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.

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.

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.

Responses and acclimation to salinity in the adults of some balanomorph barnacles

1970 ◽  
Vol 256 (810) ◽  
pp. 377-400 ◽  
Keyword(s):  
Blood Concentration ◽  
Sea Water ◽  
Freezing Point ◽  
Mantle Cavity ◽  
Salinity Acclimation ◽  
Low Salinity ◽  
Tissue Resistance ◽  
Wide Range ◽  
External Salinity ◽  
Balanus Balanoides

The responses of a number of barnacles to a wide range of salinity have been studied by observation of the activity and measurement of the depression of freezing point of the blood. In active barnacles of the species Elminius modestus, Balanus balanoides, B. crenatus, B. improvisus, B. hameri, B. balanus and Chthamalus stellatus the blood concentration conforms with changes in the external salinity. The concentration of the blood tends to remain slightly hyperosmotic to the fluid in the mantle cavity, and to the medium. With sudden changes of external salinity the blood concentration conforms within a few hours if cirral activity is maintained. When placed in such low salinities that activity is inhibited, E. modestus, B. balanoides, B. crenatus, B. improvisus, B. balanus and C. stellatus close the opercular valves with the result that the blood and mantle cavity fluid are maintained for some time at a level initially considerably hyperosmotic to the medium, but the blood is still only slightly hyperosmotic to the fluid remaining in the mantle cavity. There is no permanent control, and in time the blood concentration approximates to the external level. E. modestus, B. balanoides and B. improvisus from low salinity estuarine habitats, and B. crenatus after gradual reduction of salinity in the laboratory over a matter of days, exhibit tolerance to lower salinities than do specimens of the same species obtained from, or acclimated to normal salinities. Salinity acclimation is typical of osmoconformers lacking specific organs for effective regulation. It is concluded that the barnacles here tested are osmoconformers, able to adjust to small changes of environmental salinity by tissue acclimation, but evading too severe salinity changes by withdrawing into the protection of the shell. The deep sea B. hameri , however, does not close up when immersed in dilute sea water, and appears to be relatively stenohaline with limited ability to acclimate to low salinity. The intertidal E. modestus and B. balanoides , and the low-tidal to sublittoral B. crenatus , are tolerant, after experimental or natural acclimation, of salinities down to 14 to 17 ‰. The estuarine B. improvisus can, with gradual acclimation, be induced to be active in a salinity of about 2 ‰ . This species is remarkably tolerant of dilution of the blood, and its distribution into regions of low salinity is evidently due to a wide tissue resistance and not to any ability to regulate.

Activation of the Sodium Uptake System at High Blood Concentrations in the Amphipod Gammarus Duebeni

1964 ◽  
Vol 41 (2) ◽  
pp. 447-458
Author(s):  
A. P. M. LOCKWOOD
Keyword(s):  
Blood Volume ◽  
Blood Concentration ◽  
Sea Water ◽  
Sucrose Solution ◽  
Deionized Water ◽  
Rate Of Change ◽  
Osmotic Gradient ◽  
Uptake System ◽  
Absolute Concentration ◽  
Blood Concentrations

1. Some factors responsible for eliciting an increase in the rate of active uptake of sodium by Gammarus duebeni have been studied. 2. Animals previously acclimatized to high salinities (100-161% sea water) had their blood concentration suddenly lowered by treatment with deionized water to a level similar to, but a little above, that of animals kept in 50-66% sea water. Both groups were placed in the same tracer medium, i.e. 5% sea water labelled with 22Na and with sucrose added. The animals treated with deionized water showed an influx, on average, of 4 times that of the controls from 50 to 66% sea water. 3. No increase in influx followed treatment of animals from 161% sea water with 50% sea water or with sucrose solution isosmotic with 50% sea water, despite the fact that the osmotic gradient between 161 and 50% sea water is greater than the gradient between 100% sea water and deionized water. 4. It is concluded that in these experiments the rate of uptake is not influenced primarily by the absolute concentration of the blood, the rate of change of blood concentration, the rate of swelling of the tissues or the extent of the blood volume. 5. The possibility is considered that both the concentration of the urine and the rate of uptake of sodium may, in some circumstances, be controlled by an exteroreceptor which monitors the concentration of the medium and mediates its effect via a humoral system.

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.

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.

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.

Distribution of water in Arenicola marina (L.) equilibrated to diluted sea water

1977 ◽  
Vol 57 (2) ◽  
pp. 501-519 ◽  
Author(s):  
R. F. H. Freeman ◽  
T. J. Shuttleworth
Keyword(s):  
Volume Regulation ◽  
Sea Water ◽  
Body Fluids ◽  
The Body ◽  
External Concentration ◽  
Osmotic Concentration ◽  
Osmotic Adaptation ◽  
Arenicola Marina ◽  
Additional Information ◽  
Wide Range

It is our aim in this paper to answer three questions. All of them relate to the well-known ability of lugworms to act as isosmotic osmo-conformers over a wide range of salinities. When exposed to diluted sea water, the body fluids come into osmotic equilibrium with the lowered external concentration, and considerable amounts of water enter the body of the worm. There is no evidence of weight or volume regulation in dilute media, as assessed by a return of the body weight towards its original value. The processes of osmotic adaptation down to the lowest salinity limits for survival include, therefore, tolerance of a lowered osmotic concentration of the body fluids, and of the retention of increased amounts of water in the body. The evidence on which this view of osmotic adaptation in lugworms is based is reviewed by Oglesby (1969, 1973). Additional information on Arenicola marina is provided by Freeman & Shuttleworth (1977).

scholarly journals The Survival of Haloferax mediterranei under Stressful Conditions

2021 ◽  
Vol 9 (2) ◽  
pp. 336
Author(s):  
Laura Matarredona ◽  
Mónica Camacho ◽  
Basilio Zafrilla ◽  
Gloria Bravo-Barrales ◽  
Julia Esclapez ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Sea Water ◽  
Industrial Applications ◽  
Growth Responses ◽  
Haloferax Mediterranei ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Wide Range ◽  
High Metal ◽  
Plasma Mass Spectrometry

Haloarchaea can survive and thrive under exposure to a wide range of extreme environmental factors, which represents a potential interest to biotechnology. Growth responses to different stressful conditions were examined in the haloarchaeon Haloferax mediterranei R4. It has been demonstrated that this halophilic archaeon is able to grow between 10 and 32.5% (w/v) of sea water, at 32–52 °C, although it is expected to grow in temperatures lower than 32 °C, and between 5.75 and 8.75 of pH. Moreover, it can also grow under high metal concentrations (nickel, lithium, cobalt, arsenic), which are toxic to most living beings, making it a promising candidate for future biotechnological purposes and industrial applications. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis quantified the intracellular ion concentrations of these four metals in Hfx. mediterranei, concluding that this haloarchaeon can accumulate Li+, Co2+, As5+, and Ni2+ within the cell. This paper is the first report on Hfx. mediterranei in which multiple stress conditions have been studied to explore the mechanism of stress resistance. It constitutes the most detailed study in Haloarchaea, and, as a consequence, new biotechnological and industrial applications have emerged.

scholarly journals 1174. Phase 2 STRIVE Clinical Trial of Rezafungin for Treatment of Candidemia and/or Invasive Candidiasis Demonstrates Consistent Trough Concentrations Across Diverse Patient Populations

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S612-S613
Author(s):  
Shawn Flanagan ◽  
Christopher M Rubino ◽  
Taylor Sandison
Keyword(s):  
Body Weight ◽  
Invasive Candidiasis ◽  
Fungal Infections ◽  
Standard Of Care ◽  
Geographic Region ◽  
Continuous Variables ◽  
Phase 2 ◽  
Double Blind ◽  
Wide Range ◽  
Diverse Patient Populations

Abstract Background Rezafungin is a novel echinocandin antifungal in development for treatment as well as prevention (prophylaxis) of invasive fungal infections. STRIVE (NCT02734862) is a global, randomized, double-blind, placebo-controlled, Phase 2 trial evaluating safety and efficacy of IV rezafungin once weekly (QWk) for treatment of candidemia and/or invasive candidiasis compared with standard-of-care (IV caspofungin once daily with optional oral stepdown). Here we report pharmacokinetic (PK) data from the completed STRIVE trial analyzed by patient demographics at baseline. Methods Rezafungin Day 8 trough (Cmin) concentrations from patients treated with rezafungin were summarized categorically by race (black or white), sex (male or female), and geographic region (North America [NA], or Europe [EU]), or plotted versus continuous variables of age, body weight, body mass index (BMI), and body surface area (BSA). As the first dose of rezafungin was 400 mg for all rezafungin-treated patients, data from both dose groups (Group 1: 400 mg QWk; Group 2: 400 mg in Week 1 followed by 200 mg QWk) were combined in this analysis. Results Rezafungin mean Cmin (SD) values were 1.8 (0.7) and 2.3 (1.2) in black and white patients, 1.9 (1.0) and 2.6 (1.2) in males and females, and 1.9 (0.6) and 2.4 (1.3) in patients from NA and EU. There were small differences in point estimates between the groups, but there was a great deal of overlap and the differences are not expected to be clinically meaningful (Figure). Similarly, no trends in Cmin values were observed across a range of ages (20-80 years), weights (~40-155 kg), BMI (~15-65 kg/m2), and BSA (~1.4-2.4 m2). Figure Conclusion No meaningful differences in rezafungin Cmin values were observed in patients grouped by sex, race, or geographic region, or across a wide range of patient factors, including age and body weight and size. These findings indicate that a single rezafungin dose regimen can be expected to provide consistent PK across diverse patient populations. Disclosures Shawn Flanagan, PhD, Cidara Therapeutics, Inc. (Employee, Shareholder) Christopher M. Rubino, PharMD, Institute for Clinical Pharmacodynamics, Inc. (Employee)Spero Therapeutics (Grant/Research Support) Taylor Sandison, MD, MPH, Cidara Therapeutics, Inc. (Employee, Shareholder)

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