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 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.

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.

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.

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.

scholarly journals The Buoyancy of the Cuttlefish, Sepia Officinalis (L.)

1961 ◽  
Vol 41 (2) ◽  
pp. 319-342 ◽  
Author(s):  
E. J. Denton ◽  
J. B. Gilpin-Brown
Keyword(s):  
Atmospheric Pressure ◽  
Dry Matter ◽  
Unit Volume ◽  
Sea Water ◽  
Excess Weight ◽  
Sepia Officinalis ◽  
Wide Range ◽  
Living Tissues ◽  
Diffusion Of Gases

The excess weight in sea water of the living tissues of Sepia officinalis (L.) is approximately balanced by the cuttlebone, which accounts for about 9·3% of the animal's volume. The density of cuttlebone varies around 0·6. The cuttlefish without its cuttlebone would be about 4% denser than sea water.The chambers of the cuttlebone are independent of one another but liquids and gases are free to move within any one chamber.Animals caught and studied fresh aboard ship exhibited a much less wide range of cuttlebone densities than those kept in an aquarium.Specimens kept in aquaria vary greatly in buoyancy. These variations result from changes in density of the cuttlebone.Cuttlebones differ not in the weight of dry matter per unit volume, which is always close to 38%, but in the amount of liquid they contain. A cuttlebone of density 0·7 contains about 30% liquid whereas a cuttlebone of density 0·5 contains about 10% liquid. The remainder of the cuttlebone contains gas, but this gas is at less than atmospheric pressure. The pressure of gas varies around 0·8 atmosphere. Within the duration of the experiments described here, the mass of gas per unit volume of bone remained almost constant whatever the bone's density. The pressure of gas is lower the less dense the cuttlebone. There can be no question of an evolution of gas expelling liquid from a bone when it becomes lighter. The constancy of the mass of gas within the cuttlebone is explained in terms of the slowness of diffusion of gases into the bone.

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.

scholarly journals Osmoregulation in some palaemonid prawns

1941 ◽  
Vol 25 (2) ◽  
pp. 317-359 ◽  
Author(s):  
N. Kesava Panikkar
Keyword(s):  
Steady State ◽  
Osmotic Pressure ◽  
Regulatory Mechanism ◽  
Sea Water ◽  
External Medium ◽  
Wide Range ◽  
Osmotic Behaviour ◽  
The Difference ◽  
Slight Rise ◽  
The Individual

1. The brackish-water prawn Palaemonetes varians and the marine prawns Leander serratus and L. squilla are hypotonic in normal sea water, the blood of these species showing osmotic pressures equivalent to 2·3, 2·8 and 2·6 % NaCl respectively, in an external medium of 3·5 % NaCl.2. Palaemonetes varians is isotonic in water of about 2·0 % NaCl and the species is practically homoiosmotic, the difference in its osmotic pressure over a range of 5·0 % NaCl in the external medium being only 0·8–1·0 %. The species has a very wide range of tolerance from water that is nearly fresh to concentrated sea water equivalent to 5·2 % NaCl.3. Leander serratus is much less homoiosmotic than Palaemonetes, and has a limited tolerance to dilution and concentration of the environment. Homoiosmoticity is maintained up to a dilution of 2·5 % in the external medium when isotonicity is reached; but in lower dilutions there is a steady decline in osmotic pressure and the regulatory mechanism evidently breaks down.4. The osmotic behaviour of Leander squilla is very similar to that of L. serratus, but the homoiosmotic behaviour is more marked and it has greater tolerance to dilution of the environment.5. When Leander and Palaemonetes are transferred to very dilute sea water, the internal osmotic pressure falls gradually for about 14–24 hr., varying according to the size of the individual. After the lowest value has been registered there is a slight rise, and a steady state is thereafter maintained.6. Studies on the changes of weight of prawns when transferred to diluted media indicate that the integument (gills) is permeable to water and that, at least in Leander serratus, the amount of water entering is mainly responsible for the dilution of the blood. There is a similar fall in weight when prawns are transferred to concentrated media, due to loss of water.

Distribution of intracellular solutes in Arenicola marina (Polychaeta) equilibrated to diluted sea water

1977 ◽  
Vol 57 (4) ◽  
pp. 889-905 ◽  
Author(s):  
R. F. H. Freeman ◽  
T. J. Shuttleworth
Keyword(s):  
Osmotic Pressure ◽  
Free Amino ◽  
Body Fluid ◽  
Marine Invertebrates ◽  
Sea Water ◽  
External Medium ◽  
Inorganic Ions ◽  
Fluid Level ◽  
Arenicola Marina ◽  
Percentage Contribution

Recent studies on the osmotic responses of marine invertebrates to dilution of the external medium have tended to emphasize the osmotic and ionic regulation at the intracellular level rather than at blood/body fluid level. Even in those invertebrates, principally euryhaline crustaceans, possessing osmoregulatory mechanisms which enable them to maintain concentrations of the blood above those of dilute media, the regulation is not perfect, and there is some lowering of the blood concentration below the level exhibited in full-strength sea water (Lockwood, 1962). This requires the establishment of a new osmotic equilibrium between the intracellular solutes and those of the blood. The nature of the intracellular osmotic constituents is, however, strikingly different from those of the blood, even in those invertebrates which are stenohaline and purely marine in their distribution (Robertson, 1961). The osmotic pressure of the blood is due almost entirely to the same inorganic electrolytes as are present in sea water, although the percentage contribution of the various ions may differ. On the other hand these inorganic ions account for only about one third to one half of the intracellular osmotic pressure. The remainder is accounted for by organic solutes, most particularly free amino acids.

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

1974 ◽  
Vol 60 (2) ◽  
pp. 331-338
Author(s):  
HELEN LE B. SKAER
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Sea Water ◽  
External Medium ◽  
Inorganic Ions ◽  
Sodium Calcium

1. Mercierella enigmatica, a serpulid polychaete, lives in water ranging in concentration from fresh water to 150% sea water (< 1-55‰). 2. The concentrations of five inorganic ions (Na+, K+, Ca2+, Mg2+ and Cl-2) in the blood have been measured both during and after equilibration of the animals with media of altered salinity. 3. The concentrations of calcium and potassium have also been measured in filtrates of the blood from animals equilibrated in three media of differing salinity. 4. Concentrations of all the ions measured vary linearly with the concentration of the external medium. The levels of sodium, calcium (in filtered blood) and chloride are near the isionic line, while those of magnesium and potassium (even in filtered blood) are slightly higher in the blood over the whole range.

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