The Adaptation of Gunda Ulvae to Salinity

1931 ◽  
Vol 8 (1) ◽  
pp. 82-94
Author(s):  
C. F. A. PANTIN
Keyword(s):  
Osmotic Pressure ◽  
Electric Conductivity ◽  
Fresh Water ◽  
Salt Concentration ◽  
Sea Water ◽  
Distilled Water ◽  
Dilute Solution ◽  
Dilute Solutions ◽  
The Moment ◽  
Limiting Value

1. The rate of loss of salts by the estuarine worm, Gunda ulvae, on transference from sea water to various dilute solutions has been studied by measurement of the electric conductivity of the solutions. 2. Salts are lost by the worms from the moment of immersion in dilute solutions. Conditions affecting the rate of loss of salts are discussed. 3. The relation between the amount of salts lost and the total electrolyte content of the worm was determined. It is shown that the worms only lose 25 per cent. of their salts during the time that they imbibe a volume of water from the dilute solution equal to their initial volume. 4. The limiting internal salt concentration of worms surviving in waters containing calcium is about 6-10 per cent. of the normal concentration in sea water. No such limiting value can be found for distilled water, since salts are lost continuously till cytolysis occurs. The significance of the limiting concentration is discussed. 5. The effect of osmotic pressure, pH, dilute solutions of NaCl, NaHCO3, glycerol, CaCl2 and CaCO3 are studied. The presence of calcium reduces the rate of loss of salts. Other factors do not seem to influence this rate. 6. The relation of calcium to the maintenance of normal permeability to water and salts in the worm, and the significance of this to the problem of migration into fresh water are discussed.

scholarly journals THE EFFECT OF SALT CONCENTRATION OF THE MEDIUM ON THE RATE OF OSMOSIS OF WATER THROUGH THE MEMBRANE OF LIVING CELLS

1927 ◽  
Vol 10 (5) ◽  
pp. 665-670 ◽  
Author(s):  
Baldwin Lucke ◽  
Morton McCutcheon
Keyword(s):  
Cell Membrane ◽  
Diffusion Process ◽  
Osmotic Pressure ◽  
Salt Concentration ◽  
Sea Water ◽  
Living Cells ◽  
Water Medium ◽  
Distilled Water ◽  
Velocity Constant ◽  
Sigmoid Curve

1. Using the unfertilized egg of the sea urchin, Arbacia, as osmometer, it was found that the rate with which water enters or leaves the cell depends on the osmotic pressure of the medium: the velocity constant of the diffusion process is higher when the cell is in concentrated sea water, and lower when the sea water medium is diluted with distilled water. Differences of more than tenfold in the value of the velocity constant were obtained in this way. When velocity constants are plotted against concentration of medium, a sigmoid curve is obtained. 2. These results are believed to indicate that cells are more permeable to water when the osmotic pressure of the medium is high than when it is low. This relation would be accounted for if water should diffuse through pores in a partially hydrated gel, constituting the cell membrane. In a medium of high osmotic pressure, the gel is conceived to give up water, to shrink, and therefore to allow widening of its pores with more ready diffusion of water through them. Conversely, in solutions of lower osmotic pressure, the gel would take up water and its pores become narrow.

Taste by Touch: Some Experiments with Octopus

1963 ◽  
Vol 40 (1) ◽  
pp. 187-193
Author(s):  
M. J. WELLS
Keyword(s):  
Hydrochloric Acid ◽  
Fresh Water ◽  
Sea Water ◽  
Olfactory Organ ◽  
Distilled Water ◽  
Quinine Sulphate ◽  
Human Tongue ◽  
Half Strength

1. A method of teaching Octopus chemotactile discriminations is described. 2. The animals can be shown to be capable of distinguishing by touch between porous objects soaked in plain sea water and sea water with hydrochloric acid, sucrose or quinine sulphate added. 3. They can detect these substances in concentrations at least 100 times as dilute as the human tongue is capable of detecting them in distilled water. 4. They can be trained to distinguish between equimolar (0.2 mM) solutions of hydrochloric acid, sucrose and quinine. 5. They can also be trained to distinguish between sea water and fresh water or half-strength sea water or sea water with twice the usual quantity of salt. 6. The function of the ‘olfactory organ’ is discussed. 7. Chemotactile learning is discussed in relation to the means by which Octopus finds its way about the territory around its ‘home’

scholarly journals The Estimation of Zinc in Sea Water using Sodium Diethyldithiocarbamate

1936 ◽  
Vol 20 (3) ◽  
pp. 625-625 ◽  
Author(s):  
W. R. G. Atkins
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Sodium Diethyldithiocarbamate ◽  
Distilled Water ◽  
English Channel ◽  
Metallic Surfaces ◽  
The Earth

Sea water contains very little zinc. Values from 0–73 mg. per cubic metre have been cited in Physics of the Earth, V, 180, Washington, 1932. According to Orton it is less than 0–1 parts per million in the English Channel. Dieulafait found 2 nig. and Bodansky 7–3, erroneously quoted as 73 above. The method described here permits of the detection of as little as 8 mg. per m3 using 200 ml. of distilled water in a Hehner tube, the delicacy of the reaction being much greater than that of any other for zinc. Sea water from the English Channel gives no turbidity and so is unlikely to contain as much as 8 mg. per m3. The method is brought forward on account of its usefulness in detecting and estimating zinc in sea water contaminated by contact with metallic surfaces. Its use in fresh water has already been described (Analyst, 1935, 60, p. 400, No. 711, June), and to this paper reference may be made for some possible sources of interference and for the origin of the reagent.

The Osmoregulatory Ability of the Lampern (Lampetra Fluviatilis L.) In Sea Water During the Course of its Spawning Migration

1956 ◽  
Vol 33 (1) ◽  
pp. 235-248
Author(s):  
R. MORRIS
Keyword(s):  
Weight Loss ◽  
Osmotic Pressure ◽  
Fresh Water ◽  
Water Loss ◽  
Sea Water ◽  
Water Concentration ◽  
Rate Of Change ◽  
Plasma Chloride ◽  
Osmoregulatory Ability ◽  
Better Than

1. Although fresh-run lamperns are able to withstand the effects of increasing sea-water concentration better than maturing animals, they can only maintain their plasma chloride constant in environments more dilute than 50% sea water. This is achieved, in part, by gradually reducing the urine output from the normal fresh-water level (155.8 ml./kg./day) to a negligible rate in solutions which are mildly hypertonic to the blood (33% sea water). 2. Studies on the rate of change of weight loss, of plasma chloride and of plasma osmotic pressure following abrupt immersion in dilute sea water show that mature lamperns cannot osmoregulate and can only survive in 33% sea water by tolerating a raised blood osmotic pressure caused by water loss. 3. Similar experiments on fresh-run animals suggest that the external surfaces of their bodies are less permeable to water than mature animals. Unlike mature animals, they also show considerable variation in the way in which they respond to 33% sea water. Some are able to maintain their plasma osmotic pressure and chloride well below that of the environment. These animals also show little loss in weight, and this indicates that water is taken up actively, since this process has been shown to occur in some animals. Other fresh-run animals show raised plasma osmotic pressures in varying degrees and these are associated with larger losses of weight. These facts suggest that the hypotonic regulating mechanism gradually degenerates as the lampern enters fresh water.

Hibernation and Osmoregulation in the Diamondback Terrapin Malaclemys Centrata Centrata (Latreille)

1973 ◽  
Vol 59 (1) ◽  
pp. 45-51
Author(s):  
M. GILLES-BAILLIEN
Keyword(s):  
Osmotic Stress ◽  
Blood Plasma ◽  
Osmotic Pressure ◽  
Fresh Water ◽  
Seasonal Variations ◽  
Sea Water ◽  
Tap Water ◽  
The Other ◽  
Diamondback Terrapin ◽  
Diamondback Terrapins

1. Two batches of diamondback terrapins have been kept for a whole year, one in sea water the other in tap water, and seasonal variations have been recorded in the composition and osmotic pressure of the blood plasma. 2. All year round the sea-water animals have a higher osmotic pressure and higher concentrations of Na, K, Cl and urea than fresh-water animals. It is in July, however, that these differences are the least marked. 3. The seasonal variations recorded are linked in particular to the conditions of osmotic stress imposed by the environment. 4. The results are discussed within the framework of hibernation and of the evolution among chelonians from fresh water to sea water.

The Adaptation of Gunda Ulvae to Salinity

1931 ◽  
Vol 8 (1) ◽  
pp. 73-81
Author(s):  
E. WEIL ◽  
C. F. A. PANTIN
Keyword(s):  
Mode Of Action ◽  
Water Exchange ◽  
Sea Water ◽  
Stream Water ◽  
Tap Water ◽  
Distilled Water ◽  
Dilute Solutions ◽  
Permeable Membrane ◽  
Fresh Waters ◽  
Beneficial Effects

1. The effect of fresh waters and dilute solutions on the behaviour and water exchange of the estuarine flatworm, Gunda ulvae, has been studied. 2. In Plymouth tap water which contains little dissolved substances the majority of the worms die within 48 hours. While immersed in this water the worms swell rapidly during the first hour to about double their volume in sea water, the volume falling slightly after this. The effect is reversible. 3. In dilute sea water the worms swell to a greater extent the greater the dilution. At great dilutions the swelling is much less than would be expected if the worm behaved as though it were covered with a perfectly semi-permeable membrane. 4. In water from the stream which normally flows over the Gunda at low tide the swelling of the worms is much less than in Plymouth tap water or in distilled water. This stream-water is rich in CaCO3. 5. The effects of distilled water and of solutions of NaCl, NaHCO3, glycerol, CaCl2 and of Cambridge tap water are compared with the effects of Plymouth tap water and the stream water. It is found that the beneficial effects of the stream water can be imitated only by the solutions containing calcium. 6. The mode of action of calcium is discussed. It is suggested that it acts primarily by lowering the permeability of the worms to water.

scholarly journals The osmotic changes in some marine animals

1931 ◽  
Vol 107 (754) ◽  
pp. 606-624 ◽  
Keyword(s):  
Osmotic Pressure ◽  
Fresh Water ◽  
Marine Invertebrates ◽  
Sea Water ◽  
Body Fluids ◽  
The Body ◽  
Marine Animals

Since Bottazzi's (1897) first determinations of the osmotic pressure of the body fluids of various marine animals many researches have been performed by other authors, particularly in reference to the permeability of the membranes separating the body from its surroundings. Bottazzi (1897, 1906, 1908, b) investigated individuals belonging to very different groups of animals, and found that the osmotic pressure of the body fluids of marine invertebrates, and of elasmobranchs, is very similar to that of the surroundings, while the osmotic pressure of the blood of teleosts is quite different. Changing the osmotic pressure of the medium, the osmotic pressure of most marine invertebrates, and of elasmobranchs, was shown to change in the same direction (L. Fredericq, 1882, 1904; Quinton, 1897; Dakin, 1908) and to reach, finally, the value of the former. The blood of teleosts is much more independent of the medium, for it shown to change only about 30 percent, in concentration, on transferring the animals from sea water to fresh water or vice versa (Dakin, 1908; Dekhuyzen, 1904: Sumner, 1905); other authors, however (fredericq, 1904: Garrey, 1905) could not field even these variations.

Infra-red spectra of muscle

1952 ◽  
Vol 139 (897) ◽  
pp. 526-527 ◽  
Keyword(s):  
Water Balance ◽  
Osmotic Pressure ◽  
Sea Water ◽  
Urine Volume ◽  
The Body ◽  
Fluid Distribution ◽  
Common Mechanism ◽  
Distilled Water ◽  
Body Protein ◽  
The Third

Three rations, 350 ml. distilled water, 250 ml. distilled water plus 96·5 g carbohydrate, and 350 ml. distilled water plus 150 ml. sea water, were given daily for 3-day periods to six subjects receiving no other food or drink. The experiment was fully ‘crossed-over' and was carried out in a constant environment. On the carbohydrate ration the water balance over the third day of exposure was about 200 ml. better than on the ration consisting of water only, and the rise in the total osmotic pressure of the body was smaller. The improvement in water balance was the result of a reduction in urine volume, which was in turn due to the effects of carbohydrate upon meta­bolism. These effects were (1) the sparing of body protein, (2) the prevention of ketosis and (3) a reduction of the basal metabolic rate. It is suggested that all three may have been brought about by a common mechanism. On the sea-water ration the water balance for the third day was improved by 80 to 150 ml., but the rise in the osmotic pressure of the body was greater than when distilled water alone was given. These effects were due to the retention of most of the water of the sea water, together with the salt which it contained. It is suggested that the effects of sea-water drinking on body tonicity and fluid distribution are deleterious, and that the gain of water observed on the third day would eventually have been replaced by a loss.

scholarly journals TRANSPORT OF WATER FROM CONCENTRATED TO DILUTE SOLUTIONS IN CELLS OF NITELLA

1949 ◽  
Vol 32 (4) ◽  
pp. 559-566 ◽  
Author(s):  
W. J. V. Osterhout
Keyword(s):  
Osmotic Pressure ◽  
Living Cells ◽  
The Other ◽  
Fundamental Importance ◽  
Dilute Solution ◽  
Cell Water ◽  
Dilute Solutions ◽  
The Difference ◽  
In Cells

The transport of water from concentrated to dilute solutions which occurs in the kidney and in a variety of living cells presents a problem of fundamental importance. If the cell acts as an osmometer we may expect to bring about such transport by creating an inwardly directed osmotic drive which is higher in one part of the cell than in other regions of the same cell. The osmotic drive is defined as the difference between internal and external osmotic pressure. Experiments with Nitella show that this expectation is justified. If water is placed at one end of the cell (A) and 0.4 M sucrose with an osmotic pressure of 11.2 atmospheres at the other end (B) water enters at A, passes along inside the cell, and escapes at B leaving behind at B the solutes which cannot pass out through the protoplasm. Hence the internal osmotic pressure becomes much higher at B than at A. When 0.4 M sucrose at B is replaced by 0.3 M sucrose with an osmotic pressure of 8.1 atmospheres we find that water enters at B, passes along inside the cell, and escapes at A so that water is transported from a concentrated to a dilute solution although the difference in osmotic pressure of the 2 solutions is more than 8 atmospheres. The solution at B thus becomes more concentrated. It is evident that if metabolism produces a higher osmotic pressure and consequently a higher inwardly directed osmotic drive in one region of the cell as compared with other parts of the same cell water may be transferred from a concentrated to a dilute solution so that the former solution becomes still more concentrated.

The salt route through time and space: Following horizontal and lateral intrusion of brackish surface water into a natural floating root mat and its plant community.

2021 ◽  
Author(s):  
Milou Huizinga ◽  
Rien Aerts ◽  
Richard S.P. van Logtestijn ◽  
Sjoerd E.A.T.M. van der Zee ◽  
Jan-Philip M. Witte
Keyword(s):  
Surface Water ◽  
The Netherlands ◽  
Fresh Water ◽  
Plant Community ◽  
Salt Concentration ◽  
Sea Water ◽  
Root Zone ◽  
Salt Water ◽  
Soil Layer ◽  
Water Concentration

<p>Salinizing surface water is a large problem worldwide. In many areas agriculture is dependent on surface water irrigation, but there is an increasing fresh water scarcity. Due to natural and anthropogenic processes the salt concentration of surface water has risen and this problem is predicted to increase in the future. Prioritizing on when fresh water is needed and when brackish or salt water could be possible is therefor necessary. However, this holds not only for agricultural systems, but also for natural areas which are currently overlooked. In deltaic areas – such as The Netherlands – sea water is flowing further inland via rivers during summer. In addition to this, in the hinterland, artificial drainage of low-lying polders leads to a salt groundwater surplus that is discharged into rivers and surface water reservoirs. These processes lead to salinization and could potentially affect plant biodiversity and ecosystem functioning in surface water fed ecosystems, wetlands, and riparian zones. One of such a surface water fed ecosystems is an abandoned turf extraction site ‘De Botshol’ in The Netherlands. Floating root mats have developed from peat baulks into the open water of old turf ponds. These mats can harbor a great deal of protected terrestrial, typically glycophyte (i.e. optimally encountering < 300 mg Cl.l-1), plant species related to a floating fen habitat. Currently the surface water quality of Botshol is brackish and this provided us with an opportunity to follow the local salt route through space and time. Surface water salt concentrations fluctuated slightly between winter-spring: 1400 mg Cl.l-1 and summer-autumn: 1900 mg Cl.l-1 and we linked this to root zone processes and the plant community. We used a pore water extraction setup using micro- and macrorhizons placed at 30 – 60 – 200 cm from the edge of a floating root mat. Along this transect we measured at 10 – 25 – 50 – 70 cm depth. Via this setup we were able to find that the root zone salt concentrations fluctuated with surface water concentration, however there was a substantially lower salt concentration in the soil layer. Root zone concentrations still reached above 500 mg Cl.l-1 and this might explain differences in community composition in comparison with a fresh floating fen ecosystem (e.g. ‘Nieuwkoopse Plassen’, The Netherlands). We present this work to empirically link hydrology and ecology in relation to surface water salinization, but also to practically inform water boards and nature managers to understand possibilities and limitations of surface water salinization in relation to fen restoration and protection.</p>

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