Osmoregulation of Lampetra Fluviatilis L. and Petromyzon Marinus (Cyclostomata) in Hyperosmotic Solutions

1970 ◽  
Vol 53 (1) ◽  
pp. 231-243
Author(s):  
ALAN D. PICKERING ◽  
R. MORRIS
Keyword(s):  
Alimentary Canal ◽  
Sea Water ◽  
Petromyzon Marinus ◽  
Urine Flow ◽  
Sodium Potassium ◽  
Monovalent Ions ◽  
Anadromous Migration ◽  
Calcium Magnesium ◽  
High Concentrations ◽  
Osmoregulatory Mechanism

1. Freshly caught migrating lampreys were placed in 50% sea water and their method of osmoregulation was analysed. Some osmoregulated more successfully than others. 2. Water balance is maintained by a mechanism involving the drinking of large quantities of water (up to 99.5 ml/kg/day). Sodium, potassium and chloride are absorbed by the intestine (often against a concentration gradient) with the subsequent uptake of water. Divalent ions are not readily absorbed by the intestine and there is some evidence for the secretion of magnesium and sulphate into the gut lumen. 3. The limited urine flow (up to 6.2 ml/kg/day) is used for the excretion of calcium, magnesium and sulphate in high concentrations, but the urine is never hyperosmotic to the blood. The urinary excretion of monovalent ions is not sufficient to eliminate those entering by the intestine and extrarenal excretion at the gills must presumably occur. 4. The breakdown of this osmoregulatory mechanism during the anadromous migration involves: an increase in the permeability of the integument to water, breakdown of the swallowing mechanism which is not dependent upon the occlusion of the alimentary canal, a reduction in the ability to absorb monovalent ions and water from the ingested 50% sea water, and a loss in the large mitochondria-rich ‘chloride output cells’ of the gills. 5. The similarities between the mechanisms of ‘marine’ osmoregulation of lampreys and teleosts are discussed in terms of the evolution of the two groups, and it is concluded that almost identical osmoregulatory mechanisms have evolved independently.

scholarly journals The vapour pressure and osmotic equivalence of sea water

1954 ◽  
Vol 33 (2) ◽  
pp. 449-455 ◽  
Author(s):  
R. A. Robinson
Keyword(s):  
Sodium Chloride ◽  
Vapour Pressure ◽  
Chloride Solution ◽  
Sea Water ◽  
Complex Solution ◽  
Sodium Potassium ◽  
Sodium Chloride Solutions ◽  
Pressure Method ◽  
Pressure Lowering ◽  
Calcium Magnesium

Sea water is a complex solution in which the principal ions are sodium, potassium, calcium, magnesium, chloride and sulphate. The vapour pressure (V.P.) of such a solution can be calculated approximately by making the assumption that each salt contributes to the vapour pressure lowering in amount proportional to its concentration, but such a calculation would ignore the interactions between the various ions. The theory of these interactions has been worked out only for very dilute solutions and it is, therefore, better to rely on direct experimental determinations. Measurements have now been made by the isopiestic vapour-pressure method (Robinson & Sinclair, 1934), in which samples of sea water are equilibrated with sodium chloride solutions until they have the same vapour pressure. The results are expressed in terms of chlorinities of sea water and molalities (moles per kilogram of H2O) of sodium chloride solution which have the same vapour pressure. It is hoped that the results will be of use to physiologists who have occasion to make up salt solutions equivalent to sea water.

Studies on Salt and Water Balance in Myxine Glutinosa (L.)

1965 ◽  
Vol 42 (2) ◽  
pp. 359-371
Author(s):  
R. MORRIS
Keyword(s):  
Water Balance ◽  
Sea Water ◽  
External Medium ◽  
Freezing Point ◽  
Freezing Point Depression ◽  
High Concentration ◽  
After Effects ◽  
Monovalent Ions ◽  
Calcium Magnesium ◽  
Salt And Water Balance

1. Measurements of freezing-point depression and chemical analysis have been made of the plasma and urine of Myxine. 2. The plasma is generally slightly hypertonic to sea water whilst the urine tends to be slightly hypotonic to the blood. 3. The urinary output is low (5·4±1·6 ml./kg./day) and the majority of animals do not swallow sea water. 4. Analyses of plasma and urine indicate that the kidney participates in ionic regulation by reducing the concentrations of calcium, magnesium and sulphate in the plasma relative to sea water. Chloride seems to be conserved whilst potassium may be conserved or excreted. The high concentration of magnesium in the plasma of animals kept in static sea water may be caused by the after effects of urethane. These animals continue to excrete magnesium at normal rates. 5. The rates at which calcium, magnesium and sulphate enter an animal which does not swallow sea water are proportional to the diffusion gradients which exist between the external medium and the plasma. The situation is more complicated for monovalent ions, but there is no evidence of specialized ion-transporting cells within the gill epithelium. 6. In those animals which swallow sea water the amounts of ions absorbed from the gut are very large compared with the renal output and it would therefore seem unlikely that swallowing is part of the normal mechanism of salt and water balance. 7. It is argued that the mechanism of salt and water balance in Myxine is likely to be primitive and that the vertebrate glomerulus was probably developed originally in sea water as an ion-regulating device.

scholarly journals The Magnesium and other Inorganic Constituents of some Marine Invertebrates

1933 ◽  
Vol 19 (1) ◽  
pp. 293-296 ◽  
Author(s):  
R. A. McCance ◽  
H. L. Shipp
Keyword(s):  
Marine Invertebrates ◽  
Live Weight ◽  
Full Time ◽  
Sodium Potassium ◽  
Marine Biological Association ◽  
Part Time ◽  
Calcium Magnesium ◽  
The Common ◽  
High Concentrations ◽  
Inorganic Constituents

The sodium, potassium, calcium, magnesium and iron of a number of marine invertebrates have been determined and some of the findings are very briefly discussed.The common winkle Littorina littorea contains 330–510 mg. of magnesium per 100 g. of live weight. All the organs appear to contain these high concentrations. Boiled specimens of whelks contained about 160 mg. of magnesium per 100 g.We should like to thank the Director and Staff of the Laboratory of the Marine Biological Association for their assistance. R. A. McC. has held a part-time grant and H. L. S. a full time grant from the Medical Research Council during this work.

Ion-dependent Viscosity of Holothurian Body Wall and its Implications for the Functional Morphology of Echinoderms

1982 ◽  
Vol 99 (1) ◽  
pp. 1-8
Author(s):  
JOHN P. EYLERS
Keyword(s):  
Sea Water ◽  
Divalent Cations ◽  
Constant Load ◽  
Distilled Water ◽  
Sodium Potassium ◽  
Monovalent Ions ◽  
Cross Links ◽  
Calcium And Magnesium ◽  
Dependent Viscosity ◽  
The Relationship

Dermis from the holothurian Thyone inermis was subjected to constant load and its rate of plastic deformation (creep) was used to calculate tissue viscosity. During these tests the material was bathed in distilled water, sea water, or solutions of sodium, potassium, calcium, and magnesium salts in various combinations. Distilled water caused a threefold increase in viscosity which was reversed by sea water. Sodium and potassium decreased viscosity, while calcium and magnesium in combination with sodium increased it. Ionic cross-links shielded by monovalent ions but facilitated by divalent cations are proposed to explain this behaviour, and the relationship between this and other anomalies of echinoderm connective tissue physiology is discussed.

scholarly journals Intestinal Na+ and Cl- levels control drinking behavior in the seawater-adapted eel Anguilla japonica

1996 ◽  
Vol 199 (3) ◽  
pp. 711-716 ◽  
Author(s):  
M Ando ◽  
K Nagashima
Keyword(s):  
Sea Water ◽  
Direct Action ◽  
Choline Chloride ◽  
Drinking Behavior ◽  
Anguilla Japonica ◽  
Urine Flow ◽  
Perfusion Medium ◽  
Drinking Rate ◽  
Gastrointestinal Fluid ◽  
High Concentrations

To analyze drinking mechanisms in seawater teleosts, seawater-adapted eels were used as a model system. When the intestine of the eel was perfused with iso-osmotic mannitol, the eels drank sea water. However, when the perfusion medium was switched to iso-osmotic NaCl, seawater drinking was depressed. This depression was observed even after blocking NaCl absorption across the intestine by replacement of the perfusate with choline chloride or by treatment with furosemide, an inhibitor of NaCl and water absorption across the eel intestine. Furthermore, depression of drinking rate preceded an increase in urine flow by over 1 h. These results indicate that this depression is not due to a recovery of blood volume and suggest that intestinal Cl- itself inhibits drinking. Direct action of luminal Cl- on drinking behavior was further supported by the observation that perfusion with iso-osmotic NMDG-HCl, Tris-HCl, choline chloride and RbCl all inhibited seawater drinking. When NaCl in the perfusion medium was replaced with sodium acetate, sodium butyrate, sodium methylsulfate or NaSCN, the drinking rate was enhanced threefold, suggesting that Na+ itself stimulates drinking in the absence of Cl-. In the present study, concentrations of Na+ and Cl- in the swallowed fluid were also measured simultaneously. As the drinking rate was enhanced, the Na+ and Cl- concentrations in the gastrointestinal fluid were increased. On the basis of these results, it seems possible that high concentrations of Cl- in the intestine reduce the drinking rate, thus lowering esophageal Cl- concentration due to desalination of the ingested sea water. When Cl- concentration in the intestine falls below a certain level, Na+ will stimulate seawater drinking again.

scholarly journals The Micro-Estimation of Sodium, Potassium, Calcium, Magnesium, Chloride, and Sulphate in Sea Water and the Body Fluids of Marine Animals

1939 ◽  
Vol 16 (2) ◽  
pp. 155-177
Author(s):  
J. D. ROBERTSON ◽  
D. A. WEBB
Keyword(s):  
Magnesium Chloride ◽  
Sea Water ◽  
Barium Chloride ◽  
Uranyl Acetate ◽  
Body Fluids ◽  
The Body ◽  
Marine Animals ◽  
Sodium Potassium ◽  
Calcium Magnesium ◽  
Ceric Sulphate

Methods are presented for the estimation of sodium, potassium, calcium, magnesium, chloride and sulphate in sea water and in other solutions, such as the blood and body fluids of marine animals, whose inorganic composition is similar to that of sea water. The estimations may be performed on 1 ml. samples, and the limit of error is about 2%. Sodium is precipitated and weighed as sodium zinc uranyl acetate; potassium is precipitated as potassium silver cobaltinitrite which is titrated with ceric sulphate; calcium is titrated with ceric sulphate after two precipitations as oxalate; magnesium is precipitated with hydroxyquinoline and the precipitate brominated and estimated iodometrically; chloride is treated with silver iodate and the released iodate estimated iodometrically; sulphate is titrated with barium chloride using sodium rhodizonate as indicator.

scholarly journals Ice and mineral licks used by caribou in winter

Rangifer ◽  
1990 ◽  
Vol 10 (3) ◽  
pp. 203 ◽  
Author(s):  
Douglas C. Heard ◽  
T. Mark Williams
Keyword(s):  
Lake Water ◽  
Mineral Elements ◽  
Sodium Potassium ◽  
Barren Ground ◽  
Winter Diet ◽  
Calcium Magnesium ◽  
Mineral Licks ◽  
High Concentrations ◽  
Phosphorus And Potassium ◽  
Sodium And Potassium

In winter, barren-ground caribou obtain minerals from ice and soil licks. Between December and April we have seen caribou cratering on the surface of frozen lakes and licking the ice. Ice samples from eight licks on four lakes contained concentrations of calcium, magnesium, sodium, potassium, phosphorus, chloride and sulphate many times higher than in the surrounding unlicked ice or than would be expected in lake water. Soil licks being used in March and June had high concentrations of calcium, magnesium, sodium phosphorus and potassium. In winter caribou may be seeking supplements of all of the major mineral elements (calcium, magnesium, sodium and potassium) at ice and soil licks because lichens, their staple winter diet, are low in minerals and may also reduce the absorption of some minerals.

scholarly journals THE COMPOSITION OF FLUIDS AND SERA OF SOME MARINE ANIMALS AND OF THE SEA WATER IN WHICH THEY LIVE

1940 ◽  
Vol 23 (5) ◽  
pp. 575-584 ◽  
Author(s):  
William H. Cole
Keyword(s):  
Concentration Gradient ◽  
Sea Water ◽  
External Medium ◽  
Chloride Ions ◽  
Electrolyte Composition ◽  
Differential Distribution ◽  
Marine Animals ◽  
Sodium Potassium ◽  
Unequal Distribution ◽  
Calcium Magnesium

1. The electrolyte composition, the pH, and freezing points of the fluids of several invertebrates and one primitive chordate are reported. 2. Fluids of the worms, echinoderms, and the clam Venus were isotonic with sea water; fluids of the Arthropoda were hypertonic to sea water. 3. The pH of all fluids was below that of sea water. In the Arthropoda and Myxine less individual variation in pH appeared than in the echinoderms and worms. 4. Ratios of ionic concentrations in the fluid to those in the sea water indicated (1) uniform distribution of ions between the internal and external media for the echinoderms and Venus, (2) differential distribution of potassium and magnesium in the worms; (3) differential distribution of sulfate, magnesium, potassium, and calcium in the Arthropoda; and (4) differential distribution of calcium, magnesium, and sulfate in Myxine. 5. The unequal distribution of ions implies the expenditure of energy against a concentration gradient across the absorbing or excreting membranes, a capacity frequently overlooked in the invertebrates. 6. The sera of the Arthropoda from diluted sea water showed higher concentrations of sodium, potassium, calcium, and chloride ions relative to the respective concentrations in the external medium than in normal sea water, and also showed different orders for those ions. 7. The increase in osmotic pressure of the sera of the animals moving into brackish water is caused by unequal accumulation of sodium, potassium, calcium, and chloride ions. Sulfate and magnesium ionic ratios do not change.

scholarly journals The Inorganic Constitution of Molluscan Blood and Muscle

1947 ◽  
Vol 26 (4) ◽  
pp. 580-589 ◽  
Author(s):  
F. R. Hayes ◽  
D. Pelluet
Keyword(s):  
Inorganic Material ◽  
Sea Water ◽  
The Other ◽  
Sodium Potassium ◽  
Marine Biological Association ◽  
Calcium Magnesium ◽  
Calcium And Magnesium ◽  
Lower Chloride ◽  
Two Phases ◽  
Whole Muscle

Estimations of sodium, potassium, calcium, magnesium, chloride and sulphate have been made on the blood and muscle of marine molluscs and of the freshwater clam, Anodonta.On comparing marine blood with sea water it appears that the cephalopods show a regulatory power (i.e. difference between blood and sea water) with respect to all ions tested except sulphate. The gastropods have a regulatory power for calcium, magnesium and chloride; the pelecypods for calcium and magnesium.Calcium is always higher in blood than in sea water, while magnesium is lower. Chloride, where it differs, is lower.If muscle is considered as two phases, cells and intercellular blood space, then from whole muscle and blood analyses it is possible to calculate the spaces between the cells, which work out at 11 % for pelecypods and 18 % for the other two groups. Further calculation gives the constitution of the cells themselves, leading to the conclusion that, of the ions under consideration, only K is present in the Pelecypoda and Cephalopoda, while the Gastropoda may have some Ca and Mg as well as K.As expected the fresh-water clam contains little inorganic material. In relative proportions its blood is characterized by more calcium and less magnesium and chloride than that of marine forms. In muscle cells potassium dominates but other ions are present as well.This work was carried out at the Laboratory of the Marine Biological Association, Plymouth, in the summers of 1936 and 1937, and at the Oceanographic Institution, Woods Hole, in 1939. It is a pleasure to express our thanks to the Directors and Staffs of these establishments for accommodation,facilities and advice during the progress of the investigation.

Urine composition and kidney tubular function in southern flounder, Paralichthys lethostigma, in sea water

1968 ◽  
Vol 46 (3) ◽  
pp. 439-455 ◽  
Author(s):  
Cleveland P. Hickman Jr.
Keyword(s):  
Sea Water ◽  
Potassium Phosphate ◽  
Secretory Activity ◽  
Urine Flow ◽  
Divalent Ions ◽  
Average Percentage ◽  
Southern Flounder ◽  
Monovalent Ions ◽  
Urine Composition ◽  
Millimolar Concentration

Magnesium, sulfate, and chloride make up approximately 80% of the total millimolar concentration of major electrolytes in the urine of southern flounder in seawater, The remaining major electrolytes present are calcium, sodium, potassium, phosphate, and an unknown anion component. As a rule, more sodium was present when urine flow was very low: phosphate concentration was highly variable but its concentration was not associated with urine flow. Urine composition was independent of the glomerular filtration rate. With one exception, the urine osmolality was substantially less than the millimolar concentration, because of the low activities of the divalent ions present and because some of the urine calcium and phosphate precipitated out of solution. The urine was usually 5–15 mosmoles hypoosmotic to the blood; it occasionally became slightly hyperosmotic to the blood for a brief interval after operative procedures.The average percentage filterabilities of the plasma electrolytes, determined by centrifugal ultrafiltration, were Na, 78.4%; Cl 91.1%; K, 88.0%;Ca, 18.5%; Mg, 54.6%; PO4, 48.7%. Calculation of the quantities of electrolytes filtered, reabsorbed, secreted, and excreted showed that the urine is primarily a product of tubular secretory activity, but that at high filtration rates the absolute quantities of monovalent ions reabsorbed by the tubular epithelium may greatly exceed the quantities of divalent ions secreted. The divalent ion secretory mechanism was found to respond sensitively and specifically to ion loading produced by MgCl2 infusion or exposure to concentrated seawater. The possible location of specific ion reabsorptive and secretory activities and differences in tubular permeability to water is discussed in relation to the known morphology of the kidney.

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