| methylmercury in biota downstream of arivaca lake, arizona, usa. | concentrations of total mercury (hg) and methylmercury (mehg) were determined in water, sediment, periphyton, spiders, and amphibians from the streams and desert marsh downstream from arivaca lake, arizona, to better understand their distribution and bioaccumulation. mean concentrations of mehg in water ranged from 0.09 to 0.93 ng/l, and mean concentrations of total hg in sediment ranged from 10.4 to 126 μg/kg. hg and mehg in water and sediments downstream from arivaca lake were low enough that ... | 2014 | 24468966 |
| cliff swallows petrochelidon pyrrhonota as bioindicators of environmental mercury, cache creek watershed, california. | to evaluate mercury (hg) and other element exposure in cliff swallows (petrochelidon pyrrhonota), eggs were collected from 16 sites within the mining-impacted cache creek watershed, colusa, lake, and yolo counties, california, usa, in 1997-1998. nestlings were collected from seven sites in 1998. geometric mean total hg (thg) concentrations ranged from 0.013 to 0.208 microg/g wet weight (ww) in cliff swallow eggs and from 0.047 to 0.347 microg/g ww in nestlings. mercury detected in eggs generally ... | 2008 | 18166988 |
| the amphibian skin-associated microbiome across species, space and life history stages. | skin-associated bacteria of amphibians are increasingly recognized for their role in defence against pathogens, yet we have little understanding of their basic ecology. here, we use high-throughput 16s rrna gene sequencing to examine the host and environmental influences on the skin microbiota of the cohabiting amphibian species anaxyrus boreas, pseudacris regilla, taricha torosa and lithobates catesbeianus from the central valley in california. we also studied populations of rana cascadae over ... | 2014 | 24171949 |
| prevalence of batrachochytrium dendrobatidis in 120 archived specimens of lithobates catesbeianus (american bullfrog) collected in california, 1924-2007. | the chytrid fungus, batrachochytrium dendrobatidis (bd), has been identified as a major cause of the recent worldwide amphibian decline. numerous species in north america alone are under threat or have succumbed to bd-driven population extinctions. the american bullfrog (lithobates catesbeianus) has been reported as a tolerant carrier of bd. in this report, we used a qpcr assay to test 120 archived american bullfrog specimens collected between 1924 and 2007 in california, usa and baja california ... | 2013 | 24419668 |
| batrachochytrium dendrobatidis, a novel pathogen approaching endemism in central california. | the recent emergence of amphibian chytridiomycosis has precipitated competing hypotheses regarding the endemic versus novel nature of the causative agent, batrachochytrium dendrobatidis (bd). we conducted a retrospective survey of the california academy of sciences' (san francisco, california, usa) amphibian collection, testing for presence of bd in 4 amphibian species collected from central california between 1897 and 2005. the earliest detection of bd was found in 2 rana catesbeiana in 1961, a ... | 2009 | 19301630 |
| evaluation of tadpole mouthpart depigmentation as a diagnostic test for infection by batrachochytrium dendrobatidis for four california anurans. | the objective of this study was to evaluate the utility of gross morphologic examination of larval mouthpart defects as a diagnostic screening test to detect batrachochytrium dendrobatidis infection in four california, usa, anuran species. we examined mouthparts of 2,034 tadpoles of bufo boreas, pseudacris regilla, and rana catesbeiana collected in 2003 and 2004 and bufo canorus collected in 2004. data were recorded for three morphologic features: upper toothrows, lower toothrows, and combined j ... | 2007 | 17984265 |
| intraspecific variation of haematoloechus floedae harwood, 1932 (digenea: plagiorchiidae), from rana spp. in north and central america. | haematoloechus floedae was originally described from the lungs of rana catesbeiana in texas, and later reported in florida, in the united states. it was proposed to be synonymous with h. breviplexus, h. parviplexus, and h. varioplexus. we obtained specimens of h. floedae from rana brownorum and r. vaillanti in yucatán, mexico; r. cf. forreri and r. taylori in guanacaste, costa rica; and r. catesbeiana in georgia and california. some specimens were processed for morphological study; sequences of ... | 2005 | 17089764 |
| mercury contamination in three species of anuran amphibians from the cache creek watershed, california, usa. | fish and wildlife may bioaccumulate mercury (hg) to levels that adversely affect reproduction, growth, and survival. sources of hg within the cache creek watershed in northern california have been identified, and concentrations of hg in invertebrates and fish have been documented. however, bioaccumulation of hg by amphibians has not been evaluated. in this study, adult and juvenile american bullfrogs (lithobates catesbeianus) and foothill yellow-legged frogs (rana boylii), adult northern pacific ... | 2010 | 19353298 |