these alkaloids has been a considerable challenge for chemical ecologists. However, an extensive collection of neotropical forest arthropods has now revealed a putative arthropod source of the pumiliotoxins. Here we report on the presence of pumiliotoxins in formicine ants of the genera Brachymyrmex and Paratrechina, as well as the presence of these ants in the stomach contents of the microsympatric pumiliotoxin-containing dendrobatid frog, Dendrobates pumilio. These pumiliotoxins are major alkaloids in D. pumilio, and Brachymyrmex and Paratrechina ants now represent the only known dietary sources of these toxic alkaloids. These findings further support the significance of ant-specialization and alkaloid sequestration in the evolution of bright warning coloration in poison frogs and toads. PMID:15128938

Marine exotic isopods from the Iberian Peninsula and nearby waters.

PubMed

Martínez-Laiz, Gemma; Ros, Macarena; Guerra-García, José M

2018-01-01

Effective management of marine bioinvasions starts with prevention, communication among the scientific community and comprehensive updated data on the distribution ranges of exotic species. Despite being a hotspot for introduction due to numerous shipping routes converging at the Strait of Gibraltar, knowledge of marine exotics in the Iberian Peninsula is scarce, especially of abundant but small-sized and taxonomically challenging taxa such as the Order Isopoda. To fill this gap, we conducted several sampling surveys in 44 marinas and provide the first comprehensive study of marine exotic isopods from the Iberian Peninsula, the southern side of the Strait of Gibraltar (northern Africa) and the Balearic Islands. Exotic species included Ianiropsis serricaudis (first record for the Iberian Peninsula and Lusitanian marine province), Paracerceis sculpta (first record for the Alboran Sea ecoregion), Paradella dianae , Paranthura japonica (earliest record for the Iberian Peninsula) and Sphaeroma walkeri . Photographs with morphological details for identification for non-taxonomic experts are provided, their worldwide distribution is updated and patterns of invasion are discussed. We report an expansion in the distribution range of all species, especially at the Strait of Gibraltar and nearby areas. Ianiropsis serricaudis and Paranthura japonica are polyvectic, with shellfish trade and recreational boating being most probable vectors for their introduction and secondary spread. The subsequent finding of the studied species in additional marinas over the years points at recreational boating as a vector and indicates a future spread. We call for attention to reduce lags in the detection and reporting of small-size exotics, which usually remain overlooked or underestimated until the invasion process is at an advanced stage.

Marine exotic isopods from the Iberian Peninsula and nearby waters

PubMed Central

Ros, Macarena; Guerra-García, José M.

2018-01-01

Effective management of marine bioinvasions starts with prevention, communication among the scientific community and comprehensive updated data on the distribution ranges of exotic species. Despite being a hotspot for introduction due to numerous shipping routes converging at the Strait of Gibraltar, knowledge of marine exotics in the Iberian Peninsula is scarce, especially of abundant but small-sized and taxonomically challenging taxa such as the Order Isopoda. To fill this gap, we conducted several sampling surveys in 44 marinas and provide the first comprehensive study of marine exotic isopods from the Iberian Peninsula, the southern side of the Strait of Gibraltar (northern Africa) and the Balearic Islands. Exotic species included Ianiropsis serricaudis (first record for the Iberian Peninsula and Lusitanian marine province), Paracerceis sculpta (first record for the Alboran Sea ecoregion), Paradella dianae, Paranthura japonica (earliest record for the Iberian Peninsula) and Sphaeroma walkeri. Photographs with morphological details for identification for non-taxonomic experts are provided, their worldwide distribution is updated and patterns of invasion are discussed. We report an expansion in the distribution range of all species, especially at the Strait of Gibraltar and nearby areas. Ianiropsis serricaudis and Paranthura japonica are polyvectic, with shellfish trade and recreational boating being most probable vectors for their introduction and secondary spread. The subsequent finding of the studied species in additional marinas over the years points at recreational boating as a vector and indicates a future spread. We call for attention to reduce lags in the detection and reporting of small-size exotics, which usually remain overlooked or underestimated until the invasion process is at an advanced stage. PMID:29507825

Genetic Footprints of Iberian Cattle in America 500 Years after the Arrival of Columbus

PubMed Central

Martínez, Amparo M.; Gama, Luis T.; Cañón, Javier; Ginja, Catarina; Delgado, Juan V.; Dunner, Susana; Landi, Vincenzo; Martín-Burriel, Inmaculada; Penedo, M. Cecilia T.; Rodellar, Clementina; Vega-Pla, Jose Luis; Acosta, Atzel; Álvarez, Luz A.; Camacho, Esperanza; Cortés, Oscar; Marques, Jose R.; Martínez, Roberto; Martínez, Ruben D.; Melucci, Lilia; Martínez-Velázquez, Guillermo; Muñoz, Jaime E.; Postiglioni, Alicia; Quiroz, Jorge; Sponenberg, Philip; Uffo, Odalys; Villalobos, Axel; Zambrano, Delsito; Zaragoza, Pilar

2012-01-01

Background American Creole cattle presumably descend from animals imported from the Iberian Peninsula during the period of colonization and settlement, through different migration routes, and may have also suffered the influence of cattle directly imported from Africa. The introduction of European cattle, which began in the 18th century, and later of Zebu from India, has threatened the survival of Creole populations, some of which have nearly disappeared or were admixed with exotic breeds. Assessment of the genetic status of Creole cattle is essential for the establishment of conservation programs of these historical resources. Methodology/Principal Findings We sampled 27 Creole populations, 39 Iberian, 9 European and 6 Zebu breeds. We used microsatellite markers to assess the origins of Creole cattle, and to investigate the influence of different breeds on their genetic make-up. The major ancestral contributions are from breeds of southern Spain and Portugal, in agreement with the historical ports of departure of ships sailing towards the Western Hemisphere. This Iberian contribution to Creoles may also include some African influence, given the influential role that African cattle have had in the development of Iberian breeds, but the possibility of a direct influence on Creoles of African cattle imported to America can not be discarded. In addition to the Iberian influence, the admixture with other European breeds was minor. The Creoles from tropical areas, especially those from the Caribbean, show clear signs of admixture with Zebu. Conclusions/Significance Nearly five centuries since cattle were first brought to the Americas, Creoles still show a strong and predominant signature of their Iberian ancestors. Creole breeds differ widely from each other, both in genetic structure and influences from other breeds. Efforts are needed to avoid their extinction or further genetic erosion, which would compromise centuries of selective adaptation to a wide range of

Embryogenesis and laboratory maintenance of the foam-nesting túngara frogs, genus Engystomops (= Physalaemus)

PubMed Central

Romero-Carvajal, Andrés; Sáenz-Ponce, Natalia; Venegas-Ferrín, Michael; Almeida-Reinoso, Diego; Lee, Chanjae; Bond, Jennifer; Ryan, Michael J.; Wallingford, John B.; del Pino, Eugenia M.

2010-01-01

The vast majority of embryological research on amphibians focuses on just a single genus of frogs, Xenopus. To attain a more comprehensive understanding of amphibian development, experimentation on non-model frogs will be essential. Here, we report on the early development, rearing, and embryological analysis of túngara frogs (genus Engystomops, also called Physaleamus). The frogs Engystomops pustulosus, Engystomops coloradorum and Engystomops randi construct floating foam-nests with small eggs. We define a table of 23 stages for the developmental period in the foam-nest. Embryos were immunostained against Lim1, neural, and somite-specific proteins and the expression pattern of RetinoBlastoma Binding Protein 6 (RBBP6) was analyzed by in situ hybridization. Due to their brief life-cycle, frogs belonging to the genus Engystomops are attractive for comparative and genetic studies of development. PMID:19384855

Inference of genetic network of Xenopus frog egg: improved genetic algorithm.

PubMed

Wu, Shinq-Jen; Chou, Chia-Hsien; Wu, Cheng-Tao; Lee, Tsu-Tian

2006-01-01

An improved genetic algorithm (IGA) is proposed to achieve S-system gene network modeling of Xenopus frog egg. Via the time-courses training datasets from Michaelis-Menten model, the optimal parameters are learned. The S-system can clearly describe activative and inhibitory interaction between genes as generating and consuming process. We concern the mitotic control in cell-cycle of Xenopus frog egg to realize cyclin-Cdc2 and Cdc25 for MPF activity. The proposed IGA can achieve global search with migration and keep the best chromosome with elitism operation. The generated gene regulatory networks can provide biological researchers for further experiments in Xenopus frog egg cell cycle control.

First report of Hepatozoon sp. in the Oregon spotted frog, Rana pretiosa.

PubMed

Stenberg, Patricia L; Bowerman, William J

2010-07-01

From 2005 through 2008, we screened 650 Oregon spotted frogs (Rana pretiosa) from three populations in central Oregon, USA, for hemoparasites. A Hepatozoon sp., not previously reported in R. pretiosa, was found in one population of frogs, mostly as intracellular gamonts at a prevalence of 10.5% with parasitemias ranging from 0.02% to greater than 42% of erythrocytes within individual frogs. Intra-and extracellular merozoites were present, but rare. A potential vector, the mosquito Culex boharti, was common throughout the habitat of the population carrying Hepatozoon sp.

Bacterial flora on Cascades frogs in the Klamath Mountains of California

Treesearch

Karen Pope

2013-01-01

Amphibians are experiencing global declines due in part to the infectious disease chytridiomycosis. Some symbiotic bacteria residents on frog skin have been shown to inhibit the growth of Batrachochytrium dendrobatitis (Bd) but few studies have attempted to fully describe the resident bacterial flora of frog skin. We cultured and sequenced 130...

Natural disturbance reduces disease risk in endangered rainforest frog populations

PubMed Central

Roznik, Elizabeth A.; Sapsford, Sarah J.; Pike, David A.; Schwarzkopf, Lin; Alford, Ross A.

2015-01-01

Natural disturbances can drive disease dynamics in animal populations by altering the microclimates experienced by hosts and their pathogens. Many pathogens are highly sensitive to temperature and moisture, and therefore small changes in habitat structure can alter the microclimate in ways that increase or decrease infection prevalence and intensity in host populations. Here we show that a reduction of rainforest canopy cover caused by a severe tropical cyclone decreased the risk of endangered rainforest frogs (Litoria rheocola) becoming infected by a fungal pathogen (Batrachochytrium dendrobatidis). Reductions in canopy cover increased the temperatures and rates of evaporative water loss in frog microhabitats, which reduced B. dendrobatidis infection risk in frogs by an average of 11–28% in cyclone-damaged areas, relative to unaffected areas. Natural disturbances to the rainforest canopy can therefore provide an immediate benefit to frogs by altering the microclimate in ways that reduce infection risk. This could increase host survival and reduce the probability of epidemic disease outbreaks. For amphibian populations under immediate threat from this pathogen, targeted manipulation of canopy cover could increase the availability of warmer, drier microclimates and therefore tip the balance from host extinction to coexistence. PMID:26294048

Natural disturbance reduces disease risk in endangered rainforest frog populations.

PubMed

Roznik, Elizabeth A; Sapsford, Sarah J; Pike, David A; Schwarzkopf, Lin; Alford, Ross A

2015-08-21

Natural disturbances can drive disease dynamics in animal populations by altering the microclimates experienced by hosts and their pathogens. Many pathogens are highly sensitive to temperature and moisture, and therefore small changes in habitat structure can alter the microclimate in ways that increase or decrease infection prevalence and intensity in host populations. Here we show that a reduction of rainforest canopy cover caused by a severe tropical cyclone decreased the risk of endangered rainforest frogs (Litoria rheocola) becoming infected by a fungal pathogen (Batrachochytrium dendrobatidis). Reductions in canopy cover increased the temperatures and rates of evaporative water loss in frog microhabitats, which reduced B. dendrobatidis infection risk in frogs by an average of 11-28% in cyclone-damaged areas, relative to unaffected areas. Natural disturbances to the rainforest canopy can therefore provide an immediate benefit to frogs by altering the microclimate in ways that reduce infection risk. This could increase host survival and reduce the probability of epidemic disease outbreaks. For amphibian populations under immediate threat from this pathogen, targeted manipulation of canopy cover could increase the availability of warmer, drier microclimates and therefore tip the balance from host extinction to coexistence.

Eleutherodactylus frog introductions to Hawaii

USGS Publications Warehouse

Kraus, Fred; Campbell, Earl W.; Allison, Allen; Pratt, Thane K.

1999-01-01

As an oceanic archipelago isolated from continental source areas, Hawaii lacks native terrestrial reptiles and amphibians, Polynesians apparently introduced seven gecko and skink species after discovering the islands approximately 1500 years ago, and another 15 reptiles and five frogs have been introduced in the last century and a half (McKeown 1996). The Polynesian introductions are probably inadvertent because the species involved are known stowaway dispersers (Gibbons 1985; Dye and Steadman 1990), In contrast, most of the herpetological introductions since European contact with Hawaii have been intentional. Several frog species were released for biocontrol of insects (e.g., Dendrobates auratus, Bufo marinus, Rana rugosa, Bryan 1932; Oliver and Shaw 1953), and most of the remaining species are released or escaped pets (e.g., Phelsuma spp., Chamaeleo jacksonii, Iguana iguana, McKeown 1996), Government-approved releases have not occurred for many years, but the rate of establishment of new species has increased in the past few decades because of the importation and subsequent release of pets.

Enzymatic Regulation of Glycogenolysis in a Subarctic Population of the Wood Frog: Implications for Extreme Freeze Tolerance

PubMed Central

do Amaral, M. Clara F.; Lee, Richard E.; Costanzo, Jon P.

2013-01-01

The wood frog, Rana sylvatica, from Interior Alaska survives freezing at –16°C, a temperature 10–13°C below that tolerated by its southern conspecifics. We investigated the hepatic freezing response in this northern phenotype to determine if its profound freeze tolerance is associated with an enhanced glucosic cryoprotectant system. Alaskan frogs had a larger liver glycogen reserve that was mobilized faster during early freezing as compared to conspecifics from a cool-temperate region (southern Ohio, USA). In Alaskan frogs the rapid glucose production in the first hours of freezing was associated with a 7-fold increase in glycogen phosphorylase activity above unfrozen frog levels, and the activity of this enzyme was higher than that of frozen Ohioan frogs. Freezing of Ohioan frogs induced a more modest (4-fold) increase in glycogen phosphorylase activity above unfrozen frog values. Relative to the Ohioan frogs, Alaskan frogs maintained a higher total protein kinase A activity throughout an experimental freezing/thawing time course, and this may have potentiated glycogenolysis during early freezing. We found populational variation in the activity and protein level of protein kinase A which suggested that the Alaskan population had a more efficient form of this enzyme. Alaskan frogs modulated their glycogenolytic response by decreasing the activity of glycogen phosphorylase after cryoprotectant mobilization was well under way, thereby conserving their hepatic glycogen reserve. Ohioan frogs, however, sustained high glycogen phosphorylase activity until early thawing and consumed nearly all their liver glycogen. These unique hepatic responses of Alaskan R. sylvatica likely contribute to this phenotype’s exceptional freeze tolerance, which is necessary for their survival in a subarctic climate. PMID:24236105

The earliest direct evidence of frogs in wet tropical forests from Cretaceous Burmese amber.

PubMed

Xing, Lida; Stanley, Edward L; Bai, Ming; Blackburn, David C

2018-06-14

Frogs are a familiar and diverse component of tropical forests around the world. Yet there is little direct evidence from the fossil record for the antiquity of this association. We describe four fossil frog specimens from mid-Cretaceous (~99 mya) amber deposits from Kachin State, Myanmar for which the associated fauna provides rich paleoenvironmental context. Microcomputed tomographic analysis provides detailed three-dimensional anatomy for these small frogs, which is generally unavailable for articulated anurans in the Mesozoic. These crown-group anuran specimens provide the earliest direct evidence for anurans in a wet tropical forest. Based on a distinct combination of skeletal characters, at least one specimen has clear similarities to living alytoid frogs as well as several Mesozoic taxa known from the Jehol Biota in China. Whereas many Mesozoic frogs are from seasonal and mesic paleoenvironments, these fossils provide the earliest direct evidence of anurans in wet tropical forests.

Long-term patterns in Iberian hare population dynamics in a protected area (Doñana National Park) in the southwestern Iberian Peninsula: Effects of weather conditions and plant cover.

PubMed

Carro, Francisco; Soriguer, Ramón C

2017-01-01

The Iberian hare (Lepus granatensis) is a widely distributed endemic species in the Iberian Peninsula. To improve our knowledge of its population dynamics, the relative abundance and population trends of the Iberian hare were studied in the autumns of 1995-2012 in a protected area (Doñana National Park) by spotlighting in 2 different habitats: marshland and ecotones. The average relative abundance was 0.38 hare/km (SD = 0.63) in the marshland and 3.6 hares/km (SD = 4.09) in ecotones. The Iberian hare population exhibited local interannual fluctuations and a negative population trend during the study period (1995-2012). The results suggest that its populations are in decline. The flooding of parts of the marshland in June, July and October favor hare abundance in the ecotone. Hare abundance in the marshland increases as the flooded surface area increases in October. These effects are more pronounced if the rains are early (October) and partially flood the marsh. By contrast, when marsh grasses and graminoids are very high and thick (as measured using the aerial herbaceous biomass [biomass marshland] as a proxy), the abundance of hares decreases dramatically as does the area of the marsh that is flooded (in November). © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Archaeobatrachian paraphyly and pangaean diversification of crown-group frogs.

PubMed

Roelants, Kim; Bossuyt, Franky

2005-02-01

Current models for the early diversification of living frogs inferred from morphological, ontogenetic, or DNA sequence data invoke very different scenarios of character evolution and biogeography. To explore central controversies on the phylogeny of Anura, we analyzed nearly 4000 base pairs of mitochondrial and nuclear DNA for the major frog lineages. Likelihood-based analyses of this data set are congruent with morphological evidence in supporting a paraphyletic arrangement of archaeobatrachian frogs, with an (Ascaphus + Leiopelma) clade as the sister-group of all other living anurans. The stability of this outcome is reinforced by screening for phylogenetic bias resulting from site-specific rate variation, homoplasy, or the obligatory use of distantly related outgroups. Twenty-one alternative branching and rooting hypotheses were evaluated using a nonparametric multicomparison test and parametric bootstrapping. Relaxed molecular clock estimates situate the emergence of crown-group anurans in the Triassic, approximately 55 million years prior to their first appearance in the fossil record. The existence of at least four extant frog lineages on the supercontinent Pangaea before its breakup gains support from the estimation that three early splits between Laurasia- and Gondwana-associated families coincide with the initial rifting of these landmasses. This observation outlines the potential significance of this breakup event in the formation of separate Mesozoic faunal assemblages in both hemispheres.

Semaphoring in an earless frog: the origin of a novel visual signal.

PubMed

Lindquist, E D; Hetherington, T E

1998-10-01

Social communication in anuran amphibians (frogs and toads) is mediated predominantly by acoustic signals. Unlike most anurans, the Panamanian golden frog, Atelopus zeteki, lacks a standard tympanic middle ear and appears to have augmented its communicatory repertoire to include rotational limb motions as visual signals, referred to here as semaphores. The communicatory nature of semaphoring was inferred from experimental manipulations using mirrored self-image presentations and nonresident introductions. Male frogs semaphored significantly more when presented with a mirrored self-image than with a nonreflective control. Novel encounters between resident males and nonresident frogs demonstrated that semaphores were used directionally and were displayed toward target individuals. Females semaphored frequently and this observation represents a rare case of signaling by females in a typically male-biased communicatory regime. Semaphore actions were clearly linked to a locomotory gait pattern and appear to have originated as an elaboration of a standard stepping motion.

Effects of water vapor density on cutaneous resistance to evaporative water loss and body temperature in green tree frogs (Hyla cinerea).

PubMed

Wygoda, Mark L; Kersten, Constance A

2013-01-01

Increased cutaneous resistance to evaporative water loss (Rc) in tree frogs results in decreased water loss rate and increased body temperature. We examined sensitivity of Rc to water vapor density (WVD) in Hyla cinerea by exposing individual frogs and agar models to four different WVD environments and measuring cutaneous evaporative water loss rate and body temperature simultaneously using a gravimetric wind tunnel measuring system. We found that water loss rate varied inversely and body temperature directly with WVD but that models were affected to a greater extent than were animals. Mean Rc was significantly different between the highest WVD environment and each of the three drier environments but did not differ among the drier environments, indicating that Rc initially increases and then reaches a plateau in response to decreasing WVD. Rc was equivalent when calculated using either WVD difference or WVD deficit as the driving force for evaporation. We also directly observed secretions from cutaneous glands while measuring body temperature and tested secretions and skin samples for the presence of lipids. We found that irregular transient body temperature depressions observed during wind tunnel trials occur due to evaporative cooling from intermittent skin secretions containing lipids, although we were unable to identify lipid-secreting glands.

How the environment shapes animal signals: a test of the acoustic adaptation hypothesis in frogs.

PubMed

Goutte, S; Dubois, A; Howard, S D; Márquez, R; Rowley, J J L; Dehling, J M; Grandcolas, P; Xiong, R C; Legendre, F

2018-01-01

Long-distance acoustic signals are widely used in animal communication systems and, in many cases, are essential for reproduction. The acoustic adaptation hypothesis (AAH) implies that acoustic signals should be selected for further transmission and better content integrity under the acoustic constraints of the habitat in which they are produced. In this study, we test predictions derived from the AAH in frogs. Specifically, we focus on the difference between torrent frogs and frogs calling in less noisy habitats. Torrents produce sounds that can mask frog vocalizations and constitute a major acoustic constraint on call evolution. We combine data collected in the field, material from scientific collections and the literature for a total of 79 primarily Asian species, of the families Ranidae, Rhacophoridae, Dicroglossidae and Microhylidae. Using phylogenetic comparative methods and including morphological and environmental potential confounding factors, we investigate putatively adaptive call features in torrent frogs. We use broad habitat categories as well as fine-scale habitat measurements and test their correlation with six call characteristics. We find mixed support for the AAH. Spectral features of torrent frog calls are different from those of frogs calling in other habitats and are related to ambient noise levels, as predicted by the AAH. However, temporal call features do not seem to be shaped by the frogs' calling habitats. Our results underline both the complexity of call evolution and the need to consider multiple factors when investigating this issue. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

WHOLE FROG TECHNICAL REPORT

Science.gov Websites

able to represent the anatomy of a frog in a computer in 3D space in such a way that a high school few masks to be loaded at once and enables different masks to be exclusive. When a mask becomes can not be drawn on. This method avoids overlapping masks when segmenting objects are adjacent to each

How to Comply with Requirements to Protect California Red-legged Frog from Pesticides

EPA Pesticide Factsheets

This document describes buffer areas around certain habitats of the California red-legged frog, and limits on use of certain pesticides within those habitats and buffer zones to protect the red-legged frog from certain pesticides.

Danger Comes from All Fronts: Predator-Dependent Escape Tactics of Túngara Frogs

PubMed Central

Bulbert, Matthew W.; Page, Rachel A.; Bernal, Ximena E.

2015-01-01

The escape response of an organism is generally its last line of defense against a predator. Because the effectiveness of an escape varies with the approach behaviour of the predator, it should be advantageous for prey to alter their escape trajectories depending on the mode of predator attack. To test this hypothesis we examined the escape responses of a single prey species, the ground-dwelling túngara frog (Engystomops pustulosus), to disparate predators approaching from different spatial planes: a terrestrial predator (snake) and an aerial predator (bat). Túngara frogs showed consistently distinct escape responses when attacked by terrestrial versus aerial predators. The frogs fled away from the snake models (Median: 131°). In stark contrast, the frogs moved toward the bat models (Median: 27°); effectively undercutting the bat’s flight path. Our results reveal that prey escape trajectories reflect the specificity of their predators’ attacks. This study emphasizes the flexibility of strategies performed by prey to outcompete predators with diverse modes of attack. PMID:25874798

Detecting fish parvalbumin with commercial mouse monoclonal anti-frog parvalbumin IgG.

PubMed

Chen, Lingyun; Hefle, Sue L; Taylor, Steve L; Swoboda, Ines; Goodman, Richard E

2006-07-26

Parvalbumin is a calcium-binding muscle protein that is highly conserved across fish species and amphibians. It is the major cross-reactive allergen associated with both fish and frog allergy. We used two-dimensional electrophoretic and immunoblotting techniques to investigate the utility of a commercial monoclonal anti-frog parvalbumin IgG for detecting parvalbumin present in some commonly consumed fish species. The 2D electrophoresis and immunoblots revealed species-specific differences in proteins that appear to represent various numbers of isoforms of parvalbumin in carp (5), catfish (3), cod (1) and tilapia (2). No parvalbumin was detected in yellowfin tuna. Based on minor differences in relative intensities of protein staining and immunodetection, parvalbumin isoforms may have slight differences in the epitope region recognized by the anti-frog parvalbumin antibody. These results suggest that the frog anti-parvalbumin antibody can be used as a valuable tool to detect parvalbumins from the fish tested in this study, except yellowfin tuna.

A forty-three year museum study of northern cricket frog (Acris crepitans) abnormalities in Arkansas: upward trends and distributions.

PubMed

McCallum, Malcolm L; Trauth, Stanley E

2003-07-01

The northern cricket frog (Acris crepitans) is a resident of streams, rivers, and wetlands of eastern North America. We documented abnormalities in A. crepitans housed in the Arkansas State University Museum of Zoology Herpetology Collection. Abnormality frequency increased from 1957 to 2000 (chi 2 = 43.76, df = 3, P < 0.001). From 1957 through 1979 only 3.33% of specimens were unusual. This rate was 6.87% during the 1990s, and in 2000 it was 8.48%. High frequencies of abnormalities were identified in the following Ozark highland counties: Sharp, Lawrence, and Randolph. We observed 104 abnormalities among 1,464 frogs (7.10%). The differential abnormality frequencies observed between the Arkansas lowlands and highlands are striking. The Ozarks had significantly higher frequencies of abnormalities than other Arkansas regions (chi 2 = 59.76, df = 4, P < 0.001). The Ouachita Mountains had significantly higher frequencies than the Gulf Coastal Plain, Delta, or Arkansas River Valley (chi 2 = 13.172, df = 3, P < 0.01). There was no difference in abnormality frequency between the Gulf Coastal Plain, Delta, and Arkansas River Valley (chi 2 = 0.422, df = 2, P > 0.70). Proposed hypotheses for distributions include: 1) A. crepitans might possess naturally high abnormality levels, and land use practices of the Delta may reduce this variability; 2) an unknown xenobiotic may be in Ozark streams causing increased numbers of abnormalities; 3) the museum's collection effort may be skewed; 4) Delta habitat might be more favorable for green tree frogs (Hyla cinerea) allowing this species to drive out A. crepitans through competition; here, abnormal metamorphs are not detected because they are even less competitive than normal individuals.

Effects of the Chytrid fungus on the Tarahumara frog (Rana tarahumarae) in Arizona and Sonora, Mexico

Treesearch

Stephen F. Hale; Philip C. Rosen; James L. Jarchow; Gregory A. Bradley

2005-01-01

We conducted histological analyses on museum specimens collected 1975-1999 from 10 sites in Arizona and Sonora to test for the pathogenic chytrid fungus (Batrachochytrium dendrobatidis) in ranid frogs, focusing on the Tarahumara frog (Rana tarahumarae). During 1981-2000, frogs displaying disease signs were found in the field, and...

Dietary alkaloid sequestration in a poison frog: an experimental test of alkaloid uptake in Melanophryniscus stelzneri (Bufonidae).

PubMed

Hantak, Maggie M; Grant, Taran; Reinsch, Sherri; McGinnity, Dale; Loring, Marjorie; Toyooka, Naoki; Saporito, Ralph A

2013-12-01

Several lineages of brightly colored anurans independently evolved the ability to secrete alkaloid-containing defensive chemicals from granular glands in the skin. These species, collectively referred to as 'poison frogs,' form a polyphyletic assemblage that includes some species of Dendrobatidae, Mantellidae, Myobatrachidae, Bufonidae, and Eleutherodactylidae. The ability to sequester alkaloids from dietary arthropods has been demonstrated experimentally in most poison frog lineages but not in bufonid or eleutherodactylid poison frogs. As with other poison frogs, species of the genus Melanophryniscus (Bufonidae) consume large numbers of mites and ants, suggesting they might also sequester defensive alkaloids from dietary sources. To test this hypothesis, fruit flies dusted with alkaloid/nutritional supplement powder were fed to individual Melanophryniscus stelzneri in two experiments. In the first experiment, the alkaloids 5,8-disubstituted indolizidine 235B' and decahydroquinoline were administered to three individuals for 104 days. In the second experiment, the alkaloids 3,5-disubstituted indolizidine 239Q and decahydroquinoline were given to three frogs for 153 days. Control frogs were fed fruit flies dusted only with nutritional supplement. Gas chromatography/mass spectrometry analyses revealed that skin secretions of all experimental frogs contained alkaloids, whereas those of all control frogs lacked alkaloids. Uptake of decahydroquinoline was greater than uptake of 5,8-disubstituted indolizidine, and uptake of 3,5-disubstituted indolizidine was greater than uptake of decahydroquinoline, suggesting greater uptake efficiency of certain alkaloids. Frogs in the second experiment accumulated a greater amount of alkaloid, which corresponds to the longer duration and greater number of alkaloid-dusted fruit flies that were consumed. These findings provide the first experimental evidence that bufonid poison frogs sequester alkaloid-based defenses from dietary

Environmental isolation explains Iberian genetic diversity in the highly homozygous model grass Brachypodium distachyon.

PubMed

Marques, Isabel; Shiposha, Valeriia; López-Alvarez, Diana; Manzaneda, Antonio J; Hernandez, Pilar; Olonova, Marina; Catalán, Pilar

2017-06-15

Brachypodium distachyon (Poaceae), an annual Mediterranean Aluminum (Al)-sensitive grass, is currently being used as a model species to provide new information on cereals and biofuel crops. The plant has a short life cycle and one of the smallest genomes in the grasses being well suited to experimental manipulation. Its genome has been fully sequenced and several genomic resources are being developed to elucidate key traits and gene functions. A reliable germplasm collection that reflects the natural diversity of this species is therefore needed for all these genomic resources. However, despite being a model plant, we still know very little about its genetic diversity. As a first step to overcome this gap, we used nuclear Simple Sequence Repeats (nSSR) to study the patterns of genetic diversity and population structure of B. distachyon in 14 populations sampled across the Iberian Peninsula (Spain), one of its best known areas. We found very low levels of genetic diversity, allelic number and heterozygosity in B. distachyon, congruent with a highly selfing system. Our results indicate the existence of at least three genetic clusters providing additional evidence for the existence of a significant genetic structure in the Iberian Peninsula and supporting this geographical area as an important genetic reservoir. Several hotspots of genetic diversity were detected and populations growing on basic soils were significantly more diverse than those growing in acidic soils. A partial Mantel test confirmed a statistically significant Isolation-By-Distance (IBD) among all studied populations, as well as a statistically significant Isolation-By-Environment (IBE) revealing the presence of environmental-driven isolation as one explanation for the genetic patterns found in the Iberian Peninsula. The finding of higher genetic diversity in eastern Iberian populations occurring in basic soils suggests that these populations can be better adapted than those occurring in western areas

Chasing maximal performance: a cautionary tale from the celebrated jumping frogs of Calaveras County.

PubMed

Astley, H C; Abbott, E M; Azizi, E; Marsh, R L; Roberts, T J

2013-11-01

Maximal performance is an essential metric for understanding many aspects of an organism's biology, but it can be difficult to determine because a measured maximum may reflect only a peak level of effort, not a physiological limit. We used a unique opportunity provided by a frog jumping contest to evaluate the validity of existing laboratory estimates of maximum jumping performance in bullfrogs (Rana catesbeiana). We recorded video of 3124 bullfrog jumps over the course of the 4-day contest at the Calaveras County Jumping Frog Jubilee, and determined jump distance from these images and a calibration of the jump arena. Frogs were divided into two groups: 'rental' frogs collected by fair organizers and jumped by the general public, and frogs collected and jumped by experienced, 'professional' teams. A total of 58% of recorded jumps surpassed the maximum jump distance in the literature (1.295 m), and the longest jump was 2.2 m. Compared with rental frogs, professionally jumped frogs jumped farther, and the distribution of jump distances for this group was skewed towards long jumps. Calculated muscular work, historical records and the skewed distribution of jump distances all suggest that the longest jumps represent the true performance limit for this species. Using resampling, we estimated the probability of observing a given jump distance for various sample sizes, showing that large sample sizes are required to detect rare maximal jumps. These results show the importance of sample size, animal motivation and physiological conditions for accurate maximal performance estimates.

Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

PubMed Central

Netherlands, Edward C.; Cook, Courtney A.; Kruger, Donnavan J.D.; du Preez, Louis H.; Smit, Nico J.

2015-01-01

Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracellular parasites including trypanosomes and microfilarid nematodes were found. A significant difference (P < 0.01) in the prevalence of parasitaemia was found across species, those semi-aquatic species demonstrating the highest, followed by semi-terrestrial frog species. None of those species described as purely terrestrial and aquatic were infected. Hepatozoon and Trypanosoma species accounted for most of the infections, the former demonstrating significant differences in intensity of infection across species, families and habitat types (P = 0.028; P = 0.006; P = 0.007 respectively). Per locality, the first, the formally protected Ndumo Game Reserve, had the highest biodiversity of haemoparasite infections, with all five groups of parasites recorded. The other two sites, that is the area bordering the reserve and the Kwa Nyamazane Conservancy, had a lower diversity with no parasite infections recorded and only Hepatozoon species recorded respectively. Such findings could be ascribed to the anthropogenic impact on the latter two sites, the first by the rural village activities, and the second by the bordering commercial sugar cane agriculture. Future studies should include both morphological and molecular descriptions of the above parasites, as well as the identification of potential vectors, possibly clarifying the effects human activities may have on frog haemoparasite life cycles and as such their biodiversity. PMID:25830113

Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa.

PubMed

Netherlands, Edward C; Cook, Courtney A; Kruger, Donnavan J D; du Preez, Louis H; Smit, Nico J

2015-04-01

Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracellular parasites including trypanosomes and microfilarid nematodes were found. A significant difference (P < 0.01) in the prevalence of parasitaemia was found across species, those semi-aquatic species demonstrating the highest, followed by semi-terrestrial frog species. None of those species described as purely terrestrial and aquatic were infected. Hepatozoon and Trypanosoma species accounted for most of the infections, the former demonstrating significant differences in intensity of infection across species, families and habitat types (P = 0.028; P = 0.006; P = 0.007 respectively). Per locality, the first, the formally protected Ndumo Game Reserve, had the highest biodiversity of haemoparasite infections, with all five groups of parasites recorded. The other two sites, that is the area bordering the reserve and the Kwa Nyamazane Conservancy, had a lower diversity with no parasite infections recorded and only Hepatozoon species recorded respectively. Such findings could be ascribed to the anthropogenic impact on the latter two sites, the first by the rural village activities, and the second by the bordering commercial sugar cane agriculture. Future studies should include both morphological and molecular descriptions of the above parasites, as well as the identification of potential vectors, possibly clarifying the effects human activities may have on frog haemoparasite life cycles and as such their biodiversity.

Cryoprotectants and Extreme Freeze Tolerance in a Subarctic Population of the Wood Frog

PubMed Central

Costanzo, Jon P.; Reynolds, Alice M.; do Amaral, M. Clara F.; Rosendale, Andrew J.; Lee, Richard E.

2015-01-01

Wood frogs (Rana sylvatica) exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 μmol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 μmol ml-1 (mean ± SEM) in frogs that remained fully hydrated, and to 186.9 ± 12.4 μmol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s) that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to –8°C, either directly or following three cycles of freezing/thawing between –4 and 0°C, or –16°C increased the liver’s synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle) or two-thirds (liver) of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea) to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica. PMID:25688861

Instrumental colour of Iberian ham subcutaneous fat and lean (biceps femoris): Influence of crossbreeding and rearing system.

PubMed

Carrapiso, Ana I; García, Carmen

2005-10-01

The influence of crossbreeding (Iberian vs Iberian×Duroc 50% pigs) and rearing system (Montanera vs Pienso) on the instrumental colour of Iberian ham (subcutaneous fat and biceps femoris muscle) and the relationships to sensory appearance and chemical composition were researched by using a factorial design. In subcutaneous fat, a significant effect (p<0.05) of crossbreeding and rearing system was found: b* and chroma were larger in hams from Iberian pigs than from Iberian×Duroc (50%) pigs, and L*, a* and chroma were larger in Pienso hams than in Montanera hams. CIEL*a*b* variables of subcutaneous fat were closely related to subcutaneous fatty acid composition, the largest correlationships involving L* (L* and 18:0, 0.652, p<0.001; L* and 18:1, -0.616, p<0.001). Instrumental colour variables and sensory appearance were also correlated (L* and fat pinkness, -0.539, p<0.001). In lean (biceps femoris), instrumental colour data was not affected by crossbreeding and rearing system. CIEL*a*b* variables were not related to chemical composition (moisture, NaCl, intramuscular fat and pigment content), although they were correlated to sensory appearance (L* and marbling, 0.419, p=0.014).

California red-legged frog (Rana draytonii) movement and habitat use: Implications for conservation

USGS Publications Warehouse

Fellers, G.M.; Kleeman, P.M.

2007-01-01

Nonbreeding habitats are critically important for Rana draytonii, especially for individuals that breed in temporary bodies of water. We radiotracked 123 frogs to evaluate seasonal habitat use. Individual frogs were continuously tracked for up to 16 months. Some individuals remained at breeding ponds all year, but 66% of female and 25% of male frogs moved to nonbreeding areas, even when the breeding site retained water. Frogs at our main study site moved 150 m (median), roughly the distance to the nearest suitable nonbreeding area. The greatest straight-line distance traveled was 1.4 km, although the presumed distance traveled was 2.8 km. Females were more likely than males to move from permanent ponds (38% of females, 16% of males), but among dispersing frogs, males and females did not differ in distance moved. Some frogs left breeding sites shortly after oviposition (median = 12 days for females, 42.5 days for males), but many individuals remained until the site was nearly dry. Fog provided moisture for dispersal or migration throughout the summer. Our data demonstrate that maintaining populations of pond-breeding amphibians requires that all essential habitat components be protected; these include (1) breeding habitat, (2) nonbreeding habitat, and (3) migration corridors. In addition, a buffer is needed around all three areas to ensure that outside activities do not degrade any of the three habitat components. Copyright 2007 Society for the Study of Amphibians and Reptiles.

Urea loading enhances freezing survival and postfreeze recovery in a terrestrially hibernating frog.

PubMed

Costanzo, Jon P; Lee, Richard E

2008-09-01

We tested the hypothesis that urea, an osmolyte accumulated early in hibernation, functions as a cryoprotectant in the freeze-tolerant wood frog, Rana sylvatica. Relative to saline-treated, normouremic (10 micromol ml(-1)) frogs, individuals rendered hyperuremic (70 micromol ml(-1)) by administration of an aqueous urea solution exhibited significantly higher survival (100% versus 64%) following freezing at -4 degrees C, a potentially lethal temperature. Hyperuremic frogs also had lower plasma levels of intracellular proteins (lactate dehydrogenase, creatine kinase, hemoglobin), which presumably escaped from damaged cells, and more quickly recovered neurobehavioral functions following thawing. Experimental freezing-thawing did not alter tissue urea concentrations, but did elevate glucose levels in the blood and organs of all frogs. When measured 24 h after thawing commenced, glucose concentrations were markedly higher in urea-loaded frogs as compared to saline-treated ones, possibly because elevated urea retarded glucose clearance. Like other low-molecular-mass cryoprotectants, urea colligatively reduces both the amount of ice forming within the body and the osmotic dehydration of cells. In addition, by virtue of certain non-colligative properties, it may bestow additional protection from freeze-thaw damage not afforded by glucose.

Evaluation of use of tiletamine/zolazepam for anesthesia of bullfrogs and leopard frogs.

PubMed

Letcher, J; Durante, R

1995-07-01

Use of tiletamine hydrochloride and zolazepam hydrochloride (1:1 fixed ratio combination) as an anesthetic agent in 2 anuran species was studied. A dosage of 5 mg/kg of body weight, administered IM, resulted in variable weak tranquilization. Intramuscular administration at dosages of 10 and 20 mg/kg induced variable states of tranquilization or anesthesia in leopard frogs (Rana pipiens) and bullfrogs (R catesbeiana). The dosages of 50 mg/kg induced anesthesia with greater consistency than lower dosages in bullfrogs, but resulted in mortalities. The same dosage was uniformly fatal in leopard frogs. Neither gross nor histologic lesions were identified in the frogs that died. Depth and duration of anesthesia was dosage related. At the 20 and 50 mg/kg dosages, leopard frogs attained a greater depth of anesthesia and remained anesthetized for a significantly greater duration than did bullfrogs; however, at the 5 and 10 mg/kg dosages, bullfrogs developed greater tranquilization for longer periods than did leopard frogs. Results of this study revealed profound intraspecies variation in depth and duration of effect of tiletamine/zolazepam; therefore, the drug does not appear to be a suitable injectable anesthetic in anurans.

Adaptive Grouping Cloud Model Shuffled Frog Leaping Algorithm for Solving Continuous Optimization Problems

PubMed Central

Liu, Haorui; Yi, Fengyan; Yang, Heli

2016-01-01

The shuffled frog leaping algorithm (SFLA) easily falls into local optimum when it solves multioptimum function optimization problem, which impacts the accuracy and convergence speed. Therefore this paper presents grouped SFLA for solving continuous optimization problems combined with the excellent characteristics of cloud model transformation between qualitative and quantitative research. The algorithm divides the definition domain into several groups and gives each group a set of frogs. Frogs of each region search in their memeplex, and in the search process the algorithm uses the “elite strategy” to update the location information of existing elite frogs through cloud model algorithm. This method narrows the searching space and it can effectively improve the situation of a local optimum; thus convergence speed and accuracy can be significantly improved. The results of computer simulation confirm this conclusion. PMID:26819584

Checklist and Simple Identification Key for Frogs and Toads from District IV of The MADA Scheme, Kedah, Malaysia

PubMed Central

Jaafar, Ibrahim; Chai, Teoh Chia; Sah, Shahrul Anuar Mohd; Akil, Mohd Abdul Muin Md.

2009-01-01

A survey was conducted to catalogue the diversity of anurans in District IV of the Muda Agriculture Development Authority Scheme (MADA) in Kedah Darul Aman, Malaysia, from July 1996 to January 1997. Eight species of anurans from three families were present in the study area. Of these, the Common Grass Frog (Fejevarya limnocharis) was the most abundant, followed by Mangrove Frog (Fejevarya cancrivora), Long-legged Frog (Hylarana macrodactyla), and Common Toad (Duttaphrynus melanostictus). Puddle Frog (Occidozyga lima), Taiwanese Giant Frog (Hoplobatrachus rugulosus), and Banded Bullfrog (Kaluola pulchra) were rare during the sampling period, and only one Paddy Frog (Hylarana erythraea) was captured. A simple identification key for the anurans of this area is included for use by scientists and laymen alike. PMID:24575178

Habitat selection, movement patterns, and hazards encountered by northern leopard frogs (Lithobates pipiens) in an agricultural landscape

USGS Publications Warehouse

Knutson, Melinda G.; Herner-Thogmartin, Jennifer H.; Thogmartin, Wayne E.; Kapfer, Joshua M.; Nelson, John

2018-01-01

Telemetry data for 59 Northern Leopard Frogs (Lithobates pipiens) breeding in ponds in Houston and Winona Counties, MN; 2001-2002. Agricultural intensification is causing declines in many wildlife species, including Northern Leopard Frogs (Lithobates pipiens). Specific information about frog movements, habitat selection, and sources of mortality can be used to inform conservation-focused land management and acquisition. We studied Northern Leopard Frogs in southeastern Minnesota, part of the Driftless Area ecoregion, characterized by hills and valleys and a mix of agriculture, forests, small towns and farmsteads. In this area, small farm ponds, originally built to control soil erosion are used by the species for breeding and wintering in addition to riparian wetlands. But, this agricultural landscape may be hazardous for frogs moving between breeding, feeding, and wintering habitats. We surgically implanted transmitters into the peritoneal cavity of 59 Northern Leopard Frogs and tracked them from May to October 2001-2002. The total distance traveled by radio-tagged frogs ranged from 12 to 3316 m, the 95% home range averaged 5.3 ± 1.2 (SE) ha, and the 50% core area averaged 1.05 ± 0.3 (SE) ha. As expected, Northern Leopard Frogs selected wetlands over all other land cover classes and row crops were generally avoided at all levels of selection. Only a few tracked frogs were successful at dispersing (n = 6). Most frogs attempting to disperse (n =31) ended up missing (n = 14), died due to mowing (n = 8), or were recorded as transmitter failure (n = 2) or unknown mortalities (n = 1). For the conservation of Northern Leopard Frogs in this agricultural setting, we must consider both the aquatic and the terrestrial needs of this species. Conservation agencies that restore, manage, and acquire wetlands should consider the hazards posed by land uses adjacent to frog breeding and wintering sites and plan for movement corridors between these locations. For example

Sexual dichromatism in frogs: natural selection, sexual selection and unexpected diversity.

PubMed

Bell, Rayna C; Zamudio, Kelly R

2012-12-07

Sexual dichromatism, a form of sexual dimorphism in which males and females differ in colour, is widespread in animals but has been predominantly studied in birds, fishes and butterflies. Moreover, although there are several proposed evolutionary mechanisms for sexual dichromatism in vertebrates, few studies have examined this phenomenon outside the context of sexual selection. Here, we describe unexpectedly high diversity of sexual dichromatism in frogs and create a comparative framework to guide future analyses of the evolution of these sexual colour differences. We review what is known about evolution of colour dimorphism in frogs, highlight alternative mechanisms that may contribute to the evolution of sexual colour differences, and compare them to mechanisms active in other major groups of vertebrates. In frogs, sexual dichromatism can be dynamic (temporary colour change in males) or ontogenetic (permanent colour change in males or females). The degree and the duration of sexual colour differences vary greatly across lineages, and we do not detect phylogenetic signal in the distribution of this trait, therefore frogs provide an opportunity to investigate the roles of natural and sexual selection across multiple independent derivations of sexual dichromatism.

Is trace element concentration correlated to parasite abundance? A case study in a population of the green frog Pelophylax synkl. hispanicus from the Neto River (Calabria, southern Italy).

PubMed

De Donato, Carlo; Barca, Donatella; Milazzo, Concetta; Santoro, Raffaella; Giglio, Gianni; Tripepi, Sandro; Sperone, Emilio

2017-06-01

Bioaccumulation of 13 trace elements in the livers of 38 Pelophylax sinkl. hispanicus (Ranidae) and its helminth communities were studied and compared among three sites, each with a different degree of pollution along River Neto (south Italy) during September, 2014. Trace element concentrations in water and liver were measured using inductively coupled plasma mass spectrometry. For most elements, the highest concentration was recorded in the frogs inhabiting the third site, the one with the highest degree of pollution. The trend of trace element concentration in the liver can be represented as follows: Cu > Zn > Mn > Se > Cr. Concentrations of some elements in water and liver samples were significantly different among the three sites and this is evidenced by the bioaccumulation in the frogs. Four species of helminths, all belonging to Nematoda, were found: Rhabdias sp., Oswaldocruzia filiformis (Goeze, 1782), Cosmocerca ornata (Dujarden, 1845), Seuratascaris numidica (Seurat, 1917). The parasite survey presents an important difference of prevalence and average number of helminths in frogs between the three sites. Correlating parasitological and ecotoxicological data showed a strong positive correlation between prevalence and number of parasites with some trace elements such as Mn, Co, Ni, As, Se, and Cd.

Geochemistry and metamorphism of the Mouriscas Complex, Ossa-Morena/Central Iberian zone boundary, Iberian Massif, Central Portugal: Implications for the Cadomian and Variscan orogenies

NASA Astrophysics Data System (ADS)

Henriques, S. B. A.; Neiva, A. M. R.; Tajčmanová, L.; Dunning, G. R.

2018-01-01

The Mouriscas Complex is a deformed and metamorphosed predominantly mafic igneous complex of Ediacaran and Ordovician age and crops out at the Ossa-Morena/Central Iberian zone boundary in the Iberian Massif, Central Portugal. It comprises amphibolite with Neoproterozoic protoliths (ca. 544 Ma), protomylonitic felsic dykes derived from younger trondhjemitic protoliths (ca. 483 Ma) and garnet amphibolite derived of even younger dioritic protoliths (ca. 477 Ma). The protoliths of the Neoproterozoic amphibolites are calc-alkaline magmas of basic to intermediate compositions with intraplate and active continental margin affinities and are considered to represent the final phase of the Cadomian arc magmatism. They are interpreted to have originated as coarse-grained intrusions, likely gabbro or diorite and generated from the partial melting of meta-igneous lower crust and mantle. Their emplacement occurred near the Cadomian metamorphic event dated at ca. 540 Ma (P = 7-8 kbar and T = 640-660 °C) which is interpreted to represent a continental collision. During the Late Cambrian-Early Ordovician an extensional episode occurred in the central-southern Iberian Massif and was also observed in other areas of the Variscan Orogen. It led to mantle upwelling and to the development of an aborted intracratonic rift located at the Ossa-Morena/Central Iberian zone boundary and to the opening of the Rheic Ocean to the south of the area studied in present coordinates (i.e., between the Ossa-Morena and South Portuguese Zones). This event has been dated at ca. 477 Ma and was responsible for the melting of deep ancient mafic crust and mantle with formation of bimodal magmatism in an intra-plate setting, as indicated by the protoliths of the protomylonitic felsic dykes with trondhjemitic composition and of the garnet amphibolite. Subsequent Variscan metamorphism took place under amphibolite facies conditions (P = 4-5.5 kbar; T = 600-625 °C) at lower P-T conditions than the Cadomian

Population structure of Cicada barbara Stål (Hemiptera, Cicadoidea) from the Iberian Peninsula and Morocco based on mitochondrial DNA analysis.

PubMed

Pinto-Juma, G A; Quartau, J A; Bruford, M W

2008-02-01

We assess the genetic history and population structure of Cicada barbara in Morocco and the Iberian Peninsula, based on analysis of the mitochondrial cytochrome b gene. The divergence between Morocco and the Iberian Peninsula populations was strongly corroborated by the molecular data, suggesting genetically isolated populations with a low level of gene flow. The Ceuta population from Spanish North Africa was more similar to the Iberian populations than the surrounding Moroccan populations, suggesting that the Strait of Gibraltar has not been acting as a strict barrier to dispersal while the Rif Mountains have. The Iberian Peninsula specimens showed a signature of demographic expansion before that which occurred in Morocco, but some of the assumptions related to the demographic parameters should be considered with caution due to the small genetic variation found. The high haplotype diversity found in Morocco implies higher demographic stability than in the Iberian Peninsula populations. These results do not, however, suggest a Moroccan origin for Iberian cicadas; but the most northwest region in Africa, such as Ceuta, might have acted as a southern refuge for Iberian cicadas during the most severe climatic conditions, from where they could expand north when climate improved. The separation of two subspecies within C. barbara (C. barbara lusitanica and C. barbara barbara) finds support with these results.

Factors influencing survival and mark retention in postmetamorphic boreal chorus frogs

USGS Publications Warehouse

Swanson, Jennifer E; Bailey, Larissa L.; Muths, Erin L.; Funk, W. Chris

2013-01-01

The ability to track individual animals is crucial in many field studies and often requires applying marks to captured individuals. Toe clipping has historically been a standard marking method for wild amphibian populations, but more recent marking methods include visual implant elastomer and photo identification. Unfortunately, few studies have investigated the influence and effectiveness of marking methods for recently metamorphosed individuals and as a result little is known about this life-history phase for most amphibians. Our focus was to explore survival probabilities, mark retention, and mark migration in postmetamorphic Boreal Chorus Frogs (Psuedacris maculata) in a laboratory setting. One hundred forty-seven individuals were assigned randomly to two treatment groups or a control group. Frogs in the first treatment group were marked with visual implant elastomer, while frogs in the second treatment group were toe clipped. Growth and mortality were recorded for one year and resulting data were analyzed using known-fate models in Program MARK. Model selection results suggested that survival probabilities of frogs varied with time and showed some variation among marking treatments. We found that frogs with multiple toes clipped on the same foot had lower survival probabilities than individuals in other treatments, but individuals can be marked by clipping a single toe on two different feet without any mark loss or negative survival effects. Individuals treated with visual implant elastomer had a mark migration rate of 4% and mark loss rate of 6%, and also showed very little negative survival impacts relative to control individuals.

An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

PubMed

Dreher, Corinna E; Cummings, Molly E; Pröhl, Heike

2015-01-01

Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio) shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake) and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast) of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and other ecological

Terrestrial movements of juvenile and adult tailed frogs in relation to timber harvest in coastal British Columbia

USGS Publications Warehouse

Wahbe, Tanya R.; Bunnell, Fred L.; Bury, R. Bruce

2004-01-01

Tailed frog (Ascaphus truei Stejneger) populations are at risk in much of the Pacific Northwest, and recolonization of sites may be slow postlogging. To examine the terrestrial movements of Ascaphus in clearcuts and old growth, we employed pitfall traps and drift-fence arrays installed along streams and 100 m into upland habitat. In the fall, we captured frogs farther from streams in old growth than in clearcuts, and more frogs were captured a??25 m from streams in clearcuts. Stronger stream affinity in clearcuts was most evident with juvenile frogs, which exhibited more upstream movements than adults. Compared with inland sites where frogs remained close to streams (e.g., 12 m), frogs at our coastal sites were captured at greater distances from streams (a?Y100 m), having lower stream affinity than frogs at inland sites. Long-distance overland movements appear more likely where forested stands are present. Aggregations of Ascaphus at individual streams may not represent distinct populations and should not be managed as distinct units. Preserving groups of interconnected streams within watersheds instead of individual streams will improve the conservation status of Ascaphus. Population monitoring can ensure conservation measures promote long-term persistence.

Iberian Odonata distribution: data of the BOS Arthropod Collection (University of Oviedo, Spain)

PubMed Central

Torralba-Burrial, Antonio; Ocharan, Francisco J.

2013-01-01

Abstract Odonata are represented from the Iberian Peninsula by 79 species. However, there exists a significant gap in accessible knowledge about these species,especially regarding their distribution. This data paper describes the specimen-based Odonata data of the Arthropod Collection of the Department of Biología de Organismos y Sistemas (BOS), University of Oviedo, Spain. The specimens were mainly collected from the Iberian Peninsula (98.63% of the data records), especially the northern region. The earliest specimen deposited in the collection dates back to 1950, while the 1980’s and 2000’s are the best-represented time periods. Between 1950 and 2009, 16, 604 Odonata specimens were deposited and are documented in the dataset. Approximately 20% of the specimens belong to the families Coenagrionidae and Calopterygidae. Specimens include the holotype and paratypes of the Iberian subspecies Calopteryx haemorrhoidalis asturica Ocharan, 1983 and Sympetrum vulgatum ibericum Ocharan, 1985. The complete dataset is also provided in Darwin Core Archive format. PMID:23794917

Iberian Odonata distribution: data of the BOS Arthropod Collection (University of Oviedo, Spain).

PubMed

Torralba-Burrial, Antonio; Ocharan, Francisco J

2013-01-01

Odonata are represented from the Iberian Peninsula by 79 species. However, there exists a significant gap in accessible knowledge about these species,especially regarding their distribution. This data paper describes the specimen-based Odonata data of the Arthropod Collection of the Department of Biología de Organismos y Sistemas (BOS), University of Oviedo, Spain. The specimens were mainly collected from the Iberian Peninsula (98.63% of the data records), especially the northern region. The earliest specimen deposited in the collection dates back to 1950, while the 1980's and 2000's are the best-represented time periods. Between 1950 and 2009, 16, 604 Odonata specimens were deposited and are documented in the dataset. Approximately 20% of the specimens belong to the families Coenagrionidae and Calopterygidae. Specimens include the holotype and paratypes of the Iberian subspecies Calopteryx haemorrhoidalis asturica Ocharan, 1983 and Sympetrum vulgatum ibericum Ocharan, 1985. The complete dataset is also provided in Darwin Core Archive format.

Population estimates for the Toiyabe population of the Columbia spotted frog (Rana luteiventris), 2004–10

USGS Publications Warehouse

Adams, Michael J.; Mellison, Chad; Galvan, Stephanie K.

2013-01-01

The Toiyabe population of Columbia spotted frogs (Rana luteiventris, hereafter "Toiyabe frogs") is a geographically isolated population located in central Nevada (fig. 1). The Toiyabe population is part of the Great Basin Distinct Population Segment of Columbia spotted frogs, and is a candidate for listing under the Endangered Species Act (U.S. Fish and Wildlife Service, 2011). The cluster of breeding sites in central Nevada represents the southernmost extremity of the Columbia spotted frogs' known range (Funk and others, 2008). Toiyabe frogs are known to occur in seven drainages in Nye County, Nevada: Reese River, Cow Canyon Creek, Ledbetter Canyon Creek, Cloverdale Creek, Stewart Creek, Illinois Creek, and Indian Valley Creek. Most of the Toiyabe frog population resides in the Reese River, Indian Valley Creek, and Cloverdale Creek drainages (fig. 1; Nevada Department of Wildlife, 2003). Approximately 90 percent of the Toiyabe frogs' habitat is on public land. Most of the public land habitat (95 percent) is managed by the U.S. Forest Service (USFS), while the Bureau of Land Management (BLM) manages the remainder. Additional Toiyabe frog habitat is under Yomba Shoshone Tribal management and in private ownership (Nevada Department of Wildlife, 2003). The BLM, USFS, Nevada Department of Wildlife (NDOW), Nevada Natural Heritage Program (NNHP), Nye County, and U.S Fish and Wildlife Service (USFWS) have monitored the Toiyabe population since 2004 using mark and recapture surveys (Nevada Department of Wildlife, 2004). The USFWS contracted with the U.S. Geological Survey (USGS) to produce population estimates using these data.

Comparability of fish-based ecological quality assessments for geographically distinct Iberian regions.

PubMed

Segurado, P; Caiola, N; Pont, D; Oliveira, J M; Delaigue, O; Ferreira, M T

2014-04-01

In this work we compare two Iberian and a pan-European fish-based methods to assess ecological quality in rivers: the Fish-based Index of Biotic Integrity for Portuguese Wadeable Streams (F-IBIP), the Mediterranean Index of Biotic Integrity (IBIMED) and the pan-European Fish Index (EFI+). The results presented herein were developed in the context of the 2nd phase of the Intercalibration Exercise (IC), as required by the Water Frame Directive (WFD). The IC is aimed at ensuring comparability of the quality boundaries among the different WFD assessment methods developed by the Member States for each biological quality element. Although the two national assessment methods were developed for very distinct regions of Iberia (Western and Eastern Iberian Peninsula) they share the same methodological background: both are type-specific and guild-based multimetric indices. EFI+ is a multimetric guild-based model, but it is site-specific and uses a predictive modelling approach. The three indices were computed for all sites included in the Iberian Intercalibration database to allow the direct comparison, by means of linear regressions, of the resulting three quality values per site. The quality boundary harmonization between the two Iberian methods was only possible through an indirect comparison between the two indices, using EFI+ as a common metric. The three indices were also shown to be responsive to a common set of human induced pressures. This study highlights the need to develop general assessment methods adapted to wide geographical ranges with high species turnover to help intercalibrating assessment methods tailored for geographically more restricted regions. © 2013.

Diversity within diversity: Parasite species richness in poison frogs assessed by transcriptomics.

PubMed

Santos, Juan C; Tarvin, Rebecca D; O'Connell, Lauren A; Blackburn, David C; Coloma, Luis A

2018-08-01

Symbionts (e.g., endoparasites and commensals) play an integral role in their host's ecology, yet in many cases their diversity is likely underestimated. Although endoparasites are traditionally characterized using morphology, sequences of conserved genes, and shotgun metagenomics, host transcriptomes constitute an underused resource to identify these organisms' diversity. By isolating non-host transcripts from host transcriptomes, individual host tissues can now simultaneously reveal their endoparasite species richness (i.e., number of different taxa) and provide insights into parasite gene expression. These approaches can be used in host taxa whose endoparasites are mostly unknown, such as those of tropical amphibians. Here, we focus on the poison frogs (Dendrobatidae) as hosts, which are a Neotropical clade known for their bright coloration and defensive alkaloids. These toxins are an effective protection against vertebrate predators (e.g., snakes and birds), bacteria, and skin-biting ectoparasites (e.g., mosquitoes); however, little is known about their deterrence against eukaryotic endoparasites. With de novo transcriptomes of dendrobatids, we developed a bioinformatics pipeline for endoparasite identification that uses host annotated RNA-seq data and set of a priori parasite taxonomic terms, which are used to mine for specific endoparasites. We found a large community of helminths and protozoans that were mostly restricted to the digestive tract and a few systemic parasites (e.g., Trypanosoma). Contrary to our expectations, all dendrobatid frogs regardless of the presence of alkaloid defenses have endoparasites, with their highest species richness located in the frog digestive tract. Some of these organisms (e.g., roundworms) might prove to be generalists, as they were not found to be co-diversifying with their frog hosts. We propose that endoparasites may escape poison frogs' chemical defenses by colonizing tissues with fewer alkaloids than the frog's skin

Discovery of skin alkaloids in a miniaturized eleutherodactylid frog from Cuba

PubMed Central

Rodríguez, Ariel; Poth, Dennis; Schulz, Stefan; Vences, Miguel

2011-01-01

Four phylogenetically independent lineages of frogs are currently known to sequester lipid-soluble skin alkaloids for which a dietary source has been demonstrated. We report here a remarkable fifth such instance, in Eleutherodactylus iberia and Eleutherodactylus orientalis, two species of miniaturized frogs of the family Eleutherodactylidae from Cuba. Six pumiliotoxins and two indolizidines were found in E. iberia, one of the smallest frogs in the world and characterized by a contrasting colour pattern for which we hypothesize an aposematic function. Analyses of stomach content indicated a numerical prevalence of mites with an important proportion of oribatids—a group of arthropods known to contain one of the pumiliotoxins detected in E. iberia. This suggests that miniaturization and specialization to small prey may have favoured the acquisition of dietary skin alkaloids in these amphibians. PMID:21047848

Discovery of skin alkaloids in a miniaturized eleutherodactylid frog from Cuba.

PubMed

Rodríguez, Ariel; Poth, Dennis; Schulz, Stefan; Vences, Miguel

2011-06-23

Four phylogenetically independent lineages of frogs are currently known to sequester lipid-soluble skin alkaloids for which a dietary source has been demonstrated. We report here a remarkable fifth such instance, in Eleutherodactylus iberia and Eleutherodactylus orientalis, two species of miniaturized frogs of the family Eleutherodactylidae from Cuba. Six pumiliotoxins and two indolizidines were found in E. iberia, one of the smallest frogs in the world and characterized by a contrasting colour pattern for which we hypothesize an aposematic function. Analyses of stomach content indicated a numerical prevalence of mites with an important proportion of oribatids-a group of arthropods known to contain one of the pumiliotoxins detected in E. iberia. This suggests that miniaturization and specialization to small prey may have favoured the acquisition of dietary skin alkaloids in these amphibians.

The toxicity of Poison Dart Frog alkaloids against the Fire Ant (Solenopsis invicta)

USDA-ARS?s Scientific Manuscript database

Hundreds of alkaloids, representing over 20 structural classes, have been identified from the skin of neotropical poison frogs (Dendrobatidae). These alkaloids are derived from arthropod prey of the frogs, and are generally are believed to deter vertebrate predators. We developed a method to put ind...

The extraordinary biology and development of marsupial frogs (Hemiphractidae) in comparison with fish, mammals, birds, amphibians and other animals.

PubMed

Del Pino, Eugenia M

2018-01-03

The study of oogenesis and early development of frogs belonging to the family Hemiphractidae provide important comparison to the aquatic development of other frogs, such as Xenopus laevis, because reproduction on land characterizes the Hemiphractidae. In this review, the multinucleated oogenesis of the marsupial frog Flectonotus pygmaeus (Hemiphractidae) is analyzed and interpreted. In addition, the adaptations associated with the incubation of embryos in the pouch of the female marsupial frog Gastrotheca riobambae (Hemiphractidae) and the embryonic development of this frog are summarized. Moreover, G. riobambae gastrulation is compared with the gastrulation modes of Engystomops randi and Engystomops coloradorum (Leptodactylidae); Ceratophrys stolzmanni (Ceratophryidae); Hyalinobatrachium fleischmanni and Espadarana callistomma (Centrolenidae); Ameerega bilinguis, Dendrobates auratus, Epipedobates anthonyi, Epipedobates machalilla, Epipedobates tricolor, and Hyloxalus vertebralis (Dendrobatidae); Eleutherodactylus coqui (Terrarana: Eleutherodactylidae), and X. laevis (Pipidae). The comparison indicated two modes of frog gastrulation. In X. laevis and in frogs with aquatic reproduction, convergent extension begins during gastrulation. In contrast, convergent extension occurs in the post-gastrula of frogs with terrestrial reproduction. These two modes of gastrulation resemble the transitions toward meroblastic cleavage found in ray-finned fishes (Actinopterygii). In spite of this difference, the genes that guide early development seem to be highly conserved in frogs. I conclude that the shift of convergent extension to the post-gastrula accompanied the diversification of frog egg size and terrestrial reproductive modes. Copyright © 2018 Elsevier B.V. All rights reserved.

Diet of introduced bullfrogs (Rana catesbeiana): Predation on and diet overlap with native frogs on Daishan Island, China

USGS Publications Warehouse

Wu, Zhengjun; Li, Y.; Wang, Y.; Adams, Michael J.

2005-01-01

We examined diet of introduced Bullfrogs (Rana catesbeiana) and three native frog species (Rana limnocharis, Rana nigromaculata, and Bufo bufo gargarizans) co-occurring at a group of ponds on Daishan Island, east of China, to gain insight into the nature of potential interactions between Bullfrogs and native frog species. For postmetamorphic Bullfrogs, aquatic prey items dominated volumetrically. Prey size, diet volume and volumetric percentage of native frogs in diet increased with Bullfrog body size. The number and volumetric percentage of native frogs in the diet were not different for female and male Bullfrogs, and both were higher for adults than for juveniles. Diet overlap between males and juveniles was higher than that between males and females and between females and juveniles. Diet overlap with each native frog species of male Bullfrogs was lower than that of female Bullfrogs and juvenile Bullfrogs. We did not exam effects of Bullfrogs on native frogs but our results suggest that the primary threat posed by juvenile Bullfrogs to native frogs on Daishan Island is competition for food, whereas the primary threat posed by male Bullfrogs is direct predation. Female Bullfrogs may threaten native frogs by both competition and predation. These differences among Bullfrog groups may be attributed to differences in body size and microhabitat use.

Frogs Jump Forward: Semantic Knowledge Influences the Perception of Element Motion in the Ternus Display.

PubMed

Hsu, Patty; Taylor, J Eric T; Pratt, Jay

2015-01-01

The Ternus effect is a robust illusion of motion that produces element motion at short interstimulus intervals (ISIs; < 50 ms) and group motion at longer ISIs (> 50 ms). Previous research has shown that the nature of the stimuli (e.g., similarity, grouping), not just ISI, can influence the likelihood of perceiving element or group motion. We examined if semantic knowledge can also influence what type of illusory motion is perceived. In Experiment I, we used a modified Ternus display with pictures of frogs in a jump-ready pose facing forwards or backwards to the direction of illusory motion. Participants perceived more element motion with the forward-facing frogs and more group motion with the backward-facing frogs. Experiment 2 tested whether this effect would still occur with line drawings of frogs, or if a more life-like image was necessary. Experiment 3 tested whether this effect was due to visual asymmetries inherent in the jumping pose. Experiment 4 tested whether frogs in a "non-jumping," sedentary pose would replicate the original effect. These experiments elucidate the role of semantic knowledge in the Ternus effect. Prior knowledge of the movement of certain animate objects, in this case, frogs can also bias the perception of element or group motion.

Research on moving object detection based on frog's eyes

NASA Astrophysics Data System (ADS)

Fu, Hongwei; Li, Dongguang; Zhang, Xinyuan

2008-12-01

On the basis of object's information processing mechanism with frog's eyes, this paper discussed a bionic detection technology which suitable for object's information processing based on frog's vision. First, the bionics detection theory by imitating frog vision is established, it is an parallel processing mechanism which including pick-up and pretreatment of object's information, parallel separating of digital image, parallel processing, and information synthesis. The computer vision detection system is described to detect moving objects which has special color, special shape, the experiment indicates that it can scheme out the detecting result in the certain interfered background can be detected. A moving objects detection electro-model by imitating biologic vision based on frog's eyes is established, the video simulative signal is digital firstly in this system, then the digital signal is parallel separated by FPGA. IN the parallel processing, the video information can be caught, processed and displayed in the same time, the information fusion is taken by DSP HPI ports, in order to transmit the data which processed by DSP. This system can watch the bigger visual field and get higher image resolution than ordinary monitor systems. In summary, simulative experiments for edge detection of moving object with canny algorithm based on this system indicate that this system can detect the edge of moving objects in real time, the feasibility of bionic model was fully demonstrated in the engineering system, and it laid a solid foundation for the future study of detection technology by imitating biologic vision.

Adenomatous hyperplasia of the mucous glands in captive Archey's frogs (Leiopelma archeyi).

PubMed

Shaw, S D; Berger, L; Harvey, C; Alley, M R; Bishop, P J; Speare, R

2017-05-01

To describe the gross and light microscopic characteristics of skin lesions observed on the ventral skin of captive Archey's frogs (Leiopelma archeyi) between 2000 and 2012, and to investigate their occurrence, possible aetiology and association with survival. Postmortem skin samples were obtained for histological evaluation from 37 frogs, with and without skin lesions, that died while in captivity at Auckland Zoo between 2000 and 2012. Four frogs with skin lesions were biopsied under general anaesthesia and samples used for both light and transmission electron microscopy. The records of 94 frogs held at the University of Otago and Auckland Zoo between 2000-2012 were reviewed, which included some frogs recently collected from the wild. Information about the occurrence of skin lesions, and mortality associated with skin lesions was collated. Grossly the skin lesions varied in appearance; most were circular, pale grey papules, which measured from <0.5-1.5 mm in diameter with no umbilication. The overlying epidermis was not fragile and there was no associated inflammation. Contents often appeared clear or semi-transparent. Lesions were located predominantly on ventral surfaces including trunk, thighs, lower legs and forearms, and gular region, but not on digits. The number ranged from single to multiple, often confluent lesions covering the entire ventral surface of the frog. Histologically the lesions consisted of enlarged proliferating mucous glands that expanded the dermis and elevated the epidermis. They were semi-organised, solid or occasionally cavitated acinar structures with central lumina which sometimes contained mucus. Nuclei showed moderate anisokaryosis and mitotic figures were uncommon. Transmission electron microscopy did not show any infectious agents. Between 2000 and 2012, skin lesions were recorded in 35/94 (37%) frogs. The size and location of skin lesions varied over time, with some resolving and sometimes reappearing. Skin lesions were not

Ascent ability of brown trout, Salmo trutta, and two Iberian cyprinids − Iberian barbel, Luciobarbus bocagei, and northern straight-mouth nase, Pseudochondrostoma duriense − in a vertical slot fishway

USGS Publications Warehouse

Sanz-Ronda, Fco. Javier; Bravo-Cordoba, F.J.; Fuentes-Perez, J.F.; Castro-Santos, Theodore R.

2016-01-01

Passage performance of brown trout (Salmo trutta), Iberian barbel (Luciobarbus bocagei), and northern straight-mouth nase (Pseudochondrostoma duriense) was investigated in a vertical slot fishway in the Porma River (Duero River basin, Spain) using PIT telemetry. We analysed the effects of different fishway discharges on motivation and passage success. Both cyprinid species ascended the fishway easily, performing better than the trout despite their theoretically weaker swimming performance. Fishway discharge affected fish motivation although it did not clearly influence passage success. Observed results can guide design and operation criteria of vertical slot fishways for native Iberian fish.

A reappraisal of the Middle Triassic chirotheriid Chirotherium ibericus Navás, 1906 (Iberian Range NE Spain), with comments on the Triassic tetrapod track biochronology of the Iberian Peninsula

PubMed Central

Castanera, Diego; Gasca, José Manuel; Canudo, José Ignacio

2015-01-01

Triassic vertebrate tracks are known from the beginning of the 19th century and have a worldwide distribution. Several Triassic track ichnoassemblages and ichnotaxa have a restricted stratigraphic range and are useful in biochronology and biostratigraphy. The record of Triassic tracks in the Iberian Peninsula has gone almost unnoticed although more than 25 localities have been described since 1897. In one of these localities, the naturalist Longinos Navás described the ichnotaxon Chirotherium ibericus in 1906.The vertebrate tracks are in two sandy slabs from the Anisian (Middle Triassic) of the Moncayo massif (Zaragoza, Spain). In a recent revision, new, previously undescribed vertebrate tracks have been identified. The tracks considered to be C. ibericus as well as other tracks with the same morphology from both slabs have been classified as Chirotherium barthii. The rest of the tracks have been assigned to Chirotheriidae indet., Rhynchosauroides isp. and undetermined material. This new identification of C. barthii at the Navás site adds new data to the Iberian record of this ichnotaxon, which is characterized by the small size of the tracks when compared with the main occurrences of this ichnotaxon elsewhere. As at the Navás tracksite, the Anisian C. barthii-Rhynchosauroides ichnoassemblage has been found in other coeval localities in Iberia and worldwide. This ichnoassemblage belongs to the upper Olenekian-lower Anisian interval according to previous biochronological proposals. Analysis of the Triassic Iberian record of tetrapod tracks is uneven in terms of abundance over time. From the earliest Triassic to the latest Lower Triassic the record is very scarce, with Rhynchosauroides being the only known ichnotaxon. Rhynchosauroides covers a wide temporal range and gives poor information for biochronology. The record from the uppermost Lower Triassic to the Middle Triassic is abundant. The highest ichnodiversity has been reported for the Anisian with an

Characteristics of storms that contribute to extreme precipitation events over the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Trigo, Ricardo; Ramos, Alexandre M.; Ordoñez, Paulina; Liberato, Margarida L. R.; Trigo, Isabel F.

2014-05-01

Floods correspond to one of the most deadly natural disasters in the Iberian Peninsula during the last century. Quite often these floods are associated to intense low pressure systems with an Atlantic origin. In recent years a number of episodes have been evaluated on a case-by-case approach, with a clear focus on extreme events, thus lacking a systematic assessment. In this study we focus on the characteristics of storms for the extended winter season (October to March) that are responsible for the most extreme rainfall events over large areas of the Iberian Peninsula. An objective method for ranking daily precipitation events during the extended winter is used based on the most comprehensive database of high resolution (0.2º latitude by 0.2º longitude) gridded daily precipitation dataset available for the Iberian Peninsula. The magnitude of an event is obtained after considering the total area affected as well as its intensity in every grid point (taking into account the daily normalised departure from climatology). Different precipitation rankings are studied considering the entire Iberian Peninsula, Portugal and also the six largest river basins in the Iberian Peninsula (Duero, Ebro, Tagus, Minho, Guadiana and Guadalquivir). Using an objective cyclone detecting and tracking scheme [Trigo, 2006] the storm track and characteristics of the cyclones were obtained using the ERA-Interim reanalyses for the 1979-2008 period. The spatial distribution of extratropical cyclone positions when the precipitation extremes occur will be analysed over the considered sub-domains (Iberia, Portugal, major river basins). In addition, we distinguish the different cyclone characteristics (lifetime, direction, minimum pressure, position, velocity, vorticity and radius) with significant impacts in precipitation over the different domains in the Iberian Peninsula. This work was partially supported by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the COMPETE (Programa

An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species

PubMed Central

Dreher, Corinna E.; Cummings, Molly E.; Pröhl, Heike

2015-01-01

Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio) shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake) and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast) of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and other ecological

Towards a better understanding of the use of probiotics for preventing chytridiomycosis in Panamanian golden frogs.

PubMed

Becker, Matthew H; Harris, Reid N; Minbiole, Kevin P C; Schwantes, Christian R; Rollins-Smith, Louise A; Reinert, Laura K; Brucker, Robert M; Domangue, Rickie J; Gratwicke, Brian

2011-12-01

Populations of native Panamanian golden frogs (Atelopus zeteki) have collapsed due to a recent chytridiomycosis epidemic. Reintroduction efforts from captive assurance colonies are unlikely to be successful without the development of methods to control chytridiomycosis in the wild. In an effort to develop a protective treatment regimen, we treated golden frogs with Janthinobacterium lividum, a skin bacterium that has been used to experimentally prevent chytridiomycosis in North American amphibians. Although J. lividum appeared to colonize A. zeteki skin temporarily, it did not prevent or delay mortality in A. zeteki exposed to Batrachochytrium dendrobatidis, the causative agent of chytridiomycosis. After introduction of J. lividum, average bacterial cell counts reached a peak of 1.7 × 10(6) cells per frog ~2 weeks after treatment but declined steadily after that. When J. lividum numbers declined to ~2.8 × 10(5) cells per frog, B. dendrobatidis infection intensity increased to greater than 13,000 zoospore equivalents per frog. At this point, frogs began to die of chytridiomycosis. Future research will concentrate on isolating and testing antifungal bacterial species from Panama that may be more compatible with Atelopus skin.

Placement of intracoelomic radio transmitters and silicone passive sampling devices in northern leopard frogs (Lithobates pipiens)

USGS Publications Warehouse

Yaw, Taylor; Swanson, Jennifer E; Pierce, Clay; Muths, Erin L.; Smalling, Kelly; Vandever, Mark; Zaffarano, Bianca Anne

2017-01-01

Historically, wetland toxin exposure studies have relied on single time point samples from stationary sampling devices. Development of passive sampling devices (PSDs) that can be attached to individual animals within wetland habitats has greatly improved in recent years, presenting an innovative sampling technology that can potentially yield individual-specific, quantifiable data about chemical exposure. In this study, silicone based PSDs were attached to the ventral skin of 20 northern leopard frogs (Lithobates pipiens) with polypropylene sutures after radio transmitters had been surgically implanted into the coleomic cavity. After a recovery period frogs were released back into the wetland habitat where they were acquired. The animals were located daily using radio telemetry to assess how long PSDs would remain attached in the frogs' natural habitat. After one week, PSDs remained on 18 of the original 20 frogs. At 2 weeks 17 frogs were recovered and no PSDs remained attached. Although valuable data can be obtained over a short time period, more research will be necessary to demonstrate effectiveness of externally attaching silicone PSDs to northern leopard frogs for time periods longer than 1-2 weeks.

High level of cryptic species diversity revealed by sympatric lineages of Southeast Asian forest frogs

PubMed Central

Stuart, Bryan L; Inger, Robert F; Voris, Harold K

2006-01-01

Amphibians tend to exhibit conservative morphological evolution, and the application of molecular and bioacoustic tools in systematic studies have been effective at revealing morphologically ‘cryptic’ species within taxa that were previously considered to be a single species. We report molecular genetic findings on two forest-dwelling ranid frogs from localities across Southeast Asia, and show that sympatric evolutionary lineages of morphologically cryptic frogs are a common pattern. These findings imply that species diversity of Southeast Asian frogs remains significantly underestimated, and taken in concert with other molecular investigations, suggest there may not be any geographically widespread, forest-dwelling frog species in the region. Accurate assessments of diversity and distributions are needed to mitigate extinctions of evolutionary lineages in these threatened vertebrates. PMID:17148433

New insights into the genetic composition and phylogenetic relationship of wolves and dogs in the Iberian Peninsula.

PubMed

Pires, Ana Elisabete; Amorim, Isabel R; Borges, Carla; Simões, Fernanda; Teixeira, Tatiana; Quaresma, Andreia; Petrucci-Fonseca, Francisco; Matos, José

2017-06-01

This study investigates the gene pool of Portuguese autochthonous dog breeds and their wild counterpart, the Iberian wolf subspecies ( Canis lupus signatus ), using standard molecular markers. A combination of paternal and maternal molecular markers was used to investigate the genetic composition, genetic differentiation and genetic relationship of native Portuguese dogs and the Iberian wolf. A total of 196 unrelated dogs, including breed and village dogs from Portugal, and other dogs from Spain and North Africa, and 56 Iberian wolves (wild and captive) were analyzed for nuclear markers, namely Y chromosome SNPs, Y chromosome STR loci, autosomal STR loci, and a mitochondrial fragment of the control region I. Our data reveal new variants for the molecular markers and confirm significant genetic differentiation between Iberian wolf and native domestic dogs from Portugal. Based on our sampling, no signs of recent introgression between the two subspecies were detected. Y chromosome data do not reveal genetic differentiation among the analyzed dog breeds, suggesting they share the same patrilineal origin. Moreover, the genetic distinctiveness of the Iberian wolf from other wolf populations is further confirmed with the description of new mtDNA variants for this endemism. Our research also discloses new molecular markers for wolf and dog subspecies assignment, which might become particularly relevant in the case of forensic or noninvasive genetic studies. The Iberian wolf represents a relic of the once widespread wolf population in Europe and our study reveals that it is a reservoir of unique genetic diversity of the grey wolf, Canis lupus . These results stress the need for conservation plans that will guarantee the sustainability of this threatened top predator in Iberia.

Latest Early Pleistocene remains of Lynx pardinus (Carnivora, Felidae) from the Iberian Peninsula: Taxonomy and evolutionary implications

NASA Astrophysics Data System (ADS)

Boscaini, Alberto; Alba, David M.; Beltrán, Juan F.; Moyà-Solà, Salvador; Madurell-Malapeira, Joan

2016-07-01

The Iberian lynx (Lynx pardinus) is a critically endangered felid that, during the last fifty years, has been subject to an intensive conservation program in an attempt to save it from extinction. This species is first recorded at ca. 1.7-1.6 Ma (late Villafranchian, late Early Pleistocene) in NE Iberian Peninsula, roughly coinciding with the large faunal turnover that occurred around the middle to late Villafranchian boundary. Here we describe the largest collection of L. pardinus remains available to date from the Iberian late Early Pleistocene (Epivillafranchian), including localities from the Vallparadís Section (Vallès-Penedès Basin, NE Iberian Peninsula) and Cueva Victoria (Cartagena, SE Iberian Peninsula). The morphology and biometry of the studied material attests to the widespread occurrence of L. pardinus in the Mediterranean coast of the Iberian Peninsula since the latest Early Pleistocene, i.e., about 0.5 million years earlier than it was generally accepted (i.e., at the beginning of the Middle Pleistocene). Based on the features observed in the large sample studied in this paper, we conclude that Lynx spelaeus is a junior synonym of L. pardinus and further propose to assign all the Epivillafranchian and younger fossil lynxes from SW Europe to the extant species L. pardinus. Due to the arrival of the Eurasian lynx (Lynx lynx) into Europe at the beginning of the Late Pleistocene, the attribution of specimens younger than MIS 5e to either this species or L. pardinus solely on morphological grounds has proven equivocal. Here we discuss the main diagnostic features of both species of European lynxes and further review their evolutionary history and paleobiogeography throughout the Pleistocene.

Groundwater dependant vegetation identified by remote sensing in the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Gouveia, Célia; Pascoa, Patrícia; Kurz-Besson, Cathy

2017-04-01

Groundwater Dependant Ecosystems (GDEs) are defined as ecosystems whose composition, structure, and function depend on the water supplies from groundwater aquifers. Within GDEs, phreatophytes are terrestrial plants relying on groundwater through deep rooting. They can be found worldwide but are mostly adapted to environments facing scarce water availability or recurrent drought periods mainly in semi-arid to arid climate geographical areas, such as the Mediterranean basin. We present a map of the potential distribution of GDEs over the Iberian Peninsula (IP) obtained by remote sensing and identifying hotspots corresponding to the most vulnerable areas for rainfed vegetation facing the risk of desertification. The characterization of GDEs was assessed by remote sensing (RS), using CORINE land-cover information and the Normalized Difference Vegetation Index (NDVI) from VEGETATION recorded between 1998 and 2014 with a resolution of 1km. The methodology based on Gou et al (2015) relied on three approaches to map GDEs over the IP by: i) Detecting vegetation remaining green during the dry periods, since GDEs are more likely to show high NDVI values during summer of dry years; ii) Spotting vegetation with low seasonal changes since GDEs are more prone to have the lowest NDVI standard deviation along an entire year, and iii) Discriminating vegetation with low inter-annual variability since GDEs areas should provide the lowest NDVI changes between extreme wet and dry years. A geospatial analysis was performed to gather the potential area of GDEs (obtained with NDVI), vegetation land cover types (CORINE land cover) and climatic variables (temperature, precipitation and the Standardized Precipitation-Evapotranspiration Index SPEI). This analysis allowed the identification of hotspots of the most vulnerable areas for rainfed vegetation regarding water scarcity over the Iberian Peninsula, where protection measures should be urgently applied to sustain rainfed ecosystem and agro

Frog: Asynchronous Graph Processing on GPU with Hybrid Coloring Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Xuanhua; Luo, Xuan; Liang, Junling

GPUs have been increasingly used to accelerate graph processing for complicated computational problems regarding graph theory. Many parallel graph algorithms adopt the asynchronous computing model to accelerate the iterative convergence. Unfortunately, the consistent asynchronous computing requires locking or atomic operations, leading to significant penalties/overheads when implemented on GPUs. As such, coloring algorithm is adopted to separate the vertices with potential updating conflicts, guaranteeing the consistency/correctness of the parallel processing. Common coloring algorithms, however, may suffer from low parallelism because of a large number of colors generally required for processing a large-scale graph with billions of vertices. We propose a light-weightmore » asynchronous processing framework called Frog with a preprocessing/hybrid coloring model. The fundamental idea is based on Pareto principle (or 80-20 rule) about coloring algorithms as we observed through masses of realworld graph coloring cases. We find that a majority of vertices (about 80%) are colored with only a few colors, such that they can be read and updated in a very high degree of parallelism without violating the sequential consistency. Accordingly, our solution separates the processing of the vertices based on the distribution of colors. In this work, we mainly answer three questions: (1) how to partition the vertices in a sparse graph with maximized parallelism, (2) how to process large-scale graphs that cannot fit into GPU memory, and (3) how to reduce the overhead of data transfers on PCIe while processing each partition. We conduct experiments on real-world data (Amazon, DBLP, YouTube, RoadNet-CA, WikiTalk and Twitter) to evaluate our approach and make comparisons with well-known non-preprocessed (such as Totem, Medusa, MapGraph and Gunrock) and preprocessed (Cusha) approaches, by testing four classical algorithms (BFS, PageRank, SSSP and CC). On all the tested applications

Woody debris in north Iberian streams: influence of geomorphology, vegetation, and management.

PubMed

Diez, J R; Elosegi, A; Pozo, J

2001-11-01

The effect of stream geomorphology, maturity, and management of riparian forests on abundance, role, and mobility of wood was evaluated in 20 contrasting reaches in the Agüera stream catchment (northern Iberian Peninsula). During 1 year the volume of woody debris exceeding 1 cm in diameter was measured in all reaches. All large woody debris (phi > 5 cm) pieces were tagged, their positions mapped, and their subsequent changes noted. Volume of woody debris was in general low and ranged from 40 to 22,000 cm3 m-2; the abundance of debris dams ranged from 0 to 5.5 per 100 m of channel. Wood was especially rare and unstable in downstream reaches, or under harvested forests (both natural or plantations). Results stress that woody debris in north Iberian streams has been severely reduced by forestry and log removal. Because of the important influence of woody debris on structure and function of stream systems, this reduction has likely impacted stream communities. Therefore, efforts to restore north Iberian streams should include in-channel and riparian management practices that promote greater abundance and stability of large woody debris whenever possible.

Early-Life Diet Affects Host Microbiota and Later-Life Defenses Against Parasites in Frogs.

PubMed

Knutie, Sarah A; Shea, Lauren A; Kupselaitis, Marinna; Wilkinson, Christina L; Kohl, Kevin D; Rohr, Jason R

2017-10-01

Food resources can affect the health of organisms by altering their symbiotic microbiota and affecting energy reserves for host defenses against parasites. Different diets can vary in their macronutrient content and therefore they might favor certain bacterial communities of the host and affect the development and maintenance of the immune system, such as the inflammatory or antibody responses. Thus, testing the effect of diet, especially for animals with wide diet breadths, on host-associated microbiota and defenses against parasites might be important in determining infection and disease risk. Here, we test whether the early-life diet of Cuban tree frogs (Osteopilus septentrionalis) affects early- and later-life microbiota as well as later-life defenses against skin-penetrating, gut worms (Aplectana hamatospicula). We fed tadpoles two ecologically common diets: a diet of conspecifics or a diet of algae (Arthrospira sp.). We then: (1) characterized the gut microbiota of tadpoles and adults; and (2) challenged adult frogs with parasitic worms and measured host resistance (including the antibody-mediated immune response) and tolerance of infections. Tadpole diet affected bacterial communities in the guts of tadpoles but did not have enduring effects on the bacterial communities of adults. In contrast, tadpole diet had enduring effects on host resistance and tolerance of infections in adult frogs. Frogs that were fed a conspecific-based diet as tadpoles were more resistant to worm penetration compared with frogs that were fed an alga-based diet as tadpoles, but less resistant to worm establishment, which may be related to their suppressed antibody response during worm establishment. Furthermore, frogs that were fed a conspecific-based diet as tadpoles were more tolerant to the effect of parasite abundance on host mass during worm establishment. Overall, our study demonstrates that the diet of Cuban tree frog tadpoles affects the gut microbiota and defenses against

Phylogenomics reveals rapid, simultaneous diversification of three major clades of Gondwanan frogs at the Cretaceous–Paleogene boundary

PubMed Central

Feng, Yan-Jie; Liang, Dan; Hillis, David M.; Cannatella, David C.; Zhang, Peng

2017-01-01

Frogs (Anura) are one of the most diverse groups of vertebrates and comprise nearly 90% of living amphibian species. Their worldwide distribution and diverse biology make them well-suited for assessing fundamental questions in evolution, ecology, and conservation. However, despite their scientific importance, the evolutionary history and tempo of frog diversification remain poorly understood. By using a molecular dataset of unprecedented size, including 88-kb characters from 95 nuclear genes of 156 frog species, in conjunction with 20 fossil-based calibrations, our analyses result in the most strongly supported phylogeny of all major frog lineages and provide a timescale of frog evolution that suggests much younger divergence times than suggested by earlier studies. Unexpectedly, our divergence-time analyses show that three species-rich clades (Hyloidea, Microhylidae, and Natatanura), which together comprise ∼88% of extant anuran species, simultaneously underwent rapid diversification at the Cretaceous–Paleogene (K–Pg) boundary (KPB). Moreover, anuran families and subfamilies containing arboreal species originated near or after the KPB. These results suggest that the K–Pg mass extinction may have triggered explosive radiations of frogs by creating new ecological opportunities. This phylogeny also reveals relationships such as Microhylidae being sister to all other ranoid frogs and African continental lineages of Natatanura forming a clade that is sister to a clade of Eurasian, Indian, Melanesian, and Malagasy lineages. Biogeographical analyses suggest that the ancestral area of modern frogs was Africa, and their current distribution is largely associated with the breakup of Pangaea and subsequent Gondwanan fragmentation. PMID:28673970

Phylogenomics reveals rapid, simultaneous diversification of three major clades of Gondwanan frogs at the Cretaceous-Paleogene boundary.

PubMed

Feng, Yan-Jie; Blackburn, David C; Liang, Dan; Hillis, David M; Wake, David B; Cannatella, David C; Zhang, Peng

2017-07-18

Frogs (Anura) are one of the most diverse groups of vertebrates and comprise nearly 90% of living amphibian species. Their worldwide distribution and diverse biology make them well-suited for assessing fundamental questions in evolution, ecology, and conservation. However, despite their scientific importance, the evolutionary history and tempo of frog diversification remain poorly understood. By using a molecular dataset of unprecedented size, including 88-kb characters from 95 nuclear genes of 156 frog species, in conjunction with 20 fossil-based calibrations, our analyses result in the most strongly supported phylogeny of all major frog lineages and provide a timescale of frog evolution that suggests much younger divergence times than suggested by earlier studies. Unexpectedly, our divergence-time analyses show that three species-rich clades (Hyloidea, Microhylidae, and Natatanura), which together comprise ∼88% of extant anuran species, simultaneously underwent rapid diversification at the Cretaceous-Paleogene (K-Pg) boundary (KPB). Moreover, anuran families and subfamilies containing arboreal species originated near or after the KPB. These results suggest that the K-Pg mass extinction may have triggered explosive radiations of frogs by creating new ecological opportunities. This phylogeny also reveals relationships such as Microhylidae being sister to all other ranoid frogs and African continental lineages of Natatanura forming a clade that is sister to a clade of Eurasian, Indian, Melanesian, and Malagasy lineages. Biogeographical analyses suggest that the ancestral area of modern frogs was Africa, and their current distribution is largely associated with the breakup of Pangaea and subsequent Gondwanan fragmentation.

The gastropod Phorcus sauciatus (Koch, 1845) along the north-west Iberian Peninsula: filling historical gaps

NASA Astrophysics Data System (ADS)

Rubal, Marcos; Veiga, Puri; Moreira, Juan; Sousa-Pinto, Isabel

2014-03-01

The intertidal gastropod Phorcus sauciatus is a subtropical grazer that reaches its northern boundary in the Iberian Peninsula. Distribution of P. sauciatus along the Iberian Peninsula shows, however, gaps in its distribution. The present study was aimed at detecting possible recent changes on the population structure and distribution of P. sauciatus along the north-west Atlantic coast of the Iberian Peninsula. To achieve this aim, we adopted a qualitative sampling design to explore the presence of P. sauciatus along a region within its historical gap of distribution (north Portuguese coast). In addition, a quantitative sampling design was adopted to test hypotheses about the abundance and size structure of P. sauciatus populations among regions with different historical records of its abundance and among shores with different exposure. Results showed that P. sauciatus was present along the north Portuguese coast. However, the abundance and size structure of the newly settled populations were significantly different to those of the historically recorded populations. Moreover, P. sauciatus was able to establish populations at sheltered shores. Considering these results, we propose models for the distribution of P. sauciatus along the Iberian Peninsula, based on effects of sea surface temperature, and to explain the size-frequency of their populations based on their density.

Habitat use and home range of the endangered gold-spotted pond frog (Rana chosenica).

PubMed

Ra, Nam-Yong; Sung, Ha-Cheol; Cheong, Seokwan; Lee, Jung-Hyun; Eom, Junho; Park, Daesik

2008-09-01

Because of their complex life styles, amphibians and reptiles living in wetlands require both aquatic and terrestrial buffer zones in their protected conservation areas. Due to steep declines in wild populations, the gold-spotted pond frog (Rana chosenica) is listed as vulnerable by the IUCN. However, lack of data about its movements and use of habitat prevents effective conservation planning. To determine the habitat use and home range of this species, we radio-tracked 44 adult frogs for 37 days between 10 July and 4 Nov. 2007 to observe three different populations in the breeding season, non-breeding season, and late fall. The gold-spotted pond frog was very sedentary; its daily average movement was 9.8 m. Frogs stayed close to breeding ponds (within 6.6 m), and did not leave damp areas surrounding these ponds, except for dormancy migration to terrestrial sites such as dried crop fields. The average distance of dormancy migration of seven frogs from the edge of their breeding ponds was 32.0 m. The average size of an individual's home range was 713.8 m(2) (0.07 ha). The year-round population home range, which accounts for the home ranges of a population of frogs, was determined for two populations to be 8,765.0 m(2) (0.88 ha) and 3,700.9 m(2) (0.37 ha). Our results showed that to conserve this endangered species, appropriately sized wetlands and extended terrestrial buffer areas surrounding the wetlands (at least 1.33 ha, diameter 130 m) should be protected.

Frog egg growth, experiment S003

NASA Technical Reports Server (NTRS)

Young, R. S.; Tremor, J. W.

1971-01-01

The objective of experiment was to determine the effect of weightlessness on the ability of a fertilized frog egg to divide normally and to differentiate and form a normal embryo. This experiment was first attempted on the Gemini 8 mission and was completed only partially because of the early termination of that mission.

Pesticides in mountain yellow-legged frogs (Rana muscosa) from the Sierra Nevada Mountains of California, USA

USGS Publications Warehouse

Fellers, G.M.; McConnell, L.L.; Pratt, D.; Datta, S.

2004-01-01

In 1997, pesticide concentrations were measured in mountain yellow-legged frogs (Rana muscosa) from two areas in the Sierra Nevada Mountains of California, USA. One area (Sixty Lakes Basin, Kings Canyon National Park) had large, apparently healthy populations of frogs. A second area (Tablelands, Sequoia National Park) once had large populations, but the species had been extirpated from this area by the early 1980s. The Tablelands is exposed directly to prevailing winds from agricultural regions to the west. When an experimental reintroduction of R. muscosa in 1994 to 1995 was deemed unsuccessful in 1997, the last 20 (reintroduced) frogs that could be found were collected from the Tablelands, and pesticide concentrations in both frog tissue and the water were measured at both the Tablelands and at reference sites at Sixty Lakes. In frog tissues, dichlorodiphenyldichloroethylene (DDE) concentration was one to two orders of magnitude higher than the other organochlorines (46 ?? 20 ng/g wet wt at Tablelands and 17 ?? 8 Sixty Lakes). Both ??-chlordane and trans-nonachlor were found in significantly greater concentrations in Tablelands frog tissues compared with Sixty Lakes. Organophosphate insecticides, chlorpyrifos, and diazinon were observed primarily in surface water with higher concentrations at the Tablelands sites. No contaminants were significantly higher in our Sixty Lakes samples.

Pesticide concentrations in frog tissue and wetland habitats in alandscape dominated by agriculture

USGS Publications Warehouse

Smalling, Kelly L.; Reeves, Rebecca; Muths, Erin L.; Vandever, Mark W.; Battaglin, William A.; Hladik, Michelle; Pierce, Clay L.

2015-01-01

Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations. We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata (chorus frogs) and Lithobates pipiens (leopard frogs) at six wetlands (3 restored and 3 reference) in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources. Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0.2 μg/L. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations. Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs. Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0.08 to 1500 μg/kg wet weight. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs, possibly because of differences in life histories. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and

Breeding chorus indices are weakly related to estimated abundance of boreal chorus frogs

Treesearch

Paul Stephen Corn; Erin Muths; Amanda M. Kissel; Rick D. Scherer

2011-01-01

Call surveys used to monitor breeding choruses of anuran amphibians generate index values that are frequently used to represent the number of male frogs present, but few studies have quantified this relationship. We compared abundance of male Boreal Chorus Frogs (Pseudacris maculata), estimated using capture-recapture methods in two populations in Colorado, to call...

Influence of physicochemical characteristics and high pressure processing on the volatile fraction of Iberian dry-cured ham.

PubMed

Martínez-Onandi, Nerea; Rivas-Cañedo, Ana; Ávila, Marta; Garde, Sonia; Nuñez, Manuel; Picon, Antonia

2017-09-01

The volatile fraction of 30 Iberian dry-cured hams of different physicochemical characteristics and the effect of high pressure processing (HPP) at 600MPa on volatile compounds were investigated. According to the analysis of variance carried out on the levels of 122 volatile compounds, intramuscular fat content influenced the levels of 8 benzene compounds, 5 carboxylic acids, 2 ketones, 2 furanones, 1 alcohol, 1 aldehyde and 1 sulfur compound, salt concentration influenced the levels of 1 aldehyde and 1 ketone, salt-in-lean ratio had no effect on volatile compounds, and water activity influenced the levels of 3 sulfur compounds, 1 alcohol and 1 aldehyde. HPP-treated samples of Iberian ham had higher levels of 4 compounds and lower levels of 31 compounds than untreated samples. A higher influence of HPP treatment on volatile compounds than physicochemical characteristics was observed for Iberian ham. Therefore, HPP treatment conditions should be optimized in order to diminish its possible effect on Iberian ham odor and aroma characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Variation in the schedules of somite and neural development in frogs

PubMed Central

Sáenz-Ponce, Natalia; Mitgutsch, Christian; del Pino, Eugenia M.

2012-01-01

The timing of notochord, somite, and neural development was analyzed in the embryos of six different frog species, which have been divided into two groups, according to their developmental speed. Rapid developing species investigated were Xenopus laevis (Pipidae), Engystomops coloradorum, and Engystomops randi (Leiuperidae). The slow developers were Epipedobates machalilla and Epipedobates tricolor (Dendrobatidae) and Gastrotheca riobambae (Hemiphractidae). Blastopore closure, notochord formation, somite development, neural tube closure, and the formation of cranial neural crest cell-streams were detected by light and scanning electron microscopy and by immuno-histochemical detection of somite and neural crest marker proteins. The data were analyzed using event pairing to determine common developmental aspects and their relationship to life-history traits. In embryos of rapidly developing frogs, elongation of the notochord occurred earlier relative to the time point of blastopore closure in comparison with slowly developing species. The development of cranial neural crest cell-streams relative to somite formation is accelerated in rapidly developing frogs, and it is delayed in slowly developing frogs. The timing of neural tube closure seemed to be temporally uncoupled with somite formation. We propose that these changes are achieved through differential timing of developmental modules that begin with the elongation of the notochord during gastrulation in the rapidly developing species. The differences might be related to the necessity of developing a free-living tadpole quickly in rapid developers. PMID:23184997

Forms and prevalence of intersexuality and effects of environmental contaminants on sexuality in cricket frogs (Acris crepitans).

PubMed Central

Reeder, A L; Foley, G L; Nichols, D K; Hansen, L G; Wikoff, B; Faeh, S; Eisold, J; Wheeler, M B; Warner, R; Murphy, J E; Beasley, V R

1998-01-01

Cricket frogs (Acris crepitans) from several different sites in Illinois were collected to assess the effects of environmental contamination on the prevalence of intersex gonads. Of 341 frogs collected in 1993, 1994, and 1995, 2.7% were intersex individuals. There was no statistically significant relationship between the chemical compounds detected and cricket frog intersexuality. However, there was an association approaching significance (p = 0.07) between the detection of atrazine and intersex individuals. A comparison of reference sites with sites that had point polychlorinated biphenyl (PCB) and polychlorinated dibenzofuran (PCDF) contamination revealed a significant relationship between sex-ratio reversal and contamination with PCBs and PCDFs. The sex ratio of juvenile frogs studied from three sites with PCB and PCDF point contamination favored males over females, which was the opposite of the sex ratio in control ponds (p = 0.0007). The statistically significant correlation between organochlorine contamination and sex-ratio reversal suggests PCBs and PCDFs can influence cricket frog sexual differentiation. The current study suggests that in cricket frogs, sex ratios and the prevalence of intersex gonads are altered by environmental contamination. Images Figure 1 Figure 2 PMID:9647894

Convergent Substitutions in a Sodium Channel Suggest Multiple Origins of Toxin Resistance in Poison Frogs.

PubMed

Tarvin, Rebecca D; Santos, Juan C; O'Connell, Lauren A; Zakon, Harold H; Cannatella, David C

2016-04-01

Complex phenotypes typically have a correspondingly multifaceted genetic component. However, the genotype-phenotype association between chemical defense and resistance is often simple: genetic changes in the binding site of a toxin alter how it affects its target. Some toxic organisms, such as poison frogs (Anura: Dendrobatidae), have defensive alkaloids that disrupt the function of ion channels, proteins that are crucial for nerve and muscle activity. Using protein-docking models, we predict that three major classes of poison frog alkaloids (histrionicotoxins, pumiliotoxins, and batrachotoxins) bind to similar sites in the highly conserved inner pore of the muscle voltage-gated sodium channel, Nav1.4. We predict that poison frogs are somewhat resistant to these compounds because they have six types of amino acid replacements in the Nav1.4 inner pore that are absent in all other frogs except for a distantly related alkaloid-defended frog from Madagascar, Mantella aurantiaca. Protein-docking models and comparative phylogenetics support the role of these replacements in alkaloid resistance. Taking into account the four independent origins of chemical defense in Dendrobatidae, phylogenetic patterns of the amino acid replacements suggest that 1) alkaloid resistance in Nav1.4 evolved independently at least seven times in these frogs, 2) variation in resistance-conferring replacements is likely a result of differences in alkaloid exposure across species, and 3) functional constraint shapes the evolution of the Nav1.4 inner pore. Our study is the first to demonstrate the genetic basis of autoresistance in frogs with alkaloid defenses. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

IMMEDIATE EFFECTS OF X-IRRADIATION ON THE HEART OF THE FROG

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onkelinx, Cl.

1962-07-21

The effects of whole-body irradiations on the heartbeat of pithed frogs were studied. A strong bradycardia was observed after 1 to 5 min of irradiation and is reversible within 1 min after irradiation. A sino-auricular block was observed in some cases. No response was found in any of the frogs during the cold months. The effects of atropine, physostigmine, and eserine on the response were studied. The results suggest a vagal excitation or acetylcholine liberation from the irradiation. (D.L.C.)

Habitat fragmentation causes bottlenecks and inbreeding in the European tree frog (Hyla arborea).

PubMed Central

Andersen, Liselotte W.; Fog, Kåre; Damgaard, Christian

2004-01-01

A genetic study of the European tree frog, Hyla arborea, in Denmark was undertaken to examine the population structure on mainland Jutland and the island of Lolland after a period of reduction in suitable habitat and population sizes. The two regions have experienced the same rate of habitat loss but fragmentation has been more severe on Lolland. Genetic variation based on 12 polymorphic DNA microsatellites was analysed in 494 tree frogs sampled from two ponds in Jutland and 10 ponds on Lolland. A significant overall deviation from Hardy-Weinberg expectations could be attributed to three ponds, all on Lolland. This was most probably caused by an inbreeding effect reducing fitness, which was supported by the observed significant negative correlation between larva survival and mean F(IS) value and mean individual inbreeding coefficient. A significant reduction in genetic variation (bottleneck) was detected in most of the ponds on Lolland. Population-structure analysis suggested the existence of at least 11 genetically different populations, corresponding to most of the sampled population units. The results indicated that the populations were unique genetic units and could be used to illustrate the migration pattern between newly established ponds arisen either by natural colonization of tree frogs or by artificial introduction. A high degree of pond fidelity in the tree frogs was suggested. A severe fragmentation process reducing population size and fitness within some of the populations probably caused the significant reduction in genetic variation of tree frog populations on Lolland. PMID:15306354

Lithospheric strength across the ocean-continent transition in the NW of the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Martín-Velázquez, Silvia; Martín-González, Fidel

2014-05-01

The main objective of this work is to investigate the relation between the strength of the lithosphere and the observed pattern of seismicity across the ocean-continent transition in the NW margin of the Iberian Peninsula. The seismicity is diffuse in this intraplate area, far from the seismically active margin of the plate: the Eurasia-African plate boundary, where convergence occurs at a rate of 4-5mm/year. The earthquake epicentres are mainly limited to an E-W trending zone (onshore seismicity is more abundant than offshore), and most earthquakes occur at depths less than 30 km, however, offshore depths are up to 150 km). Moreover, one of the problems to unravel in this area is that the seismotectonic interpretations of the anomalous seismicity in the NW peninsular are contradictory. The temperature and strength profiles have been modelled in three domains along the non-volcanic rifted West Iberian Margin: 1) the oceanic lithosphere of the Iberian Abyssal Plain, 2) the oceanic lithosphere near the ocean-continent transition of the Galicia Bank, and 3) the continental lithosphere of the NW Iberian Massif. The average bathymetry and topography have been used to fit the thermal structures of the three types of lithospheres, given that the heat flow and heat production values show a varied range. The geotherms, together with the brittle and ductile rheological laws, have been used to calculate the strength envelopes in different stress regimes (compression, shear and tensile). The continental lithosphere-asthenosphere boundary is located at 123 km and several brittle-ductile transitions appear in the crust and the mantle. However, the oceanic lithospheres are thinner (110 km near the Galicia Bank and 87 km in the Iberian Abbysal Plain) and more simple (brittle behaviour in the crust and upper mantle). The earthquake distribution is best explained by lithospheres with dry compositions and shear or tensile stress regimes. These results are similar can be compared to

Effects of Terrestrial Buffer Zones on Amphibians on Golf Courses

PubMed Central

Puglis, Holly J.; Boone, Michelle D.

2012-01-01

A major cause of amphibian declines worldwide is habitat destruction or alteration. Public green spaces, such as golf courses and parks, could serve as safe havens to curb the effects of habitat loss if managed in ways to bolster local amphibian communities. We reared larval Blanchard's cricket frogs (Acris blanchardi) and green frogs (Rana clamitans) in golf course ponds with and without 1 m terrestrial buffer zones, and released marked cricket frog metamorphs at the golf course ponds they were reared in. Larval survival of both species was affected by the presence of a buffer zone, with increased survival for cricket frogs and decreased survival for green frogs when reared in ponds with buffer zones. No marked cricket frog juveniles were recovered at any golf course pond in the following year, suggesting that most animals died or migrated. In a separate study, we released cricket frogs in a terrestrial pen and allowed them to choose between mown and unmown grass. Cricket frogs had a greater probability of using unmown versus mown grass. Our results suggest that incorporating buffer zones around ponds can offer suitable habitat for some amphibian species and can improve the quality of the aquatic environment for some sensitive local amphibians. PMID:22761833

Effect of cyclic aromatics on sodium active transport in frog skin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blankemeyer, J.T.; Bowerman, M.C.

1993-01-01

A modified glass Ussing-chamber was used to mount the skin. The electrical potential difference (PD) was measured by two 3% agar-frog Ringer's bridges. Current (i.e. short-circuit current, or ISC) was passed by Ag-AgCl electrodes placed so that current density was uniform across the skin. Ringer's solution, bathing each side of the frog skin, was stirred and aerated by gas-lift pumps. The effect of toxicants on the ISC was determined by using the 15 min prior to toxicant administration as a control period, then calculating the change in ISC during the toxicant period as a percent of the control ISC. Phenolmore » and benzene are components of crude oil and crude oil waste. These hydrocarbons and phenanthrene were tested for their effect on frog skin. The results show that the effect of organics on sodium active transport of an epithelium is to alter the active transport of sodium ions. 5 refs., 3 figs., 1 tab.« less

Genome evolution and speciation genetics of clawed frogs (Xenopus and Silurana).

PubMed

Evans, Ben J

2008-05-01

Speciation of clawed frogs occurred through bifurcation and reticulation of evolutionary lineages, and resulted in extant species with different ploidy levels. Duplicate gene evolution and expression in these animals provides a unique perspective into the earliest genomic transformations after vertebrate whole genome duplication (WGD) and suggests that functional constraints are relaxed compared to before duplication but still consistently strong for millions of years following WGD. Additionally, extensive quantitative expression divergence between duplicate genes occurred after WGD. Diversification of clawed frogs was potentially catalyzed by transposition and divergent resolution--processes that occur through different genetic mechanisms but that have analogous implications for genome structure. How sex determination is maintained after genome duplication is fundamental to our understanding of why allopolyploidization is so prevalent in this group, and why clawed frogs violate Haldane's Rule for hybrid sterility. Future studies of expression subfunctionalization in polyploids will shed light on the role and purviews of cis- and trans-regulatory elements in gene regulation.

Presence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in threatened corroboree frog populations in the Australian Alps.

PubMed

Hunter, David A; Speare, Rick; Marantelli, Gerry; Mendez, Diana; Pietsch, Rod; Osborne, Will

2010-11-01

Since the early 1980s, the southern corroboree frog Pseudophryne corroboree and northern corroboree frog P. pengilleyi have been in a state of decline from their sub-alpine and high montane bog environments on the southern tablelands of New South Wales, Australia. To date, there has been no adequate explanation as to what is causing the decline of these species. We investigated the possibility that a pathogen associated with other recent frog declines in Australia, the amphibian chytrid fungus Batrachochytrium dendrobatidis, may have been implicated in the decline of the corroboree frogs. We used histology of toe material and real-time PCR of skin swabs to investigate the presence and infection rates with B. dendrobatidis in historic and extant populations of both corroboree frog species. Using histology, we did not detect any B. dendrobatidis infections in corroboree frog populations prior to their decline. However, using the same technique, high rates of infection were observed in populations of both species after the onset of substantial population declines. The real-time PCR screening of skin swabs identified high overall infection rates in extant populations of P. corroboree (between 44 and 59%), while significantly lower rates of infection were observed in low-altitude P. pengilleyi populations (14%). These results suggest that the initial and continued decline of the corroboree frogs may well be attributed to the emergence of B. dendrobatidis in populations of these species.

Urocortins of the South African clawed frog, Xenopus laevis: conservation of structure and function in tetrapod evolution.

PubMed

Boorse, Graham C; Crespi, Erica J; Dautzenberg, Frank M; Denver, Robert J

2005-11-01

Several corticotropin-releasing factor (CRF) family genes have been identified in vertebrates. Mammals have four paralogous genes that encode CRF or the urocortins 1, 2, and 3. In teleost fishes, a CRF, urotensin I (a fish ortholog of mammalian urocortin 1) and urocortin 3 have been identified, suggesting that at least three of the four mammalian lineages arose in a common ancestor of modern bony fishes and tetrapods. Here we report the isolation of genes orthologous to mammalian urocortin 1 and urocortin 3 from the South African clawed frog, Xenopus laevis. We characterize the pharmacology of the frog peptides and show that X. laevis urocortin 1 binds to and activates the frog CRF1 and CRF2 receptors at picomolar concentrations. Similar to mammals, frog urocortin 3 is selective for the CRF2 receptor. Only frog urocortin 1 binds to the CRF-binding protein, although with significantly lower affinity than frog CRF. Both urocortin genes are expressed in brain, pituitary, heart, and kidney of juvenile frogs; urocortin 1 is also expressed in skin. We also identified novel urocortin sequences in the genomes of pufferfish, zebrafish, chicken, and dog. Phylogenetic analysis supports the view that four paralogous lineages of CRF-like peptides arose before the divergence of the actinopterygian and sarcopterygian fishes. Our findings show that the functional relationships among CRF ligands and binding proteins, and their anorexigenic actions mediated by the CRF2 receptor, arose early in vertebrate evolution.

Resurrecting an Extinct Species: Archival DNA, Taxonomy, and Conservation of the Vegas Valley Leopard Frog

EPA Science Inventory

Suggestions that the extinct Vegas Valley leopard frog (Rana fisheri = Lithobates fisheri) may have been synonymous with one of several declining species has complicated recovery planning for imperiled leopard frogs in southwestern North America. To address this concern, we recon...

The reactivation of the SW Iberian passive margin: a brief review

NASA Astrophysics Data System (ADS)

Duarte, Joao; Rosas, Filipe; Terrinha, Pedro; Schellart, Wouter; Almeida, Pedro; Gutscher, Marc-André; Riel, Nicolas; Ribeiro, António

2016-04-01

On the morning of the 1st of November of 1755 a major earthquake struck offshore the Southwest Iberian margin. This was the strongest earthquake ever felt in Western Europe. The shake, fire and tsunami devastated Lisbon, was felt as far as Finland and had a profound impact on the thinkers of that time, in particular on the Enlightenment philosophers such as Voltaire, Rousseau and Kant. The Great Lisbon Earthquake is considered by many as the event that marks the birth of modern geosciences; and made of this region one of the most well studied areas in the world. After the 1755 earthquake, Kant and others authors wrote several treaties dealing with the causes and dynamics of earthquakes and tsunamis and were close to identify some key elements of what we now call plate tectonics. More than two hundred years later, in the year of 1969, the region was struck by another major earthquake. This was precisely during the period in which the theory of plate tectonics was being built. Geoscientists like Fukao (1973), Purdy (1975) and Mackenzie (1977) immediately focused their attention in the area. They suggested that these events were related with "transient" subduction of Africa below Iberia, along the East-West Azores-Gibraltar plate boundary. Several years later, Ribeiro (1989) suggested that instead of Africa being subducted below Iberia, it was the West Iberian passive margin that was being reactivated, a process that may, in time, lead to the formation of a new subduction zone. In the turning of the millennium, a subducting slab was imaged bellow the Gibraltar Straits, a remanent of the Western Mediterranean arc system that according to Gutscher et al. (2002) was related with ongoing subduction. Recently, it was proposed that a causal link between the Gibraltar subduction system and the reactivation of the SW Iberian margin might exist. In addition, the large-scale Africa-Eurasia convergence is inducing compressive stresses along the West Iberian margin. The margin

Reciprocal Trophic Interactions and Transmission of Blood Parasites between Mosquitoes and Frogs

PubMed Central

Ferguson, Laura V.; Smith, Todd G.

2012-01-01

The relationship between mosquitoes and their amphibian hosts is a unique, reciprocal trophic interaction. Instead of a one-way, predator-prey relationship, there is a cyclical dance of avoidance and attraction. This has prompted spatial and temporal synchrony between organisms, reflected in emergence time of mosquitoes in the spring and choice of habitat for oviposition. Frog-feeding mosquitoes also possess different sensory apparatuses than do their mammal-feeding counterparts. The reciprocal nature of this relationship is exploited by various blood parasites that use mechanical, salivary or trophic transmission to pass from mosquitoes to frogs. It is important to investigate the involvement of mosquitoes, frogs and parasites in this interaction in order to understand the consequences of anthropogenic actions, such as implementing biocontrol efforts against mosquitoes, and to determine potential causes of the global decline of amphibian species. PMID:26466534

An Effective Hybrid Cuckoo Search Algorithm with Improved Shuffled Frog Leaping Algorithm for 0-1 Knapsack Problems

PubMed Central

Wang, Gai-Ge; Feng, Qingjiang; Zhao, Xiang-Jun

2014-01-01

An effective hybrid cuckoo search algorithm (CS) with improved shuffled frog-leaping algorithm (ISFLA) is put forward for solving 0-1 knapsack problem. First of all, with the framework of SFLA, an improved frog-leap operator is designed with the effect of the global optimal information on the frog leaping and information exchange between frog individuals combined with genetic mutation with a small probability. Subsequently, in order to improve the convergence speed and enhance the exploitation ability, a novel CS model is proposed with considering the specific advantages of Lévy flights and frog-leap operator. Furthermore, the greedy transform method is used to repair the infeasible solution and optimize the feasible solution. Finally, numerical simulations are carried out on six different types of 0-1 knapsack instances, and the comparative results have shown the effectiveness of the proposed algorithm and its ability to achieve good quality solutions, which outperforms the binary cuckoo search, the binary differential evolution, and the genetic algorithm. PMID:25404940

Ichthyophonus sp. (Ichthyophonae, Ichthyophonida) infection in a South American amphibian, the hylid frog Hypsiboas pulchellus.

PubMed

Borteiro, Claudio; Verdes, José Manuel; Cruz, Juan Carlos; Sabalsagaray, María Jesús; Kolenc, Francisco; Martínez Debat, Claudio; Ubilla, Martín

2015-04-01

We report infection by Ichthyophonus sp. in a South American amphibian, the hylid frog Hypsiboas pulchellus in Uruguay. This frog had a large subcutaneous mass over the urostyle and dorsal musculature comprised of parasitic cysts with mild granulomatous inflammation but otherwise appeared healthy.

Phylogeography of Declining Relict and Lowland Leopard Frogs in the Desert Southwest of North America

EPA Science Inventory

We investigated the phylogeography of the closely related relict leopard frog (Rana onca) and lowland leopard frog (R. yavapaiensis) – two declining anurans from the warm-desert regions of southwestern North America. We used sequence data from two mitochondrial DNA genes to asses...

Effect of muscle type and frozen storage on the quality parameters of Iberian restructured meat preparations.

PubMed

Antequera, Teresa; Pérez-Palacios, Trinidad; Rodas, Elena; Rodríguez, Mar; Córdoba, Juan J

2014-10-01

The main objective of this study was to evaluate the effect of muscle type and frozen storage on the quality of restructured meat preparations from undervalued Iberian muscle to make use of meat from a high-quality and natural pig production system. The effect of two muscle types (i.e. white-glycolytic (W) and red-oxidative (R)) and frozen storage (lasting 0, 30, 60 and 90 days) on quality characteristics were assessed. Significant differences were found between the W and R Iberian restructured preparations in most physicochemical and some colour, texture and sensory traits, and in the fatty acid profile and oxidative measurements, suggesting that the R muscles are more suitable; however, the microbial contamination should be reduced. Frozen storage reduced but did not eliminate the initial microbial contamination, and it enhanced some quality traits in the Iberian restructured preparations, i.e. increased a* values, cohesiveness and juiciness and decreased adhesiveness and pastiness, without negatively affecting any parameter. Thus, frozen Iberian restructured preparations are recommended to be commercialized. In addition, the implementation or revision of Hazard Analysis and Critical Control Point is recommended to reduce microbial contamination. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Use of olfactory cues by newly metamorphosed wood frogs (Lithobates sylvaticus) during emigration

USGS Publications Warehouse

Zydlewski, Joseph D.; Popescu, Viorel D.; Brodie, Bekka S.; Hunter, Malcom L.

2012-01-01

Juvenile amphibians are capable of long-distance upland movements, yet cues used for orientation during upland movements are poorly understood. We used newly metamorphosed Wood Frogs (Lithobates sylvaticus) to investigate: (1) the existence of innate (i.e., inherited) directionality, and (2) the use of olfactory cues, specifically forested wetland and natal pond cues during emigration. In a circular arena experiment, animals with assumed innate directionality did not orient in the expected direction (suggested by previous studies) when deprived of visual and olfactory cues. This suggests that juvenile Wood Frogs most likely rely on proximate cues for orientation. Animals reared in semi-natural conditions (1500 l cattle tanks) showed a strong avoidance of forested wetland cues in two different experimental settings, although they had not been previously exposed to such cues. This finding is contrary to known habitat use by adult Wood Frogs during summer. Juvenile Wood Frogs were indifferent to the chemical signature of natal pond (cattle tank) water. Our findings suggest that management strategies for forest amphibians should consider key habitat features that potentially influence the orientation of juveniles during emigration movements, as well as adult behavior.

Modeling Sexual Selection in Túngara Frog and Rationality of Mate Choice.

PubMed

Vargas Bernal, Esteban; Sanabria Malagon, Camilo

2017-12-01

The males of the species of frogs Engystomops pustulosus produce simple and complex calls to lure females, as a way of intersexual selection. Complex calls lead males to a greater reproductive success than what simple calls do. However, the complex calls are also more attractive to their main predator, the bat Trachops cirrhosus. Therefore, as M. Ryan suggests in (The túngara frog: a study in sexual selection and communication. University of Chicago Press, Chicago, 1985), the complexity of the calls lets the frogs keep a trade-off between reproductive success and predation. In this paper, we verify this trade-off from the perspective of game theory. We first model the proportion of simple calls as a symmetric game of two strategies. We also model the effect of adding a third strategy, males that keep quiet and intercept females, which would play a role of intrasexual selection. Under the assumption that the decision of the males takes into account this trade-off between reproductive success and predation, our model reproduces the observed behavior reported in the literature with minimal assumption on the parameters. From the model with three strategies, we verify that the quiet strategy could only coexists with the simple and complex strategies if the rate at which quiet males intercept females is high, which explains the rarity of the quiet strategy. We conclude that the reproductive strategy of the male frog E. pustulosus is rational.

Behavioural, ecological, and evolutionary aspects of diversity in frog colour patterns.

PubMed

Rojas, Bibiana

2017-05-01

The role of colours and colour patterns in behavioural ecology has been extensively studied in a variety of contexts and taxa, while almost overlooked in many others. For decades anurans have been the focus of research on acoustic signalling due to the prominence of vocalisations in their communication. Much less attention has been paid to the enormous diversity of colours, colour patterns, and other types of putative visual signals exhibited by frogs. With the exception of some anecdotal observations and studies, the link between colour patterns and the behavioural and evolutionary ecology of anurans had not been addressed until approximately two decades ago. Since then, there has been ever-increasing interest in studying how colouration is tied to different aspects of frog behaviour, ecology and evolution. Here I review the literature on three different contexts in which frog colouration has been recently studied: predator-prey interactions, intraspecific communication, and habitat use; and I highlight those aspects that make frogs an excellent, yet understudied, group to examine the role of colour in the evolution of anti-predation strategies and animal communication systems. Further, I argue that in addition to natural-history observations, more experiments are needed in order to elucidate the functions of anuran colouration and the selective pressures involved in its diversity. To conclude, I encourage researchers to strengthen current experimental approaches, and suggest future directions that may broaden our current understanding of the adaptive value of anuran colour pattern diversity. © 2016 Cambridge Philosophical Society.

Modelling larval dispersal dynamics of common sole (Solea solea) along the western Iberian coast

NASA Astrophysics Data System (ADS)

Tanner, Susanne E.; Teles-Machado, Ana; Martinho, Filipe; Peliz, Álvaro; Cabral, Henrique N.

2017-08-01

Individual-based coupled physical-biological models have become the standard tool for studying ichthyoplankton dynamics and assessing fish recruitment. Here, common sole (Solea solea L.), a flatfish of high commercial importance in Europe was used to evaluate transport of eggs and larvae and investigate the connectivity between spawning and nursery areas along the western Iberian coast as spatio-temporal variability in dispersal and recruitment patterns can result in very strong or weak year-classes causing large fluctuations in stock size. A three-dimensional particle tracking model coupled to Regional Ocean Modelling System model was used to investigate variability of sole larvae dispersal along the western Iberian coast over a five-year period (2004-2009). A sensitivity analysis evaluating: (1) the importance of diel vertical migrations of larvae and (2) the size of designated recruitment areas was performed. Results suggested that connectivity patterns of sole larvae dispersal and their spatio-temporal variability are influenced by the configuration of the coast with its topographical structures and thus the suitable recruitment area available as well as the wind-driven mesoscale circulation along the Iberian coast.

The Sex Chromosomes of Frogs: Variability and Tolerance Offer Clues to Genome Evolution and Function

PubMed Central

Malcom, Jacob W.; Kudra, Randal S.; Malone, John H.

2014-01-01

Frog sex chromosomes offer an ideal system for advancing our understanding of genome evolution and function because of the variety of sex determination systems in the group, the diversity of sex chromosome maturation states, the ease of experimental manipulation during early development. After briefly reviewing sex chromosome biology generally, we focus on what is known about frog sex determination, sex chromosome evolution, and recent, genomics-facilitated advances in the field. In closing we highlight gaps in our current knowledge of frog sex chromosomes, and suggest priorities for future research that can advance broad knowledge of gene dose and sex chromosome evolution. PMID:25031658

Field surveys of Midwestern and Northeastern Fish and Wildlife Service lands for the presence of abnormal frogs and toads

USGS Publications Warehouse

Converse, K.A.; Mattsson, J.; Eaton-Poole, L.

2000-01-01

The national distribution of information on the discovery of malformations in Minnesota frogs in 1995 stimulated collection and examination of newly metamorphosed frogs during 1996. By late summer and early fall of 1996, malformed frogs and toads were reported on U.S. Fish and Wildlife Service (USFWS) lands in Vermont (Northeast, Region 5) and Minnesota (Midwest, Region 3). In response to these reports, biologists in USFWS Regions 3 and 5 conducted a survey, during the summer of 1997 to determine the distribution and type of malformations in frogs and toads on selected federal lands. Region 3 personnel surveyed 38 field stations at National Wildlife Refuges (NWR's) and Wetland Management Districts. Malformed frogs and toads were collected at 23 (61%) of the Region 3 sites. External malformations were detected in 110 of 6632 individuals representing seven of 13 frog species and one of three toad species examined for an overall of 1.7% affected (percentages for affected species ranged from 0.4-5.2%). In Region 5, 17 NWR's and one National Park were surveyed. Malformed frogs were collected at 10 (56%) of the Region 5 sites. External malformations were detected in 58 of 2267 individuals representing six of 11 frog species and one of two toad species examined for an overall total of 2.6% affected (percentages for affected species ranged from 1.8-15.6%). The majority of malformations observed in frogs and toads collected in Regions 3 and 5 were partially or completely missing hind limbs and digits (50%)or malformed hind limbs and digits (14%). A few individuals had an extra limb or toe, missing or malformed front limb, missing eye, or malformation of the mandible. Despite small sample sizes at some sites, malformations were confirmed to be present in eight species of frogs and two species of toads on Federal lands in USFWS Regions 3 and 5. Further study is needed to determine the extent and distribution of amphibian malformations in these Regions. Data from this study

Pesticide concentrations in frog tissue and wetland habitats in a landscape dominated by agriculture.

PubMed

Smalling, Kelly L; Reeves, Rebecca; Muths, Erin; Vandever, Mark; Battaglin, William A; Hladik, Michelle L; Pierce, Clay L

2015-01-01

Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations. We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata (chorus frogs) and Lithobates pipiens (leopard frogs) at six wetlands (3 restored and 3 reference) in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources. Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0.2 μg/L. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations. Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs. Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0.08 to 1,500 μg/kg wet weight. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs, possibly because of differences in life histories. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and implementing

Long-term changes in composition and distribution patterns in the Iberian herpetofaunal communities since the latest Pleistocene

NASA Astrophysics Data System (ADS)

Bisbal-Chinesta, Josep Francesc; Blain, Hugues-Alexandre

2018-03-01

The climate has undergone significant changes since the end of the Last Glacial Maximum and in the course of the Holocene, parallel to important cultural transformations and migrations in the human communities. The faunal record has also suffered the effects of climate change. Amphibians and reptiles in particular have been shown to be highly sensitive because they are very susceptible to temperature alterations due to their ectothermy. This research presents the first approach to the Iberian paleobiogeography of the different species of amphibians and reptiles from the Late Pleistocene (MIS3) to present times, based on a comparative synthesis of the latest research published in recent years and the fossil record of the 58 archaeo-paleontological sites with significant assemblages. The paleoherpetofaunal associations make it possible to establish two major biotic regions during the Late Pleistocene. The first biotic region was located in the center and south of the Iberian Peninsula, with thermophilic species as the most representative taxa. The second biotic region was formed by the Atlantic-Cantabrian facade and the northeast Iberian area, dominated by hygrophilous and Euro-Siberian species, with an absence of Mediterranean species. After the Last Glacial Maximum there was an unprecedented concurrence in the northern Iberian Peninsula of autochthonous taxa from that area with thermophilic species. In the early Holocene, new species with no previous record in the Iberian Peninsula entered northern Iberia from eastern Mediterranean refugia. Finally, the introduction of North African species was the last significant biogeographical change during the Middle-Late Holocene.

Oral chytridiomycosis in the mountain yellow-legged frog (Rana muscosa)

USGS Publications Warehouse

Fellers, G.M.; Green, D.E.; Longcore, J.E.

2001-01-01

The chytrid fungus Batrachochytrium dendrobatidis was originally reported in wild frog populations in Panama and Australia, and from captive frogs in the U.S. National Zoological Park (Washington, DC). This recently described fungus affects the keratinized epidermis of amphibians and has been implicated as a causative factor in the declines of frog populations. We report here the presence of B. dendrobatidis in larval and recently metamorphosed mountain yellow-legged frogs (Rana muscosa) in or near the Sierra Nevada Mountains of California, an area where declines have been documented in all five species of native anurans. Forty-one percent (158 of 387) of larval R. muscosa examined in the field with a hand lens and 18% (14 of 79) of preserved larvae had abnormalities of the oral disc. Twenty-eight larvae were collected from 10 sites where tadpoles had been observed with missing or abnormally keratinized mouthparts, and 24 of these were examined for infection. Sixty-seven percent (16 of 24) of these tadpoles were infected with B. dendrobatidis. Batrachochytrium dendrobatidis was cultured from both tadpoles and recent metamorphs from one of these sites. Tadpoles with mouthpart abnormalities or confirmed chytrid fungus infections were collected at 23 sites spanning a distance of > 440 km and an elevational range from 1658a??3550 m. Life-history traits of R. muscosa may make this species particularly susceptible to infection by Batrachochytrium. We recommend that biologists examine tadpoles for oral disc abnormalities as a preliminary indication of chytridiomycosis. Further, we believe that biologists should take precautions to prevent spreading this and other amphibian diseases from one site to another.

Oral chytridiomycosis in the mountain yellow-legged frog (Rana muscosa)

USGS Publications Warehouse

Fellers, G.M.; Green, E.D.; Longcore, J.E.

2001-01-01

The chytrid fungus Batrachochytrium dendrobatidis was originally reported in wild frog populations in Panama and Australia, and from captive frogs in the U.S. National Zoological Park (Washington, DC). This recently described fungus affects the keratinized epidermis of amphibians and has been implicated as a causative factor in the declines of frog populations. We report here the presence of B. dendrobatidis in larval and recently metamorphosed mountain yellow-legged frogs (Rana muscosa) in or near the Sierra Nevada Mountains of California, an area where declines have been documented in all five species of native anurans. Forty-one percent (158 of 387) of larval R. muscosa examined in the field with a hand lens and 18% (14 of 79) of preserved larvae had abnormalities of the oral disc. Twenty-eight larvae were collected from 10 sites where tadpoles had been observed with missing or abnormally keratinized mouthparts, and 24 of these were examined for infection. Sixty-seven percent (16 of 24) of these tadpoles were infected with B. dendrobatidis. Batrachochytrium dendrobatidis was cultured from both tadpoles and recent metamorphs from one of these sites. Tadpoles with mouthpart abnormalities or confirmed chytrid fungus infections were collected at 23 sites spanning a distance of > 440 km and an elevational range from 1658-3550 m. Life-history traits of R. muscosa may make this species particularly susceptible to infection by Batrachochytrium. We recommend that biologists examine tadpoles for oral disc abnormalities as a preliminary indication of chytridiomycosis. Further, we believe that biologists should take precautions to prevent spreading this and other amphibian diseases from one site to another.

Spatial and temporal characteristics of wildfire activity over the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Calado, Teresa; DaCamara, Carlos C.; Ermida, Sofia; Trigo, Isabel.

2013-04-01

According to the official reports of the European Commission, during the period 1980-2010 the Iberian Peninsula has contributed to 60% of the total burned area of 14 620 968 ha, which was recorded in the five Southern Member States with higher wildfire activity (Portugal, Spain, France, Italy and Greece). The aim of the present study is to assess fire activity over the Iberian Peninsula based on time series of hot spots extracted from the MODIS global daily active fire product (MOD14A1 and MYD14A1). This dataset, which contains the coordinates of MODIS pixels where fire events were identified together with the respective date and quality indicators, covers the period from July 2002 to August 2012. It is first shown that overall hot spot activity exhibits power law behaviour. A spatial analysis is then undertaken based on land cover information as obtained from Globcover - an ESA initiative relying on observations from the 300m MERIS on board the ENVISAT. Temporal analysis of hot spot activity is also performed based on daily information about meteorological conditions provided by the European Centre for Medium-Range Weather Forecasts. Results obtained allow defining a set of fire regions over the Iberian Peninsula determined essentially by the respective land cover type, which present coherent statistical behaviour in space and time. Finally, models of fire risk are developed for each region and their potential operational use by forest and civil protection services is discussed.

Cytological maps of lampbrush chromosomes of European water frogs (Pelophylax esculentus complex) from the Eastern Ukraine

PubMed Central

2013-01-01

Background Hybridogenesis (hemiclonal inheritance) is a kind of clonal reproduction in which hybrids between parental species are reproduced by crossing with one of the parental species. European water frogs (Pelophylax esculentus complex) represent an appropriate model for studying interspecies hybridization, processes of hemiclonal inheritance and polyploidization. P. esculentus complex consists of two parental species, P. ridibundus (the lake frog) and P. lessonae (the pool frog), and their hybridogenetic hybrid – P. esculentus (the edible frog). Parental and hybrid frogs can reproduce syntopically and form hemiclonal population systems. For studying mechanisms underlying the maintenance of water frog population systems it is required to characterize the karyotypes transmitted in gametes of parental and different hybrid animals of both sexes. Results In order to obtain an instrument for characterization of oocyte karyotypes in hybrid female frogs, we constructed cytological maps of lampbrush chromosomes from oocytes of both parental species originating in Eastern Ukraine. We further identified certain molecular components of chromosomal marker structures and mapped coilin-rich spheres and granules, chromosome associated nucleoli and special loops accumulating splicing factors. We recorded the dissimilarities between P. ridibundus and P. lessonae lampbrush chromosomes in the length of orthologous chromosomes, number and location of marker structures and interstitial (TTAGGG)n-repeat sites as well as activity of nucleolus organizer. Satellite repeat RrS1 was mapped in centromere regions of lampbrush chromosomes of the both species. Additionally, we discovered transcripts of RrS1 repeat in oocytes of P. ridibundus and P. lessonae. Moreover, G-rich transcripts of telomere repeat were revealed in association with terminal regions of P. ridibundus and P. lessonae lampbrush chromosomes. Conclusions The constructed cytological maps of lampbrush chromosomes of P

Effects on seventh-grade students' achievement and science anxiety of alternatives to conventional frog dissection

NASA Astrophysics Data System (ADS)

Marszalek, Christine Susan

1998-12-01

The purpose of this study in a suburban school district was to investigate and compare the level of learning and long-term retention of frog internal anatomy between seventh-grade students using an interactive CD tutorial, a desktop microworld, and conventional frog dissection. Students' anxiety toward science was also compared across the three treatment groups and between genders. Additional data on the students' preferred learning style were used to explore possible interaction effects with their respective instructional activity. Subjects participating in the study were all seventh-grade students in one junior-high school, numbering 280 in total. Classes were randomly assigned to the three modes of instruction for the dissection of a frog: a CD-tutorial dissection, a desktop microworld dissection, and a conventional dissection. The Conventional treatment was the traditional physical dissection using a preserved frog specimen and lab dissection tools. The CD-Tutorial treatment was the interactive tutorial Digital Frog from Digital Frog International. The Microworld treatment was a desktop microworld environment composed of Operation Frog on CD supplemented with other programs to provide additional avenues for learning. Data collection and testing occurred prior to treatment, one day after treatment, and three months after treatment. Data collected showed mixed results for all measures taken. The differences in achievement gained favoring the conventional treatment from pretest to both posttests appear to have leveled out somewhat over time. Although anxiety levels declined for both genders after treatment, females continued to report significantly higher science anxiety than males. There appears to be a relationship between treatment and gender in terms of effect on science anxiety. For all three measures taken--pretest, immediate posttest and delayed posttest--no significant difference in achievement by learning style was observed. Learning style alone does not

Sticking like sticky tape: tree frogs use friction forces to enhance attachment on overhanging surfaces

PubMed Central

Endlein, Thomas; Ji, Aihong; Samuel, Diana; Yao, Ning; Wang, Zhongyuan; Barnes, W. Jon P.; Federle, Walter; Kappl, Michael; Dai, Zhendong

2013-01-01

To live and clamber about in an arboreal habitat, tree frogs have evolved adhesive pads on their toes. In addition, they often have long and slender legs to facilitate not only long jumps, but also to bridge gaps between leaves when climbing. Both adhesive pads and long limbs are used in conjunction, as we will show in this study. Previous research has shown that tree frogs change from a crouched posture (where the limbs are close to the body) to a sprawled posture with extended limbs when clinging on to steeper inclines such as vertical or overhanging slopes. We investigated this change in posture in White's tree frogs (Litoria caerulea) by challenging the frogs to cling onto a tiltable platform. The platform consisted of an array of 24 three-dimensional force transducers, which allowed us to measure the ground reaction forces of the frogs during a tilt. Starting from a crouched resting position, the normal forces on the forelimbs changed sign and became increasingly negative with increasing slope angle of the platform. At about 106°±12°, tilt of the platform the frogs reacted by extending one or two of their limbs outwards. At a steeper angle (131°±11°), the frogs spread out all their limbs sideways, with the hindlimbs stretched out to their maximum reach. Although the extension was strongest in the lateral direction, limbs were significantly extended in the fore–aft direction as well. With the extension of the limbs, the lateral forces increased relative to the normal forces. The large contribution of the in-plane forces helped to keep the angle between the force vector and the platform small. The Kendall theory for the peeling of adhesive tape predicts that smaller peel angles lead to higher attachment forces. We compare our data with the predictions of the Kendall model and discuss possible implications of the sliding of the pads on the surface. The forces were indeed much larger for smaller angles and thus can be explained by peeling theory. PMID

Effect of cattle exclosures on Columbia Spotted Frog abundance

USGS Publications Warehouse

Adams, Michael J.; Pearl, Christopher; Chambert, Thierry; Mccreary, Brome; Galvan, Stephanie; Rowe, Jennifer

2018-01-01

Livestock grazing is an important land use in the western USA and can have positive or negative effects on amphibians. Columbia Spotted Frog (Rana luteiventris) often use ponds that provide water for cattle. We conducted a long-term manipulative study on US Forest Service land in northeastern Oregon to determine the effects of full and partial exclosures that limited cattle access to ponds used by frogs. We found weak evidence of a short-term increase in abundance that did not differ between full and partial exclosures and that diminished with continuing exclusion of cattle. The benefit of exclosures was small relative to the overall decline in breeding numbers that we documented. This suggests that some protection can provide a short-term boost to populations.

Prevalence of skeletal and eye malformations in frogs from north-central United States: estimations based on collections from randomly selected sites.

PubMed

Schoff, Patrick K; Johnson, Catherine M; Schotthoefer, Anna M; Murphy, Joseph E; Lieske, Camilla; Cole, Rebecca A; Johnson, Lucinda B; Beasley, Val R

2003-07-01

Skeletal malformation rates for several frog species were determined in a set of randomly selected wetlands in the north-central USA over three consecutive years. In 1998, 62 sites yielded 389 metamorphic frogs, nine (2.3%) of which had skeletal or eye malformations. A subset of the original sites was surveyed in the following 2 yr. In 1999, 1,085 metamorphic frogs were collected from 36 sites and 17 (1.6%) had skeletal or eye malformations, while in 2000, examination of 1,131 metamorphs yielded 16 (1.4%) with skeletal or eye malformations. Hindlimb malformations predominated in all three years, but other abnormalities, involving forelimb, eye, and pelvis were also found. Northern leopard frogs (Rana pipiens) constituted the majority of collected metamorphs as well as most of the malformed specimens. However, malformations were also noted in mink frogs (R. septentrionalis), wood frogs (R. sylvatica), and gray tree frogs (Hyla spp.). The malformed specimens were found in clustered sites in all three years but the cluster locations were not the same in any year. The malformation rates reported here are higher than the 0.3% rate determined for metamorphic frogs collected from similar sites in Minnesota in the 1960s, and thus, appear to represent an elevation of an earlier baseline malformation rate.

Prevalence of skeletal and eye malformations in frogs from north-central United States: estimations based on collections from randomly selected sites

USGS Publications Warehouse

Schoff, P.K.; Johnson, C.M.; Schotthoefer, A.M.; Murphy, J.E.; Lieske, C.; Cole, Rebecca A.; Johnson, L.B.; Beasley, V.R.

2003-01-01

Skeletal malformation rates for several frog species were determined in a set of randomly selected wetlands in the north-central USA over three consecutive years. In 1998, 62 sites yielded 389 metamorphic frogs, nine (2.3%) of which had skeletal or eye malformations. A subset of the original sites was surveyed in the following 2 yr. In 1999, 1,085 metamorphic frogs were collected from 36 sites and 17 (1.6%) had skeletal or eye malformations, while in 2000, examination of 1,131 metamorphs yielded 16 (1.4%) with skeletal or eye malformations. Hindlimb malformations predominated in all three years, but other abnormalities, involving forelimb, eye, and pelvis were also found. Northern leopard frogs (Rana pipiens) constituted the majority of collected metamorphs as well as most of the malformed specimens. However, malformations were also noted in mink frogs (R. septentrionalis), wood frogs (R. sylvatica), and gray tree frogs (Hyla spp.). The malformed specimens were found in clustered sites in all three years but the cluster locations were not the same in any year. The malformation rates reported here are higher than the 0.3% rate determined for metamorphic frogs collected from similar sites in Minnesota in the 1960s, and thus, appear to represent an elevation of an earlier baseline malformation rate.

Hind limb malformations in free-living northern leopard frogs (Rana pipiens) from Maine, Minnesota, and Vermont suggest multiple etiologies

USGS Publications Warehouse

Meteyer, C.U.; Loeffler, I.K.; Fallon, J.F.; Converse, K.A.; Green, E.; Helgen, J.C.; Kersten, S.; Levey, R.; Eaton-Poole, L.; Burkhart, J.G.

2000-01-01

Background Reports of malformed frogs have increased throughout the North American continent in recent years. Most of the observed malformations have involved the hind limbs. The goal of this study was to accurately characterize the hind limb malformations in wild frogs as an important step toward understanding the possible etiologies. Methods During 1997 and 1998, 182 recently metamorphosed northern leopard frogs (Rana pipiens) were collected from Minnesota, Vermont, and Maine. Malformed hind limbs were present in 157 (86%) of these frogs, which underwent necropsy and radiographic evaluation at the National Wildlife Health Center. These malformations are described in detail and classified into four major categories: (1) no limb (amelia); (2) multiple limbs or limb elements (polymelia, polydactyly, polyphalangy); (3) reduced limb segments or elements (phocomelia, ectromelia, ectrodactyly, and brachydactyly; and (4) distally complete but malformed limb (bone rotations, bridging, skin webbing, and micromelia). Results Amelia and reduced segments and/or elements were the most common finding. Frogs with bilateral hind limb malformations were not common, and in only eight of these 22 frogs were the malformations symmetrical. Malformations of a given type tended to occur in frogs collected from the same site, but the types of malformations varied widely among all three states, and between study sites within Minnesota. Conclusions Clustering of malformation type suggests that developmental events may produce a variety of phenotypes depending on the timing, sequence, and severity of the environmental insult. Hind limb malformations in free-living frogs transcend current mechanistic explanations of tetrapod limb development.

Genetic diversity and structure of Iberian Peninsula cowpeas compared to world-wide cowpea accessions using high density SNP markers.

PubMed

Carvalho, Márcia; Muñoz-Amatriaín, María; Castro, Isaura; Lino-Neto, Teresa; Matos, Manuela; Egea-Cortines, Marcos; Rosa, Eduardo; Close, Timothy; Carnide, Valdemar

2017-11-21

Cowpea (Vigna unguiculata L. Walp) is an important legume crop due to its high protein content, adaptation to heat and drought and capacity to fix nitrogen. Europe has a deficit of cowpea production. Knowledge of genetic diversity among cowpea landraces is important for the preservation of local varieties and is the basis to obtain improved varieties. The aims of this study were to explore diversity and the genetic structure of a set of Iberian Peninsula cowpea accessions in comparison to a worldwide collection and to infer possible dispersion routes of cultivated cowpea. The Illumina Cowpea iSelect Consortium Array containing 51,128 SNPs was used to genotype 96 cowpea accessions including 43 landraces and cultivars from the Iberian Peninsula, and 53 landraces collected worldwide. Four subpopulations were identified. Most Iberian Peninsula accessions clustered together with those from other southern European and northern African countries. Only one accession belonged to another subpopulation, while two accessions were 'admixed'. A lower genetic diversity level was found in the Iberian Peninsula accessions compared to worldwide cowpeas. The genetic analyses performed in this study brought some insights into worldwide genetic diversity and structure and possible dispersion routes of cultivated cowpea. Also, it provided an in-depth analysis of genetic diversity in Iberian Peninsula cowpeas that will help guide crossing strategies in breeding programs.

Regulation of 5'-adenosine monophosphate deaminase in the freeze tolerant wood frog, Rana sylvatica.

PubMed

Dieni, Christopher A; Storey, Kenneth B

2008-04-22

The wood frog, Rana sylvatica, is one of a few vertebrate species that have developed natural freeze tolerance, surviving days or weeks with 65-70% of its total body water frozen in extracellular ice masses. Frozen frogs exhibit no vital signs and their organs must endure multiple stresses, particularly long term anoxia and ischemia. Maintenance of cellular energy supply is critical to viability in the frozen state and in skeletal muscle, AMP deaminase (AMPD) plays a key role in stabilizing cellular energetics. The present study investigated AMPD control in wood frog muscle. Wood frog AMPD was subject to multiple regulatory controls: binding to subcellular structures, protein phosphorylation, and effects of allosteric effectors, cryoprotectants and temperature. The percentage of bound AMPD activity increased from 20 to 35% with the transition to the frozen state. Bound AMPD showed altered kinetic parameters compared with the free enzyme (S0.5 AMP was reduced, Hill coefficient fell to approximately 1.0) and the transition to the frozen state led to a 3-fold increase in S0.5 AMP of the bound enzyme. AMPD was a target of protein phosphorylation. Bound AMPD from control frogs proved to be a low phosphate form with a low S0.5 AMP and was phosphorylated in incubations that stimulated PKA, PKC, CaMK, or AMPK. Bound AMPD from frozen frogs was a high phosphate form with a high S0.5 AMP that was reduced under incubation conditions that stimulated protein phosphatases. Frog muscle AMPD was activated by Mg.ATP and Mg.ADP and inhibited by Mg.GTP, KCl, NaCl and NH4Cl. The enzyme product, IMP, uniquely inhibited only the bound (phosphorylated) enzyme from muscle of frozen frogs. Activators and inhibitors differentially affected the free versus bound enzyme. S0.5 AMP of bound AMPD was also differentially affected by high versus low assay temperature (25 vs 5 degrees C) and by the presence/absence of the natural cryoprotectant (250 mM glucose) that accumulates during freezing

Downscaling of Global Climate Change Estimates to Regional Scales: An Application to Iberian Rainfall in Wintertime.

NASA Astrophysics Data System (ADS)

von Storch, Hans; Zorita, Eduardo; Cubasch, Ulrich

1993-06-01

A statistical strategy to deduct regional-scale features from climate general circulation model (GCM) simulations has been designed and tested. The main idea is to interrelate the characteristic patterns of observed simultaneous variations of regional climate parameters and of large-scale atmospheric flow using the canonical correlation technique.The large-scale North Atlantic sea level pressure (SLP) is related to the regional, variable, winter (DJF) mean Iberian Peninsula rainfall. The skill of the resulting statistical model is shown by reproducing, to a good approximation, the winter mean Iberian rainfall from 1900 to present from the observed North Atlantic mean SLP distributions. It is shown that this observed relationship between these two variables is not well reproduced in the output of a general circulation model (GCM).The implications for Iberian rainfall changes as the response to increasing atmospheric greenhouse-gas concentrations simulated by two GCM experiments are examined with the proposed statistical model. In an instantaneous `2 C02' doubling experiment, using the simulated change of the mean North Atlantic SLP field to predict Iberian rainfall yields, there is an insignificant increase of area-averaged rainfall of 1 mm/month, with maximum values of 4 mm/month in the northwest of the peninsula. In contrast, for the four GCM grid points representing the Iberian Peninsula, the change is 10 mm/month, with a minimum of 19 mm/month in the southwest. In the second experiment, with the IPCC scenario A ("business as usual") increase Of C02, the statistical-model results partially differ from the directly simulated rainfall changes: in the experimental range of 100 years, the area-averaged rainfall decreases by 7 mm/month (statistical model), and by 9 mm/month (GCM); at the same time the amplitude of the interdecadal variability is quite different.

Conservation of the introgressed European water frog complex using molecular tools.

PubMed

Holsbeek, G; Maes, G E; De Meester, L; Volckaert, F A M

2009-03-01

In Belgium, the Pelophylax esculentus complex has recently been subjected to multiple introductions of non-native water frogs, increasing the occurrence of hybridisation events. In the present study, we tested the reliability of morphometric and recently developed microsatellite tools to identify introgression and to determine the origin of exotic Belgian water frogs. By analysing 150 individuals of each taxon of the P. esculentus complex and an additional 60 specimens of the introduced P. cf. bedriagae, we show that neither of the currently available tools appears to have sufficient power to reliably distinguish all Belgian water frog species. We therefore aimed at increasing the discriminatory power of a microsatellite identification tool by developing a new marker panel with additional microsatellite loci. By adding only two new microsatellite loci (RlCA5 and RlCA1b20), all taxa of the P. esculentus complex could be distinguished from each other with high confidence. Three more loci (Res3, Res5 and Res17) provided a powerful discrimination of the exotic species.

Characterization of kappa 1 and kappa 2 opioid binding sites in frog (Rana esculenta) brain membrane preparation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benyhe, S.; Varga, E.; Hepp, J.

1990-09-01

The distribution and properties of frog brain kappa-opioid receptor subtypes differ not only from those of the guinea pig brain, but also from that of the rat brain. In guinea pig cerebellum the kappa 1 is the dominant receptor subtype, frog brain contains mainly the kappa 2 subtype, and the distribution of the rat brain subtypes is intermediate between the two others. In competition experiments it has been established that ethylketocyclazocine and N-cyclopropylmethyl-norazidomorphine, which are nonselective kappa-ligands, have relatively high affinities to frog brain membranes. The kappa 2 ligands (Met5)enkephalin-Arg6-Phe7 and etorphine also show high affinities to the frog brain.more » Kappa 1 binding sites measured in the presence of 5 microM/D-Ala2-Leu5/enkephalin represent 25-30% of (3H)ethylketocyclazocine binding in frog brain membranes. The kappa 2 subtype in frog brain resembles more to the mu subtype than the delta subtype of opioid receptors, but it differs from the mu subtype in displaying low affinity toward beta-endorphin and /D-Ala2-(Me)Phe4-Gly5-ol/enkephalin (DAGO). From our data it is evident that the opioid receptor subtypes are already present in the amphibian brain but the differences among them are less pronounced than in mammalian brain.« less

Extreme precipitation events in the Iberian Peninsula and its association with Atmospheric Rivers

NASA Astrophysics Data System (ADS)

Ramos, Alexandre M.; Liberato, Margarida L. R.; Trigo, Ricardo M.

2015-04-01

Extreme precipitation events in the Iberian Peninsula during the winter half of the year have major socio-economic impacts associated with floods, landslides, extensive property damage and life losses. In recent years, a number of works have shed new light on the role played by Atmospheric Rivers (ARs) in the occurrence of extreme precipitation events in both Europe and USA. ARs are relatively narrow regions of concentrated WV responsible for horizontal transport in the lower atmosphere corresponding to the core section of the broader warm conveyor belt occurring over the oceans along the warm sector of extra-tropical cyclones. Over the North Atlantic ARs are usually W-E oriented steered by pre-frontal low level jets along the trailing cold front and subsequently feed the precipitation in the extra-tropical cyclones. It was shown that more than 90% of the meridional WV transport in the mid-latitudes occurs in the AR, although they cover less than 10% of the area of the globe. The large amount of WV that is transported can lead to heavy precipitation and floods. An automated ARs detection algorithm is used for the North Atlantic Ocean Basin allowing the identification and a comprehensive characterization of the major AR events that affected the Iberian Peninsula over the 1948-2012 period. The extreme precipitation days in the Iberian Peninsula were assessed recently by us (Ramos et al., 2014) and their association (or not) with the occurrence of AR is analyzed in detail here. The extreme precipitation days are ranked by their magnitude and are obtained after considering 1) the area affected and 2) the precipitation intensity. Different rankings are presented for the entire Iberian Peninsula, Portugal and also for the six largest Iberian river basins (Minho, Duero, Tagus, Guadiana, Guadalquivir and Ebro) covering the 1950-2008 period (Ramos et al., 2014). Results show that the association between ARs and extreme precipitation days in the western domains (Portugal

Long-term vegetation activity trends in the Iberian Peninsula and The Balearic Islands using high spatial resolution NOAA-AVHRR data (1981 - 2015).

NASA Astrophysics Data System (ADS)

Martin-Hernandez, Natalia; Vicente-Serrano, Sergio; Azorin-Molina, Cesar; Begueria-Portugues, Santiago; Reig-Gracia, Fergus; Zabalza-Martínez, Javier

2017-04-01

We have analysed trends in the Normalized Difference Vegetation Index (NDVI) in the Iberian Peninsula and The Balearic Islands over the period 1981 - 2015 using a new high resolution data set from the entire available NOAA - AVHRR images (IBERIAN NDVI dataset). After a complete processing including geocoding, calibration, cloud removal, topographic correction and temporal filtering, we obtained bi-weekly time series. To assess the accuracy of the new IBERIAN NDVI time-series, we have compared temporal variability and trends of NDVI series with those results reported by GIMMS 3g and MODIS (MOD13A3) NDVI datasets. In general, the IBERIAN NDVI showed high reliability with these two products but showing higher spatial resolution than the GIMMS dataset and covering two more decades than the MODIS dataset. Using the IBERIAN NDVI dataset, we analysed NDVI trends by means of the non-parametric Mann-Kendall test and Theil-Sen slope estimator. In average, vegetation trends in the study area show an increase over the last decades. However, there are local spatial differences: the main increase has been recorded in humid regions of the north of the Iberian Peninsula. The statistical techniques allow finding abrupt and gradual changes in different land cover types during the analysed period. These changes are related with human activity due to land transformations (from dry to irrigated land), land abandonment and forest recovery.

Surveys for California red-legged frog and arroyo toad on the Los Padres National Forest

Treesearch

Valerie K. Hubbartt; Thomas G. Murphey

2005-01-01

Starting in the spring of 1999 through the fall of 2000, USDA Forest Service biologists have conducted surveys throughout the Los Padres National Forest for the federally-listed California red-legged frog (Rana aurora draytonii) and arroyo toad (Bufo californicus). Sites known to have frogs or toads present were monitored for...

A comparative study of charge movement in rat and frog skeletal muscle fibres.

PubMed

Hollingworth, S; Marshall, M W

1981-12-01

1. The middle of the fibre voltage--clamp technique (Adrian & Marshall, 1977), modified where necessary for electrically short muscle fibres, has been used to measure non-linear charge movements in mammalian fast twitch (rat extensor digitorum longus), mammalian slow twitch (rat soleus) and frog (sartorius) muscles. 2. The maximum amount of charge moved in mammalian fast twitch muscle at 2 degrees C in hypertonic solution, was 3--5 times greater than in slow twitch muscle. The voltage distribution of fast twitch charge was 10--15 mV more positive when compared to slow twitch. 3. In both mammalian muscle types hypertonic Ringer solution negatively shifted the voltage distribution of charge some 6 mV. The steepness of charge moved around mechanical threshold was unaffected by hypertonicity. 4. The amount of charge in frog sartorius fibres at 2 degrees C in hypertonic solution was about half of that in rat fast twitch muscle; the voltage distribution of the frog charge was similar to rat soleus muscle. 5. Warming between 2 and 15 degrees C had no effect on either the amount of steady-state distribution of charge in mammalian or frog muscles. 6. At 2 degrees C, the kinetics of charge movement in fast and slow twitch mammalian muscles were similar and 2--3 times faster than frog muscle at the same temperature. In fast and slow mammalian fibres at 2 degrees C similar times were taken to shift the same fractions of the total amount of charge. The Q10 of charge movement kinetics was between 1.2 and 2.0 in the three muscles studied.

Frogs use a viscoelastic tongue and non-Newtonian saliva to catch prey

PubMed Central

Noel, Alexis C.; Guo, Hao-Yuan; Mandica, Mark

2017-01-01

Frogs can capture insects, mice and even birds using only their tongue, with a speed and versatility unmatched in the world of synthetic materials. How can the frog tongue be so sticky? In this combined experimental and theoretical study, we perform a series of high-speed films, material tests on the tongue, and rheological tests of the frog saliva. We show that the tongue's unique stickiness results from a combination of a soft, viscoelastic tongue coupled with non-Newtonian saliva. The tongue acts like a car's shock absorber during insect capture, absorbing energy and so preventing separation from the insect. The shear-thinning saliva spreads over the insect during impact, grips it firmly during tongue retraction, and slides off during swallowing. This combination of properties gives the tongue 50 times greater work of adhesion than known synthetic polymer materials such as the sticky-hand toy. These principles may inspire the design of reversible adhesives for high-speed application. PMID:28148766

Transcriptomic and macroevolutionary evidence for phenotypic uncoupling between frog life history phases

PubMed Central

Wollenberg Valero, Katharina C.; Garcia-Porta, Joan; Rodríguez, Ariel; Arias, Mónica; Shah, Abhijeet; Randrianiaina, Roger Daniel; Brown, Jason L.; Glaw, Frank; Amat, Felix; Künzel, Sven; Metzler, Dirk; Isokpehi, Raphael D.; Vences, Miguel

2017-01-01

Anuran amphibians undergo major morphological transitions during development, but the contribution of their markedly different life-history phases to macroevolution has rarely been analysed. Here we generate testable predictions for coupling versus uncoupling of phenotypic evolution of tadpole and adult life-history phases, and for the underlying expression of genes related to morphological feature formation. We test these predictions by combining evidence from gene expression in two distantly related frogs, Xenopus laevis and Mantidactylus betsileanus, with patterns of morphological evolution in the entire radiation of Madagascan mantellid frogs. Genes linked to morphological structure formation are expressed in a highly phase-specific pattern, suggesting uncoupling of phenotypic evolution across life-history phases. This gene expression pattern agrees with uncoupled rates of trait evolution among life-history phases in the mantellids, which we show to have undergone an adaptive radiation. Our results validate a prevalence of uncoupling in the evolution of tadpole and adult phenotypes of frogs. PMID:28504275

Investigation of frog abnormalities on national wildlife refuges in the Northeast U.S.

USGS Publications Warehouse

Eaton-Poole, L.; Pinkney, A.E.; Green, D.E.; Sutherland, D.R.; Babbitt, K.J.; ,

2003-01-01

To address concerns about frog abnormalities, the U.S. Fish and Wildlife Service examined over 3,643 frogs and toads on National Wildlife Refuges (NWRs) in the Northeast U.S. The objectives were to: 1) determine if certain refuges had sites where abnormalities were frequently observed; 2) evaluate if the prevalence of abnormalities at a site was consistent within a season and among years; and 3) investigate possible causes. Sampling was conducted from 1999 through 2001. A complete sample from a site consisted of ???50 metamorphs of one species. The prevalence of abnormalities ranged from 0 to 15% and fluctuated within season and among years. The most common external abnormalities were truncated limbs, and missing limbs, feet, and digits. Frogs with duplication of limb segments were rare (6). Based on radiographical examinations of 89 abnormal frogs, 55 had abnormalities due to trauma, 22 due to malformations, and 12 could not be classified. Metacercariae of the trematode Ribeiroia were detected in substantial numbers in two species from Iroquois NWR, with one specimen having supernumerary hindlimbs. We recommend continued sampling and integrated, causal evaluations on NWRs where the prevalence of abnormalities exceeds 5% or where the types of abnormalities warrant further study.

Pesticides and Population Declines of California Alpine Frogs

EPA Science Inventory

Airborne pesticides from the Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the mountain yellow-legged frog complex (Rana muscosa and R. sierrae) in the Sierra Nevada. We measured ...

Short-term occupancy and abundance dynamics of the Oregon spotted frog (Rana pretiosa) across its core range

USGS Publications Warehouse

Adams, Michael J.; Pearl, Christopher A.; Mccreary, Brome; Galvan, Stephanie

2014-01-01

The Oregon spotted frog (Rana pretiosa) occupies only a fraction of its original range and is listed as Threatened under the Endangered Species Act. We surveyed 93 sites in a rotating frame design (2010–13) in the Klamath and Deschutes Basins, Oregon, which encompass most of the species’ core extant range. Oregon spotted frogs are declining in abundance and probability of site occupancy. We did not find an association between the probability that Oregon spotted frogs disappear from a site (local extinction) and any of the variables hypothesized to affect Oregon spotted frog occupancy. This 4-year study provides baseline data, but the 4-year period was too short to draw firm conclusions. Further study is essential to understand how habitat changes and management practices relate to the status and trends of this species.

Size-sex variation in survival rates and abundance of pig frogs, Rana grylio, in northern Florida wetlands

USGS Publications Warehouse

Wood, K.V.; Nichols, J.D.; Percival, H.F.; Hines, J.E.

1998-01-01

During 1991-1993, we conducted capture-recapture studies on pig frogs, Rana grylio, in seven study locations in northcentral Florida. Resulting data were used to test hypotheses about variation in survival probability over different size-sex classes of pig frogs. We developed multistate capture-recapture models for the resulting data and used them to estimate survival rates and frog abundance. Tests provided strong evidence of survival differences among size-sex classes, with adult females showing the highest survival probabilities. Adult males and juvenile frogs had lower survival rates that were similar to each other. Adult females were more abundant than adult males in most locations at most sampling occasions. We recommended probabilistic capture-recapture models in general, and multistate models in particular, for robust estimation of demographic parameters in amphibian populations.

Underwater sonar image detection: A combination of non-local spatial information and quantum-inspired shuffled frog leaping algorithm.

PubMed

Wang, Xingmei; Liu, Shu; Liu, Zhipeng

2017-01-01

This paper proposes a combination of non-local spatial information and quantum-inspired shuffled frog leaping algorithm to detect underwater objects in sonar images. Specifically, for the first time, the problem of inappropriate filtering degree parameter which commonly occurs in non-local spatial information and seriously affects the denoising performance in sonar images, was solved with the method utilizing a novel filtering degree parameter. Then, a quantum-inspired shuffled frog leaping algorithm based on new search mechanism (QSFLA-NSM) is proposed to precisely and quickly detect sonar images. Each frog individual is directly encoded by real numbers, which can greatly simplify the evolution process of the quantum-inspired shuffled frog leaping algorithm (QSFLA). Meanwhile, a fitness function combining intra-class difference with inter-class difference is adopted to evaluate frog positions more accurately. On this basis, recurring to an analysis of the quantum-behaved particle swarm optimization (QPSO) and the shuffled frog leaping algorithm (SFLA), a new search mechanism is developed to improve the searching ability and detection accuracy. At the same time, the time complexity is further reduced. Finally, the results of comparative experiments using the original sonar images, the UCI data sets and the benchmark functions demonstrate the effectiveness and adaptability of the proposed method.

Underwater sonar image detection: A combination of non-local spatial information and quantum-inspired shuffled frog leaping algorithm

PubMed Central

Liu, Zhipeng

2017-01-01

This paper proposes a combination of non-local spatial information and quantum-inspired shuffled frog leaping algorithm to detect underwater objects in sonar images. Specifically, for the first time, the problem of inappropriate filtering degree parameter which commonly occurs in non-local spatial information and seriously affects the denoising performance in sonar images, was solved with the method utilizing a novel filtering degree parameter. Then, a quantum-inspired shuffled frog leaping algorithm based on new search mechanism (QSFLA-NSM) is proposed to precisely and quickly detect sonar images. Each frog individual is directly encoded by real numbers, which can greatly simplify the evolution process of the quantum-inspired shuffled frog leaping algorithm (QSFLA). Meanwhile, a fitness function combining intra-class difference with inter-class difference is adopted to evaluate frog positions more accurately. On this basis, recurring to an analysis of the quantum-behaved particle swarm optimization (QPSO) and the shuffled frog leaping algorithm (SFLA), a new search mechanism is developed to improve the searching ability and detection accuracy. At the same time, the time complexity is further reduced. Finally, the results of comparative experiments using the original sonar images, the UCI data sets and the benchmark functions demonstrate the effectiveness and adaptability of the proposed method. PMID:28542266

Lithobates sylvaticus (wood frog)

USGS Publications Warehouse

Fuller, Pam

2016-01-01

A single specimen found southwest of Hattiesburg in Timberton (31.270391oN, 89.327675oW; WGS 84). 23 July 2015. Gary, Kat, and Ron Lukens. Verifi ed by Kenneth Krysko, Florida Museum of Natural History (UF-Herpetology 176455). This species has never been recorded from the state of Mississippi before (Dodd 2013. Frogs of the United States and Canada – Volume 2. John Hopkins University Press, Baltimore, Maryland. 982 pp.). According to Dodd (2013), the closest population is located in east central Alabama, approximately 400 km to the northeast, as documented by Davis and Folkerts (1986. Brimleyana 12:29-50).

Taeniid species of the Iberian wolf (Canis lupus signatus) in Portugal with special focus on Echinococcus spp.☆

PubMed Central

Guerra, Diogo; Armua-Fernandez, Maria Teresa; Silva, Marta; Bravo, Inês; Santos, Nuno; Deplazes, Peter; Carvalho, Luís Manuel Madeira de

2012-01-01

Taeniid species represent relevant pathogens in human and animals, circulating between carnivorous definitive hosts and a variety of mammalian intermediate hosts. In Portugal, however, little is known about their occurrence and life cycles, especially in wild hosts. An epidemiological survey was conducted to clarify the role of the Iberian wolf as a definitive host for taeniid species, including Echinococcus spp. Wolf fecal samples (n = 68) were collected from two regions in Northern Portugal. Taeniid eggs were isolated through a sieving-flotation technique, and species identification was performed using multiplex-PCR followed by sequencing of the amplicons. Taenia hydatigena (in 11.8% of the samples), Taenia serialis (5.9%), Taenia pisiformis (2.9%), Taenia polyacantha (1.5%) and Echinococcus intermedius (Echinococcus granulosus ‘pig strain’, G7) (1.5%) were detected. This is the first study to characterize the taeniid species infecting the Portuguese Iberian wolf, with the first records of T. polyacantha and E. intermedius in this species in the Iberian Peninsula. Iberian wolves can be regarded as relevant hosts for the maintenance of the wild and synanthropic cycles of taeniids in Portugal. PMID:24533315

Heavy point frog performance under passenger vehicles : final report.

DOT National Transportation Integrated Search

2016-06-01

Federal Railroad Administration contracted with the Transportation Technology Center, Inc., Pueblo, Colorado, to conduct an : investigation of passenger vehicle performance running through heavy point frog (HPF) up to speeds of 110 mph. A NUCARS : ...

Leap Frog Digital Sensors and Definition, Integration & Testing FY 2003 Annual Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meitzler, Wayne D.; Ouderkirk, Steven J.; Shoemaker, Steven V.

2003-12-31

The objective of Leap Frog is to develop a comprehensive security tool that is transparent to the user community and more effective than current methods for preventing and detecting security compromises of critical physical and digital assets. Current security tools intrude on the people that interact with these critical assets by requiring them to perform additional functions or having additional visible sensors. Leap Frog takes security to the next level by being more effective and reducing the adverse impact on the people interacting with protected assets.

Recent decadal trends in Iberian water vapour: GPS analysis and WRF process study

NASA Astrophysics Data System (ADS)

Miranda, Pedro M. A.; Nogueira, Miguel; Semedo, Alvaro; Benevides, Pedro; Catalao, Joao; Costa, Vera

2016-04-01

A 24-year simulation of the recent Iberian climate, using the WRF model at 9km resolution forced by ERA-Interim reanalysis (1989-2012), is analysed for the decadal evolution of the upwelling forcing coastal wind and for column integrated Precipitable water vapour (PWV). Results indicate that, unlike what was found by Bakun et al. (2009) for the Peruvian region, a statistically significant trend in the upwelling favourable (northerly) wind has been accompanied by a corresponding decrease in PWV, not only inland but also over the coastal waters. Such increase is consistent with a reinforced northerly coastal jet in the maritime boundary layer contributing to atmospheric Ekman pumping of dry continental air into the coastal region. Diagnostics of the prevalence of the Iberian thermal low following Hoinka and Castro (2003) also show a positive trend in its frequency during an extended summer period (April to September). These results are consistent with recent studies indicating an upward trend in the frequency of upwelling in SW Iberia (Alves and Miranda 2013), and may be relevant for climate change applications as an increase in coastal upwelling (Miranda et al 2013) may lead to substantial regional impacts in the subtropics. The same analysis with ERA-Interim reanalysis data, which was used to force the WRF simulations, does not reveal the same signal in PWV, and indeed correlates poorly with the GPS observations, indicating that the data assimilation process makes the water vapour data in reanalysis unusable for climate change purposes. The good correlation between the WRF simulated data and GPS observations allow for a detailed analysis of the processes involved in the evolution of the PWV field. Akcnowledgements: Study done within FCT Grant RECI/GEO-MET/0380/2012, financially supported by FCT Grant UID/ GEO/50019/2013-IDL Alves JMR, Miranda PMA (2013) Variability of Iberian upwelling implied by ERA-40 and ERA-Interim reanalyses, Tellus A 2013, http

Skin microbes on frogs prevent morbidity and mortality caused by a lethal skin fungus.

PubMed

Harris, Reid N; Brucker, Robert M; Walke, Jenifer B; Becker, Matthew H; Schwantes, Christian R; Flaherty, Devon C; Lam, Brianna A; Woodhams, Douglas C; Briggs, Cheryl J; Vredenburg, Vance T; Minbiole, Kevin P C

2009-07-01

Emerging infectious diseases threaten human and wildlife populations. Altered ecological interactions between mutualistic microbes and hosts can result in disease, but an understanding of interactions between host, microbes and disease-causing organisms may lead to management strategies to affect disease outcomes. Many amphibian species in relatively pristine habitats are experiencing dramatic population declines and extinctions due to the skin disease chytridiomycosis, which is caused by the chytrid fungus Batrachochytrium dendrobatidis. Using a randomized, replicated experiment, we show that adding an antifungal bacterial species, Janthinobacterium lividum, found on several species of amphibians to the skins of the frog Rana muscosa prevented morbidity and mortality caused by the pathogen. The bacterial species produces the anti-chytrid metabolite violacein, which was found in much higher concentrations on frog skins in the treatments where J. lividum was added. Our results show that cutaneous microbes are a part of amphibians' innate immune system, the microbial community structure on frog skins is a determinant of disease outcome and altering microbial interactions on frog skins can prevent a lethal disease outcome. A bioaugmentation strategy may be an effective management tool to control chytridiomycosis in amphibian survival assurance colonies and in nature.

The Genome of the Western Clawed Frog Xenopus tropicalis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hellsten, Uffe; Harland, Richard M.; Gilchrist, Michael J.

2009-10-01

The western clawed frog Xenopus tropicalis is an important model for vertebrate development that combines experimental advantages of the African clawed frog Xenopus laevis with more tractable genetics. Here we present a draft genome sequence assembly of X. tropicalis. This genome encodes over 20,000 protein-coding genes, including orthologs of at least 1,700 human disease genes. Over a million expressed sequence tags validated the annotation. More than one-third of the genome consists of transposable elements, with unusually prevalent DNA transposons. Like other tetrapods, the genome contains gene deserts enriched for conserved non-coding elements. The genome exhibits remarkable shared synteny with humanmore » and chicken over major parts of large chromosomes, broken by lineage-specific chromosome fusions and fissions, mainly in the mammalian lineage.« less

Sensitivity of two Iberian lakes to North Atlantic atmospheric circulation modes

NASA Astrophysics Data System (ADS)

Hernández, Armand; Trigo, Ricardo M.; Pla-Rabes, Sergi; Valero-Garcés, Blas L.; Jerez, Sonia; Rico-Herrero, Mayte; Vega, José C.; Jambrina-Enríquez, Margarita; Giralt, Santiago

2015-12-01

The North Atlantic Oscillation (NAO) exerts a major influence on the climate of the North Atlantic region. However, other atmospheric circulation modes (ACMs), such as the East Atlantic (EA) and Scandinavian (SCAND) patterns, also play significant roles. The dynamics of lakes on the Iberian Peninsula are greatly controlled by climatic parameters, but their relationship with these various ACMs has not been investigated in detail. In this paper, we analyze monthly meteorological and limnological long-term datasets (1950-2011 and 1992-2011, respectively) from two lakes on the northern and central Iberian Peninsula (Sanabria and Las Madres) to develop an understanding of the seasonal sensitivity of these freshwater systems to the NAO, EA and SCAND circulation modes. The limnological variability within Lake Sanabria is primarily controlled by fluctuations in the seasonal precipitation and wind, and the primary ACMs associated with the winter limnological processes are the NAO and the SCAND modes, whereas only the EA mode appears to weakly influence processes during the summer. However, Lake Las Madres is affected by precipitation, wind and, to a lesser extent, temperature, whereas the ACMs have less influence. Therefore, we aim to show that the lakes of the Iberian Peninsula are sensitive to these ACMs. The results presented here indicate that the lake dynamics, in some cases, have a higher sensitivity to variations in the ACMs than single local meteorological variables. However, certain local features, such as geography, lake morphology and anthropic influences, are crucial to properly record the signals of these ACMs.

Rangewide phylogeography of the western U.S. endemic frog Rana boylii (Ranidae): Implications for the conservation of frogs and rivers

Treesearch

A.J. Lind; H.B. Shaffer; P.Q. Spinks; G.M. Fellers

2011-01-01

Genetic data are increasingly being used in conservation planning for declining species. We sampled both the ecological and distributional limits of the foothill yellow-legged frog, Rana boylii to characterize mitochondrial DNA (mtDNA) variation in this declining, riverine amphibian. We evaluated 1525 base pairs (bp) of cytochrome b...

Games With a Purpose: Frog and the Lily Pads

ERIC Educational Resources Information Center

Sawicki, Timothy

2005-01-01

This article describes a game involving poly spots, frog bean bags, and a basket that can be used to assess locomotor activities, e.g., hopping and throwing, while also developing teamwork strategies and mathematical abilities.

Tribute to R. G. Boutilier: the role for skeletal muscle in the hypoxia-induced hypometabolic responses of submerged frogs.

PubMed

West, T G; Donohoe, P H; Staples, J F; Askew, G N

2006-04-01

Much of Bob Boutilier's research characterised the subcellular, organ-level and in vivo behavioural responses of frogs to environmental hypoxia. His entirely integrative approach helped to reveal the diversity of tissue-level responses to O(2) lack and to advance our understanding of the ecological relevance of hypoxia tolerance in frogs. Work from Bob's lab mainly focused on the role for skeletal muscle in the hypoxic energetics of overwintering frogs. Muscle energy demand affects whole-body metabolism, not only because of its capacity for rapid increases in ATP usage, but also because hypometabolism of the large skeletal muscle mass in inactive animals impacts so greatly on in vivo energetics. The oxyconformance and typical hypoxia-tolerance characteristics (e.g. suppressed heat flux and preserved membrane ion gradients during O(2) lack) of skeletal muscle in vitro suggest that muscle hypoperfusion in vivo is possibly a key mechanism for (i) downregulating muscle and whole-body metabolic rates and (ii) redistributing O(2) supply to hypoxia-sensitive tissues. The gradual onset of a low-level aerobic metabolic state in the muscle of hypoxic, cold-submerged frogs is indeed important for slowing depletion of on-board fuels and extending overwintering survival time. However, it has long been known that overwintering frogs cannot survive anoxia or even severe hypoxia. Recent work shows that they remain sensitive to ambient O(2) and that they emerge rapidly from quiescence in order to actively avoid environmental hypoxia. Hence, overwintering frogs experience periods of hypometabolic quiescence interspersed with episodes of costly hypoxia avoidance behaviour and exercise recovery. In keeping with this flexible physiology and behaviour, muscle mechanical properties in frogs do not deteriorate during periods of overwintering quiescence. On-going studies inspired by Bob Boutilier's integrative mindset continue to illuminate the cost-benefit(s) of intermittent locomotion in

Enzymatic regulation of seasonal glycogen cycling in the freeze-tolerant wood frog, Rana sylvatica.

PubMed

do Amaral, M Clara F; Lee, Richard E; Costanzo, Jon P

2016-12-01

Liver glycogen is an important energy store in vertebrates, and in the freeze-tolerant wood frog, Rana sylvatica, this carbohydrate also serves as a major source of the cryoprotectant glucose. We investigated how variation in the levels of the catalytic subunit of protein kinase A (PKAc), glycogen phosphorylase (GP), and glycogen synthase (GS) relates to seasonal glycogen cycling in a temperate (Ohioan) and subarctic (Alaskan) populations of this species. In spring, Ohioan frogs had reduced potential for glycogen synthesis, as evidenced by low GS activity and high PKAc protein levels. In addition, glycogen levels in spring were the lowest of four seasonal samples, as energy input was likely directed towards metabolism and somatic growth during this period. Near-maximal glycogen levels were reached by mid-summer, and remained unchanged in fall and winter, suggesting that glycogenesis was curtailed during this period. Ohioan frogs had a high potential for glycogenolysis and glycogenesis in winter, as evidenced by large glycogen reserves, high levels of GP and GS proteins, and high GS activity, which likely allows for rapid mobilization of cryoprotectant during freezing and replenishing of glycogen reserves during thawing. Alaskan frogs also achieved a near-maximal liver glycogen concentration by summer and displayed high glycogenic and glycogenolytic potential in winter, but, unlike Ohioan frogs, started replenishing their energy reserves early in spring. We conclude that variation in levels of both glycogenolytic and glycogenic enzymes likely happens in response to seasonal changes in energetic strategies and demands, with winter survival being a key component to understanding the regulation of glycogen cycling in this species.

Internal pigment cells respond to external UV radiation in frogs.

PubMed

Franco-Belussi, Lilian; Nilsson Sköld, Helen; de Oliveira, Classius

2016-05-01

Fish and amphibians have pigment cells that generate colorful skins important for signaling, camouflage, thermoregulation and protection against ultraviolet radiation (UVR). However, many animals also have pigment cells inside their bodies, on their internal organs and membranes. In contrast to external pigmentation, internal pigmentation is remarkably little studied and its function is not well known. Here, we tested genotoxic effects of UVR and its effects on internal pigmentation in a neotropical frog, Physalaemus nattereri We found increases in body darkness and internal melanin pigmentation in testes and heart surfaces and in the mesenterium and lumbar region after just a few hours of UVR exposure. The melanin dispersion in melanomacrophages in the liver and melanocytes in testes increased after UV exposure. In addition, the amount of melanin inside melanomacrophages cells also increased. Although mast cells were quickly activated by UVR, only longer UVR exposure resulted in genotoxic effects inside frogs, by increasing the frequency of micronuclei in red blood cells. This is the first study to describe systemic responses of external UVR on internal melanin pigmentation, melanomacrophages and melanocytes in frogs and thus provides a functional explanation to the presence of internal pigmentation. © 2016. Published by The Company of Biologists Ltd.

Evolutionary radiation of earless frogs in the Andes: molecular phylogenetics and habitat shifts in high-elevation terrestrial breeding frogs

PubMed Central

Lehr, Edgar; Rabosky, Daniel L.

2018-01-01

The loss of hearing structures and loss of advertisement calls in many terrestrial breeding frogs (Strabomantidae) living at high elevations in South America are common and intriguing phenomena. The Andean frog genus Phrynopus Peters, 1873 has undergone an evolutionary radiation in which most species lack the tympanic membrane and tympanic annulus, yet the phylogenetic relationships among species in this group remain largely unknown. Here, we present an expanded molecular phylogeny of Phrynopus that includes 24 nominal species. Our phylogeny includes Phrynopus peruanus, the type species of the genus, and 10 other species for which genetic data were previously unavailable. We found strong support for monophyly of Phrynopus, and that two nominal species—Phrynopus curator and Phrynopus nicoleae—are junior synonyms of Phrynopus tribulosus. Using X-ray computed tomography (CT) imaging, we demonstrate that the absence of external hearing structures is associated with complete loss of the auditory skeletal elements (columella) in at least one member of the genus. We mapped the tympanum condition on to a species tree to infer whether the loss of hearing structures took place once or multiple times. We also assessed whether tympanum condition, body size, and body shape are associated with the elevational distribution and habitat use. We identified a single evolutionary transition that involved the loss of both the tympanic membrane and tympanic annulus, which in turn is correlated with the absence of advertisement calls. We also identified several species pairs where one species inhabits the Andean grassland and the other montane forest. When accounting for phylogenetic relatedness among species, we detected a significant pattern of increasing body size with increasing elevation. Additionally, species at higher elevations tend to develop shorter limbs, shorter head, and shorter snout than species living at lower elevations. Our findings strongly suggest a link between

Return of the Tarahumara frog to Arizona

Treesearch

James C. Rorabaugh; Stephen F. Hale; Michael J. Sredl; Craig Ivanyi

2005-01-01

The last wild Tarahumara frog (Rana tarahumarae) in Arizona was found dead in Big Casa Blanca Canyon, Santa Rita Mountains, in May 1983. However, the species is still well represented in the majority of its range in the northern Sierra Madre Occidental and adjacent Sky Islands of Sonora and Chihuahua. Plans to re-establish R. tarahumarae...

Novel efficient genome-wide SNP panels for the conservation of the highly endangered Iberian lynx.

PubMed

Kleinman-Ruiz, Daniel; Martínez-Cruz, Begoña; Soriano, Laura; Lucena-Perez, Maria; Cruz, Fernando; Villanueva, Beatriz; Fernández, Jesús; Godoy, José A

2017-07-21

The Iberian lynx (Lynx pardinus) has been acknowledged as the most endangered felid species in the world. An intense contraction and fragmentation during the twentieth century left less than 100 individuals split in two isolated and genetically eroded populations by 2002. Genetic monitoring and management so far have been based on 36 STRs, but their limited variability and the more complex situation of current populations demand more efficient molecular markers. The recent characterization of the Iberian lynx genome identified more than 1.6 million SNPs, of which 1536 were selected and genotyped in an extended Iberian lynx sample. We validated 1492 SNPs and analysed their heterozygosity, Hardy-Weinberg equilibrium, and linkage disequilibrium. We then selected a panel of 343 minimally linked autosomal SNPs from which we extracted subsets optimized for four different typical tasks in conservation applications: individual identification, parentage assignment, relatedness estimation, and admixture classification, and compared their power to currently used STR panels. We ascribed 21 SNPs to chromosome X based on their segregation patterns, and identified one additional marker that showed significant differentiation between sexes. For all applications considered, panels of autosomal SNPs showed higher power than the currently used STR set with only a very modest increase in the number of markers. These novel panels of highly informative genome-wide SNPs provide more powerful, efficient, and flexible tools for the genetic management and non-invasive monitoring of Iberian lynx populations. This example highlights an important outcome of whole-genome studies in genetically threatened species.

Pleistocene and Holocene Iberian flora: a complete picture and review

NASA Astrophysics Data System (ADS)

González Sampériz, Penélope

2010-05-01

A detailed analysis of the location and composition of Iberian vegetation types during the whole Pleistocene and Holocene periods shows a complex patched landscape with persistence of different types of ecosystems, even during glacial times. In addition, recent, high-resolution palaeoecological records are changing the traditional picture of post-glacial vegetation succession in the Iberian Peninsula. The main available charcoal and pollen sequences include, coniferous and deciduous forest, steppes, shrublands, savannahs and glacial refugia during the Pleistocene for Meso-thermophytes (phytodiversity reservoirs), in different proportions. This panorama suggests an environmental complexity that relates biotic responses to climate changes forced by Milankovitch cycles, suborbital forcings and by the latitudinal and physiographic particularities of the Iberian Peninsula. Thus, many factors are critical in the course of vegetational developments and strong regional differences are observed since the Early Pleistocene. Currently, the flora of Iberia is located in two biogeographical/climatic regions: the Eurosiberian and the Mediterranean. The first one includes northern and northwestern areas of the peninsula, where post-glacial responses of vegetation are very similar to Central Europe, although with some particularities due to its proximity to both the Atlantic Ocean and the Mediterranean region. The second one comprises the main territory of Iberia and shows more complex patterns and singularities, now and in the past. Steppe landscapes dominated extensive areas over all the territory during the cold spells of the Quaternary, especially during the Late Pleistocene up to the Last Glacial Maximum, but differences in composition of the dominant taxa (Compositae versus Artemisia) are observed since the Early Pleistocene, probably related to moisture regional gradients. Coastal shelves and intramountainous valleys, even in continental areas, are spots of floristic

Climatic record of the Iberian peninsula from lake Moncortes' sediments

NASA Astrophysics Data System (ADS)

Cao, Min; Huguet, Carme; Rull, Valenti; Valero, Blas; Rosell-Mele, Antoni

2014-05-01

Climatic record of the Iberian peninsula from lake Moncortes' sediments Min Cao1, Carme Huguet1, Valenti Rull2, Blas L. Valero-Garces3, Antoni Rosell-Melé1,4 1Institut de Ciència i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Catalonia, Spain; 2Institut de Botanic de Barcelona (CSIC), Passeig del Migdia s/n, 08038, Barcelona, Spain, 3 Instituto Pirenaico de Ecologıa (CSIC), Avda. Montañana 1005, 50059 Zaragoza, Spain, 4Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Catalonia, Spain. The continuing buildup of industrial greenhouse gases in the atmosphere and concomitant increase in global temperatures has made much of the world's society aware that decades to centuries of environmental change lie ahead, and that these will have profound economic, political and societal impacts. The Iberian Peninsula lies in the boundary between tropical and subtropical climates and seems to amplify the climatic signals form the northern hemisphere through both atmospheric and water circulation feedbacks, making it an ideal site to monitor Northern hemisphere climate changes. This extreme sensitivity to climatic changes also makes the Iberian Peninsula extremely vulnerable to future climate changes. This is why understanding sensitivity to climate change and the consequences it will have on both climate and the hydrological cycle is key to implement preventive measures. The aim of our study is to come up with a high resolution quantitative reconstruction of climate variability (temperature, production and precipitation) in the Iberian Peninsula from lake sediments. We also want to establish the relation between those changes and the ones observed in both ice cores from Greenland and paleotemperature records from marine sediments of the continental Iberian margin. For these reasons we sampled a core in Moncortes (42.3N, 0.99E), a lake of karstic origin with an average depth of 25m and an area of 0

Meta-Analysis of Mitochondrial DNA Variation in the Iberian Peninsula.

PubMed

Barral-Arca, Ruth; Pischedda, Sara; Gómez-Carballa, Alberto; Pastoriza, Ana; Mosquera-Miguel, Ana; López-Soto, Manuel; Martinón-Torres, Federico; Álvarez-Iglesias, Vanesa; Salas, Antonio

2016-01-01

The Iberian Peninsula has been the focus of attention of numerous studies dealing with mitochondrial DNA (mtDNA) variation, most of them targeting the control region segment. In the present study we sequenced the control region of 3,024 Spanish individuals from areas where available data were still limited. We also compiled mtDNA haplotypes from the literature involving 4,588 sequences and 28 population groups or small regions. We meta-analyzed all these data in order to shed further light on patterns of geographic variation, taking advantage of the large sample size and geographic coverage, in contrast with the atomized sampling strategy of previous work. The results indicate that the main mtDNA haplogroups show primarily clinal geographic patterns across the Iberian geography, roughly along a North-South axis. Haplogroup HV0 (where haplogroup U is nested) is more prevalent in the Franco Cantabrian region, in good agreement with previous findings that identified this area as a climate refuge during the Last Glacial Maximum (LGM), prior to a subsequent demographic re-expansion towards Central Europe and the Mediterranean. Typical sub-Saharan and North African lineages are slightly more prevalent in South Iberia, although at low frequencies; this pattern has been shaped mainly by the transatlantic slave trade and the Arab invasion of the Iberian Peninsula. The results also indicate that summary statistics that aim to measure molecular variation, or AMOVA, have limited sensitivity to detect population substructure, in contrast to patterns revealed by phylogeographic analysis. Overall, the results suggest that mtDNA variation in Iberia is substantially stratified. These patterns might be relevant in biomedical studies given that stratification is a common cause of false positives in case-control mtDNA association studies, and should be also considered when weighting the DNA evidence in forensic casework, which is strongly dependent on haplotype frequencies.

Meta-Analysis of Mitochondrial DNA Variation in the Iberian Peninsula

PubMed Central

Barral-Arca, Ruth; Pischedda, Sara; Gómez-Carballa, Alberto; Pastoriza, Ana; Mosquera-Miguel, Ana; López-Soto, Manuel; Martinón-Torres, Federico; Álvarez-Iglesias, Vanesa; Salas, Antonio

2016-01-01

The Iberian Peninsula has been the focus of attention of numerous studies dealing with mitochondrial DNA (mtDNA) variation, most of them targeting the control region segment. In the present study we sequenced the control region of 3,024 Spanish individuals from areas where available data were still limited. We also compiled mtDNA haplotypes from the literature involving 4,588 sequences and 28 population groups or small regions. We meta-analyzed all these data in order to shed further light on patterns of geographic variation, taking advantage of the large sample size and geographic coverage, in contrast with the atomized sampling strategy of previous work. The results indicate that the main mtDNA haplogroups show primarily clinal geographic patterns across the Iberian geography, roughly along a North-South axis. Haplogroup HV0 (where haplogroup U is nested) is more prevalent in the Franco Cantabrian region, in good agreement with previous findings that identified this area as a climate refuge during the Last Glacial Maximum (LGM), prior to a subsequent demographic re-expansion towards Central Europe and the Mediterranean. Typical sub-Saharan and North African lineages are slightly more prevalent in South Iberia, although at low frequencies; this pattern has been shaped mainly by the transatlantic slave trade and the Arab invasion of the Iberian Peninsula. The results also indicate that summary statistics that aim to measure molecular variation, or AMOVA, have limited sensitivity to detect population substructure, in contrast to patterns revealed by phylogeographic analysis. Overall, the results suggest that mtDNA variation in Iberia is substantially stratified. These patterns might be relevant in biomedical studies given that stratification is a common cause of false positives in case-control mtDNA association studies, and should be also considered when weighting the DNA evidence in forensic casework, which is strongly dependent on haplotype frequencies. PMID

Population status and population genetics of northern leopard frogs in Arizona

USGS Publications Warehouse

Theimer, Tad C.; Drost, Charles A.; O'Donnell, Ryan P.; Mock, Karen E.

2011-01-01

Increasing isolation of populations by habitat fragmentation threatens the persistence of many species, both from stochastic loss of small isolated populations, and from inbreeding effects in populations that have become genetically isolated. In the southwestern United States, amphibian habitat is naturally patchy in occurrence because of the prevailing aridity of the region. Streams, rivers, and other wetlands are important both as habitat and as corridors that connect populations. However, populations of some species have become more fragmented and isolated by habitat degradation and loss. Northern leopard frogs (Rana pipiens) have experienced serious declines in the Southwest. We conducted an extensive survey across the known range of northern leopard frogs in Arizona to determine the current distribution and abundance of the species. From a range that once spanned much of the northern and central part of the State, northern leopard frogs have been reduced to three or four widely separated populations, near Lyman Lake in east-central Arizona, in the Stoneman Lake area south of Flagstaff, along Truxton Wash near Peach Springs, and a population of uncertain extent on Navajo Nation lands. The Lyman Lake and Truxton Wash populations are small and extremely isolated. The Stoneman Lake population, however, is an extensive metapopulation spread across several stream drainages, including numerous ponds, wetlands, and artificial tanks. This is the only population in Arizona that is increasing in extent and numbers, but there is concern about the apparent introduction of nonnative genetic stock from eastern North America into this area. We analyzed genetic diversity within and genetic divergence among populations of northern leopard frogs, across both extant and recently extirpated populations in Arizona. We also analyzed mitochondrial DNA to place these populations into a larger phylogenetic framework and to determine whether any populations contained genetic material

Pleistocene leopards in the Iberian Peninsula: New evidence from palaeontological and archaeological contexts in the Mediterranean region

NASA Astrophysics Data System (ADS)

Sanchis, Alfred; Tormo, Carmen; Sauqué, Víctor; Sanchis, Vicent; Díaz, Rebeca; Ribera, Agustí; Villaverde, Valentín

2015-09-01

This study analyses the fossil record of leopards in the Iberian Peninsula. According to the systematic and morphometric features of new remains, identified mainly in Late Pleistocene palaeontological and archaeological sites of the Mediterranean region, they can be attributed to Panthera pardus Linnaeus 1758. The findings include the most complete leopard skeleton from the Iberian Peninsula and one of the most complete in Europe, found in a chasm (Avenc de Joan Guitón) south of Valencia. The new citations and published data are used to establish the leopard's distribution in the Iberian Peninsula, showing its maximum development during the Late Pleistocene. Some references suggest that the species survived for longer here (Lateglacial-Early Holocene) than in other parts of Europe. Finally, the contexts of appearance and origin of leopard remains are described and the processes of interaction with prehistoric human groups are assessed.

Microsatellite variation in Donax trunculus from the Iberian Peninsula, with particular attention to Galician estuaries (NW Spain)

NASA Astrophysics Data System (ADS)

Nantón, A.; Arias-Pérez, A.; Freire, R.; Fernández-Pérez, J.; Nóvoa, S.; Méndez, J.

2017-10-01

Genetic variation and population structure information is essential for conservation and stock management policies. The wedge clam Donax trunculus is an important fishing resource in the Iberian Peninsula and in some areas, such as the northwestern Spain, wild stocks have decreased greatly. Despite this, information is mainly from the southwestern Atlantic to the northwestern Mediterranean of the Iberian Peninsula. In this study, fifteen microsatellite loci were examined at 17 localities along the Iberian Peninsula to characterize its genetic diversity and population structure. Particular attention was paid to the northwestern Atlantic area, and to test if the pattern previously described for this species is confirmed when localities distributed across the Atlantic coast are included and different microsatellite markers are used. All localities displayed similar allelic richness values and heterozygosity levels but when genetic diversity levels were compared among groups of localities, tests were significant and samples from the northwestern area (Galicia) showed the lowest values. The analysis of population structure indicated that localities from the Atlantic coast are genetically homogeneous although some samples showed significant pairwise Fst values. These values were low and Bayesian analysis of genetic differentiation did not show a consistent structure along the Atlantic coast of the Iberian Peninsula. However, Atlantic samples were genetically different from those located in Mediterranean coast, which may be explained by the existence of the Almeria-Oran front. Moreover, Fuengirola, locality situated in the Alboran Sea between the Strait of Gibraltar and Mediterranean Sea, showed significant differences from all remaining localities included in the study. Overall, the data showed the existence of genetic homogeneity along the Atlantic coast of the Iberian Peninsula and support the three management units (Atlantic Ocean, the Alboran Sea and the northwestern

Electrophysiological effects of calcitonin gene-related peptide in bull-frog and guinea-pig atrial myocytes.

PubMed Central

Ono, K; Giles, W R

1991-01-01

1. Electrophysiological effects of calcitonin gene-related peptide (CGRP) on action potentials and corresponding transmembrane currents in single myocytes from bull-frog and guinea-pig atria were studied using a whole-cell voltage-clamp method. 2. CGRP at relatively low concentrations increased the height of the action potential plateau in a dose-dependent manner in both bull-frog and guinea-pig myocytes. In addition, in bull-frog cells CGRP accelerated the early phase of repolarization, thus shortening the overall duration of the action potential. In contrast, in guinea-pig myocytes CGRP prolonged the action potential duration at all concentrations that were studied. 3. Voltage-clamp measurements demonstrated that CGRP increased transmembrane calcium current (ICa) in guinea-pig myocytes without a significant change in its voltage dependence. The ED50 value for this effect on ICa was 1.28 +/- 0.55 X 10(-8) M (n = 4). The time course of the inactivation of ICa was not affected by CGRP. 4. CGRP increased the delayed rectifier K+ current (IK) at relatively low concentrations in bull-frog atria, whereas relatively high concentrations were needed to increase IK in guinea-pig myocytes. This effect was observed even after complete inhibition of ICa. 5. CGRP had no significant effect on the inwardly rectifying background K+ current, IK1, even at very high concentrations. 6. Comparison of the time course of ICa augmentation in bull-frog and guinea-pig myocytes revealed an important difference in the effect of CGRP in these two types of cells. CGRP at maximal concentrations increased ICa transiently in bull-frog myocytes, whereas this response was sustained in guinea-pig myocytes. Isoprenaline (Iso) induced sustained increase in ICa in both species. When ICa was fully activated by Iso, CGRP at high concentrations strongly inhibited ICa in the bull-frog, whereas it had little effect on ICa in guinea-pig myocytes. 7. Intracellular application of GTP gamma S (guanosine 5'-O-(3

The chorus environment and the shape of communication systems in frogs

NASA Astrophysics Data System (ADS)

Marshall, Vince

2003-04-01

Many species of frogs breed in dense and structurally complex aggregations of calling males termed choruses. Females entering a chorus are faced with the tasks of recognizing and locating mates on the basis of their advertisement calls. The chorus environment poses particular challenges for communication as signalers and receivers will face high levels of background noise and interference between signals. For females, such conditions may decrease the efficiency of communication, with the consequences of increasing the time required to find a mate or errors in mate choice. For males, it will give rise to intense competition for the attention of females. Additionally, the chorus environment for a species is not static, and will vary over both spatial and temporal scales. This complex and dynamic environment has shaped the signals and signaling behaviors of frogs in sometimes surprising ways. In this talk, some of the implications of the chorus environment for both receivers and signalers is discussed. In particular, examples from North American hylid frogs are drawn upon and research on the role of signal timing in influencing the responses of females and plasticity in aggressive behavior between neighbors in choruses are discussed.

Managing habitat to slow or reverse population declines of the Columbia spotted frog in the Northern Great Basin

USGS Publications Warehouse

Pilliod, David S.; Richard D. Scherer,

2015-01-01

Evaluating the effectiveness of habitat management actions is critical to adaptive management strategies for conservation of imperiled species. We quantified the response of a Great Basin population of the Columbia spotted frog (Rana luteiventris) to multiple habitat improvement actions aimed to reduce threats and reverse population declines. We used mark-recapture data for 1,394 adult frogs that had been marked by state, federal, and university biologists in 9 ponds representing a single population over a 16-year period from 1997 to 2012. With the use of demographic models, we assessed population-level effects of 1) a grazing exclosure constructed around 6 stock ponds that had been used to water livestock for decades before being fully fenced in 2003, and 2) the construction of 3 new stock ponds in 2003 to provide alternative water sources for livestock and, secondarily, to provide additional frog habitat. These management actions were implemented in response to a decline of more than 80% in population size from 1997 to 2002. We found evidence that excluding cattle from ponds and surrounding riparian habitats resulted in higher levels of frog production (more egg masses), higher adult frog recruitment and survival, and higher population growth rate. We also found that frogs colonized the newly constructed stock ponds within 3 years and frogs began breeding in 2 of them after 5 years. The positive effects of the cattle exclosure and additional production from the new ponds, although notable, did not result in full recovery of the population even 9 years later. This slow recovery may be partly explained by the effects of weather on recruitment rates, particularly the negative effects of harsher winters with late springs and higher fall temperatures. Although our findings point to potential successes of habitat management aimed at slowing or reversing rapidly declining frog populations, our study also suggests that recovering from severe population declines can take

Effects of CFT Legumine (5% Rotenone) on tadpole survival and metamorphosis of Chiricahua leopard frogs Lithobates chiricahuensis, Northern leopard frogs L. pipiens, and American bullfrogs L. catesbeianus

USGS Publications Warehouse

Alvarez, Guillermo; Caldwell, Colleen A.; Kruse, Carter G.

2017-01-01

Amphibians may experience collateral effects if exposed to CFT Legumine (5% rotenone), a piscicide that is used to remove invasive fish. A series of 48-h static toxicity tests assessed the acute effects of CFT Legumine on multi-aged tadpoles of the federally listed Chiricahua leopard frog Lithobates chiricahuensis, the widespread northern leopard frog L. pipiens, and the increasingly invasive American bullfrog L. catesbeianus. At the earliest Gosner stages (GS 21–25), Chiricahua leopard frogs were more sensitive to CFT Legumine (median lethal concentration [LC50] = 0.41–0.58 mg/L) than American bullfrogs (LC50 = 0.63–0.69 mg/L) and northern leopard frogs (LC50 = 0.91 and 1.17 mg/L). As tadpoles developed (i.e., increase in GS), their sensitivity to rotenone decreased. In a separate series of 48-h static nonrenewal toxicity tests, tadpoles (GS 21–25 and GS 31–36) of all three species were exposed to piscicidal concentrations of CFT Legumine (0.5, 1.0, and 2.0 mg/L) to assess postexposure effects on metamorphosis. In survivors of all three species at both life stages, the time to tail resorption was nearly doubled in comparison with that of controls. For example, mid-age (GS 31–36) Chiricahua leopard frog tadpoles required 210.7 h to complete tail resorption, whereas controls required 108.5 h. However, because tail resorption is a relatively short period in metamorphosis, the total duration of development (days from posthatch to complete metamorphosis) and the final weight did not differ in either age-group surviving nominal concentrations of 0.5-, 1.0-, and 2.0-mg/L CFT Legumine relative to controls. This research demonstrates that the CFT Legumine concentrations commonly used in field applications to remove unwanted fish could result in considerable mortality of the earliest stages of Lithobates species. In addition to acute lethality, piscicide treatments may result in delayed tail resorption, which places the tadpoles at risk by increasing

Effects of cadmium exposure on Iberian ribbed newt (Pleurodeles waltl) testes

PubMed Central

Hirako, Ayano; Takeoka, Yuki; Hayashi, Toshinori; Takeuchi, Takashi; Furukawa, Satoshi; Sugiyama, Akihiko

2017-01-01

To characterize the histomorphologic effects of cadmium on adult newt testes, male Iberian ribbed newts (6 months post-hatching) were intraperitoneally exposed to a single dose of 50 mg/kg of cadmium, with histologic analysis of the testes at 24, 48, 72, and 96 h. Beginning 24 h after cadmium exposure, apoptosis of spermatogonia and spermatocytes was observed, and congestion was observed in the interstitial vessels of the testes. Throughout the experimental period, the rates of pyknotic cells and TUNEL and cleaved caspase-3 positivity were significantly higher in the spermatogonia and spermatocytes of cadmium-treated newts compared with control newts. There were no significant differences between cadmium-treated and control newts in phospho-histone H3 positivity in the spermatogonia and spermatocytes. These results suggest that spermatogonia and spermatocytes in adult Iberian ribbed newts are highly sensitive to cadmium. This is the first report of the histomorphologic characteristics of cadmium-induced testicular dysfunction in newts. PMID:29097846

Membrane lipid layers vs. polarized water dominated by fixed ions: a comparative study of the effects of three macrocyclic ionophores on the K+ permeability of frog skeletal muscle, frog ovarian eggs, and human erythrocytes.

PubMed

Ling, G N; Ochsenfeld, M M

1986-01-01

The effects of 10(-7) M valinomycin, nonactin, and monactin on human erythrocytes, frog sartorius muscle, and frog ovarian oocytes in the presence of varying external K+ concentration were studied. The results showed essentially a consistent but relatively modest increase of the K+ permeability constant in cm/sec with all three antibiotics on human erythrocytes. No change in response to any one of the antibiotics was observed in frog muscles or in frog ovarian eggs. These results and reports of similar failure to demonstrate ionophore-mediated increase of K+ permeability in squid axon and inner membrane of the liver mitochondria led to the conclusion that lipid membrane barrier to ionic traffic may be significant in the human erythrocytes but even here one must regard the evidence as tentative. In contrast, for the majority of other cell types studied, the data indicate the primary, if not exclusive route of ion traffic, is via the nonlipid component of the cell membrane. The evidence that these nonlipid paths are the fixed charge-polarized water layer complex and that they cover much of the cell surface of many types of living cells was discussed.

The rediscovered Hula painted frog is a living fossil.

PubMed

Biton, Rebecca; Geffen, Eli; Vences, Miguel; Cohen, Orly; Bailon, Salvador; Rabinovich, Rivka; Malka, Yoram; Oron, Talya; Boistel, Renaud; Brumfeld, Vlad; Gafny, Sarig

2013-01-01

Amphibian declines are seen as an indicator of the onset of a sixth mass extinction of life on earth. Because of a combination of factors such as habitat destruction, emerging pathogens and pollutants, over 156 amphibian species have not been seen for several decades, and 34 of these were listed as extinct by 2004. Here we report the rediscovery of the Hula painted frog, the first amphibian to have been declared extinct. We provide evidence that not only has this species survived undetected in its type locality for almost 60 years but also that it is a surviving member of an otherwise extinct genus of alytid frogs, Latonia, known only as fossils from Oligocene to Pleistocene in Europe. The survival of this living fossil is a striking example of resilience to severe habitat degradation during the past century by an amphibian.

Old World frog and bird vocalizations contain prominent ultrasonic harmonics

NASA Astrophysics Data System (ADS)

Narins, Peter M.; Feng, Albert S.; Lin, Wenyu; Schnitzler, Hans-Ulrich; Denzinger, Annette; Suthers, Roderick A.; Xu, Chunhe

2004-02-01

Several groups of mammals such as bats, dolphins and whales are known to produce ultrasonic signals which are used for navigation and hunting by means of echolocation, as well as for communication. In contrast, frogs and birds produce sounds during night- and day-time hours that are audible to humans; their sounds are so pervasive that together with those of insects, they are considered the primary sounds of nature. Here we show that an Old World frog (Amolops tormotus) and an oscine songbird (Abroscopus albogularis) living near noisy streams reliably produce acoustic signals that contain prominent ultrasonic harmonics. Our findings provide the first evidence that anurans and passerines are capable of generating tonal ultrasonic call components and should stimulate the quest for additional ultrasonic species.

Clutch sizes and nests of tailed frogs from the Olympic Peninsula, Washington

USGS Publications Warehouse

Bury, R. Bruce; Loafman, P.; Rofkar, D.; Mike, K.

2001-01-01

In the summers 1995-1998, we sampled 168 streams (1,714 in of randomly selected 1-m bands) to determine distribution and abundance of stream amphibians in Olympic National Park, Washington. We found six nests (two in one stream) of the tailed frog, compared to only two nests with clutch sizes reported earlier for coastal regions. This represents only one nest per 286 in searched and one nest per 34 streams sampled. Tailed frogs occurred only in 94 (60%) of the streams and, for these waters, we found one nest per 171 in searched or one nest per 20 streams sampled. The numbers of eggs for four masses ((x) over bar = 48.3, range 40-55) were low but one single strand in a fifth nest had 96 eggs. One nest with 185 eggs likely represented communal egg deposition. Current evidence indicates a geographic trend with yearly clutches of relatively few eggs in coastal tailed frogs compared to biennial nesting with larger clutches for inland populations in the Rocky Mountains.

Daily precipitation extreme events for the Iberian Peninsula and its association with Atmospheric Rivers

NASA Astrophysics Data System (ADS)

Ramos, Alexandre M.; Trigo, Ricardo M.; Liberato, Margarida LR

2014-05-01

Extreme precipitation events in the Iberian Peninsula during the extended winter months have major socio-economic impacts such as floods, landslides, extensive property damage and life losses. These events are usually associated with low pressure systems with Atlantic origin, although some extreme events in summer/autumn months can be linked to Mediterranean low pressure systems. Quite often these events are evaluated on a casuistic base and making use of data from relatively few stations. An objective method for ranking daily precipitation events is presented here based on the extensive use of the most comprehensive database of daily gridded precipitation available for the Iberian Peninsula (IB02) and spanning from 1950 to 2008, with a resolution of 0.2° (approximately 16 x 22 km at latitude 40°N), for a total of 1673 pixels. This database is based on a dense network of rain gauges, combining two national data sets, 'Spain02' for peninsular Spain and Balearic islands, and 'PT02' for mainland Portugal, with a total of more than two thousand stations over Spain and four hundred stations over Portugal, all quality-controlled and homogenized. Through this objective method for ranking daily precipitation events the magnitude of an event is obtained after considering the area affected as well as its intensity in every grid point and taking into account the daily precipitation normalised departure from climatology. Different precipitation rankings are presented considering the entire Iberian Peninsula, Portugal and also the six largest river basins in the Iberian Peninsula. Atmospheric Rivers (AR) are the water vapour (WV) core section of the broader warm conveyor belt occurring over the oceans along the warm sector of extra-tropical cyclones. They are usually W-E oriented steered by pre-frontal low level jets along the trailing cold front and subsequently feed the precipitation in the extra-tropical cyclones. They are relatively narrow regions of concentrated WV

More similar than you think: Frog metamorphosis as a model of human perinatal endocrinology.

PubMed

Buchholz, Daniel R

2015-12-15

Hormonal control of development during the human perinatal period is critically important and complex with multiple hormones regulating fetal growth, brain development, and organ maturation in preparation for birth. Genetic and environmental perturbations of such hormonal control may cause irreversible morphological and physiological impairments and may also predispose individuals to diseases of adulthood, including diabetes and cardiovascular disease. Endocrine and molecular mechanisms that regulate perinatal development and that underlie the connections between early life events and adult diseases are not well elucidated. Such mechanisms are difficult to study in uterus-enclosed mammalian embryos because of confounding maternal effects. To elucidate mechanisms of developmental endocrinology in the perinatal period, Xenopus laevis the African clawed frog is a valuable vertebrate model. Frogs and humans have identical hormones which peak at birth and metamorphosis, have conserved hormone receptors and mechanisms of gene regulation, and have comparable roles for hormones in many target organs. Study of molecular and endocrine mechanisms of hormone-dependent development in frogs is advantageous because an extended free-living larval period followed by metamorphosis (1) is independent of maternal endocrine influence, (2) exhibits dramatic yet conserved developmental effects induced by thyroid and glucocorticoid hormones, and (3) begins at a developmental stage with naturally undetectable hormone levels, thereby facilitating endocrine manipulation and interpretation of results. This review highlights the utility of frog metamorphosis to elucidate molecular and endocrine actions, hormone interactions, and endocrine disruption, especially with respect to thyroid hormone. Knowledge from the frog model is expected to provide fundamental insights to aid medical understanding of endocrine disease, stress, and endocrine disruption affecting the perinatal period in humans

Variation in brain anatomy in frogs and its possible bearing on their locomotor ecology.

PubMed

Manzano, Adriana S; Herrel, Anthony; Fabre, Anne-Claire; Abdala, Virginia

2017-07-01

Despite the long-standing interest in the evolution of the brain, relatively little is known about variation in brain anatomy in frogs. Yet, frogs are ecologically diverse and, as such, variation in brain anatomy linked to differences in lifestyle or locomotor behavior can be expected. Here we present a comparative morphological study focusing on the macro- and micro-anatomy of the six regions of the brain and its choroid plexus: the olfactory bulbs, the telencephalon, the diencephalon, the mesencephalon, the rhombencephalon, and the cerebellum. We also report on the comparative anatomy of the plexus brachialis responsible for the innervation of the forelimbs. It is commonly thought that amphibians have a simplified brain organization, associated with their supposedly limited behavioral complexity and reduced motor skills. We compare frogs with different ecologies that also use their limbs in different contexts and for other functions. Our results show that brain morphology is more complex and more variable than typically assumed. Moreover, variation in brain morphology among species appears related to locomotor behavior as suggested by our quantitative analyses. Thus we propose that brain morphology may be related to the locomotor mode, at least in the frogs included in our analysis. © 2017 Anatomical Society.

Climate change and frog calls: long-term correlations along a tropical altitudinal gradient.

PubMed

Narins, Peter M; Meenderink, Sebastiaan W F

2014-05-22

Temperature affects nearly all biological processes, including acoustic signal production and reception. Here, we report on advertisement calls of the Puerto Rican coqui frog (Eleutherodactylus coqui) that were recorded along an altitudinal gradient and compared these with similar recordings along the same altitudinal gradient obtained 23 years earlier. We found that over this period, at any given elevation, calls exhibited both significant increases in pitch and shortening of their duration. All of the observed differences are consistent with a shift to higher elevations for the population, a well-known strategy for adapting to a rise in ambient temperature. Using independent temperature data over the same time period, we confirm a significant increase in temperature, the magnitude of which closely predicts the observed changes in the frogs' calls. Physiological responses to long-term temperature rises include reduction in individual body size and concomitantly, population biomass. These can have potentially dire consequences, as coqui frogs form an integral component of the food web in the Puerto Rican rainforest.

[Comparative sensitivity of liver monoamine oxidases of frog and whitefish to some tricyclic compounds].

PubMed

Basova, I N; Iagodina, O V

2011-01-01

There is performed a comparative analysis of action of four acridine derivatives and of one xanthene derivative (pyronine G) on activity of liver monoamine oxidase (MAO) of two species of poikilothermal freshwater animals: a representative of amphibians--the common frog Rana temnporaria and a representative of the order Salmonidae--the European whitefish Coregonus lavaretus. The studied synthetic hexamerous tricyclic compounds show the irreversible character of inhibition of intermediate potency towards the enzyme from both biological sources. There are obtained qualitative and quantitative differences in the reactional ability and selectivity of action of the studied inhibitors for liver MAO of frog and whitefish. The obtained data of the inhibitory analysis with use of specific substrates are an indirect proof for the existence in liver of the studies frog species of two molecular forms, whereas in the whitefish liver--single molecular MAO form.

Past, present and future distributions of an Iberian Endemic, Lepus granatensis: ecological and evolutionary clues from species distribution models.

PubMed

Acevedo, Pelayo; Melo-Ferreira, José; Real, Raimundo; Alves, Paulo Célio

2012-01-01

The application of species distribution models (SDMs) in ecology and conservation biology is increasing and assuming an important role, mainly because they can be used to hindcast past and predict current and future species distributions. However, the accuracy of SDMs depends on the quality of the data and on appropriate theoretical frameworks. In this study, comprehensive data on the current distribution of the Iberian hare (Lepus granatensis) were used to i) determine the species' ecogeographical constraints, ii) hindcast a climatic model for the last glacial maximum (LGM), relating it to inferences derived from molecular studies, and iii) calibrate a model to assess the species future distribution trends (up to 2080). Our results showed that the climatic factor (in its pure effect and when it is combined with the land-cover factor) is the most important descriptor of the current distribution of the Iberian hare. In addition, the model's output was a reliable index of the local probability of species occurrence, which is a valuable tool to guide species management decisions and conservation planning. Climatic potential obtained for the LGM was combined with molecular data and the results suggest that several glacial refugia may have existed for the species within the major Iberian refugium. Finally, a high probability of occurrence of the Iberian hare in the current species range and a northward expansion were predicted for future. Given its current environmental envelope and evolutionary history, we discuss the macroecology of the Iberian hare and its sensitivity to climate change.

Past, Present and Future Distributions of an Iberian Endemic, Lepus granatensis: Ecological and Evolutionary Clues from Species Distribution Models

PubMed Central

Acevedo, Pelayo; Melo-Ferreira, José; Real, Raimundo; Alves, Paulo Célio

2012-01-01

The application of species distribution models (SDMs) in ecology and conservation biology is increasing and assuming an important role, mainly because they can be used to hindcast past and predict current and future species distributions. However, the accuracy of SDMs depends on the quality of the data and on appropriate theoretical frameworks. In this study, comprehensive data on the current distribution of the Iberian hare (Lepus granatensis) were used to i) determine the species’ ecogeographical constraints, ii) hindcast a climatic model for the last glacial maximum (LGM), relating it to inferences derived from molecular studies, and iii) calibrate a model to assess the species future distribution trends (up to 2080). Our results showed that the climatic factor (in its pure effect and when it is combined with the land-cover factor) is the most important descriptor of the current distribution of the Iberian hare. In addition, the model’s output was a reliable index of the local probability of species occurrence, which is a valuable tool to guide species management decisions and conservation planning. Climatic potential obtained for the LGM was combined with molecular data and the results suggest that several glacial refugia may have existed for the species within the major Iberian refugium. Finally, a high probability of occurrence of the Iberian hare in the current species range and a northward expansion were predicted for future. Given its current environmental envelope and evolutionary history, we discuss the macroecology of the Iberian hare and its sensitivity to climate change. PMID:23272115

Oxidative stress induced in PCB 126-exposed northern leopard frogs, Rana pipiens

USGS Publications Warehouse

Huang, Y.-W.; Hoffman, D.J.; Karasov, W.H.

2007-01-01

Northern leopard frogs Rana pipiens exposed to PCB 126 (3,3',4,4',5-pentachlorobiphenyl) were examined for hepatic oxidative stress. In a dose-response study, northern leopard frogs were injected intraperitoneally with either PCB 126 in corn oil (0.2, 0.7, 2.3, or 7.8 mg/kg body weight) or corn oil alone. In a time-course study, frogs received 7.8 mg/kg or corn oil alone, and were examined at 1, 2, 3, and 4 wk after dosing. Hepatic concentrations of reduced glutathione (GSH), thiobarbituric acid-reactive substances (TBARS), and total sulfhydryls (total SH), as well as activities of glutathione peroxidase (GSH-P), GSSG reductase (GSSG-R), glucose-6-phosphate dehydrogenase (G-6-PDH), and glutathione S-transferase (GSH-S-T) were measured. In the dose-response experiment, few effects were apparent 1 wk after dosing. In the time-course experiment, significant changes were observed in the 7.8-mg/kg group at 2 wk or more posttreatment. Hepatic concentrations of GSH and TBARS were higher than in corresponding controls at wk 3 and 4; the activities of GSSG-R and GSH-S-T were higher than in controls at wk 2 and 4; and the activity of G-6-PDH was increased at wk 2 and 4. These data collectively indicate that altered glutathione metabolism and oxidative stress occurred and were indicative of both toxicity and induction of protective mechanisms in frogs exposed to PCB. A similar delay in response was reported in fish and may relate to lower metabolic rate and physiological reactions in ectothermic vertebrates

Oxidative stress induced in PCB 126-exposed northern leopard frogs, Rana pipiens.

PubMed

Huang, Yue-wern; Hoffman, David J; Karasov, William H

2007-04-15

Northern leopard frogs Rana pipiens exposed to PCB 126 (3,3',4,4',5-pentachlorobiphenyl) were examined for hepatic oxidative stress. In a dose-response study, northern leopard frogs were injected intraperitoneally with either PCB 126 in corn oil (0.2, 0.7, 2.3, or 7.8 mg/kg body weight) or corn oil alone. In a time-course study, frogs received 7.8 mg/kg or corn oil alone, and were examined at 1, 2, 3, and 4 wk after dosing. Hepatic concentrations of reduced glutathione (GSH), thiobarbituric acid-reactive substances (TBARS), and total sulfhydryls (total SH), as well as activities of glutathione peroxidase (GSH-P), GSSG reductase (GSSG-R), glucose-6-phosphate dehydrogenase (G-6-PDH), and glutathione S-transferase (GSH-S-T) were measured. In the dose-response experiment, few effects were apparent 1 wk after dosing. In the time-course experiment, significant changes were observed in the 7.8-mg/kg group at 2 wk or more posttreatment. Hepatic concentrations of GSH and TBARS were higher than in corresponding controls at wk 3 and 4; the activities of GSSG-R and GSH-S-T were higher than in controls at wk 2 and 4; and the activity of G-6-PDH was increased at wk 2 and 4. These data collectively indicate that altered glutathione metabolism and oxidative stress occurred and were indicative of both toxicity and induction of protective mechanisms in frogs exposed to PCB. A similar delay in response was reported in fish and may relate to lower metabolic rate and physiological reactions in ectothermic vertebrates.

Terrestrial activity and conservation of adult California red-legged frogs Rana aurora draytonii in coastal forests and grasslands

USGS Publications Warehouse

Bulger, J.B.; Scott, N.J.; Seymour, R.B.

2003-01-01

The federally threatened California red-legged frog Rana aurora draytonii occupies both aquatic and terrestrial habitats in its adult life stage. The terrestrial activities of this species are not well known and require documentation to assist in the development of appropriate levels of protection under the US Endangered Species Act. We studied the terrestrial activities of radio-tagged red-legged frogs (n = 8-26) inhabiting a coastal watershed in Santa Cruz County, California, during 1997-1998. In particular, we investigated (1) the use of terrestrial habitats by non-migrating adults in relation to season, breeding chronology, and precipitation, and (2) adult migration behavior, including seasonal timing, duration, distances traveled, and the use of corridors. Non-migrating red-legged frogs occupied terrestrial habitats briefly (median = 4-6 days) following infrequent summer rains, but resided nearly continuously on land (median = 20-30 days) from the onset of the winter wet-season until breeding activities commenced 1-2 months later. All of the non-migrating frogs remained within 130 m of their aquatic site of residence (median <25 m). Intervals spent on land were again brief during mid/late winter (median = 1-4 days), despite frequent and copious rainfall. Adult migration to and from breeding sites occurred from late October through mid-May (wet season). We monitored 25 migration events between aquatic sites that were 200-2800 m apart. Short distance movements ( <300 m) were completed in 1-3 days, longer movements required up to 2 months. Most migrating frogs moved overland in approximately straight lines to target sites without apparent regard to vegetation type or topography. Riparian corridors were neither essential nor preferred as migration routes. Frogs traveling overland occurred in upland habitats as far as 500 m from water. Approximately 11-22% of the adult population was estimated to migrate to and from breeding sites annually, whereas the bulk of the

Influence of pre-cure freezing on the profile of volatile compounds during the processing of Iberian hams.

PubMed

Pérez-Palacios, Trinidad; Ruiz, Jorge; Martín, Diana; Grau, Raúl; Antequera, Teresa

2010-04-15

This work was designed to study the effect of pre-cure freezing of raw thighs from Iberian pigs on the profile of volatile compounds during the processing of hams. Generation of volatile compounds during Iberian ham processing was similar in both pre-cure frozen and refrigerated hams, the main differences being at the final stage. The levels of 2-methylbutanal, 2-methyl-1-butanol, 2,3-butanediol and 2-heptanol were significantly higher in dry-cured hams that were pre-cure frozen than in refrigerated ones, whereas the content of most detected esters was statistically lower in pre-cure frozen than in refrigerated hams. The effect of pre-cure freezing of Iberian ham on the profile of volatile compounds during ripening was not remarkable. Few differences were found in the final product, which would not greatly modify the aroma and flavour features of the dry-cured hams. (c) 2010 Society of Chemical Industry.

Neglecting the call of the wild: Captive frogs like the sound of their own voice.

PubMed

Passos, Luiza Figueiredo; Garcia, Gerardo; Young, Robert John

2017-01-01

Acoustic communication is highly influential in the expression of social behavior by anuran amphibians, transmitting information about the individual's physical condition and motivation. We studied the phonotactic (approach movements) responses of wild and captive male golden mantella frogs to conspecific wild and captive playback calls to determine the impact of captivity on social behaviour mediated by vocalisations. Calls were recorded from one wild and two captive populations. Phonotaxis experiments were then conducted by attracting M. aurantiaca males across a PVC grid on the forest floor or enclosure floor to a speaker. For each playback, the following parameters were recorded to define the accuracy of phonotaxis: (1) number of jumps; (2) jump angles; (3) jump distances; (4) path straightness. During this experiment we observed that wild frogs had a similar behavioural (phonotaxis) response to calls independent of their source while frogs from Chester Zoo had a significantly stronger response to calls of other conspecifics held separately at Chester Zoo. The lack of appropriate phonotaxis response by captive bred frogs to the calls of wild conspecifics could have serious negative conservation implications, if the captive bred individuals were released back to the wild.

Neglecting the call of the wild: Captive frogs like the sound of their own voice

PubMed Central

Passos, Luiza Figueiredo; Garcia, Gerardo

2017-01-01

Acoustic communication is highly influential in the expression of social behavior by anuran amphibians, transmitting information about the individual’s physical condition and motivation. We studied the phonotactic (approach movements) responses of wild and captive male golden mantella frogs to conspecific wild and captive playback calls to determine the impact of captivity on social behaviour mediated by vocalisations. Calls were recorded from one wild and two captive populations. Phonotaxis experiments were then conducted by attracting M. aurantiaca males across a PVC grid on the forest floor or enclosure floor to a speaker. For each playback, the following parameters were recorded to define the accuracy of phonotaxis: (1) number of jumps; (2) jump angles; (3) jump distances; (4) path straightness. During this experiment we observed that wild frogs had a similar behavioural (phonotaxis) response to calls independent of their source while frogs from Chester Zoo had a significantly stronger response to calls of other conspecifics held separately at Chester Zoo. The lack of appropriate phonotaxis response by captive bred frogs to the calls of wild conspecifics could have serious negative conservation implications, if the captive bred individuals were released back to the wild. PMID:28732034

Physiology of hibernation under the ice by turtles and frogs.

PubMed

Jackson, Donald C; Ultsch, Gordon R

2010-07-01

Successful overwintering under ice by an air-breathing vertebrate requires either effective aquatic respiration if dissolved O(2) is available or the capacity for prolonged anaerobic metabolism if O(2) supplies are limiting. Frogs can remain aerobic for many weeks when submerged at low temperature, even at water PO(2) as low as 30 mmHg, but are unable to survive even 1 week in anoxic water. Fuel reserves of hibernating frogs limit aerobic submergence, whereas acidosis may limit anoxic submergence. Freshwater turtles can also satisfy all or most of their O(2) needs in well-aerated water at low temperature by aquatic respiration, but certain species, in particular painted and snapping turtles, can also survive for up to 4-5 months without O(2). Key adaptations of the painted turtles, and presumably snapping turtles, include metabolic depression and the exploitation of the shell and other bones to buffer lactic acid. As in frogs, glycogen and glucose are the only fuel sources during anoxia, and stores do not seem to be limiting in the painted turtle. Significant differences in anoxia tolerance exist among chelonian species that can be attributed, at least in part, to the magnitude of metabolic depression, the effectiveness of lactic acid buffering, and the size of glycogen stores. (c) 2010 Wiley-Liss, Inc.

Marine research in the Iberian Peninsula: A pledge for better times after an economic crisis

NASA Astrophysics Data System (ADS)

Borja, Angel; Marques, Joao-Carlos; Olabarria, Celia; Quintino, Victor

2013-10-01

The “17th Iberian Symposium of Marine Biology Studies” took place in San Sebastian (Spain), in September 2012. This contribution is an introduction to a special issue collating the most challenging papers submitted by Portuguese and Spanish scientists to the symposium. The text was structured as a novel, with the three main parts of a novel: (i) Setup: a historical context, from old times to the 1970's. This part presents the main Iberian scientific contribution to marine science, since the 15th Century, as a precedent to modern scientific research; (ii) Conflict: from the 1970's to the economic crisis. This part presents the evolution of Iberian research production, based upon a bibliometric study, from 1974 to 2012; and (iii) Resolution: what for the future?, which shows the main challenges, proposed by the authors, to the European research initiative 'Horizon 2020', including aspects such as the need of knowledge-base for marine management, the marine research as a potential source of jobs, the ecosystem-based approach, human activities and Marine Spatial Planning, moving from fisheries to aquaculture, or global change issues, among others.

Regional Climate Modelling of the Western Iberian Low-Level Wind Jet

NASA Astrophysics Data System (ADS)

Soares, Pedro M. M.; Lima, Daniela C. A.; Cardoso, Rita M.; Semedo, Álvaro

2016-04-01

The Iberian coastal low-level jet (CLLJ) is one the less studied boundary layer wind jet features in the Eastern Boundary Currents Systems (EBCS). These regions are amongst the most productive ocean ecosystems, where the atmosphere-land-ocean feedbacks, which include marine boundary layer clouds, coastal jets, upwelling and inland soil temperature and moisture, play an important role in defining the regional climate along the sub-tropical mid-latitude western coastal areas. Recently, the present climate western Iberian CLLJ properties were extensively described using a high resolution regional climate hindcast simulation. A summer maximum frequency of occurrence above 30% was found, with mean maximum wind speeds around 15 ms-1, between 300 and 400m heights (at the jet core). Since the 1990s the climate change impact on the EBCS is being studied, nevertheless some lack of consensus still persists regarding the evolution of upwelling and other components of the climate system in these areas. However, recently some authors have shown that changes are to be expected concerning the timing, intensity and spatial homogeneity of coastal upwelling and of CLLJs, in response to future warming, especially at higher latitudes, namely in Iberia and Canaries. In this study, the first climate change assessment study regarding the Western Iberian CLLJ, using a high resolution (9km) regional climate simulation, is presented. The properties of this CLLJ are studied and compared using two 30 years simulations: one historical simulation for the 1971-2000 period, and another simulation for future climate, in agreement with the RCP8.5 scenario, for the 2071-2100 period. Robust and consistent changes are found: 1) the hourly frequency of occurrence of the CLLJ is expected to increase in summer along the western Iberian coast, from mean maximum values of around 35% to approximately 50%; 2) the relative increase of the CLLJ frequency of occurrence is higher in the north off western Iberia

Hibernal habitat selection by Wood Frogs (Lithobates sylvaticus) in a northern New England montane landscape

USGS Publications Warehouse

Groff, Luke A.; Calhoun, Aram J.K.; Loftin, Cynthia S.

2016-01-01

Poikilothermic species, such as amphibians, endure harsh winter conditions via freeze-tolerance or freeze-avoidance strategies. Freeze-tolerance requires a suite of complex, physiological mechanisms (e.g., cryoprotectant synthesis); however, behavioral strategies (e.g., hibernal habitat selection) may be used to regulate hibernaculum temperatures and promote overwintering survival. We investigated the hibernal ecology of the freeze-tolerant Wood Frog (Lithobates sylvaticus) in north-central Maine. Our objectives were to characterize the species hibernaculum microclimate (temperature, relative humidity), evaluate hibernal habitat selection, and describe the spatial arrangement of breeding, post-breeding, and hibernal habitats. We monitored 15 frogs during two winters (2011/12: N = 10; 2012/13: N = 5), measured hibernal habitat features at micro (2 m) and macro (10 m) spatial scales, and recorded microclimate hourly in three strata (hibernaculum, leaf litter, ambient air). We compared these data to that of 57 random locations with logistic regression models, Akaike Information Criterion, and Kolmogorov–Smirnov tests. Hibernaculum microclimate was significantly different and less variable than leaf litter, ambient air, and random location microclimate. Model averaging indicated that canopy cover (−), leaf litter depth (+), and number of logs and stumps (+; microhabitat only) were important predictors of Wood Frog hibernal habitat. These habitat features likely act to insulate hibernating frogs from extreme and variable air temperatures. For example, decreased canopy cover facilitates increased snowpack depth and earlier snowpack accumulation and melt. Altered winter temperature and precipitation patterns attributable to climate change may reduce snowpack insulation, facilitate greater temperature variation in the underlying hibernacula, and potentially compromise Wood Frog winter survival.

Anti-apoptotic response during anoxia and recovery in a freeze-tolerant wood frog (Rana sylvatica)

PubMed Central

Gerber, Victoria E.M.; Wijenayake, Sanoji

2016-01-01

The common wood frog, Rana sylvatica, utilizes freeze tolerance as a means of winter survival. Concealed beneath a layer of leaf litter and blanketed by snow, these frogs withstand subzero temperatures by allowing approximately 65–70% of total body water to freeze. Freezing is generally considered to be an ischemic event in which the blood oxygen supply is impeded and may lead to low levels of ATP production and exposure to oxidative stress. Therefore, it is as important to selectively upregulate cytoprotective mechanisms such as the heat shock protein (HSP) response and expression of antioxidants as it is to shut down majority of ATP consuming processes in the cell. The objective of this study was to investigate another probable cytoprotective mechanism, anti-apoptosis during oxygen deprivation and recovery in the anoxia tolerant wood frog. In particular, relative protein expression levels of two important apoptotic regulator proteins, Bax and p-p53 (S46), and five anti-apoptotic/pro-survival proteins, Bcl-2, p-Bcl-2 (S70), Bcl-xL, x-IAP, and c-IAP in response to normoxic, 24 Hr anoxic exposure, and 4 Hr recovery stages were assessed in the liver and skeletal muscle using western immunoblotting. The results suggest a tissue-specific regulation of the anti-apoptotic pathway in the wood frog, where both liver and skeletal muscle shows an overall decrease in apoptosis and an increase in cell survival. This type of cytoprotective mechanism could be aimed at preserving the existing cellular components during long-term anoxia and oxygen recovery phases in the wood frog. PMID:27042393

Landscape characteristics influence pond occupancy by frogs after accounting for detectability

USGS Publications Warehouse

Mazerolle, M.J.; Desrochers, A.; Rochefort, L.

2005-01-01

Many investigators have hypothesized that landscape attributes such as the amount and proximity of habitat are important for amphibian spatial patterns. This has produced a number of studies focusing on the effects of landscape characteristics on amphibian patterns of occurrence in patches or ponds, most of which conclude that the landscape is important. We identified two concerns associated with these studies: one deals with their applicability to other landscape types, as most have been conducted in agricultural landscapes; the other highlights the need to account for the probability of detection. We tested the hypothesis that landscape characteristics influence spatial patterns of amphibian occurrence at ponds after accounting for the probability of detection in little-studied peatland landscapes undergoing peat mining. We also illustrated the costs of not accounting for the probability of detection by comparing our results to conventional logistic regression analyses. Results indicate that frog occurrence increased with the percent cover of ponds within 100, 250, and 1000 m, as well as the amount of forest cover within 1000 m. However, forest cover at 250 m had a negative influence on frog presence at ponds. Not accounting for the probability of detection resulted in underestimating the influence of most variables on frog occurrence, whereas a few were overestimated. Regardless, we show that conventional logistic regression can lead to different conclusions than analyses accounting for detectability. Our study is consistent with the hypothesis that landscape characteristics are important in determining the spatial patterns of frog occurrence at ponds. We strongly recommend estimating the probability of detection in field surveys, as this will increase the quality and conservation potential of models derived from such data. ?? 2005 by the Ecological Society of America.

Carryover aquatic effects on survival of metamorphic frogs during pond emigration

USGS Publications Warehouse

Chelgren, N.D.; Rosenberg, D.K.; Heppell, S.S.; Gitelman, A.I.

2006-01-01

In organisms with complex life cycles, physiological stressors during early life stages may have fitness-level impacts that are delayed into later stages or habitats. We tested the hypothesis that body size and date of metamorphosis, which are highly responsive to aquatic stressors, influence post-metamorphic survival and movement patterns in the terrestrial phase of an ephemeral pond-breeding frog by examining these traits in two populations of northern red-legged frogs (Rana aurora aurora). To increase variation of body size at metamorphosis, we manipulated food availability for 314 of 1045 uniquely marked tadpoles and estimated the probability that frogs survived and emigrated using concentric rings of drift fencing surrounding ponds and Bayesian capture-recapture modeling. The odds of surviving and emigrating from the ponds to the innermost drift fences, ???12 m, increased by factors of 2.20 (95% credibility intervals 1.39-4.23) and 2.54 (0.94-4.91) with each millimeter increase in snout-vent length and decreased by factors of 0.91 (0.85-0.96) and 0.89 (0.80-1.00) with each day's delay in metamorphosis for the two ponds. The odds of surviving and moving to the next ring of fencing, 12 m to ???40 m from the ponds, increased by a factor of 1.20 (0.45-4.06) with each millimeter increase in size. Our results demonstrated that body size and timing of metamorphosis relate strongly to the performance of newly metamorphosed frogs during their initial transition into terrestrial habitat. Carryover effects of aquatic stressors that reduce size and delay metamorphosis may have population-level impacts that are not expressed until terrestrial stages. Since changes in both aquatic and terrestrial systems are implicated in many amphibian declines, quantifying both immediate and delayed effects of stressors on demographic rates is critical to sound management. ?? 2006 by the Ecological Society of America.

Calling at the highway: The spatiotemporal constraint of road noise on Pacific chorus frog communication.

PubMed

Nelson, Danielle V; Klinck, Holger; Carbaugh-Rutland, Alexander; Mathis, Codey L; Morzillo, Anita T; Garcia, Tiffany S

2017-01-01

Loss of acoustic habitat due to anthropogenic noise is a key environmental stressor for vocal amphibian species, a taxonomic group that is experiencing global population declines. The Pacific chorus frog ( Pseudacris regilla ) is the most common vocal species of the Pacific Northwest and can occupy human-dominated habitat types, including agricultural and urban wetlands. This species is exposed to anthropogenic noise, which can interfere with vocalizations during the breeding season. We hypothesized that Pacific chorus frogs would alter the spatial and temporal structure of their breeding vocalizations in response to road noise, a widespread anthropogenic stressor. We compared Pacific chorus frog call structure and ambient road noise levels along a gradient of road noise exposures in the Willamette Valley, Oregon, USA. We used both passive acoustic monitoring and directional recordings to determine source level (i.e., amplitude or volume), dominant frequency (i.e., pitch), call duration, and call rate of individual frogs and to quantify ambient road noise levels. Pacific chorus frogs were unable to change their vocalizations to compensate for road noise. A model of the active space and time ("spatiotemporal communication") over which a Pacific chorus frog vocalization could be heard revealed that in high-noise habitats, spatiotemporal communication was drastically reduced for an individual. This may have implications for the reproductive success of this species, which relies on specific call repertoires to portray relative fitness and attract mates. Using the acoustic call parameters defined by this study (frequency, source level, call rate, and call duration), we developed a simplified model of acoustic communication space-time for this species. This model can be used in combination with models that determine the insertion loss for various acoustic barriers to define the impact of anthropogenic noise on the radius of communication in threatened species

Detection of Iberian ham aroma by a semiconductor multisensorial system.

PubMed

Otero, Laura; Horrillo, M A Carmen; García, María; Sayago, Isabel; Aleixandre, Manuel; Fernández, M A Jesús; Arés, Luis; Gutiérrez, Javier

2003-11-01

A semiconductor multisensorial system, based on tin oxide, to control the quality of dry-cured Iberian hams is described. Two types of ham (submitted to different drying temperatures) were selected. Good responses were obtained from the 12 elements forming the multisensor for different operating temperatures. Discrimination between the two types of ham was successfully realised through principal component analysis (PCA).

Endemic infection of the amphibian chytrid fungus in a frog community post-decline.

PubMed

Retallick, Richard W R; McCallum, Hamish; Speare, Rick

2004-11-01

The chytrid fungus Batrachochytrium dendrobatidis has been implicated in the decline and extinction of numerous frog species worldwide. In Queensland, Australia, it has been proposed as the cause of the decline or apparent extinction of at least 14 high-elevation rainforest frog species. One of these, Taudactylus eungellensis, disappeared from rainforest streams in Eungella National Park in 1985-1986, but a few remnant populations were subsequently discovered. Here, we report the analysis of B. dendrobatidis infections in toe tips of T. eungellensis and sympatric species collected in a mark-recapture study between 1994 and 1998. This longitudinal study of the fungus in individually marked frogs sheds new light on the effect of this threatening infectious process in field, as distinct from laboratory, conditions. We found a seasonal peak of infection in the cooler months, with no evidence of interannual variation. The overall prevalence of infection was 18% in T. eungellensis and 28% in Litoria wilcoxii/jungguy, a sympatric frog that appeared not to decline in 1985-1986. No infection was found in any of the other sympatric species. Most importantly, we found no consistent evidence of lower survival in T. eungellensis that were infected at the time of first capture, compared with uninfected individuals. These results refute the hypothesis that remnant populations of T. eungellensis recovered after a B. dendrobatidis epidemic because the pathogen had disappeared. They show that populations of T. eungellensis now persist with stable, endemic infections of B. dendrobatidis.

Distortion product otoacoustic emissions provide clues to hearing mechanisms in the frog ear

NASA Astrophysics Data System (ADS)

Vassilakis, Pantelis N.; Meenderink, Sebastiaan W. F.; Narins, Peter M.

2004-12-01

2 f1-f2 and 2 f2-f1 distortion product otoacoustic emissions (DPOAEs) were recorded from both ears of male and female Rana pipiens pipiens and Rana catesbeiana. The input-output (I/O) curves obtained from the amphibian papilla (AP) of both frog species are analogous to I/O curves recorded from mammals suggesting that, similarly to the mammalian cochlea, there may be an amplification process present in the frog AP. DPOAE level dependence on L1-L2 is different from that in mammals and consistent with intermodulation distortion expectations. Therefore, if a mechanical structure in the frog inner ear is functioning analogously to the mammalian basilar membrane, it must be more broadly tuned. DPOAE audiograms were obtained for primary frequencies spanning the animals' hearing range and selected stimulus levels. The results confirm that DPOAEs are produced in both papillae, with R. catesbeiana producing stronger emissions than R. p. pipiens. Consistent with previously reported sexual dimorphism in the mammalian and anuran auditory systems, females of both species produce stronger emissions than males. Moreover, it appears that 2 f1-f2 in the frog is generated primarily at the DPOAE frequency place, while 2 f2-f1 is generated primarily at a frequency place around the primaries. Regardless of generation place, both emissions within the AP may be subject to the same filtering mechanism, possibly the tectorial membrane..

The use of normalized climatological anomalies to rank precipitation events in the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Ramos, Alexandre M.; Trigo, Ricardo M.; Liberato, Margarida L. R.

2013-04-01

Extreme precipitation events in the Iberian Peninsula during winter months have major socio-economic impacts such as flooding, landslides, extensive property damage and life losses, and are usually associated to deep low pressure systems with Atlantic origin, although some extreme events in summer/autumn months are fed by the Mediterranean. Quite often these events are evaluated on a casuistic base and with relatively few stations. An objective method for ranking daily precipitation events is presented based on the extensive use of the most comprehensive database of daily precipitation available for the Iberian Peninsula (IB02) and spanning from 1950 to 2003, with a resolution of 0.2° (approximately 16 x 22 km at latitude 40°N), for a total of 1673 pixels. This database is based on a dense network of rain gauges, combining two national data sets, 'Spain02' for peninsular Spain and Balearic islands (Herrera et al., 2012), and 'PT02' for mainland Portugal (Belo-Pereira et al., 2011), with a total of more than two thousand stations over Spain and four hundred stations over Portugal, all quality-controlled and homogenized. The daily precipitation data from 1950 to 2003 are compared with a 30-year (1961-90) precipitation climatology to achieve a daily normalized departure from the climatology. The magnitude of an event is given daily by an index that is obtained after multiplying 1) the area (in percentage) that has precipitation anomalies above two standard deviations by 2) the mean values of these anomalies over this area. With this criterion we are able to evaluate not only the spatial extent of the precipitation events but also their spatially integrated intensity. In addition, to stress out the hydrological responses to precipitation, rankings taking into account the sum of the normalized anomalies over different time periods (3 days, 5 days and 10 days) were also computed. Here different precipitation rankings will be presented considering the entire Iberian

Whole-genome sequence of the Tibetan frog Nanorana parkeri and the comparative evolution of tetrapod genomes.

PubMed

Sun, Yan-Bo; Xiong, Zi-Jun; Xiang, Xue-Yan; Liu, Shi-Ping; Zhou, Wei-Wei; Tu, Xiao-Long; Zhong, Li; Wang, Lu; Wu, Dong-Dong; Zhang, Bao-Lin; Zhu, Chun-Ling; Yang, Min-Min; Chen, Hong-Man; Li, Fang; Zhou, Long; Feng, Shao-Hong; Huang, Chao; Zhang, Guo-Jie; Irwin, David; Hillis, David M; Murphy, Robert W; Yang, Huan-Ming; Che, Jing; Wang, Jun; Zhang, Ya-Ping

2015-03-17

The development of efficient sequencing techniques has resulted in large numbers of genomes being available for evolutionary studies. However, only one genome is available for all amphibians, that of Xenopus tropicalis, which is distantly related from the majority of frogs. More than 96% of frogs belong to the Neobatrachia, and no genome exists for this group. This dearth of amphibian genomes greatly restricts genomic studies of amphibians and, more generally, our understanding of tetrapod genome evolution. To fill this gap, we provide the de novo genome of a Tibetan Plateau frog, Nanorana parkeri, and compare it to that of X. tropicalis and other vertebrates. This genome encodes more than 20,000 protein-coding genes, a number similar to that of Xenopus. Although the genome size of Nanorana is considerably larger than that of Xenopus (2.3 vs. 1.5 Gb), most of the difference is due to the respective number of transposable elements in the two genomes. The two frogs exhibit considerable conserved whole-genome synteny despite having diverged approximately 266 Ma, indicating a slow rate of DNA structural evolution in anurans. Multigenome synteny blocks further show that amphibians have fewer interchromosomal rearrangements than mammals but have a comparable rate of intrachromosomal rearrangements. Our analysis also identifies 11 Mb of anuran-specific highly conserved elements that will be useful for comparative genomic analyses of frogs. The Nanorana genome offers an improved understanding of evolution of tetrapod genomes and also provides a genomic reference for other evolutionary studies.

Persistence at distributional edges: Columbia spotted frog habitat in the arid Great Basin, USA

PubMed Central

Arkle, Robert S; Pilliod, David S

2015-01-01

A common challenge in the conservation of broadly distributed, yet imperiled species is understanding which factors facilitate persistence at distributional edges, locations where populations are often vulnerable to extirpation due to changes in climate, land use, or distributions of other species. For Columbia spotted frogs (Rana luteiventris) in the Great Basin (USA), a genetically distinct population segment of conservation concern, we approached this problem by examining (1) landscape-scale habitat availability and distribution, (2) water body-scale habitat associations, and (3) resource management-identified threats to persistence. We found that areas with perennial aquatic habitat and suitable climate are extremely limited in the southern portion of the species’ range. Within these suitable areas, native and non-native predators (trout and American bullfrogs [Lithobates catesbeianus]) are widespread and may further limit habitat availability in upper- and lower-elevation areas, respectively. At the water body scale, spotted frog occupancy was associated with deeper sites containing abundant emergent vegetation and nontrout fish species. Streams with American beaver (Castor canadensis) frequently had these structural characteristics and were significantly more likely to be occupied than ponds, lakes, streams without beaver, or streams with inactive beaver ponds, highlighting the importance of active manipulation of stream environments by beaver. Native and non-native trout reduced the likelihood of spotted frog occupancy, especially where emergent vegetation cover was sparse. Intensive livestock grazing, low aquatic connectivity, and ephemeral hydroperiods were also negatively associated with spotted frog occupancy. We conclude that persistence of this species at the arid end of its range has been largely facilitated by habitat stability (i.e., permanent hydroperiod), connectivity, predator-free refugia, and a commensalistic interaction with an ecosystem

Persistence at distributional edges: Columbia spotted frog habitat in the arid Great Basin, USA.

PubMed

Arkle, Robert S; Pilliod, David S

2015-09-01

A common challenge in the conservation of broadly distributed, yet imperiled species is understanding which factors facilitate persistence at distributional edges, locations where populations are often vulnerable to extirpation due to changes in climate, land use, or distributions of other species. For Columbia spotted frogs (Rana luteiventris) in the Great Basin (USA), a genetically distinct population segment of conservation concern, we approached this problem by examining (1) landscape-scale habitat availability and distribution, (2) water body-scale habitat associations, and (3) resource management-identified threats to persistence. We found that areas with perennial aquatic habitat and suitable climate are extremely limited in the southern portion of the species' range. Within these suitable areas, native and non-native predators (trout and American bullfrogs [Lithobates catesbeianus]) are widespread and may further limit habitat availability in upper- and lower-elevation areas, respectively. At the water body scale, spotted frog occupancy was associated with deeper sites containing abundant emergent vegetation and nontrout fish species. Streams with American beaver (Castor canadensis) frequently had these structural characteristics and were significantly more likely to be occupied than ponds, lakes, streams without beaver, or streams with inactive beaver ponds, highlighting the importance of active manipulation of stream environments by beaver. Native and non-native trout reduced the likelihood of spotted frog occupancy, especially where emergent vegetation cover was sparse. Intensive livestock grazing, low aquatic connectivity, and ephemeral hydroperiods were also negatively associated with spotted frog occupancy. We conclude that persistence of this species at the arid end of its range has been largely facilitated by habitat stability (i.e., permanent hydroperiod), connectivity, predator-free refugia, and a commensalistic interaction with an ecosystem

Persistence at distributional edges: Columbia spotted frog habitat in the arid Great Basin, USA

USGS Publications Warehouse

Arkle, Robert S.; Pilliod, David S.

2015-01-01

A common challenge in the conservation of broadly distributed, yet imperiled species is understanding which factors facilitate persistence at distributional edges, locations where populations are often vulnerable to extirpation due to changes in climate, land use, or distributions of other species. For Columbia spotted frogs (Rana luteiventris) in the Great Basin (USA), a genetically distinct population segment of conservation concern, we approached this problem by examining (1) landscape-scale habitat availability and distribution, (2) water body-scale habitat associations, and (3) resource management-identified threats to persistence. We found that areas with perennial aquatic habitat and suitable climate are extremely limited in the southern portion of the species’ range. Within these suitable areas, native and non-native predators (trout and American bullfrogs [Lithobates catesbeianus]) are widespread and may further limit habitat availability in upper- and lower-elevation areas, respectively. At the water body scale, spotted frog occupancy was associated with deeper sites containing abundant emergent vegetation and nontrout fish species. Streams with American beaver (Castor canadensis) frequently had these structural characteristics and were significantly more likely to be occupied than ponds, lakes, streams without beaver, or streams with inactive beaver ponds, highlighting the importance of active manipulation of stream environments by beaver. Native and non-native trout reduced the likelihood of spotted frog occupancy, especially where emergent vegetation cover was sparse. Intensive livestock grazing, low aquatic connectivity, and ephemeral hydroperiods were also negatively associated with spotted frog occupancy. We conclude that persistence of this species at the arid end of its range has been largely facilitated by habitat stability (i.e., permanent hydroperiod), connectivity, predator-free refugia, and a commensalistic interaction with an ecosystem

Frogs as integrative models for understanding digestive organ development and evolution.

PubMed

Womble, Mandy; Pickett, Melissa; Nascone-Yoder, Nanette

2016-03-01

The digestive system comprises numerous cells, tissues and organs that are essential for the proper assimilation of nutrients and energy. Many aspects of digestive organ function are highly conserved among vertebrates, yet the final anatomical configuration of the gut varies widely between species, especially those with different diets. Improved understanding of the complex molecular and cellular events that orchestrate digestive organ development is pertinent to many areas of biology and medicine, including the regeneration or replacement of diseased organs, the etiology of digestive organ birth defects, and the evolution of specialized features of digestive anatomy. In this review, we highlight specific examples of how investigations using Xenopus laevis frog embryos have revealed insight into the molecular and cellular dynamics of digestive organ patterning and morphogenesis that would have been difficult to obtain in other animal models. Additionally, we discuss recent studies of gut development in non-model frog species with unique feeding strategies, such as Lepidobatrachus laevis and Eleutherodactylous coqui, which are beginning to provide glimpses of the evolutionary mechanisms that may generate morphological variation in the digestive tract. The unparalleled experimental versatility of frog embryos make them excellent, integrative models for studying digestive organ development across multiple disciplines. Copyright © 2016 Elsevier Ltd. All rights reserved.

Frogs as integrative models for understanding digestive organ development and evolution

PubMed Central

Womble, Mandy; Pickett, Melissa; Nascone-Yoder, Nanette

2016-01-01

The digestive system comprises numerous cells, tissues and organs that are essential for the proper assimilation of nutrients and energy. Many aspects of digestive organ function are highly conserved among vertebrates, yet the final anatomical configuration of the gut varies widely between species, especially those with different diets. Improved understanding of the complex molecular and cellular events that orchestrate digestive organ development is pertinent to many areas of biology and medicine, including the regeneration or replacement of diseased organs, the etiology of digestive organ birth defects, and the evolution of specialized features of digestive anatomy. In this review, we highlight specific examples of how investigations using Xenopus laevis frog embryos have revealed insight into the molecular and cellular dynamics of digestive organ patterning and morphogenesis that would have been difficult to obtain in other animal models. Additionally, we discuss recent studies of gut development in non-model frog species with unique feeding strategies, such as Lepidobatrachus laev is and Eleutherodactylouscoqui, which are beginning to provide glimpses of the evolutionary mechanisms that may generate morphological variation in the digestive tract. The unparalleled experimental versatility of frog embryos make them excellent, integrative models for studying digestive organ development across multiple disciplines. PMID:26851628

Extinction debt from climate change for frogs in the wet tropics

PubMed Central

Brook, Barry W.; Hoskin, Conrad J.; Pressey, Robert L.; VanDerWal, Jeremy; Williams, Stephen E.

2016-01-01

The effect of twenty-first-century climate change on biodiversity is commonly forecast based on modelled shifts in species ranges, linked to habitat suitability. These projections have been coupled with species–area relationships (SAR) to infer extinction rates indirectly as a result of the loss of climatically suitable areas and associated habitat. This approach does not model population dynamics explicitly, and so accepts that extinctions might occur after substantial (but unknown) delays—an extinction debt. Here we explicitly couple bioclimatic envelope models of climate and habitat suitability with generic life-history models for 24 species of frogs found in the Australian Wet Tropics (AWT). We show that (i) as many as four species of frogs face imminent extinction by 2080, due primarily to climate change; (ii) three frogs face delayed extinctions; and (iii) this extinction debt will take at least a century to be realized in full. Furthermore, we find congruence between forecast rates of extinction using SARs, and demographic models with an extinction lag of 120 years. We conclude that SAR approaches can provide useful advice to conservation on climate change impacts, provided there is a good understanding of the time lags over which delayed extinctions are likely to occur. PMID:27729484

Extinction debt from climate change for frogs in the wet tropics.

PubMed

Fordham, Damien A; Brook, Barry W; Hoskin, Conrad J; Pressey, Robert L; VanDerWal, Jeremy; Williams, Stephen E

2016-10-01

The effect of twenty-first-century climate change on biodiversity is commonly forecast based on modelled shifts in species ranges, linked to habitat suitability. These projections have been coupled with species-area relationships (SAR) to infer extinction rates indirectly as a result of the loss of climatically suitable areas and associated habitat. This approach does not model population dynamics explicitly, and so accepts that extinctions might occur after substantial (but unknown) delays-an extinction debt. Here we explicitly couple bioclimatic envelope models of climate and habitat suitability with generic life-history models for 24 species of frogs found in the Australian Wet Tropics (AWT). We show that (i) as many as four species of frogs face imminent extinction by 2080, due primarily to climate change; (ii) three frogs face delayed extinctions; and (iii) this extinction debt will take at least a century to be realized in full. Furthermore, we find congruence between forecast rates of extinction using SARs, and demographic models with an extinction lag of 120 years. We conclude that SAR approaches can provide useful advice to conservation on climate change impacts, provided there is a good understanding of the time lags over which delayed extinctions are likely to occur. © 2016 The Author(s).

Blood parasites of frogs from an equatorial African montane forest in western Uganda.

PubMed

Readel, Anne M; Goldberg, Tony L

2010-04-01

In a survey of blood parasites in Ugandan frogs, 30 (17%) of 180 frogs were infected with at least 1 species of Hepatozoon or Trypanosoma, or with microfilariae. There were significant differences in the prevalence of parasitism among species, with parasitemia detected in only 3 of 9 species. The intensity of blood parasite infection ranged from 1 to 1,080 infected cells per 5,000 cells examined. Seasonal changes in the prevalence and intensity of parasitemia were not observed, nor was there any association between parasitemia and infection with the pandemic fungus Batrachochytrium dendrobatidis.

A Hopping Good Time: Wood Frogs in the Classroom.

ERIC Educational Resources Information Center

Shimkanin, John; Ulm, Glenn; King, Trina

1998-01-01

Presents a case for using wood frogs to study biology with students. Offers tips on where to find the eggs, how to care for them, what to expect as they hatch, and how to engage students in a study of their stages of development. (DDR)

WEAKLY SYNCHRYRONIZED SUBPOPULATION DYNAMICS IN WISCONSIN FROGS AND TOADS

EPA Science Inventory

Spatial synchrony in population dynamics is a topic of increasing interest in basic and applied ecology. We used data from 18 years of frog and toad calling surveys conducted throughout Wisconsin to determine the level of intraspecific synchrony among survey sites, and the relat...

Acid mine drainage in the Iberian Pyrite Belt: 1. Hydrochemical characteristics and pollutant load of the Tinto and Odiel rivers.

PubMed

Nieto, Jose M; Sarmiento, Aguasanta M; Canovas, Carlos R; Olias, Manuel; Ayora, Carlos

2013-11-01

Acid mine drainage in the Iberian Pyrite Belt is probably the worst case in the world of surface water pollution associated with mining of sulphide mineral deposits. The Iberian Pyrite Belt is located in SW Iberian Peninsula, and it has been mined during the last 4,500 years. The central and eastern part of the Iberian Pyrite Belt is drained by the Tinto and Odiel rivers, which receive most of the acidic leachates from the mining areas. As a result, the main channels of the Tinto and Odiel rivers are very rich in metals and highly acidic until reaching the Atlantic Ocean. A significant amount of the pollutant load transported by these two rivers is delivered during the rainy season, as is usual in rivers of Mediterranean climate regions. Therefore, in order to have an accurate estimation of the pollutant loads transported by the Tinto and Odiel rivers, a systematic sampling on a weekly basis and a high temporal resolution sampling of floods events were both performed. Results obtained show that metal fluxes are strongly dependent on the study period, highlighting the importance of inter-annual studies involving dry and wet years.

Design and Dynamic Model of a Frog-inspired Swimming Robot Powered by Pneumatic Muscles

NASA Astrophysics Data System (ADS)

Fan, Ji-Zhuang; Zhang, Wei; Kong, Peng-Cheng; Cai, He-Gao; Liu, Gang-Feng

2017-09-01

Pneumatic muscles with similar characteristics to biological muscles have been widely used in robots, and thus are promising drivers for frog inspired robots. However, the application and nonlinearity of the pneumatic system limit the advance. On the basis of the swimming mechanism of the frog, a frog-inspired robot based on pneumatic muscles is developed. To realize the independent tasks by the robot, a pneumatic system with internal chambers, micro air pump, and valves is implemented. The micro pump is used to maintain the pressure difference between the source and exhaust chambers. The pneumatic muscles are controlled by high-speed switch valves which can reduce the robot cost, volume, and mass. A dynamic model of the pneumatic system is established for the simulation to estimate the system, including the chamber, muscle, and pneumatic circuit models. The robot design is verified by the robot swimming experiments and the dynamic model is verified through the experiments and simulations of the pneumatic system. The simulation results are compared to analyze the functions of the source pressure, internal volume of the muscle, and circuit flow rate which is proved the main factor that limits the response of muscle pressure. The proposed research provides the application of the pneumatic muscles in the frog inspired robot and the pneumatic model to study muscle controller.

Expression analysis and identification of antimicrobial peptide transcripts from six North American frog species

USGS Publications Warehouse

Robertson, Laura S.; Fellers, Gary M.; Marranca, Jamie Marie; Kleeman, Patrick M.

2013-01-01

Frogs secrete antimicrobial peptides onto their skin. We describe an assay to preserve and analyze antimicrobial peptide transcripts from field-collected skin secretions that will complement existing methods for peptide analysis. We collected skin secretions from 4 North American species in the field in California and 2 species in the laboratory. Most frogs appeared healthy after release; however, Rana boylii in the Sierra Nevada foothills, but not the Coast Range, showed signs of morbidity and 2 died after handling. The amount of total RNA extracted from skin secretions was higher in R. boylii and R. sierrae compared to R. draytonii, and much higher compared to Pseudacris regilla. Interspecies variation in amount of RNA extracted was not explained by size, but for P. regilla it depended upon collection site and date. RNA extracted from skin secretions from frogs handled with bare hands had poor quality compared to frogs handled with gloves or plastic bags. Thirty-four putative antimicrobial peptide precursor transcripts were identified. This study demonstrates that RNA extracted from skin secretions collected in the field is of high quality suitable for use in sequencing or quantitative PCR (qPCR). However, some species do not secrete profusely, resulting in very little extracted RNA. The ability to measure transcript abundance of antimicrobial peptides in field-collected skin secretions complements proteomic analyses and may provide insight into transcriptional mechanisms that could affect peptide abundance.

Frog skin cultures secrete anti-yellow fever compounds.

PubMed

Muñoz-Camargo, Carolina; Méndez, Margarita Correa; Salazar, Vivian; Moscoso, Johanna; Narváez, Diana; Torres, Maria Mercedes; Florez, Franz Kaston; Groot, Helena; Mitrani, Eduardo

2016-11-01

There is an urgent need to develop novel antimicrobial substances. Antimicrobial peptides (AMPs) are considered as promising candidates for future therapeutic use. Because of the re-emergence of the Flavivirus infection, and particularly the yellow fever virus (YFV), we have compared the antiviral activities from skin secretions of seven different frog species against YFV (strain 17D). Secretions from Sphaenorhynchus lacteus, Cryptobatrachus boulongeri and Leptodactylus fuscus displayed the more powerful activities. S. lacteus was found to inhibit viral lysis of Vero E6 cells even at the highest viral concentration evaluated of 10 LD 50 . We also report the identification of a novel frenatin-related peptide from S. lacteus and found that this peptide-on its own-can lead to 35% protection against YVF, while displaying no cytotoxicity against somatic cells even at fivefold higher concentrations. These results are attractive and support the need for continued exploration of new sources of AMPs from frog skin secretions such as those described here in the development of new compounds for the treatment of infectious diseases in general and specific viral infections in particular.

First line of defence: the role of sloughing in the regulation of cutaneous microbes in frogs

PubMed Central

Cramp, Rebecca L.; McPhee, Rebecca K.; Meyer, Edward A.; Ohmer, Michel E.; Franklin, Craig E.

2014-01-01

Amphibian populations worldwide are currently experiencing unprecedented declines due to the combined effects of emerging infectious disease and climate change. The skin is the first line of defence in preventing establishment of pathogens and associated infections. Although amphibians undergo regular sloughing of the outer layer of the skin, the potential for regular sloughing to play a role in influencing cutaneous microbial populations and pathogens has been largely overlooked. In the present study, we assessed the effect of skin sloughing on cultivable cutaneous bacterial abundance in the green tree frog (Litoria caerulea). We also examined the effects of temperature and hydric environment on sloughing frequency and microbial re-establishment rates. Our data showed that cultivable cutaneous bacterial abundance was significantly reduced by sloughing events, and frogs kept at ‘summer’ temperatures (23–33°C) sloughed almost twice as frequently as those maintained at ‘winter’ temperatures (13–23°C). No effect of hydric environment on sloughing frequency was observed, but we did find that sloughing in L. caerulea appeared to be linked to ambient light cycles. Examination of the effect of sloughing on microbial recolonization indicated that at cool temperatures, an extended intermoult interval allowed microbial abundance to reach higher levels than at warmer ‘summer’ temperatures (when the intermoult interval was significantly reduced). Our data suggest that sloughing may significantly influence the establishment and/or maintenance of cutaneous bacterial populations (pathogenic, mutualistic and/or commensal) and this, in turn, may be affected by environmental factors, such as ambient light and temperature. These findings are likely to be important for our understanding of the ecology of skin-based pathogens, such as the amphibian chytrid fungus, Batrachochytrium dendrobatidis. PMID:27293633

Integrated Analysis of Climate, Soil, Topography and Vegetative Growth in Iberian Viticultural Regions

PubMed Central

Fraga, Helder; Malheiro, Aureliano C.; Moutinho-Pereira, José; Cardoso, Rita M.; Soares, Pedro M. M.; Cancela, Javier J.; Pinto, Joaquim G.; Santos, João A.

2014-01-01

The Iberian viticultural regions are convened according to the Denomination of Origin (DO) and present different climates, soils, topography and management practices. All these elements influence the vegetative growth of different varieties throughout the peninsula, and are tied to grape quality and wine type. In the current study, an integrated analysis of climate, soil, topography and vegetative growth was performed for the Iberian DO regions, using state-of-the-art datasets. For climatic assessment, a categorized index, accounting for phenological/thermal development, water availability and grape ripening conditions was computed. Soil textural classes were established to distinguish soil types. Elevation and aspect (orientation) were also taken into account, as the leading topographic elements. A spectral vegetation index was used to assess grapevine vegetative growth and an integrated analysis of all variables was performed. The results showed that the integrated climate-soil-topography influence on vine performance is evident. Most Iberian vineyards are grown in temperate dry climates with loamy soils, presenting low vegetative growth. Vineyards in temperate humid conditions tend to show higher vegetative growth. Conversely, in cooler/warmer climates, lower vigour vineyards prevail and other factors, such as soil type and precipitation acquire more important roles in driving vigour. Vines in prevailing loamy soils are grown over a wide climatic diversity, suggesting that precipitation is the primary factor influencing vigour. The present assessment of terroir characteristics allows direct comparison among wine regions and may have great value to viticulturists, particularly under a changing climate. PMID:25251495

Integrated analysis of climate, soil, topography and vegetative growth in Iberian viticultural regions.

PubMed

Fraga, Helder; Malheiro, Aureliano C; Moutinho-Pereira, José; Cardoso, Rita M; Soares, Pedro M M; Cancela, Javier J; Pinto, Joaquim G; Santos, João A

2014-01-01

The Iberian viticultural regions are convened according to the Denomination of Origin (DO) and present different climates, soils, topography and management practices. All these elements influence the vegetative growth of different varieties throughout the peninsula, and are tied to grape quality and wine type. In the current study, an integrated analysis of climate, soil, topography and vegetative growth was performed for the Iberian DO regions, using state-of-the-art datasets. For climatic assessment, a categorized index, accounting for phenological/thermal development, water availability and grape ripening conditions was computed. Soil textural classes were established to distinguish soil types. Elevation and aspect (orientation) were also taken into account, as the leading topographic elements. A spectral vegetation index was used to assess grapevine vegetative growth and an integrated analysis of all variables was performed. The results showed that the integrated climate-soil-topography influence on vine performance is evident. Most Iberian vineyards are grown in temperate dry climates with loamy soils, presenting low vegetative growth. Vineyards in temperate humid conditions tend to show higher vegetative growth. Conversely, in cooler/warmer climates, lower vigour vineyards prevail and other factors, such as soil type and precipitation acquire more important roles in driving vigour. Vines in prevailing loamy soils are grown over a wide climatic diversity, suggesting that precipitation is the primary factor influencing vigour. The present assessment of terroir characteristics allows direct comparison among wine regions and may have great value to viticulturists, particularly under a changing climate.

The First Call Note Plays a Crucial Role in Frog Vocal Communication.

PubMed

Yue, Xizi; Fan, Yanzhu; Xue, Fei; Brauth, Steven E; Tang, Yezhong; Fang, Guangzhan

2017-08-31

Vocal Communication plays a crucial role in survival and reproductive success in most amphibian species. Although amphibian communication sounds are often complex consisting of many temporal features, we know little about the biological significance of each temporal component. The present study examined the biological significance of notes of the male advertisement calls of the Emei music frog (Babina daunchina) using the optimized electroencephalogram (EEG) paradigm of mismatch negativity (MMN). Music frog calls generally contain four to six notes separated approximately by 150 millisecond intervals. A standard stimulus (white noise) and five deviant stimuli (five notes from one advertisement call) were played back to each subject while simultaneously recording multi-channel EEG signals. The results showed that the MMN amplitude for the first call note was significantly larger than for that of the others. Moreover, the MMN amplitudes evoked from the left forebrain and midbrain were typically larger than those from the right counterpart. These results are consistent with the ideas that the first call note conveys more information than the others for auditory recognition and that there is left-hemisphere dominance for processing information derived from conspecific calls in frogs.

Climatic influences on the breeding biology of the agile frog ( Rana dalmatina)

NASA Astrophysics Data System (ADS)

Combes, Magali; Pinaud, David; Barbraud, Christophe; Trotignon, Jacques; Brischoux, François

2018-02-01

Severe population declines of amphibians have been shown to be attributed to climate change. Nevertheless, the various mechanisms through which climate can influence population dynamics of amphibians remain to be assessed, notably to disentangle the relative synergetic or antagonistic influences of temperature and precipitations on specific life history stages. We investigated the impact of rainfall and temperature on the egg-clutch abundance in a population of agile frog ( Rana dalmatina) during 29 years (1987-2016) on 14 breeding sites located in Brenne Natural Park, France. Specifically, we examined the influence of environmental conditions occurring during five temporal windows of the year cycle corresponding to specific life history stages. Overall, our results suggest that the year-to-year fluctuations of egg-clutch abundances in Brenne Natural Park were partly dependent on local climatic conditions (rainfall and temperature). Climate seemed to influence breeding frogs during the autumn-winter period preceding reproduction. Spring and summer conditions did not influence reproduction. Additionally, we failed to detect effects of climatic conditions on newly metamorphosed individuals. Other factors such as density dependence and inter-specific interactions with introduced predators are likely to play a significant role in reproduction dynamics of the studied frog populations.

Climatic influences on the breeding biology of the agile frog (Rana dalmatina).

PubMed

Combes, Magali; Pinaud, David; Barbraud, Christophe; Trotignon, Jacques; Brischoux, François

2017-12-19

Severe population declines of amphibians have been shown to be attributed to climate change. Nevertheless, the various mechanisms through which climate can influence population dynamics of amphibians remain to be assessed, notably to disentangle the relative synergetic or antagonistic influences of temperature and precipitations on specific life history stages. We investigated the impact of rainfall and temperature on the egg-clutch abundance in a population of agile frog (Rana dalmatina) during 29 years (1987-2016) on 14 breeding sites located in Brenne Natural Park, France. Specifically, we examined the influence of environmental conditions occurring during five temporal windows of the year cycle corresponding to specific life history stages. Overall, our results suggest that the year-to-year fluctuations of egg-clutch abundances in Brenne Natural Park were partly dependent on local climatic conditions (rainfall and temperature). Climate seemed to influence breeding frogs during the autumn-winter period preceding reproduction. Spring and summer conditions did not influence reproduction. Additionally, we failed to detect effects of climatic conditions on newly metamorphosed individuals. Other factors such as density dependence and inter-specific interactions with introduced predators are likely to play a significant role in reproduction dynamics of the studied frog populations.

Reliability of an ELISA test for diagnosing oestrosis in Iberian ibex.

PubMed

Arias, María Sol; Moreno, Virginia; Sarasa, Mathieu; Paz-Silva, Adolfo; Sánchez-Andrade, Rita; Morrondo, Patrocinio; Díez-Baños, Pablo; Granados, José E; Sánchez, Antonio; Pérez, Jesús M

2014-04-01

Oestrosis is one of the most prevalent parasitosis affecting the Iberian ibex, Capra pyrenaica . To date, both the diagnosis of oestrosis and the determination of the intensity of parasitism require the use of invasive methods (necropsy), which necessarily limit research possibilities. We analyzed the immune humoral response (IgM and IgG) against Oestrus ovis L. excretory/secretory larval antigens in 32 sera taken from Iberian ibex from the Sierra Nevada Natural Space (southern Spain). Three antigens were collected: L1OES (from L1 larvae), L2OES (L2), and L3OES (L3). Necropsy was considered as the gold standard. The percentage of ibexes harboring Oestrus spp. larvae was 88%, the mean intensity of parasitism being 16.96 ± 14.96 larvae per parasitized host (range: 2-52). In our sample, first-instar larvae (L1) were found in 9% of ibexes, while 69% of hosts carried L2 larvae and 88% L3 larvae. Positive correlations between L1 and L2 numbers, and between L2 and L3 numbers were detected. The best results with the immunoenzymatic assay were obtained using IgG antibodies against the L1OES antigens (specificity = 89%; sensitivity = 100%; positive predictive value = 100%; negative predictive value = 57%). The IgG seroprevalence against L1OES was 78%. Thus, the analysis of IgG antibodies against antigens collected from L1 O. ovis larvae would seem to be a noninvasive method for reliably diagnosing oestrosis in naturally infested Iberian ibex. Nevertheless, additional immunological and methodological advances are still required because false positive and false negative results still represent a non-negligible part of the results of the ELISA tests.

Ecophysiology Tracks Phylogeny and Meets Ecological Models in an Iberian Gecko.

PubMed

Rato, C; Carretero, M A

2015-01-01

Because fitness of ectotherms, including reptiles, is highly dependent on temperature and water availability, the study of ecophysiological traits, such as preferred temperature (T p) and water loss rates (WLRs), may provide mechanistic evidence on the restricting factors to the species ranges. The Moorish gecko, Tarentola mauritanica, is a species complex with a circum-Mediterranean distribution. In the Iberian Peninsula, two sister parapatric forms of the complex, known as the Iberian and the European clades, are found. Ecological models previously performed using presence records and bioclimatic variables suggest niche divergence between both lineages correlated with precipitation rather than with temperature. In this study, we test this correlative hypothesis using ecophysiological evidence. In the laboratory, we analyzed the T p and WLRs for 84 adult males from seven distinct populations ascribed to one of the two lineages present in Iberia. Specifically, we evaluated the existence of trait conservatism versus adaptation among populations, lineages, or both. In addition, we tested for a trade-off between water and thermal traits and assessed whether climate regime of sampling localities had any influence on the ecophysiological patterns found. We found that T p is quite conserved at both the population and lineage levels and independent from body size. In contrast, water loss experiments revealed some variation among populations, but the regression analysis failed to detect correlation between T p and WLR at any level. Overall, the European lineage displayed a trend for higher water loss and was more diverse among populations when compared with the Iberian lineage. The lack of correspondence between ecophysiological traits and local climatic conditions favors phylogenetic signal versus adaptation. This suggests divergent evolutionary responses to the environment, mainly acting on water ecology, in both lineages, which may account for the differences in their

Mesozoic and Cenozoic exhumation history of the SW Iberian Variscides inferred from low-temperature thermochronology

NASA Astrophysics Data System (ADS)

Vázquez-Vílchez, Mercedes; Jabaloy-Sánchez, Antonio; Azor, Antonio; Stuart, Finlay; Persano, Cristina; Alonso-Chaves, Francisco M.; Martín-Parra, Luis Miguel; Matas, Jerónimo; García-Navarro, Encarnación

2015-11-01

The post-Paleozoic tectonothermal evolution of the SW Iberian Variscides is poorly known mainly due to the scarce low-temperature geochronological data available. We have obtained new apatite fission-tracks and apatite (U-Th)/He ages to constrain the Mesozoic and Cenozoic tectonic evolution of this portion of the Iberian Massif located just north of the Betic-Rif Alpine orogen. We have obtained nine apatite fission-track ages on samples from Variscan and pre-Variscan granitoids. These ages range from 174.4 (± 10.8) to 54.1 (± 4.9) Ma, with mean track lengths between 10.3 and 13.9 μm. We have also performed 5 (U-Th)/He datings on some of the same samples, obtaining ages between 74.6 (± 1.6) and 18.5 (± 1.4) Ma. Time-temperature path modeling of these low-temperature geochronological data leads us to envisage four post-Paleozoic tectonically controlled exhumation episodes in the SW Iberian Variscides. Three of these episodes occurred in Mesozoic times (Middle Triassic to Early Jurassic, Early Cretaceous, and Late Cretaceous) at rates of ≈ 1.1 to 2.5 °C Ma- 1, separated by periods with almost no cooling. We relate these Mesozoic cooling events to the formation of important marginal reliefs during the rifting and opening of the central and northern Atlantic realm. The fourth exhumation episode occurred in Cenozoic times at rates of ≈ 3.2 to 3.6 °C Ma- 1, being only recorded in samples next to faults with topographic escarpments. These samples cooled below 80 °C at ≈ 20 Ma at rates of 3-13 °C Ma- 1 due to roughly N-S oriented compressional stresses affecting the whole Iberian plate, which, in the particular case of SW Iberia, reactivated some of the previous Late Paleozoic thrusts.

Towards green loyalty: the influences of green perceived risk, green image, green trust and green satisfaction

NASA Astrophysics Data System (ADS)

Chrisjatmiko, K.

2018-01-01

The paper aims to present a comprehensive framework for the influences of green perceived risk, green image, green trust and green satisfaction to green loyalty. The paper also seeks to account explicitly for the differences in green perceived risk, green image, green trust, green satisfaction and green loyalty found among green products customers. Data were obtained from 155 green products customers. Structural equation modeling was used in order to test the proposed hypotheses. The findings show that green image, green trust and green satisfaction has positive effects to green loyalty. But green perceived risk has negative effects to green image, green trust and green satisfaction. However, green perceived risk, green image, green trust and green satisfaction also seems to be a good device to gain green products customers from competitors. The contributions of the paper are, firstly, a more complete framework of the influences of green perceived risk, green image, green trust and green satisfaction to green loyalty analyses simultaneously. Secondly, the study allows a direct comparison of the difference in green perceived risk, green image, green trust, green satisfaction and green loyalty between green products customers.

Odorous and Non-Fatal Skin Secretion of Adult Wrinkled Frog (Rana rugosa) Is Effective in Avoiding Predation by Snakes

PubMed Central

Yoshimura, Yuri; Kasuya, Eiiti

2013-01-01

The roles played by nonfatal secretions of adult anurans in the avoidance of predation remain unknown. The adult Wrinkled frog (Rana rugosa) has warty skin with the odorous mucus secretion that is not fatal to the snake Elaphe quadrivirgata. We fed R. rugosa or Fejervarya limnocharis, which resembles R. rugosa in appearance and has mucus secretion, to snakes and compared the snakes’ responses to the frogs. Compared to F. limnocharis, R. rugosa was less frequently bitten or swallowed by snakes. The snakes that bit R. rugosa spat out the frogs and showed mouth opening (gaping) behavior, while the snakes that bit F. limnocharis did not show gaping behavior. We also compared the responses of the snakes to R. rugosa and F. limnocharis secretions. We coated palatable R. japonica with secretions from R. rugosa or F. limnocharis. The frogs coated by R. rugosa secretion were less frequently bitten or swallowed than those coated by F. limnocharis secretion. We concluded that compared to different frog species of similar sizes, the adult R. rugosa was less frequently preyed upon by, and that its skin secretion was effective in avoiding predation by snakes. PMID:24278410

Odorous and non-fatal skin secretion of adult wrinkled frog (Rana rugosa) is effective in avoiding predation by snakes.

PubMed

Yoshimura, Yuri; Kasuya, Eiiti

2013-01-01

The roles played by nonfatal secretions of adult anurans in the avoidance of predation remain unknown. The adult Wrinkled frog (Rana rugosa) has warty skin with the odorous mucus secretion that is not fatal to the snake Elaphe quadrivirgata. We fed R. rugosa or Fejervarya limnocharis, which resembles R. rugosa in appearance and has mucus secretion, to snakes and compared the snakes' responses to the frogs. Compared to F. limnocharis, R. rugosa was less frequently bitten or swallowed by snakes. The snakes that bit R. rugosa spat out the frogs and showed mouth opening (gaping) behavior, while the snakes that bit F. limnocharis did not show gaping behavior. We also compared the responses of the snakes to R. rugosa and F. limnocharis secretions. We coated palatable R. japonica with secretions from R. rugosa or F. limnocharis. The frogs coated by R. rugosa secretion were less frequently bitten or swallowed than those coated by F. limnocharis secretion. We concluded that compared to different frog species of similar sizes, the adult R. rugosa was less frequently preyed upon by, and that its skin secretion was effective in avoiding predation by snakes.

Importance of riparian remnants for frog species diversity in a highly fragmented rainforest.

PubMed

Rodríguez-Mendoza, Clara; Pineda, Eduardo

2010-12-23

Tropical forests undergo continuous transformation to other land uses, resulting in landscapes typified by forest fragments surrounded by anthropogenic habitats. Small forest fragments, specifically strip-shaped remnants flanking streams (referred to as riparian remnants), can be particularly important for the maintenance and conservation of biodiversity within highly fragmented forests. We compared frog species diversity between riparian remnants, other forest fragments and cattle pastures in a tropical landscape in Los Tuxtlas, Mexico. We found similar species richness in the three habitats studied and a similar assemblage structure between riparian remnants and forest fragments, although species composition differed by 50 per cent. Frog abundance was halved in riparian remnants compared with forest fragments, but was twice that found in pastures. Our results suggest that riparian remnants play an important role in maintaining a portion of frog species diversity in a highly fragmented forest, particularly during environmentally stressful (hot and dry) periods. In this regard, however, the role of riparian remnants is complementary, rather than substitutive, with respect to the function of other forest fragments within the fragmented forest.

Characterization of Staphylococcus spp. and Micrococcus spp. isolated from Iberian ham throughout the ripening process.

PubMed

Rodríguez, M; Núñez, F; Córdoba, J J; Sanabria, C; Bermúdez, E; Asensio, M A

1994-12-01

The Iberian dry cured ham is an uncooked meat product highly appreciated because of its characteristic flavour. This product is obtained from highly marbled Iberian pig hindlegs after 18-24 months of maturation under natural environmental conditions. The role of Micrococcaceae in the development of the aroma characteristics of this products remains unclear. Identification of Gram-positive, catalase-positive cocci isolated from Mannitol Salt Agar plates showed that Staphylococcus xylosus followed by Staphylococcus equorum are the predominant organisms, even after 16 months of maturing. A remarkable variety of types of both staphylococci and micrococci are detected at any sampling time. The metabolic activities of these organisms could contribute to the characteristics of the final product.

Effects of the herbicide imazapyr on juvenile Oregon spotted frogs

USGS Publications Warehouse

Yahnke, Amy E.; Grue, Christian E.; Hayes, Marc P.; Troiano, Alexandra T.

2013-01-01

Conflict between native amphibians and aquatic weed management in the Pacific Northwest is rarely recognized because most native stillwater-breeding amphibian species move upland during summer, when herbicide application to control weeds in aquatic habitats typically occurs. However, aquatic weed management may pose a risk for aquatic species present in wetlands through the summer, such as the Oregon spotted frog (OSF, Rana pretiosa), a state endangered species in Washington. Acute toxicity of herbicides used to control aquatic weeds tends to be low, but the direct effects of herbicide tank mixes on OSFs have remained unexamined. We exposed juvenile OSFs to tank mixes of the herbicide imazapyr, a surfactant, and a marker dye in a 96-h static-renewal test. The tank mix was chosen because of its low toxicity to fish and its effectiveness in aquatic weed control. Concentrations were those associated with low-volume (3.5 L/ha) and high-volume (7.0 L/ha) applications of imazapyr and a clean-water control. Following exposure, frogs were reared for two months in clean water to identify potential latent effects on growth. Endpoints evaluated included feeding behavior, growth, and body and liver condition indices. We recorded no mortalities and found no significant differences for any end point between the herbicide-exposed and clean-water control frogs. The results suggest that imazapyr use in wetland restoration poses a low risk of direct toxic effects on juvenile OSFs.

Frog brain uridine diphosphate galactose–N-acetylgalactosaminyl-N-acetylneuraminylgalactosylglucosylceramide galactosyltransferase

PubMed Central

Yip, Morris C. M.; Dain, Joel A.

1970-01-01

1. The enzyme that catalyses the transfer of galactose from UDP-galactose to N-acetylgalactosaminyl-(1→4)-N-acetylneuraminyl-(2→3)-galactosyl-(1→4)-glucosylceramide (GM2) was found mainly in the heavy- and light-microsomal fractions of the adult frog brain. 2. The subcellular distribution of the enzyme, UDP-galactose–GM2 galactosyltransferase, parallels that of gangliosides in adult frog brain. 3. The enzymic activity was first detected at late gastrulation (Shumway stage 11½) and increased until the completion of the operculum (Shumway stage 25) and then decreased in the tadpoles. 4. In adult frog brain, the enzyme exhibited a pH optimum of 7.2–7.3 in both cacodylate and tris buffers. The enzyme required 10mm-Mn2+ for maximal activity and the Km for Mn2+ was determined as 2.2mm. The half-maximal velocity was obtained at a GM2 concentration of 0.18mm. Inhibition of the enzymic reaction was found when the GM2 concentration was greater than 1.38mm. 5. The enzymic activity was also inhibited by the products in the pathway of ganglioside synthesis, i.e. either by a mixture of gangliosides or by individual ganglioside components. The most active inhibitor was disialoganglioside. The degree of inhibition is a function of the individual ganglioside concentration. 6. A product-inhibition mechanism for the regulation of ganglioside biosynthesis is discussed. PMID:5484669

The disappearing northern leopard frog (Lithobates pipiens): conservation genetics and implications for remnant populations in western Nevada

PubMed Central

Rogers, Serena D; Peacock, Mary M

2012-01-01

Global amphibian declines suggest a major shift in the amount and quality of habitat for these sensitive taxa. Many species that were once widespread are now experiencing declines either in part of or across their historic range. The northern leopard frog (Rana [Lithobates] pipiens] has undergone significant declines particularly in the western United States and Canada. Leopard frog population losses in Nevada are largely due to habitat fragmentation and the introduction of nonnative fish, amphibian, and plant species. Only two populations remain in the Truckee and Carson River watersheds of western Nevada which represents the western boundary of this species range. We used sequence data for an 812 base pair fragment of the mitochondrial NADH dehydrogenase 1 (ND1) gene to support a native origin for western Nevada populations. All frogs had a single haplotype (W07) from the distinct western North America ND1 haplotype clade. Data from seven polymorphic microsatellite loci show that Truckee and Carson River populations are highly differentiated from each other and from leopard frogs collected from eastern Nevada sites. Lack of gene flow among and distinct color morphs among the western Nevada populations likely predates the current geographical isolation. Comparisons with other peripheral L. pipiens populations show western Nevada populations have similar levels of gene diversity despite their contemporary isolation (HE 0.411, 0.482). Restoration of leopard frog populations in these watersheds will be challenging given well-entrenched nonnative bullfrog populations and major changes to the riparian zone over the past century. Declines of once common amphibian species has become a major conservation concern. Contemporary isolation of populations on a species range periphery such as the leopard frog populations in the Truckee and Carson rivers further exacerbate extirpation risk as these populations are likely to have fewer genetic resources to adaptively respond to

We Made Your Bed, Why Won’t You Lie in It? Food Availability and Disease May Affect Reproductive Output of Reintroduced Frogs

PubMed Central

Valdez, Jose; Stockwell, Michelle; Fardell, Loren; Clulow, Simon; Clulow, John; Mahony, Michael

2016-01-01

Mitigation to offset the impacts of land development is becoming increasingly common, with reintroductions and created habitat programs used as key actions. However, numerous reviews cite high rates of poor success from these programs, and a need for improved monitoring and scientific testing to evaluate outcomes and improve management actions. We conducted extensive monitoring of a released population of endangered green and golden bell frogs, Litoria aurea, within a created habitat, as well as complementary surveys of a surrounding wild population. We then compared differences between the created habitat and natural ponds where extant frogs either bred or didn’t breed in order to determine factors that contributed to the breeding failure within the created habitat. We evaluated differences of L. aurea abundance, abundance of other fauna, vegetation, water quality, habitat structure, invasive fish, and disease between the three pond types (created habitat, breeding ponds, non-breeding ponds). We discovered that vegetation and invertebrate diversity were low within the created habitat, potentially reducing energy and nutritional resources required for breeding. Also, a greater proportion of frogs in the created habitat were carrying the chytrid fungal pathogen, Batrachochytrium dendrobatidis, compared to the wild populations. In addition to causing the potentially fatal disease, chytridiomycosis, this pathogen has been shown to reduce reproductive functioning in male L. aurea, and subsequently may have reduced reproductive activities in the created habitat. Conspecific attraction, pond hydrology, and aquatic vegetation may also have had some influence on breeding behaviours, whilst the presence of the invasive mosquitofish, Gambusia holbrooki, and heterospecific tadpoles were unlikely to have deterred L. aurea from breeding within the created habitat. Through the use of scientific testing and monitoring, this study is able to make recommendations for future

The Galicia-Ossa-Morena Zone: Proposal for a new zone of the Iberian Massif. Variscan implications

NASA Astrophysics Data System (ADS)

Arenas, Ricardo; Díez Fernández, Rubén; Rubio Pascual, Francisco J.; Sánchez Martínez, Sonia; Martín Parra, Luis Miguel; Matas, Jerónimo; González del Tánago, José; Jiménez-Díaz, Alberto; Fuenlabrada, Jose M.; Andonaegui, Pilar; Garcia-Casco, Antonio

2016-06-01

Correlation of a group of allochthonous terranes (referred to as basal, ophiolitic and upper units) exposed in the NW and SW of the Iberian Massif, is used to propose a new geotectonic zone in the southern branch of the Variscan Orogen: the Galicia-Ossa-Morena Zone. Recent advances in SW Iberia identify most of the former Ossa-Morena Zone as another allochthonous complex of the Iberian Massif, the Ossa-Morena Complex, equivalent to the Cabo Ortegal, Órdenes, Malpica-Tui, Bragança and Morais complexes described in NW Iberia. The new geotectonic zone and its counterparts along the rest of the Variscan Orogen constitute an Internal Variscan Zone with ophiolites and units affected by high-P metamorphism. The Galicia-Ossa-Morena Zone includes a Variscan suture and pieces of continental crust bearing the imprint of Ediacaran-Cambrian events related to the activity of peri-Gondwanan magmatic arcs (Cadomian orogenesis). In the Iberian Massif, the general structure of this geotectonic zone represents a duplication of the Gondwanan platform, the outboard sections being juxtaposed on top of domains located closer to the mainland before amalgamation. This interpretation offers an explanation that overcomes some issues regarding the differences between the stratigraphic and paleontological record of the central and southern sections of the Iberian Massif. Also, equivalent structural relationships between other major geotectonic domains of the rest of the Variscan Orogen are consistent with our interpretation and allow suspecting similar configurations along strike of the orogen. A number of issues may be put forward in this respect that potentially open new lines of thinking about the architecture of the Variscan Orogen.

Differential uptake of gold nanoparticles by 2 species of tadpole, the wood frog (Lithobates sylvaticus) and the bullfrog (Lithobates catesbeianus).

PubMed

Thompson, Lucas B; Carfagno, Gerardo L F; Andresen, Kurt; Sitton, Andrea J; Bury, Taylor; Lee, Laura L; Lerner, Kevin T; Fong, Peter P

2017-12-01

Engineered nanoparticles are aquatic contaminants of emerging concern that exert ecotoxicological effects on a wide variety of organisms. We exposed cetyltrimethylammonium bromide-capped spherical gold nanoparticles to wood frog and bullfrog tadpoles with conspecifics and in combination with the other species continuously for 21 d, then measured uptake and localization of gold. Wood frog tadpoles alone and in combination with bullfrog tadpoles took up significantly more gold than bullfrogs. Bullfrog tadpoles in combination with wood frogs took up significantly more gold than controls. The rank order of weight-normalized gold uptake was wood frogs in combination > wood frogs alone > bullfrogs in combination > bullfrogs alone > controls. In all gold-exposed groups of tadpoles, gold was concentrated in the anterior region compared with the posterior region of the body. The concentration of gold nanoparticles in the anterior region of wood frogs both alone and in combination with bullfrogs was significantly higher than the corresponding posterior regions. We also measured depuration time of gold in wood frogs. After 21 d in a solution of gold nanoparticles, tadpoles lost >83% of internalized gold when placed in gold-free water for 5 d. After 10 d in gold-free water, tadpoles lost 94% of their gold. After 15 d, gold concentrations were below the level of detection. Our finding of differential uptake between closely related species living in similar habitats with overlapping geographical distributions argues against generalizing toxicological effects of nanoparticles for a large group of organisms based on measurements in only one species. Environ Toxicol Chem 2017;36:3351-3358. © 2017 SETAC. © 2017 SETAC.

Asymmetrical effects of introduced Rana catesbeiana on native ranid frogs in Oregon, USA

USGS Publications Warehouse

Pearl, Christopher A.; Adams, Michael J.; Bury, R. Bruce; McCreary, B.

2004-01-01

Introduced American Bullfrogs (Rana catesbeiana) have become widely established in the Pacific Northwest over the last century and are thought to be an important predator of native amphibians throughout the western United States. The Northern Red-Legged Frog (Rana aurora aurora) and Oregon Spotted Frog (Rana pretiosa) historically coexisted in portions of the Pacific Northwest now invaded by R. catesbeiana, but R. pretiosa has declined more severely than R. a. aurora. We investigated whether microhabitat and behavioral differences that facilitate sympatric coexistence of the natives predict which species is more susceptible to predation by introduced R. catesbeiana. Our laboratory experiments demonstrate that R. catesbeiana adults prefer aquatic microhabitats, that R. pretiosa juveniles are more aquatic than R. a. aurora, and that adult R. catesbeiana consume more R. pretiosa than R. a. aurora juveniles. Mean and maximum jump distances of R. pretiosa were shorter than equally sized R. a. aurora, and the difference between these two species increased with larger frog sizes. Our examination of field survey data indicates that R. pretiosa coexist with R. catesbeiana less frequently than R. a. aurora. We conclude that R. catesbeiana is a greater threat to survival of R. pretiosa than to R. a. aurora and suggest that microhabitat use and escape abilities of native ranid frogs may be linked to this asymmetrical effect. Analysis of behavioral and microhabitat differences among related native species may be a useful tool in predicting the effects of introduced predators on amphibians and can assist in developing conservation priorities for these species.

Asymmetrical Effects of Introduced Bullfrogs (Rana catesbeiana) on Native Ranid Frogs in Oregon

USGS Publications Warehouse

Pearl, C.A.; Adams, M.J.; Bury, R.B.; McCreary, B.

2004-01-01

Introduced American Bullfrogs (Rana catesbeiana) have become widely established in the Pacific Northwest over the last century and are thought to be an important predator of native amphibians throughout the western United States. The Northern Red-Legged Frog (Rana aurora aurora) and Oregon Spotted Frog (Rana pretiosa) historically coexisted in portions of the Pacific Northwest now invaded by R. catesbeiana, but R. pretiosa has declined more severely than R. a. aurora. We investigated whether microhabitat and behavioral differences that facilitate sympatric coexistence of the natives predict which species is more susceptible to predation by introduced R. catesbeiana. Our laboratory experiments demonstrate that R. catesbeiana adults prefer aquatic microhabitats, that R. pretiosa juveniles are more aquatic than R. a. aurora, and that adult R. catesbeiana consume more R. pretiosa than R. a. aurora juveniles. Mean and maximum jump distances of R. pretiosa were shorter than equally sized R. a. aurora, and the difference between these two species increased with larger frog sizes. Our examination of field survey data indicates that R. pretiosa coexist with R. catesbeiana less frequently than R. a. aurora. We conclude that R. catesbeiana is a greater threat to survival of R. pretiosa than to R. a. aurora and suggest that microhabitat use and escape abilities of native ranid frogs may be linked to this asymmetrical effect. Analysis of behavioral and microhabitat differences among related native species may be a useful tool in predicting the effects of introduced predators on amphibians and can assist in developing conservation priorities for these species.

Increasing sea surface temperature and range shifts of intertidal gastropods along the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Rubal, Marcos; Veiga, Puri; Cacabelos, Eva; Moreira, Juan; Sousa-Pinto, Isabel

2013-03-01

There are well-documented changes in abundance and geographical range of intertidal invertebrates related to climate change at north Europe. However, the effect of sea surface warming on intertidal invertebrates has been poorly studied at lower latitudes. Here we analyze potential changes in the abundance patterns and distribution range of rocky intertidal gastropods related to climate change along the Iberian Peninsula. To achieve this aim, the spatial distribution and range of sub-tropical, warm- and cold-water species of intertidal gastropods was explored by a fully hierarchical sampling design considering four different spatial scales, i.e. from region (100 s of km apart) to quadrats (ms apart). Variability on their patterns of abundance was explored by analysis of variance, changes on their distribution ranges were detected by comparing with previous records and their relationship with sea water temperature was explored by rank correlation analyses. Mean values of sea surface temperature along the Iberian coast, between 1949 and 2010, were obtained from in situ data compiled for three different grid squares: south Portugal, north Portugal, and Galicia. Lusitanian species did not show significant correlation with sea water temperature or changes on their distributional range or abundance, along the temperature gradient considered. The sub-tropical species Siphonaria pectinata has, however, increased its distribution range while boreal cold-water species showed the opposite pattern. The latter was more evident for Littorina littorea that was almost absent from the studied rocky shores of the Iberian Peninsula. Sub-tropical and boreal species showed significant but opposite correlation with sea water temperature. We hypothesized that the energetic cost of frequent exposures to sub-lethal temperatures might be responsible for these shifts. Therefore, intertidal gastropods at the Atlantic Iberian Peninsula coast are responding to the effect of global warming as it

Taxonomic variation in oviposition by tailed frogs (Aschaphus spp.).

Treesearch

Nancy E. Karraker; David S. Pilliod; Michael J. Adams; Evelyn L. Bull; Paul Stephen Corn; Lowell V. Diller; Linda A. Dupuis; Marc P. Hayes; Blake R. Hossack; Garth R. Hodgson; Erin J. Hyde; Kirk Lohman; Bradford R. Norman; Lisa M. Ollivier; Christopher A. Pearl; Charles R. Peterson

2006-01-01

Tailed frogs (Ascaphus spp.) oviposit in cryptic locations in streams of the Pacific Northwest and Rocky Mountains. This aspect of their life history has restricted our understanding of their reproductive ecology. The recent split of A. montanus in the Rocky Mountains from A. truei was based on molecular...

Peptidomic analysis of skin secretions supports separate species status for the tailed frogs, Ascaphus truei and Ascaphus montanus

USGS Publications Warehouse

Conlon, J.M.; Bevier, C.R.; Coquet, L.; Leprince, J.; Jouenne, T.; Vaudry, H.; Hossack, B.R.

2007-01-01

The tailed frog Ascaphus truei Stejneger, 1899 is the most primitive extant anuran and the sister taxon to the clade of all other living frogs. The species occupies two disjunct ranges in the Northwest region of North America: the Cascade Mountains and coastal area from British Columbia to Northern California, and an inland range in the northern Rocky Mountains and the Blue and Wallowa mountains. A previous study led to the isolation of eight peptides with antimicrobial activity (termed the ascaphins) from skin secretions of A. truei from the coastal range. The present study has used peptidomic analysis to identify the products of orthologous ascaphin genes in electrically-stimulated skin secretions from inland range specimens. Structural characterization of the peptides demonstrated that ascaphins from the inland range contained the following amino acid substitutions compared with orthologs from the coastal range frogs: ascaphin-1 (Ala12 → Glu), ascaphin-3 (Asp4 → Glu), ascaphin-4 (Ala19 → Ser), ascaphin-5 (Lys12 → Thr), and ascaphin-7 (Gly8 → Ser and Ser20 → Asn). Orthologs of ascaphins-2, -6, and -8 were not identified but a paralog of ascaphin-5, identical to ascaphin-5 from coastal range frogs, was found. The data support the claims, derived from analysis of the nucleotide sequences of mitochondrial genes, that the inland populations of the tailed frog should be recognized as a distinct species, the Rocky Mountain tailed frog Ascaphus montanus and that the divergence of the species from A. truei probably occurred in the late Miocene (approximately 10 Mya).

Low temperature tolerance, cold hardening and acclimation in tadpoles of the neotropical túngara frog (Engystomops pustulosus).

PubMed

Vo, Pacific; Gridi-Papp, Marcos

2017-05-01

Many frogs from temperate climates can tolerate low temperatures and increase their thermal tolerance through hardening and acclimation. Most tropical frogs, on the other hand, fail to acclimate to low temperatures. This lack of acclimation ability is potentially due to lack of selection pressure for acclimation because cold weather is less common in the tropics. We tested the generality of this pattern by characterizing the critical temperature minimum (CTMin), hardening, and acclimation responses of túngara frogs (Engystomops pustulosus). These frogs belong to a family with unknown thermal ecology. They are found in a tropical habitat with a highly constant temperature regime. The CTMin of the tadpoles was on average 12.5°C. Pre-metamorphic tadpoles hardened by 1.18°C, while metamorphic tadpoles hardened by 0.36°C. When raised at 21°C, tadpoles acclimated expanding their cold tolerance by 1.3°C in relation to larvae raised at 28°C. These results indicate that the túngara frog has a greatly reduced cold tolerance when compared to species from temperate climates, but it responds to cold temperatures with hardening and acclimation comparable to those of temperate-zone species. Cold tolerance increased with body length but cold hardening was more extensive in pre-metamorphic tadpoles than in metamorphic ones. This study shows that lack of acclimation ability is not general to the physiology of tropical anurans. Copyright © 2017 Elsevier Ltd. All rights reserved.

Budgett's frog (Lepidobatrachus laevis): A new amphibian embryo for developmental biology.

PubMed

Amin, Nirav M; Womble, Mandy; Ledon-Rettig, Cristina; Hull, Margaret; Dickinson, Amanda; Nascone-Yoder, Nanette

2015-09-15

The large size and rapid development of amphibian embryos has facilitated ground-breaking discoveries in developmental biology. Here, we describe the embryogenesis of the Budgett's frog (Lepidobatrachus laevis), an unusual species with eggs that are over twice the diameter of laboratory Xenopus, and embryos that can tolerate higher temperatures to develop into a tadpole four times more rapidly. In addition to detailing their early development, we demonstrate that, like Xenopus, these embryos are amenable to explant culture assays and can express exogenous transcripts in a tissue-specific manner. Moreover, the steep developmental trajectory and large scale of Lepidobatrachus make it exceptionally well-suited for morphogenesis research. For example, the developing organs of the Budgett's frog are massive compared to those of most model species, and are composed of larger individual cells, thereby affording increased subcellular resolution of early vertebrate organogenesis. Furthermore, we found that complete limb regeneration, which typically requires months to achieve in most vertebrate models, occurs in a matter of days in the Budgett's tadpole, which substantially accelerates the pace of experimentation. Thus, the unusual combination of the greater size and speed of the Budgett's frog model provides inimitable advantages for developmental studies-and a novel inroad to address the mechanisms of spatiotemporal scaling during evolution. Copyright © 2015 Elsevier Inc. All rights reserved.

The phylogeographical history of the Iberian steppe plant Ferula loscosii (Apiaceae): a test of the abundant-centre hypothesis.

PubMed

Pérez-Collazos, E; Sanchez-Gómez, P; Jiménez, F; Catalán, P

2009-03-01

The geology and climate of the western Mediterranean area were strongly modified during the Late Tertiary and the Quaternary. These geological and climatic events are thought to have induced changes in the population histories of plants in the Iberian Peninsula. However, fine-scale genetic spatial architecture across western Mediterranean steppe plant refugia has rarely been investigated. A population genetic analysis of amplified fragment length polymorphism variation was conducted on present-day, relict populations of Ferula loscosii (Apiaceae). This species exhibits high individual/population numbers in the middle Ebro river valley and, according to the hypothesis of an abundant-centre distribution, these northern populations might represent a long-standing/ancestral distribution centre. However, our results suggest that the decimated southern and central Iberian populations are more variable and structured than the northeastern ones, representing the likely vestiges of an ancestral distribution centre of the species. Phylogeographical analysis suggests that F. loscosii likely originated in southern Spain and then migrated towards the central and northeastern ranges, further supporting a Late Miocene southern-bound Mediterranean migratory way for its oriental steppe ancestors. In addition, different glacial-induced conditions affected the southern and northern steppe Iberian refugia during the Quaternary. The contrasting genetic homogeneity of the Ebro valley range populations compared to the southern Iberian ones possibly reflects more severe bottlenecks and subsequent genetic drift experienced by populations of the northern Iberia refugium during the Pleistocene, followed by successful postglacial expansion from only a few founder plants.

Chiricahua leopard frog status in the Galiuro Mountains, Arizona, with a monitoring framework for the species' entire range

Treesearch

Lawrence L. C. Jones; Michael J. Sredl

2005-01-01

The Chiricahua leopard frog (Rana chiricahuensis) was historically widespread in suitable habitat throughout its range. Reports of recent population declines led to inventories of Chiricahua leopard frog localities. Surveys reported here establish a new baseline of occurrence in the Galiuros: only two of 21 historical localities were found to be...

Physiological effects and tissue residues from exposure of leopard frogs to commercial naphthenic acids.

PubMed

Smits, Judit E G; Hersikorn, Blair D; Young, Rozlyn F; Fedorak, Phillip M

2012-10-15

Naphthenic acids (NAs) have been cited as one of the main causes of the toxicity related to oil sands process-affected materials and have recently been measured in biological tissues (fish). However, adverse effects have not been a consistent finding in toxicology studies on vertebrates. This study set out to determine two factors: 1) whether exposure to commercial NAs (Refined Merichem) resulted in detectable tissue residues in native amphibians (northern leopard frogs, Lithobates pipiens), and 2) whether such exposure would produce clinical or subclinical toxicity. Frogs were kept in NA solutions (0, 20, or 40 mg/L) under saline conditions comparable to that on reclaimed wetlands in the Athabasca oil sands for 28 days. These exposures resulted in proportional NA concentrations in muscle tissue of the frogs, estimated by gas chromatography-mass spectrometry analyses. Detailed studies determined if the increasing concentrations of NAs, and subsequently increased tissue NA levels, caused a proportional compromise in the health of the experimental animals. Physiological investigations included innate immune function, thyroid hormone levels, and hepatic detoxification enzyme induction, none of which differed in response to increased exposures or tissue concentrations of NAs. Body mass did increase in both the salt- and NA-exposed animals, likely related to osmotic pressure and uptake of water through the skin. Our results demonstrate that commercial NAs are absorbed and deposited in muscle tissue, yet they show few negative physiological or toxicological effects on the frogs. Copyright © 2012. Published by Elsevier B.V.

Ecology of the Columbia spotted frog in northeastern Oregon.

Treesearch

Evelyn L. Bull

2005-01-01

The Columbia spotted frog (Rana luteiventris) is one of several amphibians in the Western United States experiencing population declines. The breeding, postbreeding, and overwintering habitat and ecology of this species were investigated in 10 study sites in northeastern Oregon from 1997 through 2004. A variety of habitats with permanent water were...

Demography and movement in a relocated population of Oregon Spotted Frogs (Rana pretiosa): Influence of season and gender

USGS Publications Warehouse

Chelgren, N.D.; Pearl, C.A.; Adams, M.J.; Bowerman, J.

2008-01-01

We used five years of recapture data and Bayesian estimation to assess seasonal survival, movement, and growth of Oregon Spotted Frogs (Rana pretiosa) relocated into created ponds at Dilman Meadow in Oregon, USA. We evaluate hypotheses specific to the relocation and elucidate aspects of R. pretiosa life history that are poorly known. The odds of survival of relocated individuals during the first year following relocation were 0.36 times the survival odds of relocated and non-relocated frogs after one year since the relocation. Survival rate was higher for large frogs. After accounting for frog size, we found little variation in survival between ponds at Dilman Meadow. Survival was lowest for males during the breeding/post-breeding redistribution period, suggesting a high cost of breeding for males. The highest survival rates occurred during winter for both genders, and one small spring was used heavily during winter but was used rarely during the rest of the year. Individual growth was higher in ponds that were not used for breeding, and increased with increasing pond age. Our study supports other evidence that R. pretiosa use different habitats seasonally and are specific in their overwintering habitat requirements. Because frogs were concentrated during winter, predator-free overwintering springs are likely to be of particular value for R. pretiosa populations. ?? 2008 by the American Society of Ichthyologists and Herpetologists.

Effects of environmentally relevant sub-chronic atrazine concentrations on African clawed frog (Xenopus laevis) survival, growth and male gonad development.

PubMed

Rimayi, Cornelius; Odusanya, David; Weiss, Jana M; de Boer, Jacob; Chimuka, Luke; Mbajiorgu, Felix

2018-06-01

Sub-chronic toxicity of environmentally relevant atrazine concentrations on exposed tadpoles and adult male African clawed frogs (Xenopus laevis) was evaluated in a quality controlled laboratory for 90 days. The aim of this study was to determine the effects of atrazine on the survival, growth and gonad development of African clawed frogs. After exposure of tadpoles to atrazine concentrations of 0 (control), 0.01, 200 and 500 μg L -1 in water, mortality rates of 0, 0, 3.3 and 70% respectively were recorded for the 90 day exposure period. Morphometry showed significantly reduced tadpole mass in the 500 μg L -1 atrazine exposed tadpoles (p < 0.05). Light microscopy on testes of adult frogs exposed to the same atrazine concentrations using hematoxylin and eosin (H&E) and Van Gieson staining techniques revealed gonadal atrophy, disruption of germ cell lines, seminiferous tubule structure damage and formation of extensive connective tissue around seminiferous tubules of frogs exposed to 200 μg L -1 and 500 μg L -1 atrazine concentrations. Ultrastructural analysis of the cellular organelles using transmission electron microscopy (TEM) revealed significant amounts of damaged mitochondria in testosterone producing Leydig cells as well as Sertoli cells. Biochemical analysis revealed reduced serum testosterone levels in adult frogs at all exposure levels as well as presence of six atrazine metabolites in frog serum and liver. The results indicate that atrazine concentrations greater than the calculated LC50 of 343.7 μg L -1 cause significant mortality in tadpoles, while concentrations ≥200 μg L -1 adversely affect reproductive health of adult frogs and development of tadpoles sub-chronically exposed to atrazine. Copyright © 2018 Elsevier B.V. All rights reserved.

AIRBORNE PESTICIDES AND POPULATION DECLINES OF A CALIFORNIA ALPINE FROG

EPA Science Inventory

The mountain yellow-legged frog (Rana muscosa) has disappeared from most of its historic localities in the Sierra Nevada of California, and airborne pesticides from the Central Valley have been implicated as a causal agent. To determine the distribution and temporal variation of ...

Accumulation of pesticides in pacific chorus frogs (Pseudacris regilla) from California's Sierra Nevada Mountains, USA

USGS Publications Warehouse

Smalling, Kelly L.; Fellers, Gary M.; Kleeman, Patrick M.; Kuivila, Kathryn

2013-01-01

Pesticides are receiving increasing attention as potential causes of amphibian declines, acting singly or in combination with other stressors, but limited information is available on the accumulation of current-use pesticides in tissue. The authors examined potential exposure and accumulation of currently used pesticides in pond-breeding frogs (Pseudacris regilla) collected from 7 high elevations sites in northern California. All sites sampled are located downwind of California's highly agricultural Central Valley and receive inputs of pesticides through precipitation and/or dry deposition. Whole frog tissue, water, and sediment were analyzed for more than 90 current-use pesticides and pesticide degradates using gas chromatography–mass spectrometry. Two fungicides, pyraclostrobin and tebuconazole, and one herbicide, simazine, were the most frequently detected pesticides in tissue samples. Median pesticide concentration ranged from 13 µg/kg to 235 µg/kg wet weight. Tebuconazole and pyraclostrobin were the only 2 compounds observed frequently in frog tissue and sediment. Significant spatial differences in tissue concentration were observed, which corresponded to pesticide use in the upwind counties. Data generated indicated that amphibians residing in remote locations are exposed to and capable of accumulating current-use pesticides. A comparison of P. regilla tissue concentrations with water and sediment data indicated that the frogs are accumulating pesticides and are potentially a more reliable indicator of exposure to this group of pesticides than either water or sediment.

Fatal attraction: adaptations to prey on native frogs imperil snakes after invasion of toxic toads.

PubMed

Hagman, Mattias; Phillips, Benjamin L; Shine, Richard

2009-08-07

Adaptations that enhance fitness in one situation can become liabilities if circumstances change. In tropical Australia, native snake species are vulnerable to the invasion of toxic cane toads. Death adders (Acanthophis praelongus) are ambush foragers that (i) attract vertebrate prey by caudal luring and (ii) handle anuran prey by killing the frog then waiting until the frog's chemical defences degrade before ingesting it. These tactics render death adders vulnerable to toxic cane toads (Bufo marinus), because toads elicit caudal luring more effectively than do native frogs, and are more readily attracted to the lure. Moreover, the strategy of delaying ingestion of a toad after the strike does not prevent fatal poisoning, because toad toxins (unlike those of native frogs) do not degrade shortly after the prey dies. In our laboratory and field trials, half of the death adders died after ingesting a toad, showing that the specialized predatory behaviours death adders use to capture and process prey render them vulnerable to this novel prey type. The toads' strong response to caudal luring also renders them less fit than native anurans (which largely ignored the lure): all toads bitten by adders died. Together, these results illustrate the dissonance in behavioural adaptations that can arise following the arrival of invasive species, and reveal the strong selection that occurs when mutually naive species first interact.

Drought trends in the Iberian Peninsula over the last 112 years

NASA Astrophysics Data System (ADS)

Gouveia, Célia M.; Ramos, Patrícia; Russo, Ana; Trigo, Ricardo M.

2015-04-01

The Iberian Peninsula is often affected by drought events with strong influences in ecosystems and the related social and economic impacts (Gouveia et al. 2012, Trigo et al., 2013). In the last decades the severity of droughts in Iberia have increased due to the higher atmospheric evaporative demand (Vicente-Serrano et al., 2014). The need for a deeper knowledge of drought frequency, duration and intensity over the Iberian Peninsula during the last 112 years is reinforced by the findings showing that the period of 1970-2010 over the Mediterranean region was considered drier when compared with 1901-1970. Together with the increasing dryness, the projections point for an increase of drought conditions during the twenty-first century (Hoerling et al., 2012) will tend to exacerbate these problems. The evolution of drought in the Iberian Peninsula was analyzed, using the Standardized Precipitation Evapotranspiration Index (SPEI) and the Standardized Precipitation Index (SPI), for the period 1901-2012, and the sub-periods 1901-1937, 1938-1974 and 1975-2012. We have used SPI and SPEI for the time scale of 12 months, as obtained from CRU TS3.21 database between 1901 and 2012, using a spatial resolution of 0.5°. The drought indices were analyzed in order to identify significant trends during the entire period and sub-periods. Trends in annual precipitation and PET were also performed. Drought's duration, magnitude and time spanned between drought events were computed. SPI and SPEI significant trends show areas with opposite signals in the period 1901-2012, following precipitation patterns. Precipitation trends are significant and positive in the Northwestern region of the IP, and significant and negative in the Southern areas. SPEI identified dryer conditions and an increase in the area affected by droughts, which is in agreement with the increase in PET on the majority of the territory. The same spatial differences were identified in the drought duration, magnitude and

Budgett’s frog (Lepidobatrachus laevis): a new amphibian embryo for developmental biology

PubMed Central

Amin, Nirav M.; Womble, Mandy; Ledon-Rettig, Cris; Hull, Margaret; Dickinson, Amanda; Nascone-Yoder, Nanette

2015-01-01

The large size and rapid development of amphibian embryos has facilitated ground-breaking discoveries in developmental biology. Here, we describe the embryogenesis of the Budgett’s frog (Lepidobatrachus laevis), an unusual species with eggs that are over twice the diameter of laboratory Xenopus, and embryos that can tolerate higher temperatures to develop into a tadpole four times more rapidly. In addition to detailing their early development, we demonstrate that, like Xenopus, these embryos are amenable to explant culture assays and can express exogenous transcripts in a tissue-specific manner. Moreover, the steep developmental trajectory and large scale of Lepidobatrachus make it exceptionally well-suited for morphogenesis research. For example, the developing organs of the Budgett’s frog are massive compared to those of most model species, and are composed of larger individual cells, thereby affording increased subcellular resolution of early vertebrate organogenesis. Furthermore, we found that complete limb regeneration, which typically requires months to achieve in most vertebrate models, occurs in a matter of days in the Budgett’s tadpole, which substantially accelerates the pace of experimentation. Thus, the unusual combination of the greater size and speed of the Budgett’s frog model provides inimitable advantages for developmental studies—and a novel inroad to address the mechanisms of spatiotemporal scaling during evolution. PMID:26169245

Transient response of the Northwestern Iberian upwelling regime.

PubMed

Ferreira Cordeiro, Nuno Gonçalo; Dubert, Jesus; Nolasco, Rita; Desmond Barton, Eric

2018-01-01

The hydrography and dynamics of NW Iberian margin were explored for July 2009, based on a set of in situ and remote sensing observations. Zonal sections of standard CTD casts, towed CTD (SeaSoar), Acoustic Doppler Current Profilers (ADCP) and Lagrangian surveys were made to characterize cycles of upwelling and relaxation in this region. Two periods of northerly winds, bounded by relaxation periods, were responsible for the formation of an upwelling front extending to the shelf edge. An equatorward flow was quickly set up on the shelf responding to the northerly wind pulses. South of Cape Silleiro, the development and subsequent relaxation of an upwelling event was intensively surveyed in the shelf, following a Lagrangian drifter transported by the upwelling jet. This region is part of an upwelling center extending from Cape Silleiro to Porto, where the surface temperature was colder than the neighboring regions, under upwelling favorable winds. As these winds relaxed, persistent poleward flow developed, originating south of the upwelling center and consisting in an inner-shelf tongue of warm waters. During an event of strong southerly wind, the poleward flow was observed to extend to the whole continental shelf. Although the cruise was executed during summertime, the presence of river-plumes was observed over the shelf. The interaction of the plumes with the circulation on the shelf was also described in terms of coastal convergence and offshore advection. The sampling of the offshore and slope regions showed the presence of the Iberian poleward current offshore and a persistent equatorward flow over the upper slope.

Clinal patterns in genetic variation for northern leopard frog (Rana pipiens): Conservation status and population histories

USGS Publications Warehouse

Stockwell, Craig A.; Fisher, Justin D.L.; McLean, Kyle I.

2016-01-01

The security of the northern leopard frog (Rana pipiens) varies spatially with populations east and west of North Dakota considered as secure and at risk, respectively. We used genetic markers to characterize the conservation status of northern leopard frog populations across North Dakota. We used multiple regression analyses and model selection to evaluate correlations of expected heterozygosity (HE) with the direct and additive effects of: i) geographic location,ii) wetland density and iii) average annual precipitation. There was lower genetic diversity in the western portion of the state due to lower levels of diversity for populations southwest of the Missouri River. This may reflect a refugial/colonization signature for the only non-glaciated area of North Dakota. Genetic diversity was also positively associated with wetland densities which is consistent with the reliance of this species on a mosaic of wetlands. Our findings suggest that populations in the southwestern part of North Dakota are of higher conservation concern, a finding consistent with the higher risk noted for northern leopard frog populations in most states west of North Dakota. Our findings also pose the hypothesis that climate change induced changes in wetland densities will reduce genetic diversity of northern leopard frog populations.

Allozyme comparison of three Trypanosoma species (Kinetoplastida: Trypanosomatidae) of toads and frogs by starch-gel electrophoresis.

PubMed

Martin, D S; Desser, S S; Hong, H

1992-04-01

Six metabolic enzymes, glucose-6-phosphate dehydrogenase, glucosephosphate isomerase, isocitrate dehydrogenase, malate dehydrogenase, phosphoglucomutase, and purine nucleoside phosphorylase, from clonal isolates of 3 presumptive species of Trypanosoma (T. fallisi, T. ranarum, and T. rotatorium) from 3 anuran hosts (Bufo americanus, Rana clamitans, and Rana catesbeiana) were compared using starch-gel electrophoresis. Although bands were shared among the different zymodemes of isolates of the same host genus, low genetic polymorphism of the enzyme loci was observed with few apparent shared bands between samples isolated from frogs and toads. A distance value calculated between toad and frog trypanosome isolates suggests the likelihood of long-time separation of species. Cluster analysis based on overall similarity distinguished the trypanosomes of toads and frogs as separate taxa, suggesting that host specificity and observed morphological differences are consistent with heritable allozyme differences.

Temperature dependence of blood viscosity in frogs and turtles: effect on heat exchange with environment.

PubMed

Langille, B L; Crisp, B

1980-09-01

The temperature dependence of the viscosity of blood from frogs and turtles has been assessed for temperatures between 5 and 40 degrees C. Viscosity of turtles' blood was, on average, reduced from 3.50 +/- 0.16 to 2.13 +/- 0.10 cP between 10 and 30 degrees C, a decline of 39%. Even larger changes in viscosity were observed for frogs' blood with viscosity falling from 4.55 +/- 0.32 to 2.55 +/- 0.25 cP over the same temperature range, a change of 44%. Blood viscosity was highly correlated with hematocrit in both species at all temperatures. Viscosity of blood from both frogs and turtles showed a large standard deviation at all temperatures and this was attributed to large individual-to-individual variations in hematocrit. Turtles heat faster than they cool, regardless of whether tests are performed at temperatures above or below the range of thermal preference. The effect of temperature dependence of blood viscosity on heating and cooling rates is demonstrated.

Revisiting the Iberian honey bee (Apis mellifera iberiensis) contact zone: maternal and genome-wide nuclear variations provide support for secondary contact from historical refugia.

PubMed

Chávez-Galarza, Julio; Henriques, Dora; Johnston, J Spencer; Carneiro, Miguel; Rufino, José; Patton, John C; Pinto, M Alice

2015-06-01

Dissecting diversity patterns of organisms endemic to Iberia has been truly challenging for a variety of taxa, and the Iberian honey bee is no exception. Surveys of genetic variation in the Iberian honey bee are among the most extensive for any honey bee subspecies. From these, differential and complex patterns of diversity have emerged, which have yet to be fully resolved. Here, we used a genome-wide data set of 309 neutrally tested single nucleotide polymorphisms (SNPs), scattered across the 16 honey bee chromosomes, which were genotyped in 711 haploid males. These SNPs were analysed along with an intergenic locus of the mtDNA, to reveal historical patterns of population structure across the entire range of the Iberian honey bee. Overall, patterns of population structure inferred from nuclear loci by multiple clustering approaches and geographic cline analysis were consistent with two major clusters forming a well-defined cline that bisects Iberia along a northeastern-southwestern axis, a pattern that remarkably parallels that of the mtDNA. While a mechanism of primary intergradation or isolation by distance could explain the observed clinal variation, our results are more consistent with an alternative model of secondary contact between divergent populations previously isolated in glacial refugia, as proposed for a growing list of other Iberian taxa. Despite current intense honey bee management, human-mediated processes have seemingly played a minor role in shaping Iberian honey bee genetic structure. This study highlights the complexity of the Iberian honey bee patterns and reinforces the importance of Iberia as a reservoir of Apis mellifera diversity. © 2015 John Wiley & Sons Ltd.

Elevated genetic structure in the coastal tailed frog (Ascaphus truei) in managed redwood forests.

PubMed

Aguilar, Andres; Douglas, Robert B; Gordon, Eric; Baumsteiger, Jason; Goldsworthy, Matthew O

2013-03-01

Landscape alterations have dramatic impacts on the distribution of genetic variation within and among populations and understanding these effects can guide contemporary and future conservation strategies. We initiated a landscape-scale genetic study of the coastal tailed frog (Ascaphus truei) on commercial timberlands within the southern range of the species in Mendocino County (CA, USA). In total, 294 individuals from 13 populations were analyzed at 9 microsatellite loci. None of the sampled populations departed from mutation-drift equilibrium, indicating recent population bottlenecks were not detected in contemporary samples. Fine-scale analysis indicated sampled populations were structured at the watershed level (mean F (ST) = 0.077 and mean G'(ST) = 0.425). Landscape analyses suggested wet and moist areas may serve as significant corridors for gene flow within watersheds in this region (r (2) = 0.32-0.54 for moisture-related features). Results indicate populations of frogs may have persisted at this scale through intense periods of timber harvest, making southern range edge populations of coastal tailed frogs resilient to past land use practices.

Widespread occurrence of the chytrid fungus batrachochytrium dendrobatidis on oregon spotted frogs (rana pretiosa)

USGS Publications Warehouse

Pearl, C.A.; Bowerman, J.; Adams, M.J.; Chelgren, N.D.

2009-01-01

The pathogen Batrachochytrium dendrobatidis (Bd) has been associated with amphibian declines in multiple continents, including western North America. We investigated Bd prevalence in Oregon spotted frog (Rana pretiosa), a species that has declined across its range in the Pacific Northwest. Polymerase chain reaction analysis of skin swabs indicated that Bd was prevalent within populations (420 of 617 juvenile and adults) and widespread among populations (36 of 36 sites) where we sampled R. pretiosa in Oregon and Washington. We rarely detected Bd in R. pretiosa larvae (2 of 72). Prevalence of Bd in postmetamorphic R. pretiosa was inversely related to frog size. We found support for an interactive effect of elevation and sampling date on Bd: prevalence of Bd generally increased with date, but this effect was more pronounced at lower elevations. We also found evidence that the body condition of juvenile R. pretiosa with Bd decreased after their first winter. Our data indicate that some Oregon spotted frog populations are currently persisting with relatively high Bd prevalence, but the risk posed by Bd is unknown. ?? 2010 International Association for Ecology and Health.

Influence of water temperature on acetylcholinesterase activity in the pacific tree frog (Hyla regilla)

USGS Publications Warehouse

Johnson, Catherine S.; Schwarzbach, Steven E.; Henderson, John D.; Wilson, Barry W.; Tjeerdema, Ronald S.

2005-01-01

This investigation evaluated whether acetylcholinesterase (AChE) in Pacific tree frogs (Hyla regilla) from different geographical locations was influenced by different temperatures during early aquatic life stages, independent of pesticide exposure. Tadpoles were collected from both a California coastal pond and a Sierra Nevada mountain range pond, USA. Groups of frogs from each location were raised in temperatures representative of either the Sierra Nevada (8°C) or the coastal (19°C) location. Metamorphs from both locations raised as tadpoles at 19°C had AChE activities of 42.3 and 38.7 nm/min/mg protein, while those raised as tadpoles at 8°C had activities of 26.9 and 28.2 nm/min/mg protein. A two-way analysis of variance revealed temperature to be the significant factor in determining AChE activity (F = 22.3, p < 0.001), although origin was not important (F = 0.09, p = 0.75). Interpretations regarding the influence of pesticides upon AChE activity in Pacific tree frogs must consider the influence of environmental temperature to enable cross-population comparisons.

Helminth parasites of the leopard frog Lithobates sp. Colima (Amphibia: Ranidae) from Colima, Mexico.

PubMed

Cabrera-Guzmán, Elisa; Garrido-Olvera, Lorena; León-Règagnon, Virginia

2010-08-01

The helminth fauna inhabiting Lithobates sp. Colima from Ticuizitán, Colima, Mexico, comprises 10 species: 4 digeneans ( Clinostomum sp., Glypthelmins quieta , Haematoloechus sp., and Langeronia macrocirra ), 5 nematodes ( Aplectana itzocanensis , Cosmocerca podicipinus , Foleyellides striatus , Oswaldocruzia subauricularis , and Rhabdias sp.), and 1 cestode (Cyclophyllidea). Glypthelmins quieta , L. macrocirra , and A. itzocanensis represent new host records. These observations, added to previous records from Acapulco, Guerrero, Mexico, indicate that the helminth fauna of Lithobates sp. from Colima comprises 25 taxa. Frogs are being parasitized by 3 infection routes: ingestion of intermediate host, skin penetration by larval forms, and transmission by vectors. Species of Aplectana , Cosmocerca , Foleyellides , and Oswaldocruzia occurred in high prevalence in Colima, similar to a previous study on the same frog species from Guerrero. In Colima, Glypthelmins , Haematoloechus , and Rhabdias also occurred in high prevalence. Haematoloechus species reached the highest mean intensity in both localities. The semiaquatic habits of this species of frog and the availability of particular feeding resources appear to determine the helminth composition and infection levels; however, co-speciation events also play an important role structuring these helminth communities.

Modified Shuffled Frog Leaping Optimization Algorithm Based Distributed Generation Rescheduling for Loss Minimization

NASA Astrophysics Data System (ADS)

Arya, L. D.; Koshti, Atul

2018-05-01

This paper investigates the Distributed Generation (DG) capacity optimization at location based on the incremental voltage sensitivity criteria for sub-transmission network. The Modified Shuffled Frog Leaping optimization Algorithm (MSFLA) has been used to optimize the DG capacity. Induction generator model of DG (wind based generating units) has been considered for study. Standard test system IEEE-30 bus has been considered for the above study. The obtained results are also validated by shuffled frog leaping algorithm and modified version of bare bones particle swarm optimization (BBExp). The performance of MSFLA has been found more efficient than the other two algorithms for real power loss minimization problem.

Wear Fast, Die Young: More Worn Teeth and Shorter Lives in Iberian Compared to Scottish Red Deer

PubMed Central

Pérez-Barbería, F. J.; Carranza, J.; Sánchez-Prieto, C.

2015-01-01

Teeth in Cervidae are permanent structures that are not replaceable or repairable; consequently their rate of wear, due to the grinding effect of food and dental attrition, affects their duration and can determine an animal's lifespan. Tooth wear is also a useful indicator of accumulative life energy investment in intake and mastication and their interactions with diet. Little is known regarding how natural and sexual selection operate on dental structures within a species in contrasting environments and how these relate to life history traits to explain differences in population rates of tooth wear and longevity. We hypothesised that populations under harsh environmental conditions should be selected for more hypsodont teeth while sexual selection may maintain similar sex differences within different populations. We investigated the patterns of tooth wear in males and females of Iberian red deer (Cervus elaphus hispanicus) in Southern Spain and Scottish red deer (C. e. scoticus) across Scotland, that occur in very different environments, using 10343 samples from legal hunting activities. We found higher rates of both incisor and molar wear in the Spanish compared to Scottish populations. However, Scottish red deer had larger incisors at emergence than Iberian red deer, whilst molars emerged at a similar size in both populations and sexes. Iberian and Scottish males had earlier tooth depletion than females, in support of a similar sexual selection process in both populations. However, whilst average lifespan for Iberian males was 4 years shorter than that for Iberian females and Scottish males, Scottish males only showed a reduction of 1 year in average lifespan with respect to Scottish females. More worn molars were associated with larger mandibles in both populations, suggesting that higher intake and/or greater investment in food comminution may have favoured increased body growth, before later loss of tooth efficiency due to severe wear. These results

Wear Fast, Die Young: More Worn Teeth and Shorter Lives in Iberian Compared to Scottish Red Deer.

PubMed

Pérez-Barbería, F J; Carranza, J; Sánchez-Prieto, C

2015-01-01

Teeth in Cervidae are permanent structures that are not replaceable or repairable; consequently their rate of wear, due to the grinding effect of food and dental attrition, affects their duration and can determine an animal's lifespan. Tooth wear is also a useful indicator of accumulative life energy investment in intake and mastication and their interactions with diet. Little is known regarding how natural and sexual selection operate on dental structures within a species in contrasting environments and how these relate to life history traits to explain differences in population rates of tooth wear and longevity. We hypothesised that populations under harsh environmental conditions should be selected for more hypsodont teeth while sexual selection may maintain similar sex differences within different populations. We investigated the patterns of tooth wear in males and females of Iberian red deer (Cervus elaphus hispanicus) in Southern Spain and Scottish red deer (C. e. scoticus) across Scotland, that occur in very different environments, using 10343 samples from legal hunting activities. We found higher rates of both incisor and molar wear in the Spanish compared to Scottish populations. However, Scottish red deer had larger incisors at emergence than Iberian red deer, whilst molars emerged at a similar size in both populations and sexes. Iberian and Scottish males had earlier tooth depletion than females, in support of a similar sexual selection process in both populations. However, whilst average lifespan for Iberian males was 4 years shorter than that for Iberian females and Scottish males, Scottish males only showed a reduction of 1 year in average lifespan with respect to Scottish females. More worn molars were associated with larger mandibles in both populations, suggesting that higher intake and/or greater investment in food comminution may have favoured increased body growth, before later loss of tooth efficiency due to severe wear. These results

Parasite species of the endangered Iberian wolf (Canis lupus signatus) and a sympatric widespread carnivore.

PubMed

Figueiredo, Ana; Oliveira, Lucia; Madeira de Carvalho, Luís; Fonseca, Carlos; Torres, Rita Tinoco

2016-08-01

Parasites have a profound impact on wildlife population dynamics. However, until some years ago, studies on the occurrence and prevalence of wildlife parasites were neglected comparatively with the studies on humans and domestic animals. In this study, we determined the parasite prevalence of two sympatric wild canids: the endangered Iberian wolf (Canis lupus signatus) and the widespread red fox (Vulpes vulpes), in central Portugal. From November 2014 to July 2015, fresh fecal samples from both species were collected monthly in several transects distributed throughout the study area. All samples were submitted to several coprological techniques. In total, 6 helminth parasites (Crenosoma vulpis, Angiostrongylus vasorum, Toxocara canis, Trichuris vulpis, Ancylostomatidae, Toxascaris leonina), and a protozoa (Balantidium coli) were identified based on size and morphology. The red fox was infected by seven different parasites while the Iberian wolf was infected by four. All parasites present in wolf were also present in the red fox. C. vulpis had the higher prevalence in red fox, while Ancylostomatidae were the most prevalent parasites in wolf. To our knowledge, this is the first study in this isolated subpopulation of the Iberian wolf. Our results show that both carnivores carry parasites that are of concern as they are pathogenic to humans and other wild and domestic animals. We suggest that surveillance programs must also include monitoring protocols of wildlife; particularly endangered species.

Effects of temperature and hydric environment on survival of the Panamanian Golden Frog infected with a pathogenic chytrid fungus.

PubMed

Bustamante, Heidi M; Livo, Lauren J; Carey, Cynthia

2010-06-01

Considerable controversy exists concerning whether or not climate changes (particularly global warming) are causing outbreaks of a lethal amphibian pathogen, the chytrid fungus Batrachochytrium dendrobatidis (Longcore, Pessier & D.K. Nichols 1999). In the present study, groups of Panamanian golden frogs (Atelopus zeteki Dunn, 1993), a critically endangered amphibian thought to be nearly extinct in Panama, were exposed to varying dosages of zoospores of Batrachochytrium dendrobatidis, temperatures and hydric environments in order to learn whether this species is susceptible to this pathogen and, if so, how environmental factors affect survival. This pathogen proved to be highly lethal for A. zeteki. Frogs exposed to a dosage of 100 Bd zoospores survived significantly (P<0.0001) longer than those that had been exposed to 10(4) or 10(6) zoospores. Exposed frogs housed at 23 °C survived significantly (P<0.0001) longer than those that were housed at 17 °C. Exposed frogs held in dry conditions survived significantly longer than those in wet conditions (P<0.0001). As a laboratory study, these results do not directly test hypotheses about the relation between climate change and the decline of these frogs in the field, but they inform the discussion about how environmental conditions can have an impact on the interaction between a susceptible amphibian and this pathogen. These data do not support the contention that rising global temperatures are necessary to cause the death of amphibians infected with this pathogen because the pathogen was equally lethal at 17 as at 23 °C, and frogs at the warmer temperature lived significantly longer than those at the cooler one. © 2010 ISZS, Blackwell Publishing and IOZ/CAS.

Lessons learned from the ATLAS performance studies of the Iberian Cloud for the first LHC running period

NASA Astrophysics Data System (ADS)

Sánchez-Martínez, V.; Borges, G.; Borrego, C.; del Peso, J.; Delfino, M.; Gomes, J.; González de la Hoz, S.; Pacheco Pages, A.; Salt, J.; Sedov, A.; Villaplana, M.; Wolters, H.

2014-06-01

In this contribution we describe the performance of the Iberian (Spain and Portugal) ATLAS cloud during the first LHC running period (March 2010-January 2013) in the context of the GRID Computing and Data Distribution Model. The evolution of the resources for CPU, disk and tape in the Iberian Tier-1 and Tier-2s is summarized. The data distribution over all ATLAS destinations is shown, focusing on the number of files transferred and the size of the data. The status and distribution of simulation and analysis jobs within the cloud are discussed. The Distributed Analysis tools used to perform physics analysis are explained as well. Cloud performance in terms of the availability and reliability of its sites is discussed. The effect of the changes in the ATLAS Computing Model on the cloud is analyzed. Finally, the readiness of the Iberian Cloud towards the first Long Shutdown (LS1) is evaluated and an outline of the foreseen actions to take in the coming years is given. The shutdown will be a good opportunity to improve and evolve the ATLAS Distributed Computing system to prepare for the future challenges of the LHC operation.

The maternal genetic make-up of the Iberian Peninsula between the Neolithic and the Early Bronze Age.

PubMed

Szécsényi-Nagy, Anna; Roth, Christina; Brandt, Guido; Rihuete-Herrada, Cristina; Tejedor-Rodríguez, Cristina; Held, Petra; García-Martínez-de-Lagrán, Íñigo; Arcusa Magallón, Héctor; Zesch, Stephanie; Knipper, Corina; Bánffy, Eszter; Friederich, Susanne; Meller, Harald; Bueno Ramírez, Primitiva; Barroso Bermejo, Rosa; de Balbín Behrmann, Rodrigo; Herrero-Corral, Ana M; Flores Fernández, Raúl; Alonso Fernández, Carmen; Jiménez Echevarria, Javier; Rindlisbacher, Laura; Oliart, Camila; Fregeiro, María-Inés; Soriano, Ignacio; Vicente, Oriol; Micó, Rafael; Lull, Vicente; Soler Díaz, Jorge; López Padilla, Juan Antonio; Roca de Togores Muñoz, Consuelo; Hernández Pérez, Mauro S; Jover Maestre, Francisco Javier; Lomba Maurandi, Joaquín; Avilés Fernández, Azucena; Lillios, Katina T; Silva, Ana Maria; Magalhães Ramalho, Miguel; Oosterbeek, Luiz Miguel; Cunha, Claudia; Waterman, Anna J; Roig Buxó, Jordi; Martínez, Andrés; Ponce Martínez, Juana; Hunt Ortiz, Mark; Mejías-García, Juan Carlos; Pecero Espín, Juan Carlos; Cruz-Auñón Briones, Rosario; Tomé, Tiago; Carmona Ballestero, Eduardo; Cardoso, João Luís; Araújo, Ana Cristina; Liesau von Lettow-Vorbeck, Corina; Blasco Bosqued, Concepción; Ríos Mendoza, Patricia; Pujante, Ana; Royo-Guillén, José I; Esquembre Beviá, Marco Aurelio; Dos Santos Goncalves, Victor Manuel; Parreira, Rui; Morán Hernández, Elena; Méndez Izquierdo, Elena; Vega Y Miguel, Jorge; Menduiña García, Roberto; Martínez Calvo, Victoria; López Jiménez, Oscar; Krause, Johannes; Pichler, Sandra L; Garrido-Pena, Rafael; Kunst, Michael; Risch, Roberto; Rojo-Guerra, Manuel A; Haak, Wolfgang; Alt, Kurt W

2017-11-15

Agriculture first reached the Iberian Peninsula around 5700 BCE. However, little is known about the genetic structure and changes of prehistoric populations in different geographic areas of Iberia. In our study, we focus on the maternal genetic makeup of the Neolithic (~ 5500-3000 BCE), Chalcolithic (~ 3000-2200 BCE) and Early Bronze Age (~ 2200-1500 BCE). We report ancient mitochondrial DNA results of 213 individuals (151 HVS-I sequences) from the northeast, central, southeast and southwest regions and thus on the largest archaeogenetic dataset from the Peninsula to date. Similar to other parts of Europe, we observe a discontinuity between hunter-gatherers and the first farmers of the Neolithic. During the subsequent periods, we detect regional continuity of Early Neolithic lineages across Iberia, however the genetic contribution of hunter-gatherers is generally higher than in other parts of Europe and varies regionally. In contrast to ancient DNA findings from Central Europe, we do not observe a major turnover in the mtDNA record of the Iberian Late Chalcolithic and Early Bronze Age, suggesting that the population history of the Iberian Peninsula is distinct in character.

Crustal structure of an intraplate thrust belt: The Iberian Chain revealed by wide-angle seismic, magnetotelluric soundings and gravity data

NASA Astrophysics Data System (ADS)

Seillé, Hoël; Salas, Ramon; Pous, Jaume; Guimerà, Joan; Gallart, Josep; Torne, Montserrat; Romero-Ruiz, Ivan; Diaz, Jordi; Ruiz, Mario; Carbonell, Ramon; Mas, Ramón

2015-11-01

The Iberian Chain is a Cenozoic intraplate thrust belt located within the Iberian plate. Unlike other belts in the Iberia Peninsula, the scarcity of geophysical studies in this area results in a number of unknowns about its crustal structure. The Iberian Chain crust was investigated by means of a NE-SW refraction/wide-angle reflection seismic transect and two magnetotelluric profiles across the chain, oriented along the same direction. The seismic profile was designed to sample the crust by means of three shots designed to obtain a reversed profile. The resulting velocity-depth model shows a moderate thickening of the crust toward the central part of the profile, where crustal thickness reaches values above 40 km, thinning toward de SW Tajo and NE Ebro foreland basins. The crustal thickening is concentrated in the upper crust. The seismic results are in overall agreement with regional trends of Bouguer gravity anomaly and the main features of the seismic model were reproduced by gravity modeling. The magnetotelluric data consist of 39 sites grouped into two profiles, with periods ranging from 0.01 s to 1000 s. Dimensionality analyses show significant 3D effects in the resistivity structure and therefore we carried out a joint 3D inversion of the full impedance tensor and magnetic transfer functions. The Mesozoic and Cenozoic basins along the Chain are well characterized by shallow high conductive zones and low velocities. Elongated conductors reaching mid-crustal depths evidence the presence of major faults dominating the crustal structure. The results from the interpretation of these complementary geophysical data sets provided the first images of the crustal structure of the Iberian Chain. They are consistent with a Cenozoic shortening responsible of the upper crust thickening as well as of the uplift of the Iberian Chain and the generation of its present day topography.

Freshwater macroinvertebrate samples from a water quality monitoring network in the Iberian Peninsula.

PubMed

Escribano, Nora; Oscoz, Javier; Galicia, David; Cancellario, Tommaso; Durán, Concha; Navarro, Patricia; Ariño, Arturo H

2018-06-05

This dataset gathers information about the macroinvertatebrate samples and environmental variables collected on rivers of the Ebro River Basin (NE Iberian Peninsula), the second largest catchment in the Iberian Peninsula. The collection is composed of 1,776 sampling events carried out between 2005 and 2015 at more than 400 sampling sites. This dataset is part of a monitoring network set up by the Ebro Hydrographic Confederation, the official body entrusted with the care of the basin, to fulfill the requirements of the European Water Framework Directive. Biological indices based on the freshwater macroinvertebrate communities were used to evaluate the ecological status of the water bodies within the basin. Samples were qualitatively screened for all occurring taxa. Then, all individuals from all taxa in a quantitative subsample of each sample were counted. Biological indices were calculated to estimate water quality at each sampling site. All samples are kept at the Museum of Zoology of the University of Navarra.

Freshwater macroinvertebrate samples from a water quality monitoring network in the Iberian Peninsula

PubMed Central

Escribano, Nora; Oscoz, Javier; Galicia, David; Cancellario, Tommaso; Durán, Concha; Navarro, Patricia; Ariño, Arturo H.

2018-01-01

This dataset gathers information about the macroinvertatebrate samples and environmental variables collected on rivers of the Ebro River Basin (NE Iberian Peninsula), the second largest catchment in the Iberian Peninsula. The collection is composed of 1,776 sampling events carried out between 2005 and 2015 at more than 400 sampling sites. This dataset is part of a monitoring network set up by the Ebro Hydrographic Confederation, the official body entrusted with the care of the basin, to fulfill the requirements of the European Water Framework Directive. Biological indices based on the freshwater macroinvertebrate communities were used to evaluate the ecological status of the water bodies within the basin. Samples were qualitatively screened for all occurring taxa. Then, all individuals from all taxa in a quantitative subsample of each sample were counted. Biological indices were calculated to estimate water quality at each sampling site. All samples are kept at the Museum of Zoology of the University of Navarra. PMID:29870034

The use of radio-collars for monitoring wildlife diseases: a case study from Iberian ibex affected by Sarcoptes scabiei in Sierra Nevada, Spain

PubMed Central

2013-01-01

Background Wildlife radio tracking has gained popularity during the recent past. Ecologists and conservationists use radio-collars for different purposes: animal movement monitoring, home range, productivity, population estimation, behaviour, habitat use, survival, and predator-prey interaction, among others. The aim of our present study is to highlight the application of radio-collars for wildlife diseases monitoring. The spread of wildlife diseases and the efficacy of management actions for controlling them propose serious challenges for ecologists and conservationists, since it is difficult to re-capture (or simply observe) the same animal in pre-determined temporal interval, but such difficulty is overcome by the use of gps-gsm radio collars. Methods In the present study we report, for the first time to our knowledge, the use of radio-collars in the monitoring of Iberian ibex affected by Sarcoptes scabiei in Sierra Nevada mountain range, Spain. Twenty-five moderate or slightly mangy animals were radio-collared between 2006 and 2013. Results The radio-collars allowed us to confirm the presence of resistance to S. scabiei within Iberian ibex population. Twenty (80%) of the collared animals recovered totally from mange, while the disease progressed in the other five Iberian ibex (20% of the collared animals) and the animals died. The average estimated recovery time of the resistant animals was 245 ± 277 days, and the estimated average survival time of the non-resistant Iberian ibex was 121 ± 71 days. Non-resistant animals survived at least 100 days, while all of them died with less than 200 days. Sixty per cent of the resistant animals were recovered with less than 200 days. Conclusions We report, for the first time, the successful use of radio collars for wildlife diseases monitoring using Iberian ibex/S. scabiei as a model. By using radio collars we documented that most of the Sarcoptes-infected Iberian ibex are resistant to this disease, and we

Effects of teleconnection patterns on the atmospheric routes, precipitation and deposition amounts in the north-eastern Iberian Peninsula

NASA Astrophysics Data System (ADS)

Izquierdo, Rebeca; Alarcón, Marta; Aguillaume, Laura; Àvila, Anna

2014-06-01

The North Atlantic Oscillation (NAO) has been identified as one of the atmospheric patterns which mostly influence the temporal evolution of precipitation and temperature in the Mediterranean area. Recently, the Western Mediterranean Oscillation (WeMO) has also been proposed to describe the precipitation variability in the eastern Iberian Peninsula. This paper examines whether the chemical signature and/or the chemical deposition amounts recorded over NE Iberian Peninsula are influenced by these climatic variability patterns. Results show a more relevant role of the WeMO compared to NAO in the deposition of either marine (Cl-, Na+, Mg2+) or anthropogenic pollutants (H+, NH4+, NO3- and SO42-). A cluster classification of provenances indicated that in winter (December to March) fast Atlantic air flows correspond to positive WeMO indices, while negative WeMOi are associated to Northeastern and Southwestern circulations. The negative phase of WeMO causes the entry of air masses from the Mediterranean into the Iberian Peninsula, that are enriched with marine ions and ions of anthropogenic origin (NH4+, NO3- and SO42-). For these later, this suggests the advection over the Mediterranean of polluted air masses from southern Europe and the scavenging and deposition of this pollution by precipitation during the WeMO negative phases. This will carry transboundary pollutants to the NE Iberian Peninsula. However, local pollutants may also contribute, as precipitation events from the Mediterranean and the Atlantic (associated to both WeMO phases) may incorporate emissions that accumulate locally during the winter anticyclonic episodes typical of the region.

Release of “neurokinin” on nervous and electrical stimulation of a frog stomach muscle preparation

PubMed Central

Singh, I.

1964-01-01

Activation of a frog stomach muscle preparation by electrical stimulation of a vagus nerve or by direct stimulation released two polypeptides. One was destroyed by trypsin or chymotrypsin in about 10 min; the activity of the other was enhanced by trypsin for about 10 min, but was destroyed by chymotrypsin. Similar stimulation of dog stomach muscle did not release these polypeptides. Correspondingly, the transmission from vagus nerve to stomach muscle in the frog was resistant to atropine, but was blocked by atropine in the dog. PMID:14190475

Origin of sex chromosomes in six groups of Rana rugosa frogs inferred from a sex-linked DNA marker.

PubMed

Oike, Akira; Watanabe, Koichiro; Min, Mi-Sook; Tojo, Koji; Kumagai, Masahide; Kimoto, Yuya; Yamashiro, Tadashi; Matsuo, Takanori; Kodama, Maho; Nakamura, Yoriko; Notsu, Masaru; Tochimoto, Takeyoshi; Fujita, Hiroyuki; Ota, Maki; Ito, Etsuro; Yasumasu, Shigeki; Nakamura, Masahisa

2017-08-01

Each vertebrate species, as a general rule, has either the XX/XY or ZZ/ZW chromosomes by which sex is determined. However, the Japanese Rana (R.) rugosa frog is an exception, possessing both sex-determining combinations within one species, varying with region of origin. We collected R. rugosa frogs from 104 sites around Japan and South Korea and determined the nucleotide sequences of the mitochondrial 12S ribosomal RNA gene. Based on the sequences, R. rugosa frogs were divided into four groups from Japan and one from South Korea. The ZZ/ZW type is reportedly derived from the XX/XY type, although recently a new ZZ/ZW type of R. rugosa was reported. However, it still remains unclear from where the sex chromosomes in the five groups of this species were derived. In this study, we successfully isolated a sex-linked DNA maker and used it to classify R. rugosa frogs into several groupings. From the DNA marker as well as from nucleotide analysis of the promoter region of the androgen receptor (AR) gene, we identified another female heterogametic group, designated, West-Central. The sex chromosomes in the West-Central originated from the West and Central groups. The results indicate that a sex-linked DNA marker is a verifiable tool to determine the origin of the sex chromosomes in R. rugosa frogs in which the sex-determining system has changed, during two independent events, from the male to female heterogamety. © 2017 Wiley Periodicals, Inc.

Inverse Effects on Growth and Development Rates by Means of Endocrine Disruptors in African Clawed Frog Tadpoles ("Xenopus Laevis")

ERIC Educational Resources Information Center

Hackney, Zachary Carl

2007-01-01

Previous work on fish, frogs, and salamanders, showed the ability for estrogen (EE2) and anthropogenic endocrine disruptors to skew sex ratios and cause hermaphrodism. This study addressed the effects of estrogens on growth and development rates of African clawed frog tadpoles ("Xenopus laevis") during their gender determination stages. The…

Outbreak of ringworm in a traditional Iberian pig farm in Spain.

PubMed

García-Sánchez, Alfredo; Bazán, Javier; de Mendoza, Javier Hermoso; Martínez, Remigio; Sánchez, Sergio; de Mendoza, Miguel Hermoso

2011-03-01

An outbreak of dermatophytosis caused by Microsporum nanum in a traditional Iberian extensive farm is described. The morbidity was 100% among lactating sows; however, suckling and weaning pigs, as well as boars never developed the lesions seen in the sows. The clinical aspects of porcine ringworm caused by this fungus are discussed and the ecology of the organism is reviewed. © 2009 Blackwell Verlag GmbH.

Strategies for assessing the implications of malformed frogs for environmental health.

PubMed Central

Burkhart, J G; Ankley, G; Bell, H; Carpenter, H; Fort, D; Gardiner, D; Gardner, H; Hale, R; Helgen, J C; Jepson, P; Johnson, D; Lannoo, M; Lee, D; Lary, J; Levey, R; Magner, J; Meteyer, C; Shelby, M D; Lucier, G

2000-01-01

The recent increase in the incidence of deformities among natural frog populations has raised concern about the state of the environment and the possible impact of unidentified causative agents on the health of wildlife and human populations. An open workshop on Strategies for Assessing the Implications of Malformed Frogs for Environmental Health was convened on 4-5 December 1997 at the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina. The purpose of the workshop was to share information among a multidisciplinary group with scientific interest and responsibility for human and environmental health at the federal and state level. Discussions highlighted possible causes and recent findings directly related to frog deformities and provided insight into problems and strategies applicable to continuing investigation in several areas. Possible causes of the deformities were evaluated in terms of diagnostics performed on field amphibians, biologic mechanisms that can lead to the types of malformations observed, and parallel laboratory and field studies. Hydrogeochemistry must be more integrated into environmental toxicology because of the pivotal role of the aquatic environment and the importance of fates and transport relative to any potential exposure. There is no indication of whether there may be a human health factor associated with the deformities. However, the possibility that causal agents may be waterborne indicates a need to identify the relevant factors and establish the relationship between environmental and human health in terms of hazard assessment. PMID:10620528

Effects of tumor promoters on sodium ion transport across frog skin.

PubMed

Civan, M M; Rubenstein, D; Mauro, T; O'Brien, T G

1985-05-01

Phorbol esters are tumor promoters and mitogens whose effects may be mediated by changes in ion transport across membranes. Clarification of the transport effects of these agents should be facilitated by using a well-characterized model epithelial system whose intracellular and transmural parameters are readily measurable. The current results constitute a preliminary study of the effects of 12-O-tetradecanoylphorbol-13-acetate (TPA), phorbol-12,13-dibutyrate (PDBU), and phorbol on the short-circuit current (Isc) across frog skin. TPA produced two effects: a stimulation of Isc of variable magnitude and a far more constant inhibition of the natriferic action of vasopressin. These effects appear related to the action of TPA as a tumor promoter insofar as PDBU (an active ester) also inhibited the natriferic response to vasopressin, whereas phorbol (inactive as a tumor promoter) had no significant effect. TPA is largely active from the mucosal medium, inhibits the natriferic response to adenosine 3',5'-cyclic monophosphate (cAMP) as well as that to vasopressin, and does not stimulate Isc in the presence of 10(-4) M mucosal amiloride. Inhibition of prostaglandin E1 production by indomethacin had no effect on the actions of TPA. The results indicate that frog skin is a promising model for studying the transport effects of the phorbol esters. The data further suggest that TPA acts on frog skin by activating the physiological amiloride- and cAMP-sensitive channels gating apical Na+ entry from the mucosal medium into the epithelial cells.

The Pharmacokinetics of Enrofloxacin in Adult African Clawed Frogs (Xenopus laevis)

PubMed Central

Howard, Antwain M; Papich, Mark G; Felt, Stephen A; Long, Charles T; McKeon, Gabriel P; Bond, Emmitt S; Torreilles, Stéphanie L; Luong, Richard H; Green, Sherril L

2010-01-01

Pharmacokinetics of enrofloxacin, a fluoroquinolone antibiotic, was determined in adult female Xenopus laevis after single-dose administration (10 mg/kg) by intramuscular or subcutaneous injection. Frogs were evaluated at various time points until 8 h after injection. Plasma was analyzed for antibiotic concentration levels by HPLC. We computed pharmacokinetic parameters by using noncompartmental analysis of the pooled concentrations (naive pooled samples). After intramuscular administration of enrofloxacin, the half-life was 5.32 h, concentration maximum was 10.85 µg/mL, distribution volume was 841.96 mL/kg, and area under the time–concentration curve was 57.59 µg×h/mL; after subcutaneous administration these parameters were 4.08 h, 9.76 µg/mL, 915.85 mL/kg, and 47.42 µg×h/mL, respectively. According to plasma pharmacokinetics, Xenopus seem to metabolize enrofloxacin in a manner similar to mammals: low levels of the enrofloxacin metabolite, ciprofloxacin, were detected in the frogs’ habitat water and plasma. At necropsy, there were no gross or histologic signs of toxicity after single-dose administration; toxicity was not evaluated for repeated dosing. The plasma concentrations reached levels considered effective against common aquatic pathogens and suggest that a single, once-daily dose would be a reasonable regimen to consider when treating sick frogs. The treatment of sick frogs should be based on specific microbiologic identification of the pathogen and on antibiotic susceptibility testing. PMID:21205443

Amphibian pathogens in Southeast Asian frog trade.

PubMed

Gilbert, Martin; Bickford, David; Clark, Leanne; Johnson, Arlyne; Joyner, Priscilla H; Ogg Keatts, Lucy; Khammavong, Kongsy; Nguyễn Văn, Long; Newton, Alisa; Seow, Tiffany P W; Roberton, Scott; Silithammavong, Soubanh; Singhalath, Sinpakhone; Yang, Angela; Seimon, Tracie A

2012-12-01

Amphibian trade is known to facilitate the geographic spread of pathogens. Here we assess the health of amphibians traded in Southeast Asia for food or as pets, focusing on Batrachochytrium dendrobatidis (Bd), ranavirus and general clinical condition. Samples were collected from 2,389 individual animals at 51 sites in Lao PDR, Cambodia, Vietnam and Singapore for Bd screening, and 74 animals in Cambodia and Vietnam for ranavirus screening. Bd was found in one frog (n = 347) in Cambodia and 13 in Singapore (n = 419). No Bd was found in Lao PDR (n = 1,126) or Vietnam (n = 497), and no ranavirus was found in Cambodia (n = 70) or Vietnam (n = 4). Mild to severe dermatological lesions were observed in all East Asian bullfrogs Hoplobatrachus rugolosus (n = 497) sampled in farms in Vietnam. Histologic lesions consistent with sepsis were found within the lesions of three frogs and bacterial sepsis in two (n = 4); one had Gram-negative bacilli and one had acid-fast organisms consistent with mycobacterium sp. These results confirm that Bd is currently rare in amphibian trade in Southeast Asia. The presence of Mycobacterium-associated disease in farmed H. rugolosus is a cause for concern, as it may have public health implications and indicates the need for improved biosecurity in amphibian farming and trade.

Evidence of auditory insensitivity to vocalization frequencies in two frogs.

PubMed

Goutte, Sandra; Mason, Matthew J; Christensen-Dalsgaard, Jakob; Montealegre-Z, Fernando; Chivers, Benedict D; Sarria-S, Fabio A; Antoniazzi, Marta M; Jared, Carlos; Almeida Sato, Luciana; Felipe Toledo, Luís

2017-09-21

The emergence and maintenance of animal communication systems requires the co-evolution of signal and receiver. Frogs and toads rely heavily on acoustic communication for coordinating reproduction and typically have ears tuned to the dominant frequency of their vocalizations, allowing discrimination from background noise and heterospecific calls. However, we present here evidence that two anurans, Brachycephalus ephippium and B. pitanga, are insensitive to the sound of their own calls. Both species produce advertisement calls outside their hearing sensitivity range and their inner ears are partly undeveloped, which accounts for their lack of high-frequency sensitivity. If unheard by the intended receivers, calls are not beneficial to the emitter and should be selected against because of the costs associated with signal production. We suggest that protection against predators conferred by their high toxicity might help to explain why calling has not yet disappeared, and that visual communication may have replaced auditory in these colourful, diurnal frogs.

Biophysical Properties of Frog Virus and Its Deoxyribonucleic Acid: Fate of Radioactive Virus in the Early Stage of Infection 1

PubMed Central

Smith, William R.; McAuslan, Brian R.

1969-01-01

Frog virus (FV-3) was banded by isopycnic centrifugation in cesium chloride, sucrose, or potassium tartrate. Two bands of infectivity were regularly found at positions in cesium chloride corresponding to densities of 1.26 and 1.30 g/cm3, respectively. Deoxyribonucleic acid from either band had the following characteristics: double-stranded; a Tm of 76.3 C in 0.1 SSC (0.015 m NaCl plus 0.015 m sodium citrate) and a buoyant density of 1.720 g/cm3 in cesium chloride, corresponding to a guanine plus cytosine content of 56 to 58% and a molecular weight of 130 × 106 daltons, determined by velocity sedimentation. These data, together with electron micrographs of sections of cells infected with material from either band suggest that two types of infectious frog virus particles exists, rather than a second virus in the frog virus stocks. The composition of frog virus was determined. It was found that highly purified preparations of frog virus were composed of 55.8% protein, 30.1% deoxyribonucleic acid, and 14.2% lipid. The kinetics of adsorption and uncoating of FV-3 was studied with radioactive virus. Uncoating is comparatively rapid and in contrast to poxvirus is unaffected by inhibitors of protein synthesis. Images PMID:4980848

Diversity and abundance of forest frogs (Anura: Leptodactylidae) before and after Hurricane Georges in the Cordillera Central of Puerto Rico

USGS Publications Warehouse

Vilella, F.J.; Fogarty, J.H.

2005-01-01

Caribbean hurricanes often impact terrestrial vertebrates in forested environments. On 21 September 1998, Hurricane Georges impacted Puerto Rico with sustained winds in excess of 166 km/hr, causing damage to forests of the island's principal mountain range; the Cordillera Central. We estimated forest frog abundance and diversity from call counts conducted along marked transects before and after Hurricane Georges in two forests reserves of the Cordillera Central (Maricao and Guilarte). We used distance sampling to estimate density of Eleutherodactylus coqui and recorded counts of other species. After the hurricane, the abundance of E. coqui increased in both reserves compared to prehurricane levels while abundance of other frog species decreased. In Maricao, relative abundance of E. richmondi (P = 0.013) and E. brittoni (P = 0.034) were significantly lower after the hurricane. Moreover, species richness and evenness of the Maricao and Guilarte frog assemblages declined after the hurricane. Our results on abundance patterns of the forest frog assemblages of Maricao and Guilarte Forests were similar to those reported from the Luquillo Experimental Forest after Hurricane Hugo in September 1989. Long-term demographic patterns of the forest frog assemblages in the Cordillera Central may be associated with changes due to the ecological succession in post-hurricane forests. Copyright 2005 College of Arts and Sciences.

The effects of four arthropod diets on the body and organ weights of the leopard frog, Rana pipiens, during vitellogenesis.

PubMed

Lehman, G C

1978-12-01

Wild-caught adult Rana pipiens females were captured in midsummer and fed diets of crickets, flies sowbugs or wax moth larvae during a three-month period of active vitellogenesis. The cricket diet supported the most extensive body weight gain during this time and promoted a prolonged period of weight increase in an additional long-term study. Synchronous growth of the oocytes occurred in all four groups, but the ovaries and oviducts of cricket-fed animals were significantly larger than those of frogs on the other three diets. The significantly higher liver weights of frogs fed wax moth larvae may have reflected an augmentation of hepatic energy stores. Fat body weights were also highest in this group of animals. Frogs fed crickets and wax moth larvae possessed larger fat bodies than did the midsummer control animals killed immediately after their arrival in the laboratory. In contrast, frogs fed flies and sowbugs had smaller fat bodies than did the initial controls, suggesting that animals on these diets had utilized fat body lipid during vitellogenesis. Gastrocnemius and final body weights were lowest in frogs fed wax moth larvae. These findings may have reflected the nutritional content of the diet or the reduction in appetite frequently noted in these animals during observations of feeding behavior.

Movement ecology and seasonal distribution of mountain yellow-legged frogs, Rana muscosa, in a high-elevation Sierra Nevada basin.

Treesearch

K.L. Pope; K.R. Matthews

2001-01-01

Movement ecology and seasonal distribution of mountain yellow-legged frogs (Rana muscosa) in Dusy Basin (3470 m), Kings Canyon National Park, California, were characterized using passive integrated transponder (PIT) surveys and visual encounter surveys. We individually PIT-tagged 500 frogs during the summers of 1997 and 1998 and monitored these individuals during seven...

INTRAOCULAR PRESSURE AND EXAMINATION FINDINGS IN THREE SPECIES OF CENTRAL AND SOUTH AMERICAN TREE FROGS (CRUZIOHYLA CRASPEDOPUS, CRUZIOHYLA CALCARIFER, AND ANOTHECA SPINOSA).

PubMed

Lewin, Andrew C; Hausmann, Jennifer C; Miller, Paul E

2017-09-01

The purpose of this prospective study was to describe intraocular pressure (IOP) and examination findings in three tree frog species (Cruziohyla craspedopus [fringe leaf frog], Cruziohyla calcarifer [splendid leaf frog], and Anotheca spinosa [spiny-headed or coronated tree frog]). Thirty-one C. craspedopus, four C. calcarifer, and five A. spinosa were weighed, sexed based on phenotype where possible, and examined using slit-lamp biomicroscopy and indirect ophthalmoscopy. IOP was measured using the TonoVet and TonoLab rebound tonometers while the frogs were held two ways (unrestrained, then restrained). Statistical differences were determined using one-way analysis of variance (ANOVA) and t-tests. Mean ± SD IOP (TonoVet and TonoLab, respectively) was 15.1 ± 2.5 mmHg and 15.6 ± 4.1 mmHg in C. craspedopus; 14.8 ± 1.5 mmHg and 18.8 ± 3.1 mmHg in C. calcarifer; and 9.1 ± 2.1 mmHg and 10.8 ± 1.4 mmHg in A. spinosa. There was no significant difference in IOP in C. craspedopus by eye (Right vs Left), tonometer, or restraint method. IOP in female C. craspedopus was 1-3 mm Hg higher than in males with both devices (P < 0.05). IOP was statistically significantly different between all species for the TonoLab and between Cruziohyla genus frogs and A. spinosa for the TonoVet (P < 0.05). There was no difference in IOP measurements between the TonoVet and TonoLab in C. craspedopus. IOP varied by gender in C. craspedopus and between species, but not by tonometer. Ocular abnormalities were minimal in this group of captive bred frogs.

Evaluation of three enzyme-linked immunosorbent assays for sarcoptic mange diagnosis and assessment in the Iberian ibex, Capra pyrenaica.