Water Uptake and Loss in Relation to the Salinity of the Medium in the Amphipod Crustacean Gammarus Duebeni

1973 ◽  
Vol 58 (1) ◽  
pp. 149-163
Author(s):  
A. P. M. LOCKWOOD ◽  
C. B. E. INMAN
Keyword(s):  
Body Surface ◽  
Sea Water ◽  
Tritiated Water ◽  
Prima Facie ◽  
Urine Flow ◽  
The Body ◽  
Osmotic Gradient ◽  
Prima Facie Case ◽  
Urine Production ◽  
Water Saturated

1. The water fluxes across the body surface and the rate of urine production have been studied in the euryhaline amphipod Gammarus duebeni. 2. Urine flow rates (fPOs) have been determined from measurements of loss of [131I]sodium diatrizoate from the body, and the expected urine flow (fPdiff) has been calculated from determinations of the osmotic gradient between blood and medium and the flux of tritiated water. 3. For animals in 2% and 40% sea water the ratio fPOs/fPdiff are 1.16 and 1.44 respectively, and thus approximate fairly closely to unity. This implies that in these media the water subsequently excreted as urine enters the body by osmosis and that there is little interference with the free diffusion of water at the body surface due to passage through long pores or across unstirred layers. 4. In sea water the ratio fPOs/fPdiff is normally (assuming an osmotic gradient of 10 m-osmoles) almost twice unity but urine production is approximately halved when the animals are exposed to sea water saturated with an inhibitor of active sodium uptake (thionine). 5. It is suggested that there is a prima facie case for assuming that part of the fluid subsequently excreted by this species, when in sea water, is taken into the body initially by a process dependent upon active ion transport.

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.

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.

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.

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.

Potassium metabolism and the accumulation of 137Caesium by decapod Crustacea

1962 ◽  
Vol 42 (2) ◽  
pp. 199-241 ◽  
Author(s):  
G. W. Bryan ◽  
Eileen Ward
Keyword(s):  
Body Surface ◽  
Soft Tissues ◽  
Sea Water ◽  
The Body ◽  
Limiting Factor ◽  
Freshwater Crayfish ◽  
Marine Animals ◽  
Decapod Crustacea ◽  
Concentration Factors ◽  
Potassium Metabolism

SUMMARYThe accumulation of 137Cs from sea water has been examined in relation to potassium metabolism in the lobster Homarus vulgaris and in the prawn Palaemon serratus. In unfed animals 137Cs is taken up and lost far more slowly than 42K. Although all the inactive K in the animals can be exchanged with 42K, higher whole-animal concentration factors are reached for 137Cs (about eight for lobsters and twenty-five for prawns). This is because both species have higher plasma/medium ratios for 137Cs than K at equilibrium despite the selective excretion of 137Cs. Also, except for the hepatopancreas in lobsters and fed prawns, all soft tissues can probably attain higher tissue/plasma ratios for 137Cs than inactive K.Uptake of both isotopes has also been studied in the freshwater crayfish Austropotamobius pallipes pallipes. In crayfish in o-i % sea water 137Cs is not concentrated to the same extent as K by whole animals (50-200 for 137Cs against about 4500 for K). Although the situation between plasma and tissues resembles that in the marine animals, 137Cs cannot be accumulated in the plasma to the same degree as K. Crayfish selectively excrete 137Cs in the urine relative to K at a lower concentration than in the plasma.In the accumulation of 137Cs by all species, muscle is the principal limiting factor in uptake and loss, but with 42K the body surface becomes more limiting.Experiments on the absorption of 137Cs from food in prawns and freshwater crayfish have been carried out. In prawns in a constant environment, feeding is probably less important than uptake over the body surface while in crayfish feeding is probably much more important.

scholarly journals Adaptive Changes of the Water Permeability of the Teleostean Gill Epithelium in Relation to External Salinity

1969 ◽  
Vol 51 (2) ◽  
pp. 529-546 ◽  
Author(s):  
R. MOTAIS ◽  
J. ISAIA ◽  
J. C. RANKIN ◽  
J. MAETZ
Keyword(s):  
Fresh Water ◽  
Water Flow ◽  
Sea Water ◽  
Tritiated Water ◽  
Osmotic Gradient ◽  
Ionic Exchange ◽  
Gill Epithelium ◽  
Osmotic Water ◽  
Water Fish ◽  
External Salinity

1. Cannulation of afferent and efferent branchial vessels in the eel permitted studies of tritiated water clearance. It was observed that most of the diffusional water flow occurs through the gills. 2. Diffusional and osmotic water flows have been measured in a fresh-water (Carassius), a marine (Serranus) stenohaline fish and in two euryhaline species (Platichthys and Anguilla) adapted to either fresh water or sea water, and are found to be lower than in any comparable epithelia so far studied. 3. The diffusional water flow deduced from THO turnover is significantly smaller in the sea-water fish. 4. The osmotic water flow, determined indirectly by measuring drinking rate and urine flow, is smaller in the sea-water fishes despite a greater osmotic gradient across the gills. 5. Attempts to compare diffusional and osmotic permeabilities for the gill are hindered by our ignorance of the extent of solute (salt)-solvent interaction in the epitheium. It is suggested that the gill of the fresh-water-adapted fishes is semi permeable, while that of the sea-water teleosts may not be, because of the very high ionic exchange across the gill. 6. The surprisingly low diffusional and osmotic permeabilities of the gill epithelium in sea-water fish may be possibly related to the absence of water-filled pores.

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.

Internal Volume and Pressure Regulation in Carcinus Maenas

1978 ◽  
Vol 74 (1) ◽  
pp. 123-132
Author(s):  
J.R. W. NORFOLK
Keyword(s):  
Internal Pressure ◽  
Sea Water ◽  
Alternative Hypothesis ◽  
Carcinus Maenas ◽  
External Environment ◽  
Mean Value ◽  
Urine Flow ◽  
Pressure Regulation ◽  
Urine Production ◽  
Internal Volume

In Carcinus, in dilute media, internal volume and pressure were found to be regulated by the intermittent release of urine which maintained internal pressure at a mean value of 15 cm water, compared to a mean value of 10 cm for crabs in sea water. Following transfer of crabs from 100% to 50% sea water, urine production (measured by a continuous collection method) was observed to increase within 5 min of dilution of the medium, by which time the estimated increase in internal pressure would have been only 1.3 cm water. Such a pressure increase is considered inadequate to stimulate a rise in urine production, since artificially raising internal pressure of crabs in sea water did not result in an increase in urine flow, until the pressure was in excess of 20 cm water. The results support the hypothesis that the stimulus to increase urine production by crabs in dilute media is not raised internal pressure due to osmotic influx of water. An alternative hypothesis, namely that of changes in urine production being in response to direct monitoring of the external environment, is suggested.

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.

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