The Urine of Gammarus Duebeni and G. Pulex

1961 ◽  
Vol 38 (3) ◽  
pp. 647-658
Author(s):  
A. P. M. LOCKWOOD
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Blood Concentration ◽  
Sea Water ◽  
The Body ◽  
Absolute Level ◽  
The Absolute ◽  
Urine Formation ◽  
Concentration Of Urine

1. A study has been made of the relation between blood, urine and medium concentrations in the two amphipod Crustacea G. duebeni and G. pulex. 2. G. duebeni produces urine hypotonic to the blood but hypertonic to the medium when it is in media more dilute than 50% sea water. 3. G. pulex forms urine which is hypotonic both to blood and medium when in 2-20% sea water. 4. G. duebeni begins to form hypotonic urine within 2 hr. of transference from 110 to 160% sea water to fresh water. Hypotonic urine formation begins in these circumstances when the blood concentration is up to twice that at which hypotonic urine is formed by animals fully adapted to their medium. 5. It is concluded (a) that the concentration of urine produced by G. duebeni is not dictated solely by the absolute level of the blood concentration; (b) that the formation of urine hypotonic to the blood in a brackish-water animal functions primarily as a means of conserving ions in the body; (c) that the ability to regulate the concentration of the urine with rapidity will be important in an animal living in environments of fluctuating salinities.

scholarly journals Studies on Adaptation to Salinity in Gammarus Spp

1940 ◽  
Vol 17 (2) ◽  
pp. 153-163
Author(s):  
L. C. BEADLE ◽  
J. B. CRAGG
Keyword(s):  
Osmotic Pressure ◽  
Fresh Water ◽  
Brackish Water ◽  
Blood Concentration ◽  
Sea Water ◽  
Marine Species ◽  
Eriocheir Sinensis ◽  
Tolerance Range ◽  
High Concentration ◽  
Ion Absorption

1. Four species of Gammarus were studied: the fresh-water G. pulex, the brackish water G. duebeni, and two normally marine species G. locusta and obtusatus, the former of which has also been recorded from brackish water. 2. The relation between osmotic pressure and chloride of the blood and of the external medium, after sudden transfer to salinities which could be withstood for at least 24 hr., is shown in Fig. 1. 3. The changes in blood osmotic pressure are due to salt and not to water movements. 4. The marine species G. obtusatus and locusta maintain a very hypertonic blood in dilute sea water and can withstand 50% (270 mM.) and 25% (135 mM.) sea water respectively. 5. The brackish water G. duebeni has a tolerance range from pure sea water to water containing a trace of salt, but is not as well adapted to fresh water as G. pulex. 6. For a wide salinity tolerance range two mechanisms are necessary, (a) for regulating the blood concentration within certain limits, and (b) for maintaining a low intracellular concentration of certain ions (e.g. C1) in spite of changes in blood concentration. Defection of the latter mechanism can alone account for the inability of G. pulex to withstand direct transfer to more than about 40% sea water (115 mM.). 7. On the basis of this work and that of others on other animals the following hypothesis is suggested. Adaptation to fresh water has proceeded by two main stages: (a) Probably by active ion absorption, a high blood concentration is maintained (as in Eriocheir sinensis and Telphusa fluviatile) and is associated with a large blood/tissue C1 gradient. Such animals can still be transferred suddenly to a high concentration of sea water. (b) Evolution of the renal salt-reabsorption mechanism, and lowering of both blood concentration and blood/tissue C1 gradient to levels more easily maintained (as in G. pulex and most fresh-water animals). The consequent loss of power to maintain a large blood/tissue C1 gradient entails inability to withstand transfer to more than low concentrations of sea water, unless, as in certain species, a special mechanism is evolved for preventing the blood concentration from rising.

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 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.

The accumulation of 137Cs by brackish water invertebrates and its relation to the regulation of potassium and sodium

1963 ◽  
Vol 43 (2) ◽  
pp. 541-565 ◽  
Author(s):  
G. W. Bryan
Keyword(s):  
New Media ◽  
Brackish Water ◽  
Sea Water ◽  
Indirect Evidence ◽  
The Body ◽  
Limiting Factor ◽  
Wide Range ◽  
Concentration Factors ◽  
The Relationship ◽  
Potamopyrgus Jenkinsi

The relationship between the ability of brackish water invertebrates to regulate Na and K and the extent to which the radioactive fission product 137Cs can be accumulated has been studied.The brackish water isopod Sphaeroma hookeri and the gastropod Potamopyrgus jenkinsi have been acclimatised to a wide range of sea-water dilutions. Unfed Sphaeroma can survive in sea-water concentrations of 100–2·5%, while Potamopyrgus can live fairly indefinitely in concentrations of 50–0·1%. Measurements of Na and K in the whole animals of both species and in the blood of Sphaeroma have been made. Salt movements are quite rapid and acclimatization to new media is achieved by both species in less than 10 h. Concentration factors for inactive K in particular increase to high values in the more dilute media.Uptake of the isotopes 42K and 137Cs from solution has been examined in both species over a range of sea-water concentrations. All of the body K is exchangeable with 42K and in Sphaeroma exchange of 42K between the blood and tissues is so rapid that the body surface appears to be the limiting factor in the uptake of the isotope. Both species exchange 42K more rapidly in the higher concentrations of sea water and one reason for this may be the existence of an exchange diffusion component of exchange which increases as the salinity of the medium is raised. Indirect evidence suggests that the excretion of 42K in urine is probably not an important factor in exchange.

DROWNING AND THE TREATMENT OF NON-FATAL SUBMERSION

PEDIATRICS ◽  
1966 ◽  
Vol 37 (4) ◽  
pp. 684-698
Author(s):  
Jerome Imburg ◽  
Thomas C. Hartney
Keyword(s):  
Ventricular Fibrillation ◽  
Pulmonary Function ◽  
Fresh Water ◽  
Animal Studies ◽  
Sea Water ◽  
The Body ◽  
Positive Pressure ◽  
Cardiac Massage ◽  
Central Nervous System Damage ◽  
Intermittent Positive Pressure Breathing

Animal studies have shown that fluid enters the body via the lungs in sea-water and fresh-water drowning. In fresh-water drowning in dogs, there is marked and rapid hemodilution with death due to ventricular fibrillation in about 4 minutes. In sea-water drowning in dogs, there is hemoconcentration; the blood water is lost into the sea water in the lungs with bradycardia and death due to asystole in 6 to 8 minutes. Studies of human drowning victims show similar, but less striking, changes in hemodynamics. In human non-fatal submersion the problems are usually those produced by impaired pulmonary function and central nervous system damage due to hypoxia. Hemodilution and ventricular fibrillation have not been documented in human nonfatal submersion. Therapeutic measures may be divided into those of an immediate urgent nature to be employed at the accident scene: expired air resuscitation, which should be started on reaching the unconscious victim in the water, and external cardiac massage, when indicated. Later measures to be instituted in the hospital include: cardiac resuscitation, intermittent positive-pressure breathing, hypothermia, tracheostomy and tracheal tiolet, oxygen therapy, antibiotics, steroids, and intravenous fluids to correct defects in blood elements (hemoglobin, electrolytes, pH). Later, pulmonary function should be studied for impairment due to alveolar damage and fibrosis. Permanent neurologic sequellae may develop.

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 The Physiology of Contractile Vacuoles

1934 ◽  
Vol 11 (4) ◽  
pp. 364-381
Author(s):  
J. A. KITCHING
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Tap Water ◽  
Marine Species ◽  
The Body ◽  
Contractile Vacuole ◽  
Body Volume ◽  
Water Value ◽  
Contractile Vacuoles ◽  
Sustained Increase

1. The rate of output of fluid from the contractile vacuole of a fresh-water Peritrich Ciliate was decreased to a new steady value immediately the organism was placed in a mixture of tap water and sea water. The rate of output returned to its original value immediately the organism was replaced in tap water. The contractile vacuole was stopped when the organism was treated with a mixture containing more than 12 per cent, of sea water. 2. Transference of various species of marine Peritricha from 100 per cent, sea water to mixtures of sea water and tap water led to an immediate increase of the body volume to a new and generally steady value. Return of the organism to 100 per cent, sea water led to an immediate decrease of the body volume to its original value or less. 3. Marine Peritricha showed little change in rate of output when treated with concentrations of sea water between 100 and 75 per cent. In more dilute mixtures the rate of output was immediately increased, and then generally fell off slightly to a new steady value which was still considerably above the original (100 per cent. sea water) value. The maximum sustained increase was approximately x 80. Return of the organism to 100 per cent, sea water led to an immediate return of the rate of output to approximately its original value. 4. When individuals of some marine species were placed in very dilute concentrations of sea water, the pellicle was frequently raised up in blisters by the formation of drops of fluid underneath it, and the contractile vacuole stopped. 5. Evidence is brought forward to suggest that in the lower concentrations of sea water marine forms lost salts. 6. The contractile vacuole probably acts as an osmotic controller in fresh-water Protozoa. Its function in those marine Protozoa in which it occurs remains obscure.

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.

Lack of glomerular intermittency in the river lamprey lampetra fluviatilis acclimated to sea water and following acute transfer to iso-osmotic brackish water

1999 ◽  
Vol 202 (8) ◽  
pp. 939-946 ◽  
Author(s):  
J.A. Brown ◽  
J.C. Rankin
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Urine Output ◽  
Neural Control ◽  
Sea Water ◽  
Osmotic Gradient ◽  
Vascular Perfusion ◽  
Lampetra Fluviatilis ◽  
River Lamprey ◽  
Firm Evidence

Previous studies have suggested that in the lamprey Lampetra fluviatilis, in contrast to teleost fish, all glomeruli are actively filtering. In the present study, we have applied the ferrocyanide technique to obtain more definitive values for the population of filtering nephrons in the lamprey under conditions of high (in fresh water) and low (in sea water) glomerular filtration rate (GFR) and when the branchial osmotic gradient was eliminated by acute transfer of freshwater lampreys to iso-osmotic brackish water. These studies demonstrated that the renal antidiuresis in lampreys acclimated to full-strength sea water does not involve any reduction in the filtering population of glomeruli. Transfer to brackish water significantly reduced GFR and thereby urine flow rate (287+/−23 ml kg-1 24 h-1 in fresh water; 6.9+/−2.5 ml kg-1 24 h-1 in brackish water). In four of the eight fish examined, 100 % of glomeruli remained filtering; in the other four fish, non-filtering glomeruli occurred in patches along the kidney, always associated with an absence of vascular perfusion, which implies possible endocrine/neural control of vascular tone. The numbers of non-filtering glomeruli were always small, and these glomeruli do not appear to make a major contribution to the overall decline in urine output. The results provide firm evidence that although lampreys, like teleosts, show considerable variations in urine output, the renal mechanisms by which lampreys and the teleosts achieve this differ fundamentally, with glomerular intermittency playing little or no part in the lamprey.

Studies on the Permeability To Water Of Selected Marine, Freshwater And Euryhaline Teleosts

1969 ◽  
Vol 50 (3) ◽  
pp. 689-703 ◽  
Author(s):  
DAVID H. EVANS
Keyword(s):  
Fresh Water ◽  
Brown Trout ◽  
Water Permeability ◽  
Sea Water ◽  
Tritiated Water ◽  
Marine Species ◽  
The Body ◽  
Freshwater Species ◽  
Silver Eel ◽  
As Species

Measurements were made of the flux of tritiated water across various marine, freshwater and euryhaline teleosts. The effects of temperature, body size, species differences, salinity, stress and anaesthetization were studied. 2. The Q10 of the flux of water across teleosts is approximately 1·90 and the flux is related to the 0·88 power of the body weight. 3. All of the freshwater species studied were more permeable to water than the marine species. Euryhaline teleosts appear to have about the same permeability as species to which they are most closely related. 4. While the flounder and the yellow eel are more permeable to water in fresh water than in sea water, the silver eel and the brown trout do not change their permeability and the 3-spined stickleback is less permeable to water in fresh water than in sea water. 5. While stress markedly increases the permeability to water of large brown trout, it has no effect on small brown trout and seems to decrease the water permeability of the plaice. 6. Anaesthetization has no effect on the water permeability of the goldfish but markedly increases the permeability to water of the silver eel. 7. The relationship between the flux of water and either the drinking rate in sea water or the urine flow in fresh water is discussed.

Sign in / Sign up

Export Citation Format

Share Document