Toxicity of Amphibian Breeding Ponds in the Sudbury Region

1993 ◽  
Vol 50 (7) ◽  
pp. 1497-1503 ◽  
Author(s):  
Joseph Freda ◽  
D. Gordon McDonald

We measured the survival of transplanted embryos and tadpoles of the wood frog (Rana sylvatica), the American toad (Bufo americanus), and the spotted salamander (Ambystoma maculatum) in 16 ponds located approximately 60 km south of Sudbury, Ontario. Mortality of embryos of all species and mortality of B. americanus tadpoles were correlated only with water pH. In two low-pH ponds, high concentrations of dissolved organic compounds might have been a toxic component. Aluminum and pH were correlated with mortality for only R. sylvatica tadpoles. Overall, Al did not appear to be very toxic in both laboratory and field exposures possibly due to complexation by dissolved organic compounds.

1985 ◽  
Vol 63 (11) ◽  
pp. 2649-2656 ◽  
Author(s):  
Joseph Freda ◽  
William A. Dunson

Amphibian embryos exposed to water of low pH were killed by two distinct mechanisms. At very low pH levels, embryos stopped development soon after exposure to test solutions. At higher but still lethal pH levels, embryos became curled within a shrunken perivitelline space and failed to hatch (curling defect). The addition of Ca, Mg, and to a lesser extent Na (> 10 mg/L), prevented the early mortality of embryos in acidic water. However, increasing concentrations of these ions also caused the curling defect. Embryos of Ambystoma maculatum and Ambystoma jeffersonianum were generally able to hatch even though they became curled, but Rana sylvatica remained trapped and died. Consequently, as the concentration of Ca, Mg, or Na was increased at low pH, greater numbers of embryos of A. maculatum and A. jeffersonianum hatched, while survival of embryos of R. sylvatica was drastically reduced.


Author(s):  
Mario Vincenzo Russo ◽  
Ivan Notardonato ◽  
Alberto Rosada ◽  
Giuseppe Ianiri ◽  
Pasquale Avino

This paper shows a characterization of the organic and inorganic fraction of river waters (Tiber and Marta) and ores/soil samples collected in the Northern Latium region of Italy for evaluating the anthropogenic/natural source contribution to the environmental pollution of this area. For organic compounds, organochloride volatile compounds in Tiber and Marta rivers were analyzed by two different clean-up methods (i.e., liquid–liquid extraction and static headspace) followed by gas chromatography–electron capture detector (GC-ECD) analysis. The results show very high concentrations of bromoform (up to 1.82 and 3.2 µg L−1 in Tiber and Marta rivers, respectively), due to the presence of greenhouse crops, and of chloroform and tetrachloroethene, due to the presence of handicrafts installations. For the qualitative and quantitative assessment of the inorganic fraction, it is highlighted the use of a nuclear analytical method, instrumental neutron activation analysis, which allows having more information as possible from the sample without performing any chemical-physical pretreatment. The results have evidenced high levels of mercury (mean value 88.6 µg g−1), antimony (77.7 µg g−1), strontium (12,039 µg g−1) and zinc (103 µg g−1), whereas rare earth elements show levels similar to the literature data. Particular consideration is drawn for arsenic (414 µg g−1): the levels found in this paper (ranging between 1 and 5100 µg g−1) explain the high content of such element (as arsenates) in the aquifer, a big issue in this area.


Author(s):  
Natalia V. Karimova ◽  
Michael R Alves ◽  
Man Luo ◽  
Vicki Grassian ◽  
Robert Benny Gerber

Water systems often contain complex macromolecular systems that absorb light. In marine environments, these light absorbing components are often at the air-water interface and can participate in the chemistry of...


2012 ◽  
Vol 46 (19) ◽  
pp. 10455-10462 ◽  
Author(s):  
Manuela van Pinxteren ◽  
Conny Müller ◽  
Yoshiteru Iinuma ◽  
Christian Stolle ◽  
Hartmut Herrmann

1956 ◽  
Vol 34 (3) ◽  
pp. 174-177 ◽  
Author(s):  
David J. McCallion

A histological study of the poison glands of the toad demonstrated that one of the components of their secretion is adrenalin or adrenalin precursor substances. The poison glands are arranged in aggregates of two or three making up the warts on the skin. Larger aggregates of poison glands on the head are the parotoid glands. Each poison gland is a large vesicle, deep in the corium of the skin, and opening through a pore in the skin by way of a conical duct. The glandular epithelium of the poison gland is a flat acellular layer of cytoplasm containing a large number of flattened nuclei. Forcibly discharged glands disintegrate, are resorbed, and are replaced by new glands regenerated from the Malpighian layer of the epidermis.


1991 ◽  
Vol 261 (6) ◽  
pp. R1346-R1350 ◽  
Author(s):  
J. P. Costanzo ◽  
R. E. Lee

Erythrocytes from the freeze-tolerant wood frog (Rana sylvatica) were subjected to in vitro tests of freeze tolerance, cryoprotection, and osmotic fragility. The responses of cells from frogs acclimated to 4 or 15 degrees C were similar. Erythrocytes that were frozen in saline hemolyzed at -4 degrees C or lower. The addition of high concentrations (150 and 1,500 mM) of glucose or glycerol, cryoprotectants produced naturally by freeze-tolerant frogs, significantly reduced cell injury at -8 degrees C, but concentrations of 1.5 or 15 mM were ineffective. Hemolysis was reduced by 94% with 1,500 mM glycerol and by 84% with 1,500 mM glucose; thus glycerol was the more effective cryoprotectant. Mean fragility values for frog erythrocytes incubated in hypertonic and hypotonic saline were 1,938 and 49 mosM, respectively. Survival in freeze tolerance and cryoprotection experiments was comparable for erythrocytes from frogs and humans, suggesting that these cells may respond similarly to freezing-related stresses. However, the breadth of osmotic tolerance, standardized for differences in isotonicity, was greater for frog erythrocytes than for human erythrocytes. Our data suggest that erythrocytes from R. sylvatica are adequately protected by glucose under natural conditions of freezing and thawing.


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