The Osmoregulatory Ability of the Lampern (Lampetra Fluviatilis L.) In Sea Water During the Course of its Spawning Migration

1956 ◽  
Vol 33 (1) ◽  
pp. 235-248
Author(s):  
R. MORRIS
Keyword(s):  
Weight Loss ◽  
Osmotic Pressure ◽  
Fresh Water ◽  
Water Loss ◽  
Sea Water ◽  
Water Concentration ◽  
Rate Of Change ◽  
Plasma Chloride ◽  
Osmoregulatory Ability ◽  
Better Than

1. Although fresh-run lamperns are able to withstand the effects of increasing sea-water concentration better than maturing animals, they can only maintain their plasma chloride constant in environments more dilute than 50% sea water. This is achieved, in part, by gradually reducing the urine output from the normal fresh-water level (155.8 ml./kg./day) to a negligible rate in solutions which are mildly hypertonic to the blood (33% sea water). 2. Studies on the rate of change of weight loss, of plasma chloride and of plasma osmotic pressure following abrupt immersion in dilute sea water show that mature lamperns cannot osmoregulate and can only survive in 33% sea water by tolerating a raised blood osmotic pressure caused by water loss. 3. Similar experiments on fresh-run animals suggest that the external surfaces of their bodies are less permeable to water than mature animals. Unlike mature animals, they also show considerable variation in the way in which they respond to 33% sea water. Some are able to maintain their plasma osmotic pressure and chloride well below that of the environment. These animals also show little loss in weight, and this indicates that water is taken up actively, since this process has been shown to occur in some animals. Other fresh-run animals show raised plasma osmotic pressures in varying degrees and these are associated with larger losses of weight. These facts suggest that the hypotonic regulating mechanism gradually degenerates as the lampern enters fresh water.

Urea and Osmoregulation in the Diamondback Terrapin Malaclemys Centrata Centrata (Latreille)

1970 ◽  
Vol 52 (3) ◽  
pp. 691-697
Author(s):  
M. GILLES-BAILLIEN
Keyword(s):  
Osmotic Pressure ◽  
Fresh Water ◽  
Water Loss ◽  
Sea Water ◽  
Urea Concentration ◽  
Diamondback Terrapin ◽  
Salt Balance ◽  
Second Stage

1. The blood of the diamondback terrapin going from fresh water to 50% sea water shows an increase in its osmotic pressure which is mainly due to an increase in Na and Cl concentrations. 2. The blood of terrapins living in sea water compared with the blood of terrapins living in 50% sea water shows a higher osmotic pressure which is the result solely of a higher urea concentration; Na and Cl concentrations are no longer affected in this second stage of adaptation. 3. Urine of 50% sea-water terrapins and of sea-water terrapins is generally isosmotic to the blood while the urine of fresh-water terrapins is usually hypo-osmotic. 4. The bladder appears to play an essential part in reducing water loss in the sea-water terrapins but is not implicated in the salt balance. 5. When each animal is considered individually, the urea concentration in the urine is always higher than in the serum, suggesting that the high urea concentration in the blood of terrapins adapted to sea water is due to an urea accumulation in the bladder.

scholarly journals Comparative study on the corrosion behavior of mild steel in effluents, sea and fresh water

2020 ◽  
Vol 12 (1) ◽  
pp. 280-284
Author(s):  
Naja’atu Auwal Usman ◽  
Usman Muhammad Tukur ◽  
Bishir Usman
Keyword(s):  
Weight Loss ◽  
Corrosion Rate ◽  
Mild Steel ◽  
Water Sample ◽  
Fresh Water ◽  
Immersion Time ◽  
Sea Water ◽  
Oxygen Demand ◽  
Chloride Ion ◽  
X Rays

The corrosion rate of mild steel behavior exposed to effluents (EF), sea water (SW) and fresh water (FW) were study using weight loss, scanning electron spectroscopy (SEM) and x-rays diffraction (XRD). The results show that the weight loss of mild steel in different water samples increases with increasing in immersion time and temperature respectively. The corrosion rate of water was found to be higher in sea water (0.003g cm2 week-2), effluents (0.021g cm-2 week-2) and fresh water (0.020g cm-2 week-2) respectively. The corrosion rate and behaviour of mild steel in the water sample were affected by some physical and chemical parameters such as pH, turbidity, conductivity and biological oxygen demand (BOD). Effluents (EF) were found to have pH (5.20), turbidity (13.3nut), conductivity (4203µs/cm) and BOD (0.119mg/dm3). Sea water (SW) were found to have pH (7.60), turbidity (173nut), conductivity (30800µs/cm) and BOD (0.028mg/dm3). Fresh water (FW) were found to have pH (7.60), turbidity (127nut), conductivity (419µs/cm) and BOD (0.651mg/dm3). Similarly, the presences of elements such as chloride ion (Cl-), Fe, Ba, Br, S, La, Nb and Mo from XRF confirm that the corrosion rate is higher in sea water. SEM microgram revealed that corrosion rates of EF, SW and FW were of different nature, both the samples have rough surface with various cracks after immersion. This clearly shows that the sea water has the highest corrosion products follow by effluent than fresh water sample. Both the weight loss and corrosion rate increases as the immersion time and temperature increases. Keywords: Corrosion rate, Mild steel, Weight loss, AAS, SEM, XRF, Immersion Time, Temperature  

Hibernation and Osmoregulation in the Diamondback Terrapin Malaclemys Centrata Centrata (Latreille)

1973 ◽  
Vol 59 (1) ◽  
pp. 45-51
Author(s):  
M. GILLES-BAILLIEN
Keyword(s):  
Osmotic Stress ◽  
Blood Plasma ◽  
Osmotic Pressure ◽  
Fresh Water ◽  
Seasonal Variations ◽  
Sea Water ◽  
Tap Water ◽  
The Other ◽  
Diamondback Terrapin ◽  
Diamondback Terrapins

1. Two batches of diamondback terrapins have been kept for a whole year, one in sea water the other in tap water, and seasonal variations have been recorded in the composition and osmotic pressure of the blood plasma. 2. All year round the sea-water animals have a higher osmotic pressure and higher concentrations of Na, K, Cl and urea than fresh-water animals. It is in July, however, that these differences are the least marked. 3. The seasonal variations recorded are linked in particular to the conditions of osmotic stress imposed by the environment. 4. The results are discussed within the framework of hibernation and of the evolution among chelonians from fresh water to sea water.

The Adaptation of Gunda Ulvae to Salinity

1931 ◽  
Vol 8 (1) ◽  
pp. 82-94
Author(s):  
C. F. A. PANTIN
Keyword(s):  
Osmotic Pressure ◽  
Electric Conductivity ◽  
Fresh Water ◽  
Salt Concentration ◽  
Sea Water ◽  
Distilled Water ◽  
Dilute Solution ◽  
Dilute Solutions ◽  
The Moment ◽  
Limiting Value

1. The rate of loss of salts by the estuarine worm, Gunda ulvae, on transference from sea water to various dilute solutions has been studied by measurement of the electric conductivity of the solutions. 2. Salts are lost by the worms from the moment of immersion in dilute solutions. Conditions affecting the rate of loss of salts are discussed. 3. The relation between the amount of salts lost and the total electrolyte content of the worm was determined. It is shown that the worms only lose 25 per cent. of their salts during the time that they imbibe a volume of water from the dilute solution equal to their initial volume. 4. The limiting internal salt concentration of worms surviving in waters containing calcium is about 6-10 per cent. of the normal concentration in sea water. No such limiting value can be found for distilled water, since salts are lost continuously till cytolysis occurs. The significance of the limiting concentration is discussed. 5. The effect of osmotic pressure, pH, dilute solutions of NaCl, NaHCO3, glycerol, CaCl2 and CaCO3 are studied. The presence of calcium reduces the rate of loss of salts. Other factors do not seem to influence this rate. 6. The relation of calcium to the maintenance of normal permeability to water and salts in the worm, and the significance of this to the problem of migration into fresh water are discussed.

scholarly journals Biodegradation of poly(ε-caprolactone) in natural water environments

2017 ◽  
Vol 19 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Aleksandra Heimowska ◽  
Magda Morawska ◽  
Anita Bocho-Janiszewska
Keyword(s):  
Weight Loss ◽  
Surface Morphology ◽  
Baltic Sea ◽  
Fresh Water ◽  
Sea Water ◽  
Characteristic Parameters ◽  
The Baltic Sea ◽  
Loss Of Weight ◽  
Water Pond ◽  
The Baltic

AbstractThe environmental degradation of poly(ε-caprolactone)[PCL] in natural fresh water (pond) and in The Baltic Sea is presented in this paper. The characteristic parameters of both environments were measured during experiment and their influence on the biodegradation of the samples was discussed. The loss of weight and changes of surface morphology of polymer samples were tested during the period of incubation. The poly(ε-caprolactone) was more biodegradable in natural sea water than in pond. PCL samples were completely assimilated over the period of six weeks incubation in The Baltic Sea water, but after forty two weeks incubation in natural fresh water the polymer weight loss was about 39%. The results have confirmed that the investigated polymers are susceptible to an enzymatic attack of microorganisms, but their activity depends on environments.

Corrosion of Metals in Tropical Environments

CORROSION ◽  
1960 ◽  
Vol 16 (10) ◽  
pp. 512t-518t ◽  
Author(s):  
C. R. SOUTHWELL ◽  
B. W. FORGESON ◽  
A. L ALEXANDER
Keyword(s):  
Weight Loss ◽  
Carbon Steel ◽  
Fresh Water ◽  
Sea Water ◽  
Exposure Period ◽  
Natural Environments ◽  
Wrought Iron ◽  
Tropical Water ◽  
Tropical Environments ◽  
The Tropics

Abstract This paper discusses the corrosion of Aston process wrought iron when exposed to five natural environments in the tropics. Data are reported covering an exposure period of eight years during which the metal was immersed at mean tide and continuously in fresh water and in the sea. Data are presented also from atmospheric exposures including both marine and inland atmospheres. Results indicate that corrosion (measured by weight loss) in fresh water is about equal to that which occurs at mean tide, while corrosion proceeds at the greatest rate during continuous immersion in the sea. Millscale on wrought iron accelerates pitting most severely on metal immersed continuously in the sea, although to a lesser degree than structural steel similarly exposed. It is suggested further that during the earlier exposure of wrought iron and mild steel to tropical water there is little difference in the rates at which the two metals corrode. After eight years, however, the steel shows a significantly greater weight loss. The corrosion of metallic couples of wrought iron and carbon steel in both fresh water and sea water is discussed. 4.2.7

scholarly journals The osmotic changes in some marine animals

1931 ◽  
Vol 107 (754) ◽  
pp. 606-624 ◽  
Keyword(s):  
Osmotic Pressure ◽  
Fresh Water ◽  
Marine Invertebrates ◽  
Sea Water ◽  
Body Fluids ◽  
The Body ◽  
Marine Animals

Since Bottazzi's (1897) first determinations of the osmotic pressure of the body fluids of various marine animals many researches have been performed by other authors, particularly in reference to the permeability of the membranes separating the body from its surroundings. Bottazzi (1897, 1906, 1908, b) investigated individuals belonging to very different groups of animals, and found that the osmotic pressure of the body fluids of marine invertebrates, and of elasmobranchs, is very similar to that of the surroundings, while the osmotic pressure of the blood of teleosts is quite different. Changing the osmotic pressure of the medium, the osmotic pressure of most marine invertebrates, and of elasmobranchs, was shown to change in the same direction (L. Fredericq, 1882, 1904; Quinton, 1897; Dakin, 1908) and to reach, finally, the value of the former. The blood of teleosts is much more independent of the medium, for it shown to change only about 30 percent, in concentration, on transferring the animals from sea water to fresh water or vice versa (Dakin, 1908; Dekhuyzen, 1904: Sumner, 1905); other authors, however (fredericq, 1904: Garrey, 1905) could not field even these variations.

The salt route through time and space: Following horizontal and lateral intrusion of brackish surface water into a natural floating root mat and its plant community.

2021 ◽  
Author(s):  
Milou Huizinga ◽  
Rien Aerts ◽  
Richard S.P. van Logtestijn ◽  
Sjoerd E.A.T.M. van der Zee ◽  
Jan-Philip M. Witte
Keyword(s):  
Surface Water ◽  
The Netherlands ◽  
Fresh Water ◽  
Plant Community ◽  
Salt Concentration ◽  
Sea Water ◽  
Root Zone ◽  
Salt Water ◽  
Soil Layer ◽  
Water Concentration

<p>Salinizing surface water is a large problem worldwide. In many areas agriculture is dependent on surface water irrigation, but there is an increasing fresh water scarcity. Due to natural and anthropogenic processes the salt concentration of surface water has risen and this problem is predicted to increase in the future. Prioritizing on when fresh water is needed and when brackish or salt water could be possible is therefor necessary. However, this holds not only for agricultural systems, but also for natural areas which are currently overlooked. In deltaic areas – such as The Netherlands – sea water is flowing further inland via rivers during summer. In addition to this, in the hinterland, artificial drainage of low-lying polders leads to a salt groundwater surplus that is discharged into rivers and surface water reservoirs. These processes lead to salinization and could potentially affect plant biodiversity and ecosystem functioning in surface water fed ecosystems, wetlands, and riparian zones. One of such a surface water fed ecosystems is an abandoned turf extraction site ‘De Botshol’ in The Netherlands. Floating root mats have developed from peat baulks into the open water of old turf ponds. These mats can harbor a great deal of protected terrestrial, typically glycophyte (i.e. optimally encountering < 300 mg Cl.l-1), plant species related to a floating fen habitat. Currently the surface water quality of Botshol is brackish and this provided us with an opportunity to follow the local salt route through space and time. Surface water salt concentrations fluctuated slightly between winter-spring: 1400 mg Cl.l-1 and summer-autumn: 1900 mg Cl.l-1 and we linked this to root zone processes and the plant community. We used a pore water extraction setup using micro- and macrorhizons placed at 30 – 60 – 200 cm from the edge of a floating root mat. Along this transect we measured at 10 – 25 – 50 – 70 cm depth. Via this setup we were able to find that the root zone salt concentrations fluctuated with surface water concentration, however there was a substantially lower salt concentration in the soil layer. Root zone concentrations still reached above 500 mg Cl.l-1 and this might explain differences in community composition in comparison with a fresh floating fen ecosystem (e.g. ‘Nieuwkoopse Plassen’, The Netherlands). We present this work to empirically link hydrology and ecology in relation to surface water salinization, but also to practically inform water boards and nature managers to understand possibilities and limitations of surface water salinization in relation to fen restoration and protection.</p>

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.

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.

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