Studies on Ionic Regulation in Carcinus Maenas (L.)

1961 ◽  
Vol 38 (1) ◽  
pp. 135-152
Author(s):  
J. SHAW
Keyword(s):  
Body Weight ◽  
Sea Water ◽  
Carcinus Maenas ◽  
Sodium Concentration ◽  
Sodium Balance ◽  
Uptake Mechanism ◽  
Sodium Influx ◽  
Urine Production ◽  
Sodium Loss ◽  
Total Sodium

1. The mechanism of sodium balance in Carcinus maenas has been investigated. 2. Measurements of sodium outflux showed no evidence of a decrease in surface permeability to sodium in dilute sea water. 3. The rate of urine production in normal sea water was 3.6% body weight per day and the sodium loss through the urine was insignificant compared with the total sodium loss. In 40% sea water the urine rate was increased to 30% body weight per day and the loss in the urine accounted for 20% of the total loss. 4. Measurements of sodium influx and calculation of the active component showed that the active uptake mechanism was fully saturated at all external concentrations in which the animals could survive. 5. Regulation of the blood sodium concentration is effected largely by the activation of the sodium uptake mechanism. This prevents the blood concentration falling below a critical level as long as the external concentration itself is not too low.

Studies on Sodium Balance in Gammarus Duebeni Lilljeborg and G. Pulex Pulex (L.)

1961 ◽  
Vol 38 (1) ◽  
pp. 1-15
Author(s):  
J. SHAW ◽  
D. W. SUTCLIFFE
Keyword(s):  
Loss Rate ◽  
Sea Water ◽  
Sodium Concentration ◽  
Sodium Balance ◽  
Nacl Solution ◽  
Uptake Mechanism ◽  
External Concentration ◽  
Sodium Influx ◽  
Low Concentrations ◽  
Sodium Loss

1. The mechanisms of sodium balance in Gammarus duebeni and G. pulex, adapted to various external concentrations, were compared. 2. G. duebeni could be adapted to live in 1 mm/l. NaCl solution and, in some cases, to concentrations down to 0.2 mM/l. G. pulex could survive in concentrations as low as 0.06 mM/l. 3. The sodium loss rate in G. duebeni adapted to 2% sea water was much higher than in G. pulex but was reduced to about the same level when the animals were adapted to low external concentrations. 4. In both species there was a non-linear relationship between sodium influx and the external sodium concentration. In G. duebeni the uptake mechanism was saturated at an external concentration of about 10 mM/l., whereas in G. pulex saturation was reached at a much lower concentration. The maximum rate of uptake was greater in G. duebeni than in G. pulex. 5. In both species adaptation to low concentrations involved a small increase in the sodium influx and a reduction in the loss rate. 6. The most important factor in the superiority of G. pulex over G. duebeni in surviving at low external concentrations is the high affinity for sodium displayed by the uptake mechanism in G. pulex.

Sodium Regulation in the Fresh-Water Amphipod, Gammarus Pulex (L.)

1967 ◽  
Vol 46 (3) ◽  
pp. 499-518
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Fresh Water ◽  
Body Surface ◽  
Loss Rate ◽  
Sodium Concentration ◽  
The Body ◽  
Uptake Mechanism ◽  
Sodium Influx ◽  
Sodium Uptake ◽  
Sodium Loss ◽  
Total Sodium

1. Sodium influx and loss rates in Gammarus pulex were measured at constant temperatures. The sodium loss rate was immediately influenced by a change in temperature, with a Q10 of 1.5 to 2.0 at temperatures between 0.3 and 21.5° C. The sodium influx rate is apparently influenced in the same way. 2. The sodium uptake mechanism in G. pulex from three localities was half-saturated at an external concentration of 0.10-0.15 mM/l. sodium. 3. The total sodium loss rate remained approximately constant in animals acclimatized to the range of external concentrations from 2 to about 0.2 mM/l. sodium. 18% of the sodium was lost in urine with a sodium concentration estimated at 30-50 mM/l. The remainder of the sodium loss was due to diffusion across the body surface. 4. In animals acclimatized to concentrations below about 0.2 mM/l. sodium the sodium loss rate was reduced, due to (a) a lower diffusion rate following a fall in the blood sodium concentration, and (b) the elaboration of a more dilute urine. 5. There was a very close association between changes in the blood sodium concentration, the elaboration of a very dilute urine, and the rate of sodium uptake at the body surface. The results indicate that a fall in the blood sodium concentration leads to simultaneous activation of the sodium uptake mechanisms at the body surface and in the antennary glands. 6. It is estimated that, by producing a dilute urine, total sodium uptake in G. pulex is shared equally between the renal uptake mechanism and the mechanism situated at the body surface. 7. In sea-water media G. pulex drinks and expels fluid from the gut. In a medium slightly hyperosmotic to the normal blood concentration the amount imbibed was equal to the normal rate of urine flow when in fresh water.

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.

The Physiology of the Antennal Gland of Carcinus Maenas (L.)

1969 ◽  
Vol 51 (1) ◽  
pp. 11-16
Author(s):  
R. BINNS
Keyword(s):  
Body Weight ◽  
Sea Water ◽  
Carcinus Maenas ◽  
Urine Flow ◽  
The Body ◽  
Antennal Gland ◽  
Urine Production ◽  
The Mean ◽  
Gland Function ◽  
Water Clearance

1. The space measured by inulin distribution, the ‘inulin volume’, has been determined, and represents approximately 20% of the body weight in crabs ranging in size from 20.0 to 57.2 g. 2. After the injection of labelled inulin into crabs, the increase in activity of the medium is equal to the fall in blood inulin in all dilutions of sea water. Clearance of inulin from the blood is due only to urine production, and therefore the molecule can be used for quantitative investigations of antennal gland function. 3. Urine production in various concentrations of sea water has been determined by measuring the clearance of inulin from the blood and the rates at which the tracer appeared in the external media. By these methods the mean rate of urine production in 100% sea water was estimated to be 4.4% body weight per day. In dilute sea water the rate of urine production increases; for example, in 50% sea water the urine flow is four times greater than in normal sea water.

Studies on Fresh-Water Osmoregulation in the Ammocoete Larva of Lampetra Planeri (Bloch)

1970 ◽  
Vol 52 (2) ◽  
pp. 275-290
Author(s):  
R. MORRIS ◽  
J. M. BULL
Keyword(s):  
Sodium Concentration ◽  
Sodium Balance ◽  
Sodium Influx ◽  
Environmental Concentration ◽  
Carrier Mechanism ◽  
Controlling Mechanism ◽  
Lampetra Planeri ◽  
Reverse Situation ◽  
Sodium Loss ◽  
Term Response

1. Sodium influx in ammocoete larvae increases exponentially with external sodium concentration (0-1.0 mM/l.) and sodium-depleted animals show a 20% increase compared with normal animals. 2. Sodium loss decreases as the environmental concentration decreases, although the reverse situation is expected from considering diffusion outflux alone. 3. It is argued that part of the sodium loss is back-transported by the transport mechanism and this accounts for the reduced sodium loss from sodium-depleted animals whose sodium carrier activity is increased. The curves relating back-transport to environmental sodium differ from those derived by Kirschner for isolated frog skin. 4. Sodium influx increases as sodium loss increases, indicating a self mechanism whose features are discussed. In the ammocoete, the sodium carrier mechanism appears to change in affinity for sodium (short-term response) and can also change in concentration (long-term response), and it is suggested that these features, together with permeability changes, may form the basis of the controlling mechanism for sodium balance.

The Relative Losses of Sodium in the Urine and Across the Body surface in the Amphipod, Gammarus Duebeni

1965 ◽  
Vol 42 (1) ◽  
pp. 59-69
Author(s):  
A. P. M. LOCKWOOD
Keyword(s):  
Body Surface ◽  
Sea Water ◽  
Average Rate ◽  
The Body ◽  
High Rate ◽  
Water Turnover ◽  
Urine Production ◽  
Sodium Loss ◽  
And Diffusion ◽  
Total Sodium

1. The relative contributions of urine production and diffusion across the body surface to the loss of sodium from the body of the amphipod Gammarus duebeni have been investigated. 2. When the urine is isotonic to the blood some 80% of the total sodium loss is via the urine. 3. As the gradient between blood and medium is increased in dilute media production of urine hypotonic to the blood counteracts the tendency for sodium loss to increase. 4. In consequence, the average rate of sodium uptake at the body surface by animals acclimatized to 2% sea water needs to be only about twice that of animals acclimatized to 50% sea water. 5. It is suggested that the conservation of ions within the body by the production of hypotonic urine is likely to be found to be a common feature of the smaller brackish water crustacea, especially those with a high rate of water turnover.

The Physiology of the Antennal Gland of Carcinus Maenas (L.)

1969 ◽  
Vol 51 (1) ◽  
pp. 29-39
Author(s):  
R. BINNS
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sea Water ◽  
Carcinus Maenas ◽  
Complete Recovery ◽  
Sodium Concentration ◽  
Urine Concentration ◽  
Antennal Gland ◽  
Amino Acid Load ◽  
Urine Production

1. Amino acids are actively reabsorbed by the antennal gland of Carcinus in all concentrations of sea water, but there is never complete recovery of these molecules from the urine; even in animals in 100% sea water amino acids are eliminated in the urine. 2. The urine concentration of amino acids is related to (i) the blood amino acid concentration and (ii) the rate of urine production. An increase in either or both of these factors, for example, when animals are in dilute sea water, raises the U/B ratio of amino acids. 3. The rate of reabsorption of amino acids increases as the amino acid load on the antennal gland is raised. When reabsorption is maximal, the rate of transport is about seven times greater than at normal concentrations of amino acids in blood and urine when the animal is in 100% sea water. 4. Increases in blood amino acid concentrations when crabs are placed directly into dilute sea water are taken to be the result of changes in free amino acids of muscle which occur under these conditions. This intracellular regulation in dilute media is initiated when the blood sodium concentration is approximately 400 mM/l.

The Sodium Balance Mechanism in the Fresh-Water Amphipod, Gammarus Lagustris Sars

1967 ◽  
Vol 46 (3) ◽  
pp. 519-528
Author(s):  
D. W. SUTCLIFFE ◽  
J. SHAW
Keyword(s):  
Fresh Water ◽  
Loss Rate ◽  
Sodium Concentration ◽  
The Body ◽  
Sodium Balance ◽  
External Concentration ◽  
Sodium Influx ◽  
Influx Rate ◽  
Sodium Loss ◽  
Balance Mechanism

1. The sodium balance mechanism of Gammarus lacustris in fresh water is virtually identical with that found in G. pulex. 2. The sodium transporting system at the body surface has a very high affinity for sodium ions. The system is half-saturated at an external concentration of about 0.14 mM/l. and fully saturated at about 1 mM/l. sodium. 3. The lowest external concentration at which sodium balance was maintained was 0.06 mM/l. 4. Both the total sodium loss rate and the sodium influx rate remained approximately constant in animals acclimatized to the range of external concentrations from 2 to 0.3 mM/l. NaCl. At lower concentrations the loss rate was reduced and the influx increased by a factor of about 1.5. 5. Changes in the sodium influx and loss rates are very closely linked together, and it is shown how these changes are related to the external sodium concentration.

Urinary Bladder Volume and the Reabsorption of Water from the Urine of Crabs

1974 ◽  
Vol 60 (1) ◽  
pp. 167-181
Author(s):  
J. A. RIEGEL ◽  
A. P. M. LOCKWOOD ◽  
J. R. W. NORFOLK ◽  
N. C. BULLEID ◽  
P. A. TAYLOR
Keyword(s):  
Body Weight ◽  
Urinary Bladder ◽  
Blood Volume ◽  
Ethacrynic Acid ◽  
Sea Water ◽  
Carcinus Maenas ◽  
Bladder Volume ◽  
Active Secretion ◽  
51Cr Edta

1. Measurements have been made to determine the blood volume, bladder volume, clearance of 131I-sodium diatrizoate and U/H for diatrizoate in the crabs Carcinus maenas and Macropipus (Portunus) depurator. 2. Observed values of clearance blood volume and bladder volume in the two species at 18 °C were: Clearance (as % blood volume per day), Macropipus 56.1±14.5; Carcinus 27.1±5.8; Blood volume (as % body weight), Macropipus 21.0±4.0; Carcinus 19.2±3.0; Bladder volume (as % blood volume), Macropipus 12.1 ±5.0; Carcinus 11.0±8.0. 3. It is shown that the measured U/H differs from that to be expected if no reabsorption of water or secretion of diatrizoate occurs. 4. 14C-inulin and 51Cr-EDTA are excreted in an essentially similar manner to 131I-diatrizoate by Carcinus, implying that any active secretion of diatrizoate must be small in magnitude. 5. Injections of ethacrynic acid decrease the U/H ratio for diatrizoate relative to that in control Carcinus injected with sea water. In some Carcinus the concentration of diatrizoate in the urine comes to exceed that initially present in the blood. Both these points are taken, with 3, as support for the conclusion that water can be withdrawn from the primary urine of Carcinus.

Sodium Regulation and Adaptation to Fresh Water in Gammarid Crustaceans

1968 ◽  
Vol 48 (2) ◽  
pp. 359-380
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Body Weight ◽  
Fresh Water ◽  
Body Surface ◽  
Sea Water ◽  
Sodium Concentration ◽  
The Body ◽  
Outward Diffusion ◽  
Gammarus Zaddachi ◽  
Freshwater Habitats ◽  
Sodium Regulation

1. Sodium uptake and loss rates are given for three gammarids acclimatized to media ranging from fresh water to undiluted sea water. 2. In Gammarus zaddachi and G. tigrinus the sodium transporting system at the body surface is half-saturated at an external concentration of about 1 mM/l. and fully saturated at about 10 mM/l. sodium. In Marinogammarus finmarchicus the respective concentrations are six to ten times higher. 3. M. finmarchicus is more permeable to water and salts than G. zaddachi and G. tigrinus. Estimated urine flow rates were equivalent to 6.5% body weight/hr./ osmole gradient at 10°C. in M. finmarchicus and 2.8% body weight/hr./osmole gradient in G. zaddachi. The permeability of the body surface to outward diffusion of sodium was four times higher in M. finmarchicus, but sodium losses across the body surface represent at least 50% of the total losses in both M. finmarchicus and G. zaddachi. 4. Calculations suggest that G. zaddachi produces urine slightly hypotonic to the blood when acclimatized to the range 20% down to 2% sea water. In fresh water the urine sodium concentration is reduced to a very low level. 5. The process of adaptation to fresh water in gammarid crustaceans is illustrated with reference to a series of species from marine, brackish and freshwater habitats.

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