Effect of low pH on sodium regulation in two species of Daphnia

1984 ◽  
Vol 62 (10) ◽  
pp. 1965-1970 ◽  
Author(s):  
Magda Havas ◽  
Thomas C. Hutchinson ◽  
Gene E. Likens
Keyword(s):  
Daphnia Magna ◽  
Hard Water ◽  
Low Ph ◽  
Soft Water ◽  
Sodium Influx ◽  
Daphnia Middendorffiana ◽  
Sodium Loss ◽  
Sodium Regulation

The effect of low pH on sodium-22 influx and outflux of Daphnia magna and Daphnia middendorffiana was assessed. Experiments were conducted in both hard and soft water with experimental pHs ranging from 3.5 to 8.0. In hard water, at and below pH 4.0, there was a net loss of sodium from both species. The rate of sodium loss (outflux) increased significantly, while the rate of uptake (influx) remained constant at pH 4.0 compared with the reference pH 8.0. Only at extremely low pH (pH 3.5) was sodium influx inhibited in hard water. In soft water, D. magna responded quite differently. Sodium influx was inhibited by 23% at pH 5.0 and by 69% at pH 4.5 compared with the control (pH 6.5). Sodium outflux was stimulated to 125% of the control at pH 4.5. The net loss of sodium in soft water was due to both an increase in sodium outflux and a decrease in sodium influx, while in hard water the effect was primarily on sodium outflux. Daphnia magna and D. middendorffiana have problems with sodium regulation below pH 5.5 in soft water and below pH 4.5 in hard water, which indicates that they are considerably more sensitive to low pH in soft water than in hard water.

The Influence of Calcium on the Physiological Responses of the Rainbow Trout, Salmo Gairdneri, to Low Environmental pH

1980 ◽  
Vol 88 (1) ◽  
pp. 109-132
Author(s):  
D. G. McDONALD ◽  
H. HŌBE ◽  
C. M. WOOD
Keyword(s):  
Rainbow Trout ◽  
Calcium Concentration ◽  
Physiological Responses ◽  
Hard Water ◽  
Low Ph ◽  
Soft Water ◽  
Salmo Gairdneri ◽  
Minor Depression ◽  
Regulatory Failure ◽  
A Minor

The physiological responses of 1- to 2-year-old rainbow trout to low pH are dependent on the environmental calcium concentration. Trout, maintained for 5 days in moderately hard water ([Ca2+] = 1·6–2·7 m-equiv/1) at a mean pH of 4·3, developed a major blood acidosis but exhibited only a minor depression in plasma ion levels. In acidified soft water ([Ca2+] = 0·3 m-equiv/1), only a minor acidosis occurred, but plasma ion levels fell and there were substantially greater mortalities. Lethal bioassays performed on fingerling trout over a range of pH levels (3·0–4·8) revealed an important influence of external [Ca2+] on resistance to acid exposure. Terminal physiological measurements on adult fish succumbing to low pH in soft water indicate the singular importance of iono-regulatory failure as the toxic mechanism of action under these circumstances.

Aluminum Bioaccumulation and Toxicity to Daphnia magna in Soft Water at Low pH

1985 ◽  
Vol 42 (11) ◽  
pp. 1741-1748 ◽  
Author(s):  
Magda Havas
Keyword(s):  
Daphnia Magna ◽  
Negative Correlation ◽  
Laboratory Experiments ◽  
Low Ph ◽  
Al Toxicity ◽  
Soft Water ◽  
Consistent Pattern ◽  
Additional Source ◽  
Zooplanktivorous Fish ◽  
Al Content

Aluminum may be either harmful or beneficial to Daphnia magna (Straus) depending on pH and on the Al concentration in the water. My results are based on laboratory experiments conducted at various concentrations of total Al (0.02–1.02 mg/L) in soft water (2.5 and 12.5 mg Ca/L) adjusted from pH 6.5 to 4.5. Maximum Al toxicity and maximum Al bioaccumulation were observed at pH 6.5 (at and above 0.32 mg total Al/L). At lower pHs ([Formula: see text]), H+ was toxic to D. magna. Aluminum (1.02 mg/L) temporarily ameliorated H+ toxicity at pH 4.5. Calcium reduced H+ toxicity at pH 5.0 and Al toxicity at pH 6.5. Mortality in the presence of Al and also at low pH was associated with a net loss of Na and Cl from the daphnids. The Ca content of the daphnids was highly variable and showed no consistent pattern apart from a negative correlation with the Al content of the daphnids at pH 5.0 and 5.5. The 24-h bioconcentration ratio for Al was 10 000 at pH 6.5,4000 at pH 5.0, and negligible at pH 4.5. The rapid uptake of Al, particularly at circumneutral pHs, may be an additional source of Al for zooplanktivorous fish and other predators.

Sodium Regulation in the Freshwater Mollusc Limnaea Stagnalis (L.) (Gastropoda: Pulmonata)

1970 ◽  
Vol 53 (1) ◽  
pp. 147-163 ◽  
Author(s):  
PETER GREENAWAY
Keyword(s):  
Blood Volume ◽  
Tap Water ◽  
Sodium Concentration ◽  
Sodium Balance ◽  
Uptake Mechanism ◽  
Sodium Influx ◽  
Sodium Uptake ◽  
Limnaea Stagnalis ◽  
Total Body ◽  
Sodium Regulation

1. Sodium regulation in normal, sodium-depleted and blood-depleted snails has been investigated. 2. Limnaea stagnalis has a sodium uptake mechanism with a high affinity for sodium ions, near maximum influx occurring in external sodium concentrations of 1.5-2 mM-Na/l and half maximum influx at 0.25 mM-Na/l. 3. L. stagnalis can maintain sodium balance in media containing 0.025 mM-Na/l. Adaptation to this concentration is achieved mainly by an increased rate of sodium uptake and a fall of 37 % in blood sodium concentration, but also by a reduction of the sodium loss rate and a decrease in blood volume. 4. A loss of 23% of total body sodium is necessary to stimulate increased sodium uptake. This loss causes near maximal stimulation of the sodium uptake mechanism. 5. An experimentally induced reduction of blood volume in L. stagnalis increases sodium uptake to three times the normal level. 6. About 40% of sodium influx from artificial tap water containing 0.35 mM-Na/l into normal snails is due to an exchange component. Similar exchange components of sodium influx were also observed in sodium-depleted and blood-depleted snails in the same external sodium concentration.

Studies on Freshwater Osmoregulation in the Ammocoete larva of Lampetra Planeri (Bloch)

1968 ◽  
Vol 48 (3) ◽  
pp. 597-609
Author(s):  
R. MORRIS ◽  
J. M. BULL
Keyword(s):  
Low Temperature ◽  
Extracellular Space ◽  
Ringer Solution ◽  
Temperature Treatment ◽  
Sodium Influx ◽  
Sodium Chloride Solutions ◽  
Low Temperature Treatment ◽  
Lampetra Planeri ◽  
Equilibrium Concentrations ◽  
Sodium Loss

1. An investigation has been made of the factors which cause sodium loss from ammocoetes when they are immersed in de-ionized water at 1° and 10° C. 2. Sodium influx ceases when animals are first immersed in de-ionized water, but can recommence when the animal loses sufficient sodium to the environment. The concentration of sodium required for influx to take place decreases with succeeding periods of immersion in de-ionized water at 10° C. and reaches minimum equilibrium concentrations as low as 0.005 mM-Na/l. 3. Low temperature inhibits sodium influx and thus promotes net loss of sodium to de-ionized water. 4. Low temperature also decreases the initial loss of sodium to de-ionized water and probably lowers the permeability of the external surfaces of the animal to ions. This effect is small compared with the inhibition of ion uptake so that the combined result is to increase the net loss of sodium from the animal. 5. Since animals lose calcium to de-ionized water and show a decreased rate of sodium loss when calcium salts are added, it is believed that the high rates of sodium loss in de-ionized water are attributable to the effect of calcium on permeability. 6. Lack of calcium may also explain why animals which have been depleted of sodium by low-temperature treatment take up sodium much faster at higher temperatures from dilute Ringer solutions than from pure sodium chloride solutions. 7. When animals lose ions to de-ionized water at low temperature, sodium and chloride are lost from the extracellular space, whilst the muscle cells lose potassium. These ions are recovered into the extracellular space when animals are allowed to take up ions at 10° C. from diluted Ringer solution later.

Sodium Regulation in the Amphipod Gammarus Duebeni Lilljeborg form Freshwater Localities in Ireland

1968 ◽  
Vol 48 (2) ◽  
pp. 339-358
Author(s):  
D. W. SUTCLIFFE ◽  
J. SHAW
Keyword(s):  
Fresh Water ◽  
Loss Rate ◽  
Sea Water ◽  
Detailed Comparison ◽  
Urine Concentration ◽  
Sodium Influx ◽  
Fresh Waters ◽  
Low Sodium ◽  
Characteristic Features ◽  
Sodium Regulation

1. A quantitative study of sodium influx and loss was made on populations of Gammarus duebeni obtained from four freshwater localities in Ireland. 2. Characteristic features of sodium regulation in animals from the four localities were as follows, (a) The sodium influx increases gradually with increasing external sodium concentrations, but a maximum (saturation) level is abruptly reached at an external concentration of 1-2 mM/l. and the transporting system is half saturated at about 0.5 mM/l. sodium, (b) Over the range of sodium concentrations found in fresh waters a low rate of sodium uptake is sufficient to balance sodium losses at concentrations down to between 0.5 and 0.25 mM/l. At lower concentrations the influx is increased and the loss rate is reduced. (c) Calculations suggest that hypotonic urine containing approximately 40 mM/l sodium is produced at external concentrations ranging from fresh water to 40 % sea water. At external concentrations below 0.25 mM/l. sodium the urine concentration is probably reduced to well below 40 mM/l. sodium. 3. A detailed comparison is made of sodium regulation at external concentrations ranging between 0.07 and 1 mM/l. sodium in G. duebeni from fresh water in Ireland and from fresh water and brackish water in Britain. It is suggested that G. duebeni in Ireland constitutes a distinct physiological race adapted for living in fresh waters with relatively low sodium concentrations.

Effects of environmental pH on the ionic composition of the white sucker (Catostomus commersoni) and pumpkinseed (Lepomis gibbosus)

1984 ◽  
Vol 62 (2) ◽  
pp. 249-259 ◽  
Author(s):  
Grant A. Fraser ◽  
Harold H. Harvey
Keyword(s):  
Ionic Composition ◽  
Hard Water ◽  
Soft Water ◽  
Whole Body ◽  
Lepomis Gibbosus ◽  
White Sucker ◽  
Catostomus Commersoni ◽  
Handling Stress ◽  
Plasma Ions ◽  
Acid Tolerant

White sucker (Catostomus commersoni) exposed to soft water ([Ca2+] = 0.207 mequiv./L) below pH 5 showed [Na+] and [Cl−] losses, that were approximately the same in plasma and whole body. At pH 4.5 (6- to 19-day exposure), body and plasma [Na+] were approximately 17% lower than in white sucker held at pH 6.6, and 42% lower in fish at pH 4 (<2 days). Since plasma ions are known to be affected by handling stress, whole-body [Na+] and [Cl−] in fishes may be a more useful indicator of ionoregulation status under field conditions. Pumpkinseed (Lepomis gibbosus) were clearly more acid tolerant, as indicated by greater survival and reduced ion loss in the same acid environments as white sucker. After 19 days exposure at pH 4.5, body Na+ was reduced by 8%; at pH 4 body Na+ was reduced by 38%. Hence, at pH 4, the net Na+ loss experienced by this acid-tolerant fish was similar to that observed in white sucker; however, the rate of loss in white sucker was 11-fold greater. White sucker in acidified, decarbonated hard water ([Ca2+] = 2.110 mequiv./L) at pH 4 (6 or 19 days), showed a 35% lower whole-body [Na+] than in fish held at pH levels of 4.5, 5, and 6.3; [Cl−] was 39% less. However, at pH 4 the ratio of whole-body Na+:Cl− losses was 1.4:1 in hard water and 1.08:1 in soft water. Total Na+ loss at pH 4 was similar to that in white sucker held at the same pH in soft water; however, the rate of loss in soft water was 15-fold greater.

Can natural levels of Al influence Cu speciation and toxicity to Daphnia magna in a Swedish soft water lake?

Chemosphere ◽  
2015 ◽  
Vol 138 ◽  
pp. 205-210 ◽  
Author(s):  
S. Hoppe ◽  
J.-P. Gustafsson ◽  
H. Borg ◽  
M. Breitholtz
Keyword(s):  
Daphnia Magna ◽  
Soft Water ◽  
Water Lake ◽  
Soft Water Lake
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