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 Salt and Water Balance in the East African Fresh-Water Crab, Potamon Niloticus (M. Edw.)

1959 ◽  
Vol 36 (1) ◽  
pp. 157-176 ◽  
Author(s):  
J. SHAW
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Sea Water ◽  
Freezing Point ◽  
Salt Content ◽  
The Body ◽  
Sodium Balance ◽  
East African ◽  
Sodium Loss ◽  
Salt And Water Balance

1. The mechanisms of salt and water balance in the East African fresh-water crab, Potamon niloticus, have been investigated. 2. The freezing-point depression of the blood is equivalent to that of a 271 mM./l. NaCl solution. 3. The animals cannot survive in solutions more concentrated than 75% sea water. Above the normal blood concentration, the blood osmotic pressure follows that of the medium. 4. The urine is iso-osmotic with the blood and is produced at a very slow rate. The potassium content is only half that of the blood. 5. The animal loses sodium at a rate of 8 µM./10 g./hr. mainly through the body surface. Potassium loss occurs at one-sixteenth of this rate. 6. Sodium balance can be maintained at a minimum external concentration of 0.05 mM./l. Potassium requires a concentration of 0.07 mM./l. 7. Active absorption of both sodium and potassium occurs. The rate of uptake of sodium depends on the extent of previous sodium loss. The rate of sodium uptake may be affected by such environmental factors as the salt content of the water, temperature and oxygen tension. 8. The normal oxygen consumption rate is 0.72 mg./10 g./hr. A minimum of 2.3% is used in doing osmotic work to maintain salt balance. 9. The salt and water balance in Potamon is discussed in relation to the adaptation of the Crustacea to fresh water. The importance of permeability changes is stressed.

Distribution of dry matter between the tissues and coelom in Arenicola marina (L.) equilibrated to diluted sea water

1977 ◽  
Vol 57 (1) ◽  
pp. 97-107 ◽  
Author(s):  
R. F. H. Freeman ◽  
T. J. Shuttleworth
Keyword(s):  
Water Balance ◽  
Water Content ◽  
Dry Matter ◽  
Sea Water ◽  
External Medium ◽  
Comprehensive Review ◽  
Arenicola Marina ◽  
Wide Range ◽  
Salt And Water Balance

The observations of Schlieper (1929) established the lugworm Arenicola marina (L.) as an osmoconformer which remains virtually isosmotic with the external medium over a wide range of salinities. In a recent comprehensive review of salt and water balance in lugworms, Oglesby (1973) describes ‘the extensive swelling associated with transfer of lugworms to lower salinities’, and ‘when maintained in salinities lower than about 50% s.w. in the laboratory, lugworms are rendered incapable of such vital physiological activities as burrowing and burrow ventilation’. Under these conditions, lugworms exhibit little or no ability to regulate their volume or water content.

The ice nucleating ability of macromolecules in immersion freezing decreases in the presence of salts: Implications for freezing point depression calculations

2021 ◽  
Author(s):  
Jon F. Went ◽  
Jeanette D. Wheeler ◽  
François J. Peaudecerf ◽  
Nadine Borduas-Dedekind
Keyword(s):  
Sea Water ◽  
Freezing Point ◽  
Pure Water ◽  
Salt Content ◽  
Mixed Phase ◽  
Cloud Formation ◽  
Sea Spray ◽  
Freezing Point Depression ◽  
Immersion Freezing ◽  
Mixed Phase Clouds

<p>Cloud formation represents a large uncertainty in current climate predictions. In particular, ice in mixed-phase clouds requires the presence of ice nucleating particles (INPs) or ice nucleating macromolecules (INMs). An influential population of INPs has been proposed to be organic sea spray aerosols in otherwise pristine ocean air. However, the interactions between INMs present in sea water and their freezing behavior under atmospheric immersion freezing conditions warrants further research to constrain the role of sea spray aerosols on cloud formation. Indeed, salt is known to lower the freezing temperature of water, through a process called freezing point depression (FPD). Yet, current FPD corrections are solely based on the salt content and assume that the INMs’ ice nucleation abilities are identical with and without salt. Thus, we measured the effect of salt content on the ice nucleating ability of INMs, known to be associated with marine phytoplankton, in immersion freezing experiments in the Freezing Ice Nuclei Counter (FINC) (Miller et al., AMTD, 2020). We measured eight INMs, namely taurine, isethionate, xylose, mannitol, dextran, laminarin, and xanthan as INMs in pure water at temperatures relevant for mixed-phase clouds (e.g. 50% activated fraction at temperatures above –23 °C at 10 mM concentration). Subsequently, INMs were analyzed in artificial sea water containing 36 g salt L<sup>-1</sup>. Most INMs, except laminarin and xanthan, showed a loss of ice activity in artificial sea water compared to pure water, even after FPD correction. Based on our results, we hypothesize sea salt has an inhibitory effect on the ice activity of INMs. This effect influences our understanding of how INMs nucleate ice as well as challenges our use of FPD correction and subsequent extrapolation to ice activity under mixed-phase cloud conditions.</p>

The Water Balance of a Serpulid Polychaete, Mercierella Enigmatica (Fauvel)

1974 ◽  
Vol 60 (2) ◽  
pp. 321-330
Author(s):  
HELEN LE B. SKAER
Keyword(s):  
Body Weight ◽  
Water Balance ◽  
Blood Volume ◽  
Blood Concentration ◽  
Volume Regulation ◽  
Sea Water ◽  
External Medium ◽  
Wide Range ◽  
Natural Range ◽  
Passive Movements

1. The serpulid polychaete Mercierella enigmatica is found naturally in a wide range of salinities - from fresh water to 150% sea water (< 1-55‰ < 25.8-1421 mOsm). 2. Changes in body weight, blood volume and blood osmolality have been measured both during and after equilibration of animals with media of altered salinity. 3. The blood remains similar in osmolality to the external medium over a very wide range of salinity (43-1620 mOsm); osmoregulation occurs only at the lowest limit of the natural range. 4. Mercierella enigmatica shows volume regulation; after 4 days of equilibration with a medium of altered salinity the blood volume shows much less change than the blood concentration. 5. During equilibration there appear to be passive movements of both water and salts between the animals and their environment.

Salt and Water Balance in Salmon Smolts

1970 ◽  
Vol 52 (3) ◽  
pp. 553-564
Author(s):  
W. T. W. POTTS ◽  
MARGARET A. FOSTER ◽  
J. W. STATHER
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Sodium Pump ◽  
Sea Water ◽  
High Rate ◽  
Exchange Diffusion ◽  
Rapid Changes ◽  
Alternative Hypotheses ◽  
Salt And Water Balance

1. Salmon smolts adapted to sea water maintain a high rate of turnover of both sodium and chloride, but when adapted to fresh water the rate of turnover is low. 2. Only a small part of the influx takes place through the gut. 3. On immediate transfer from sea water to dilute sea water or to fresh water the influxes decline rapidly, but on transfer from fresh water to sea water the restoration of the fluxes takes place slowly. 4. The alternative hypotheses that the rapid changes are due to exchange diffusion or to rapid adjustments of the sodium pump are discussed.

Salt and Water Balance of the Spiny Lobster, Panulirus Argus: The Role of the Antennal Glands

1977 ◽  
Vol 70 (1) ◽  
pp. 221-230
Author(s):  
D. F. MALLEY
Keyword(s):  
Water Balance ◽  
Sea Water ◽  
Spiny Lobster ◽  
Water Levels ◽  
Panulirus Argus ◽  
Antennal Glands ◽  
Salt And Water Balance

1. Panulirus argus in full sea water differs from most other marine isosmotic decapods by regulating Cl− levels in the haemolymph slightly below those in sea water and by having haemolymph K+ levels similar to those in sea water. The species is typical in regulating haemolymph Na+ and Ca2+ above, and Mg2+ and SO42- below, sea-water levels of these ions. Its haemolymph Mg2+ and SO42- concentrations are amongst the lowest reported in marine decapods. 2. The antennal glands contribute to this regulation of Mg2+ SO42- and Cl− by producing urine with markedly, and approximately equally, elevated Mg2+ and SO42- levels, and slightly elevated Cl− levels, compared with those in the haemolymph. The antennal glands show a small tendency to conserve water. Note: Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6.

Osmoregulation in Ligia Oceanica and Idotea Granulosa

1963 ◽  
Vol 40 (2) ◽  
pp. 381-392
Author(s):  
MARY E. TODD
Keyword(s):  
Blood Concentration ◽  
Sea Water ◽  
Freezing Point ◽  
Freezing Point Depression ◽  
External Concentration ◽  
Osmotic Concentration ◽  
Test Range ◽  
The Mean ◽  
The Difference ◽  
Idotea Granulosa

1. The osmoregulatory response of Ligia oceanica and Idotea granulosa to the range of the experimental variables was similar. They were both hyperosmotic relative to the medium and the difference between internal and external concentration increased as the salinity of the medium decreased. 2. In 100% sea water the osmotic concentration of the blood of Ligia oceanica was markedly above that of the medium, whereas in Idotea granulosa the blood was only marginally hyperosmotic. 3. In Ligia oceanica the blood concentration changed little in 100 and 75% sea water, but dropped significantly between 75 and 50% sea water, whereas blood concentration in Idotea granulosa dropped significantly throughout the test range of salinities. 4. The more efficient osmoregulation of Ligia oceanica in 25% sea water is reflected in the mean freezing-point depression of the blood, Δi = 1.65, compared with Δi = 0.90 in Idotea granulosa. 5. In both species the osmotic concentration of the blood was influenced by season, by temperature and by a temperature-salinity interaction. 6. Neither size nor sex of the animal influenced osmotic concentration of the blood.

Studies on Salt and Water Balance in Caddis Larvae (Trichoptera)

1961 ◽  
Vol 38 (3) ◽  
pp. 501-519 ◽  
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Water Balance ◽  
Sea Water ◽  
Salt Water ◽  
Chloride Concentration ◽  
Malpighian Tubule ◽  
Free Water ◽  
The Body ◽  
Chloride Uptake ◽  
Concentrated Solution ◽  
Salt And Water Balance

1. Limnephilus affinis larvae tolerate external salt concentrations up to at least 410 mM./l. NaCl (about 75% sea water) and survive for short periods in 470 mM./l. NaCl (about 85/ sea water). 2. The body wall is highly permeable to water, but relatively impermeable to sodium and chloride. Most of the sodium and chloride uptake from salt water occurs via the mouth. 3. The sodium and chloride levels in the haemolymph are powerfully regulated. Both are maintained strongly hypotonic against large external concentration gradients. 4. The Malpighian tubule-rectal system is very sensitive to changes in the haemolymph chloride level. The chloride concentration in the rectal fluid can be at least three times greater than the concentration in the haemolymph, and slightly greater than the concentration in the external medium. 5. The rectal fluid is hyper-osmotic to the haemolymph and to the medium at high external salt concentrations. 6. At external concentrations greater than about 200 mM./l. NaCl, water balance is maintained by regulating the haemolymph roughly iso-osmotic with the medium. This is partly achieved by increasing the non-electrolyte fraction in the haemolymph. A small quantity of osmotically free water is available to replace any osmotic loss. This can be obtained by drinking salt water and producing a concentrated solution of salts in the rectum.

Osmotic Regulation in Mosquito Larvae

1950 ◽  
Vol 27 (2) ◽  
pp. 145-157 ◽  
Author(s):  
J. A. RAMSAY
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
External Medium ◽  
Freezing Point ◽  
Anterior Part ◽  
Osmotic Regulation ◽  
Opposite Process ◽  
Normal Environment ◽  
Different Parts

1. The processes of osmotic regulation in the larvae of Aedes aegypti and of A. detritus have been studied by determination of the freezing-point of samples of fluid collected from different parts of the gut. 2. In A. aegypti, kept in fresh water (its normal environment), the fluid passing down the intestine to the rectum is isotonic with the haemolymph. In the rectum it becomes strongly hypotonic before being eliminated. 3. In A. detritus, kept in sea water (its normal environment), the opposite process is observed, the fluid in the rectum becoming hypertonic to the haemolymph and approximately isotonic with the external medium before being eliminated. 4. In A. detritus, which is able to live in dilute media as well as in sea water, the only two specimens from fresh water available for examination were found to have the rectal fluid hypotonic to the haemolymph. 5. The ability of A. detritus, not possessed by A. aegypti, to produce an hypertonic fluid in the rectum is tentatively associated with a region in the anterior part of the rectum and lined with an epithelium distinctly different from that in the remainder of the rectum. This anterior region has not been found in A. aegypti.

The Mechanism of Marine Osmoregulation in the Lampern (Lampetra Fluviatilis L.) and the Causes of its Breakdown During the Spawning Migration

1958 ◽  
Vol 35 (3) ◽  
pp. 649-665
Author(s):  
R. MORRIS
Keyword(s):  
Urine Output ◽  
Sea Water ◽  
Freezing Point ◽  
Spawning Migration ◽  
Lampetra Fluviatilis ◽  
Monovalent Ions

1. Some fresh-run lamperns can osmoregulate in 50% sea water (Δ = 0.970° C), where they can maintain plasma freezing-point depressions of about 057° C. 2. An analysis of the mechanism of osmoregulation in these animals shows that it is similar in many respects to that employed by marine teleosts. The lampern swallows sea water and absorbs a solution containing a high proportion of monovalent ions into its blood. It has been calculated that chloride is excreted by an extra-renal route, presumably by means of chloride excretory cells which have been discovered in the gills. The rate of extra-renal loss of water is high and the urine output is negligible. 3. Many fresh-run animals are unable to osmoregulate. In some cases the capacity to swallow sea water becomes reduced, whilst in others the number of chloride excretory cells is diminished--an indication that the extra-renal excretory mechanism is failing. Both of these mechanisms regress simultaneously in some animals.

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