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.

Sodium Influx and Loss in Freshwater and Brackish-Water Populations of the Amphipod Gammarus Duebeni Lilljeborg

1971 ◽  
Vol 54 (1) ◽  
pp. 255-268
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Body Surface ◽  
Brackish Water ◽  
Sea Water ◽  
Sodium Concentration ◽  
The Body ◽  
Experimental Population ◽  
Sodium Ions ◽  
Sodium Influx ◽  
Wide Range ◽  
Freshwater Habitats

1. Sodium influx was examined in Gammarus duebeni from freshwater habitats on the Kintyre and Stranraer peninsulas in western Britain, and from a brackish-water habitat in Ireland. The affinity for sodium ions in the uptake mechanism at the body surface was similar in animals from the three localities. 2. Compared with the parent population from Kintyre, an experimental population established for 2 years in water with a lower sodium concentration showed an increased affinity for sodium. 3. Sodium losses in the urine of animals from the above localities were negligible at external salinities below about 2% sea water. In contrast, urinary sodium losses in animals from a brackish-water population in Britain were higher at salinities ranging from 40% sea water to well below 2% sea water. 4. The affinity for sodium ions in uptake mechanisms at the body surface and in the antennary glands of G. duebeni from a wide range of habitats shows a market correlation with the sodium concentration of the habitat. The permeability of the body surface to outward movement of sodium is similar in G. duebeni from brackishwater and freshwater habitats. 5. It is suggested that most of the observed physiological differences between populations of G. duebeni are phenotypic in origin. The status of the freshwater ‘race’ in Ireland is briefly discussed.

Sodium Regulation in the Amphipod Gammarus Duebeni From Brackish-Water and Fresh-Water Localities in Britain

1967 ◽  
Vol 46 (3) ◽  
pp. 529-550 ◽  
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Fresh Water ◽  
Body Surface ◽  
Brackish Water ◽  
Loss Rate ◽  
Sea Water ◽  
The Body ◽  
Sodium Ions ◽  
Sodium Uptake ◽  
Sodium Loss ◽  
Sodium Regulation

1. A quantitative study of sodium influx and loss rates was made on Gammarus duebeni obtained from brackish-water localities. Both influx and loss rates were immediately doubled by a rise in temperature from 10 to 20° C. 2. It is estimated that when animals are fully acclimatized to a series of media decreasing from 50 to 2% sea water the rate of sodium uptake at the body surface is doubled to balance the rate of sodium loss, which is also doubled. The increased loss rate is due equally to an increase in the rate of diffusion across the body surface and to loss in hypotonic urine containing about 160-190 mM/l. sodium. Diffusion losses normally account for at least 35% of the total losses, even when the urine is isotonic with the blood. 3. The sodium-transporting system at the body surface is fully saturated at an external concentration of about 10 mM/l. NaCl (2% sea water). The system has a low affinity for sodium ions and is only half-saturated at 1.5-2.5 mM/l. sodium. The overall rate of uptake is increased to its maximum rate to balance sodium losses when in fresh water. 4. When acclimatized to fresh water (0.25 mM/l. NaCl) the sodium loss rate is greatly reduced. This was partly due to a lower rate of diffusion across the body surface following a fall in the blood sodium concentration, and mainly due to elaboration of a very dilute urine. 5. It is suggested that increases in sodium uptake in the antennary glands, resulting in a hypotonic urine, are linked with increases in uptake at the body surface. Both uptake systems are possibly activated by a single internal regulator responding to changes in the blood concentration. 6. Sodium regulation at concentrations below 10 mM/l. NaCl was examined in G. duebeni obtained from fresh-water streams on the Lizard peninsula, the Kintyre peninsula, and the Isle of Man. The regulation of sodium uptake and loss is very similar to regulation in brackish-water animals, and the sodium-transporting system has the same low affinity for sodium ions at concentrations below about 10 mM/l. 7. It is suggested that fresh-water localities in north-west Europe, excluding Ireland, have been colonized from brackish water without any modifications in the sodium-regulatory mechanism. But the fresh-water animals tolerate very low sodium concentrations better than brackish-water animals. This is apparently due to natural selection of individuals in which the sodium uptake rate is higher than the average uptake rate in brackish-water animals.

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.

Active Transport and Sodium Fluxes at Moult in the Amphipod, Gammarus Duebeni

1969 ◽  
Vol 51 (3) ◽  
pp. 591-605
Author(s):  
A. P. M. LOCKWOOD ◽  
W. R. H. ANDREWS
Keyword(s):  
Fresh Water ◽  
Body Surface ◽  
Major Part ◽  
Sea Water ◽  
Sucrose Solution ◽  
The Body ◽  
Active Sodium ◽  
Sodium Influx ◽  
Sodium Uptake ◽  
High Level

1. The sodium fluxes of individual Gammarus duebeni, which moulted in sea water, have been followed daily from the morning following moult for at least 6 days. 2. Sodium influx from sea water declined from 15.1µM/animal/hr. on the first morning after moult to 1.7µM/animal/hr. by the tenth day after moult. 3. Sodium influx from 10 mM/l. NaCl plus sucrose solution isotonic with sea water declines from 4.48µM/animal/hr. to 0.14µM/animal/hr. in inter-moult animals. 4. Thionine inhibits over 90% of the influx from 10 mM/l NaCl plus isotonic sucrose on the first day after moult, and this, together with other evidence, suggests that the major part of the influx from this medium is due to active sodium uptake. The rate of active uptake is comparable with, or faster than, the rate of uptake by animals acclimatized to fresh water. 5. The influx occurs primarily across the body surface. It is suggested that the high level of sodium uptake is associated with the water uptake which occurs at moult.

Plasma Chloride and Sodium, and Chloride Space in the European Eel, Anguilla Anguilla L

1972 ◽  
Vol 57 (1) ◽  
pp. 113-131
Author(s):  
R. KIRSCH
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Chloride Concentration ◽  
Anguilla Anguilla ◽  
The Body ◽  
European Eel ◽  
Plasma Chloride ◽  
Sea Water Adaptation ◽  
Sodium Regulation ◽  
High Degree

1. New intra-vascular cannulation techniques are described, and also an extra-corporal blood circuit containing an artificial heart and a counting cell. This makes possible a continuous study of the radioactivity of the blood. 2. Plasma chloride concentration varies greatly in fresh-water eels despite good sodium regulation. 3. The fresh-water to sea-water adaptation of eels is frequently accompanied by a temporary hypermineralization of the internal medium. This necessitates a high degree of cellular euryhalinity. 4. The sea-water-adapted eel maintains strict homeostasis of its plasma chloride and sodium. 5. The chloride distribution space decreases by 10% when eels are transferred from fresh water to sea water. The internal distribution of chloride is also modified and its fluxes between the ion compartments of the body are considerably increased.

Sodium Regulation in the Amphipod Gammarus Duebeni Lilljeborg form Freshwater Localities in Ireland

1968 ◽  
Vol 48 (2) ◽  
pp. 339-358
Author(s):  
D. W. SUTCLIFFE ◽  
J. SHAW
Keyword(s):  
Fresh Water ◽  
Loss Rate ◽  
Sea Water ◽  
Detailed Comparison ◽  
Urine Concentration ◽  
Sodium Influx ◽  
Fresh Waters ◽  
Low Sodium ◽  
Characteristic Features ◽  
Sodium Regulation

1. A quantitative study of sodium influx and loss was made on populations of Gammarus duebeni obtained from four freshwater localities in Ireland. 2. Characteristic features of sodium regulation in animals from the four localities were as follows, (a) The sodium influx increases gradually with increasing external sodium concentrations, but a maximum (saturation) level is abruptly reached at an external concentration of 1-2 mM/l. and the transporting system is half saturated at about 0.5 mM/l. sodium, (b) Over the range of sodium concentrations found in fresh waters a low rate of sodium uptake is sufficient to balance sodium losses at concentrations down to between 0.5 and 0.25 mM/l. At lower concentrations the influx is increased and the loss rate is reduced. (c) Calculations suggest that hypotonic urine containing approximately 40 mM/l sodium is produced at external concentrations ranging from fresh water to 40 % sea water. At external concentrations below 0.25 mM/l. sodium the urine concentration is probably reduced to well below 40 mM/l. sodium. 3. A detailed comparison is made of sodium regulation at external concentrations ranging between 0.07 and 1 mM/l. sodium in G. duebeni from fresh water in Ireland and from fresh water and brackish water in Britain. It is suggested that G. duebeni in Ireland constitutes a distinct physiological race adapted for living in fresh waters with relatively low sodium concentrations.

Ionic Regulation of the Baltic and Fresh-Water Races of the Isopod Mesidotea (Saduria) Entomon (L.)

1968 ◽  
Vol 48 (1) ◽  
pp. 141-158 ◽  
Author(s):  
P. C. CROGHAN ◽  
A. P. M. LOCKWOOD
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Sodium Concentration ◽  
Relative Volume ◽  
Ice Age ◽  
Ionic Regulation ◽  
Sodium Influx ◽  
Active Uptake ◽  
Concentrated Solution ◽  
The Baltic

1. The isopod Mesidotea entomon has colonized the Baltic and certain Swedish lakes since the end of the last Ice Age. 2. The ionic regulation of Baltic animals and fresh-water animals (L. Mälaren) has been compared. 3. It has been possible to adapt Baltic animals to very dilute media, but 5% Askö sea water (5.5 mM/l. Na) appears to be the limit of adaptation. The haemolymph sodium concentration of Baltic animals from the very dilute media was considerably lowered. 4. The haemolymph sodium concentration in Mälaren animals is high (250 mM/l. Na) and comparable with that in Baltic animals in much more concentrated solution. The haemolymph ionic ratios of the Baltic and freshwater animals are similar. The Cl:Na ratio rises slightly in the more concentrated haemolymph samples. 5. From the concentration of ions in the haemolymph and in the total body water, the relative volume of the haemolymph was calculated. Mälaren animals appear to have a much larger haemolymph volume. 6. The permeability of the animals was determined from the rate of loss of sodium into de-ionized water. The permeability of the Mälaren animals is considerably reduced compared to the Baltic animals. Permeability is not related to the medium to which the animals had been adapted. 7. The sodium influx was determined using 22Na. The rate of active uptake was calculated from this. The maximal rate of active uptake was similar in Baltic and Mälaren animals. The sodium concentration of the medium at which active uptake was half maximum (KM) was considerably lower in Malaren animals than in Baltic animals. 8. The evolution of Mesidotea as a fresh-water animal is interpreted as a result of a reduction in permeability of the external surfaces to NaCl and an increase in the affinity of the active transport mechanism enabling the animal to maintain the haemolymph NaCl concentration in a steady state in fresh water.

Sodium Balance in Eriocheir Sinensis (M. EDW.). The Adaptation of the Crustacea to Fresh Water

1961 ◽  
Vol 38 (1) ◽  
pp. 153-162
Author(s):  
J. SHAW
Keyword(s):  
Fresh Water ◽  
Body Surface ◽  
Eriocheir Sinensis ◽  
Vital Role ◽  
The Body ◽  
Sodium Balance ◽  
Progressive Reduction ◽  
Uptake Mechanism ◽  
Active Uptake ◽  
Main Factors

1. In Eriocheir sinensis active uptake of sodium plays a vital role in the maintenance of sodium balance. At external concentrations down to about 6 mM./l. the active uptake mechanism is fully saturated and the uptake rate just balances the rate of loss, which occurs primarily through the body surface. At lower external concentrations balance may be achieved, at least in part, by the activation of the uptake mechanism. 2. A hypothesis is put forward to account for the mechanism of adaptation of the Crustacea to fresh water. Two main factors are involved: (a) a progressive reduction in the permeability of the body surface to salts and, (b) the acquisition of an active uptake mechanism with a high affinity for the ions which it transports. 3. This hypothesis is discussed in relation to previous theories on the adaptation of the Crustacea to fresh water.

Sodium Regulation in the Crayfish Astacus Fluviatilis

1960 ◽  
Vol 37 (1) ◽  
pp. 83-99 ◽  
Author(s):  
G. W. BRYAN
Keyword(s):  
Tap Water ◽  
Sodium Concentration ◽  
The Body ◽  
Urine Sodium ◽  
Compartment System ◽  
Single Compartment ◽  
Blood And Urine Samples ◽  
Astacus Fluviatilis ◽  
Sodium Regulation ◽  
Total Sodium

1. In Bristol tap water containing 0.4 mM./l. sodium and artificial tap water containing 2 mM./l. sodium, Astacus maintains a blood sodium concentration of about 203 mM./l. This value was not markedly affected by starvation periods of up to a month. 2. Methods of taking small blood and urine samples from individual crayfish at intervals over several hundred hours have been described. 3. Under steady state conditions, curves for the uptake and loss of 22Na by the blood are described by equations derived for a one-compartment system. 4. The volume of this single compartment, which exchanges sodium with the medium, is larger than the actual blood volume by an amount roughly equivalent to the sodium in the tissues. Exchange of sodium between the blood and tissues is probably very rapid. 5. Sodium losses in the urine account for about 6% of the total sodium outflux found using 22Na. The urine sodium concentration of about 6 mM./l. was temporarily increased by conditions such as heavy feeding when the blood may have gained additional sodium. 6. Potential difference measurements across the body surface indicate that the high blood sodium concentration is maintained by active uptake of sodium.

Osmoregulation in the Larva of the Marine Caddis Fly, Philanisus Plebeius (Walk.) (Trichoptera)

1972 ◽  
Vol 57 (3) ◽  
pp. 821-838
Author(s):  
JOHN P. LEADER
Keyword(s):  
Sodium Chloride ◽  
Osmotic Pressure ◽  
Body Surface ◽  
Sea Water ◽  
Electrical Potential ◽  
Chloride Ion ◽  
Chloride Ions ◽  
The Body ◽  
Electrical Potential Difference ◽  
Caddis Fly

1. The larva of Philanisus plebeius is capable of surviving for at least 10 days in external salt concentrations from 90 mM/l sodium chloride (about 15 % sea water) to 900 mM/l sodium chloride (about 150 % sea water). 2. Over this range the osmotic pressure and the sodium and chloride ion concentrations of the haemolymph are strongly regulated. The osmotic pressure of the midgut fluid and rectal fluid is also strongly regulated. 3. The body surface of the larva is highly permeable to water and sodium ions. 4. In sea water the larva is exposed to a large osmotic flow of water outwards across the body surface. This loss is replaced by drinking the medium. 5. The rectal fluid of larvae in sea water, although hyperosmotic to the haemolymph, is hypo-osmotic to the medium, making it necessary to postulate an extra-renal site of salt excretion. 6. Measurements of electrical potential difference across the body wall of the larva suggest that in sea water this tissue actively transports sodium and chloride ions out of the body.

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