Cadmium toxicity and snail–digenean interactions in a population of Lymnaea spp.

2003 ◽  
Vol 77 (1) ◽  
pp. 49-55 ◽  
Author(s):  
N.J. Morley ◽  
M. Crane ◽  
J.W. Lewis
Keyword(s):  
Metal Toxicity ◽  
Cadmium Toxicity ◽  
Exposure Period ◽  
Diplostomum Spathaceum ◽  
Lymnaea Peregra

AbstractThe toxicity of cadmium to a population of Lymnaea peregra and L. stagnalis naturally infected with a range of digeneans and collected from a number of sites in the lower Thames Valley, UK was investigated. Lymnaeid snails were exposed to 100 μg l-1 cadmium and the effects on host survival and emergence of cercariae recorded. Overwintered L. peregra, but not L. stagnalis, showed significantly reduced survival compared to seasonally infected snails, i.e. snails which have acquired an infection during the spring or summer. A significant increase in survival with increasing snail size was demonstrated for L. stagnalis and for seasonally infected L. peregra only. Only L. stagnalis infected with Diplostomum spathaceum and L. peregra infected individually with D. spathaceum, Sanguinicola inermis, Echinoparyphium recurvatum and Notocotylus attenuatus demonstrated a significantly reduced survival compared to laboratory-bred controls. The exposure of L. stagnalis to cadmium resulted in a significant reduction in the emergence of D. spathaceum over a 5-day period but cadmium-exposed L. peregra showed no difference in the emergence of E. recurvatum cercariae over a 3-day exposure period. The mechanisms and importance of metal toxicity to snail–digenean interactions are discussed.

On Some Larval Trematodes from Lymnaea peregra (Muller) in Scotland

1966 ◽  
Vol 40 (1-2) ◽  
pp. 245-252 ◽  
Author(s):  
Modupé O. Williams
Keyword(s):  
Diplostomum Spathaceum ◽  
Lymnaea Peregra

Out of 550 Lymnaea peregra (Muller) collected from a pond near Glasgow, Scotland, 29% were infected with sporocysts and cercariae of Cotylurus cornutus (Rudolphi, 1809), 0·9% with sporocysts and cercariae of Apatemon gracilis minor (Yamaguti, 1953), 0·18% with sporocysts and cercariae of Diplostomum spathaceum (Rudolphi, 1819), 0·8% with sprocysts and cercariae of Diplostomum gasterostei Williams, 1966, 9·0% with rediae and cercariae of Notocotylus attenuatus (Rudolphi, 1809), 3·6% with rediae and cercariae of Hypoderaeum conoideum (Bloch, 1782), 7·27% with sporocysts and cercariae of Haplometra cylindracea, (Looss, 1899), and 13·6% with metacercariae of Echinoparyphium recurvatum (Linstow, 1873).The pattern of development of Cotylurus cornutus in the duck is described.

Toxicity of cadmium and zinc to the decaudised cercarial life-span of Diplostomum spathaceum (Trematoda: Diplostomidae)

Parasitology ◽  
2003 ◽  
Vol 127 (5) ◽  
pp. 497-506 ◽  
Author(s):  
N. J. MORLEY ◽  
M. CRANE ◽  
J. W. LEWIS
Keyword(s):  
Life Span ◽  
Prolonged Exposure ◽  
Water Hardness ◽  
Exposure Period ◽  
Fish Host ◽  
Metal Exposure ◽  
Experimental Conditions ◽  
Metal Concentrations ◽  
Specific Level ◽  
Diplostomum Spathaceum

The toxicity of cadmium and zinc at concentrations ranging from 0·1 to 10 000 μg/l to the life-span of decaudised cercarial bodies (cercariae that have shed their tails) of Diplostomum spathaceum was investigated. The effects of metal exposure at 3 temperatures (12, 20, and 25 °C) and 3 levels of water hardness (distilled water, soft water and hard water) were studied. In general, under most experimental conditions increasing metal concentrations reduced the life-span of decaudised cercariae. Increasing water hardness and decreasing water temperature caused an increase in the life-span of both control and metal exposed decaudised cercariae. However, at certain isolated metal concentrations, associated with a specific level of water hardness and temperature, increased survival above controls occurred. Differences in the relative toxicity of cadmium and zinc were dependent on the environmental conditions of exposure. The decaudised cercarial life-span under metal exposure was found to be generally independent of the overall cercarial survival and tail loss in most experimental conditions. Prolonged exposure to cadmium and zinc caused changes in the decaudised cercarial life-span when compared to individuals decaudised during the initial 24 h exposure period to those which were decaudised during the final 24 h period of cercarial survival. The validity of studying the decaudised cercarial life-span as an indicator of ‘fitness’ of larvae to migrate through the tissues of the target fish host, in terms of glycogen utilization, was assessed for those cercariae decaudised during the initial 24 h exposure period only. A limited reduction in the decaudised cercarial life-span during this period compared to controls was recorded, which may possibly indicate a reduced penetration ‘fitness’ of cercariae exposed to cadmium and zinc. The importance and relevance of these findings to parasite migration and establishment in the fish host are discussed.

Subcellular Partitioning and the Prediction of Cadmium Toxicity to Aquatic Organisms

2006 ◽  
Vol 3 (6) ◽  
pp. 395 ◽  
Author(s):  
Wen-Xiong Wang ◽  
Philip S. Rainbow
Keyword(s):  
Metal Toxicity ◽  
Cadmium Toxicity ◽  
Quality Criteria ◽  
Aquatic Organisms ◽  
Metal Exposure ◽  
Water Quality Criteria ◽  
Cellular Interactions ◽  
Cd Toxicity ◽  
Free Ion ◽  
Site Of Action

Environmental Context. There is a considerable interest in predicting cadmium (Cd) toxicity to aquatic organisms, largely stemming from environmental Cd pollution and the need to establish water quality criteria to protect aquatic ecosystems. Chemistry-orientated models have been developed over the past decades to predict Cd toxicity, focusing on identifying which Cd forms are present in the aquatic environment, and investigating their interaction with the biological site of action. Understanding the cellular fates of Cd may provide an alternative method to predict Cd toxicity, as the complex cellular interactions of Cd within the organisms can, in this way, be addressed. Abstract. The internal metal sequestration strategies of different aquatic organisms are complex and variable; thus it is a formidable task to predict metal toxicity. Metals accumulated by aquatic organisms are associated with different subcellular compartments (i.e. heat-sensitive proteins, heat-stable proteins (metallothioneins), granules, cellular debris, and organelles). Such subcellular partitioning is dynamic in response to metal exposure and other environmental conditions, and is metal- and organism-specific. Previous models predicting metal toxicity have relied on the free ion metal activity (i.e. the free ion activity model) or more recently on the metal binding with the proposed toxicological site of action (i.e. the biotic ligand model). Neither of these models considers the complexity of internal metal subcellular fractionation, which may significantly affect metal toxicity in aquatic organisms and subsequent trophic transfer of metals to consumers. Recent studies in small aquatic organisms have revealed that the subcellular partitioning model (SPM) may provide an improved method to predict Cd toxicity, but more studies are needed in the future.

Diplostomum spathaceum (Rud. 1819): effect of miracidial age and lifespan on miracidial infectivity

1991 ◽  
Vol 65 (1) ◽  
pp. 28-30 ◽  
Author(s):  
G. D. B. Waadu
Keyword(s):  
Life Span ◽  
Constant Illumination ◽  
Free Swimming ◽  
Diplostomum Spathaceum ◽  
Different Ages ◽  
Lymnaea Peregra ◽  
Effect Of Age

ABSTRACTExperiments were performed to study the effect of age and lifespan on the infection success of Diplostomum spathaceum miracidia. Specimens of Lymnaea peregra and L. stagnalis were individually exposed to single miracidia of D. spathaceum of different ages under conditions of constant illumination at 20°C. The life-span of the free-swimming miracidium of D. spathaceum is 24 h at 20°C. It was observed that as the miracidium ages, its ability to successfully infect snails declines rapidly.

Toxicity of cadmium and zinc mixtures to the decaudized cercarial life span of Diplostomum spathaceum

2005 ◽  
Vol 79 (4) ◽  
pp. 353-359 ◽  
Author(s):  
N.J. Morley ◽  
M. Crane ◽  
J.W. Lewis
Keyword(s):  
Life Span ◽  
Prolonged Exposure ◽  
Exposure Period ◽  
Fish Host ◽  
High Dose ◽  
Metal Mixtures ◽  
Diplostomum Spathaceum ◽  
Low Concentrations ◽  
Metal Treatment ◽  
Pre Treatment

AbstractThe effects of cadmium and zinc mixtures at concentrations ranging from 0.1 to 10,000 μg l−1 on the life-span of decaudized cercarial bodies (cercariae that have shed their tails) of Diplostomum spathaceum (Trematoda: Diplostomatidae) was investigated. Cercariae were exposed to metal mixtures of equal and unequal concentrations, and a low-dose pre-treatment followed by a high-dose exposure mixtures. Metal mixtures demonstrated variable effects on decaudized cercariae either by increasing or reducing their life-span compared to single metal exposures dependent on concentration and the type of mixed metal treatment. Prolonged exposure to equal metal mixtures at low concentrations (0.1–100 μg l−1) resulted in a reduction in the life-span of decaudized cercariae at 0.1 and 100 μg l−1 in those individuals decaudized during the initial 24 h exposure period compared with those decaudized during the final 24 h period of cercarial survival, whilst in controls there was no significant life-span change between the two time periods. Decaudized cercariae which were exposed to low concentrations (0.1–100 μg l−1) of equal metal mixtures were also evaluated for their role as an indicator of larval ‘fitness’ for migrating through the tissues of their target fish host for those individuals decaudized during the initial 24 h exposure period, and demonstrated only a limited change in their life-span compared to control and single metal exposures. The importance of metal mixtures in parasite establishment in the fish host is discussed.

scholarly journals A Rhamnolipid Biosurfactant Reduces Cadmium Toxicity during Naphthalene Biodegradation

2000 ◽  
Vol 66 (10) ◽  
pp. 4585-4588 ◽  
Author(s):  
Todd R. Sandrin ◽  
Andrea M. Chech ◽  
Raina M. Maier
Keyword(s):  
Cell Surface ◽  
Metal Toxicity ◽  
Cadmium Toxicity ◽  
Cadmium Uptake ◽  
Equimolar Concentration ◽  
Reduced Toxicity ◽  
Rhamnolipid Biosurfactant ◽  
Naphthalene Biodegradation

ABSTRACT A model cocontaminated system was developed to determine whether a metal-complexing biosurfactant, rhamnolipid, could reduce metal toxicity to allow enhanced organic biodegradation by aBurkholderia sp. isolated from soil. Rhamnolipid eliminated cadmium toxicity when added at a 10-fold greater concentration than cadmium (890 μM), reduced toxicity when added at an equimolar concentration (89 μM), and had no effect at a 10-fold smaller concentration (8.9 μM). The mechanism by which rhamnolipid reduces metal toxicity may involve a combination of rhamnolipid complexation of cadmium and rhamnolipid interaction with the cell surface to alter cadmium uptake.

Cadmium toxicity and accumulation in eggs and alevins of Atlantic salmon Salmo salar

1982 ◽  
Vol 60 (8) ◽  
pp. 2006-2014 ◽  
Author(s):  
P. J. Rombough ◽  
E. T. Garside
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Cadmium Toxicity ◽  
Exposure Period ◽  
Cadmium Content ◽  
Atlantic Salmon Salmo Salar ◽  
Inhibition Of Growth ◽  
Ambient Concentration ◽  
Yolk Absorption ◽  
Dose Dependent

Embryos and alevins of Atlantic salmon (Salmo salar) were exposed to cadmium concentrations of between 0.47 μg Cd/L and 27 mg Cd/L from fertilization to near complete yolk absorption. The most sensitive indicator of cadmium toxicity was the inhibition of growth in alevins, with significant reduction occurring in 0.47 μg Cd/L. The LC50 for the interval from fertilization to viable hatch was estimated to lie between 300 and 800 μg Cd/L. Newly hatched alevins had a 24-day LC50 of between 1.5 and 2.7 mg Cd/L. Sensitivity increased sharply in late alevins and significant mortality was recorded in concentrations as low as 8.2 μg Cd/L. Cadmium uptake by eggs was rapid, with dose-dependent saturation levels reached within 24 h and maintained until hatch. Although the total cadmium content of eggs increased with ambient concentration, the degree of bioaccumulation declined. The cadmium contents of newly hatched alevins were much lower but directly proportional to those of eggs. Uptake by alevins was logarithmic, independent of ambient concentration above about 1 μg Cd/L, and did not reach equilibrium during the exposure period (46 days).

Effect of water temperature on the ability of Diplostomum spathaceum miracidia to establish in lymnaeid snails

1991 ◽  
Vol 65 (3) ◽  
pp. 179-185 ◽  
Author(s):  
G. D. B. Waadu ◽  
L. H. Chappell
Keyword(s):  
Water Temperature ◽  
Apparent Effect ◽  
Effect Of Water ◽  
Diplostomum Spathaceum ◽  
Different Temperatures ◽  
Lymnaea Peregra

ABSTRACTThe effects of water temperature on the ability of Diplostomum spathaceum miracida to infect and establish patent infections in Lymnaea peregra and L. stagnalis were investigated. Snails were infected over a range of temperatures (6–20°C) and kept thereafter at 20°C or were infected at 20°C and kept at either 14, 20, or 25°C. Infection success was determined after 8 weeks by either observing cercarial shedding or examining snail viscera for sporocysts. The establishment of miracidia declined at lower water temperatures despite maintenance for 8 weeks at 20°C while exposure of snails to miracidia at 20°C and maintenance at different temperatures had little apparent effect. Infection success under these conditions was related more to the numbers of miracidia to which the snails were exposed. However, under this latter experimental regime, the time taken for the infection to become patent clearly depended upon maintenance temperature.

Toxic effects of inhaled DMMP on the kidneys of Fischer-344 rats

1987 ◽  
Vol 45 ◽  
pp. 880-881
Author(s):  
D.R. Mattie ◽  
C.J. Hixson
Keyword(s):  
Left Kidney ◽  
Inhalation Exposure ◽  
Electron Microscopic Examination ◽  
Exposure Period ◽  
Male Rats ◽  
Continuous Exposure ◽  
Fischer 344 Rats ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Fischer 344

Dimethylmethylphosphonate (DMMP) is a simple organophosphate used industrially as a flame retardant and to lower viscosity in polyester and epoxy resins. The military considered the use of DMMP as a nerve gas simulant. Since military use of DMMP involved exposure by inhalation, there was a need for a subchronic inhalation exposure to DMMP to fully investigate its toxic potential.Male Fischer-344 rats were exposed to 25 ppm or 250 ppm DMMP vapor on a continuous basis for 90 days. An equal number of control rats were sham-exposed. Following the 90-day continuous exposure period, 15 male rats were sacrificed from each group. Two rats from each group had the left kidney perfused for electron microscopic examination. The kidneys were perfused from a height of 150 cm water with 1% glutaraldehyde in Sorensen's 0.1M phosphate buffer pH 7.2. An additional kidney was taken from a rat in each group and fixed by immersion in 2.5% glutaraldehyde and 2% paraformaldehyde in 0.1M cacodylate buffer pH 7.4. A portion of the 9 kidneys collected for electron microscopy were processed into Epon 812. Thin sections, stained with uranyl acetate and lead citrate, were examined with a JEOL 100B Transmission Electron Microscope. Microvilli height was measured on photographs of the cells of proximal tubules. This data, along with morphologic features of the cells, allows the proximal convoluted tubules (PCT) to be identified as being S1, S2, or S3 segment PCT.

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