Osmotic Balance in Hydrobia Ulv Ae and Potamopyrgus Jenkinsi (Gastropoda: Hydrobiidae)

1964 ◽  
Vol 41 (3) ◽  
pp. 665-677
Author(s):  
MARY E. TODD
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Freezing Point ◽  
Phenol Red ◽  
Ecological Groups ◽  
Experimental Conditions ◽  
Osmotic Concentration ◽  
Hydrobia Ulvae ◽  
Osmotic Balance ◽  
Potamopyrgus Jenkinsi

1. Osmotic balance was studied in Hydrobia ulvae and Potamopyrgus jenkinsi over the range 100% sea water to fresh water, by determining the freezing-point depression of the urine in the different solutions. 2. Hydrobia ulvae was slightly hyperosmotic from 100 to 50% sea water, and sometimes initially markedly hyperosmotic in 25% sea water at 5°C. The urine was always markedly hyperosmotic relative to fresh water, and the animals were withdrawn. Experiments with phenol red indicated that the tissues were not shut off from the medium. 3. Potamopyrgus jenkinsi was hyperosmotic from fresh water to 100% sea water. Osmotic balance in fresh water is maintained in part by the excretion of a urine hypo-osmotic relative to the blood. 4. There was some variation in the reaction of different ecological groups of Hydrobia ulvae and Potamopyrgus jenkinsi to the experimental conditions. 5. In the Hydrobiidae, whether transformed from a lower to a higher salinity or vice versa, survival outside the viable range was longer at 5°C. than at 15°C., although, within the range, activity occurred more rapidly at 15°C. 6. In fresh water, winter animals of both species had a higher osmotic concentration of the urine than summer animals, but no differences in osmotic concentration correlated with temperature were demonstrated.

Characteristics of Sea-Water Ice Slurry for Cooling of Fish

2013 ◽  
Vol 388 ◽  
pp. 123-127 ◽  
Author(s):  
Agus Sunjarianto Pamitran ◽  
Helmi Dadang Ardiansyah ◽  
Mach Novviali
Keyword(s):  
Solid Surface ◽  
Chemical Equilibrium ◽  
Sea Water ◽  
Freezing Point ◽  
Good Time ◽  
Ice Slurry ◽  
High Quality ◽  
Experimental Conditions ◽  
Water Ice ◽  
Cooling Method

A more effective of cooling method is necessary for fish storage to get high quality and long freshness of fish. Ice block is not sufficient for fish storage because of its hard-solid surface that can damage the fish. Moreover for some remote area it is difficult to find ice block in good time with reasonable/low price. One solution for this problem is the using of sea-water ice slurry for fish cooling. Ice slurry is formed when the sea-water temperature goes down to its freezing point, when the early nucleation is formed. Crystal ice can be formed when chemical equilibrium is occurred. The purpose of this present study is to observe the characteristics of ice slurry generation using scraper blade evaporator and orbital rod evaporator. The experiment is done under some experimental conditions.

The evolution of under-ice melt ponds, or double diffusion at the freezing point

1974 ◽  
Vol 64 (3) ◽  
pp. 507-528 ◽  
Author(s):  
Seelye Martin ◽  
Peter Kauffman
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Freezing Point ◽  
Salt Water ◽  
Ice Sheet ◽  
Water Layer ◽  
Double Diffusion ◽  
Theoretical Models ◽  
Interfacial Region ◽  
Ice Melt

In an experimental and theoretical study, we model a phenomenon observed in the summer Arctic, where a fresh-water layer at a temperature of 0°C floats both over a sea-water layer at its freezing point and under an ice layer. Our results show that the ice growth in this system takes place in three phases. First, because the fresh-water density decreases upon supercooling, the rapid diffusion of heat relative to salt from the fresh to the salt water causes a density inversion and thereby generates a high Rayleigh number convection in the fresh water. In this convection, supercooled water rises to the ice layer, where it nucleates into thin vertical interlocking ice crystals. When these sheets grow down to the interface, supercooling ceases. Second, the presence of the vertical ice sheets both constrains the temperatureTand salinitysto lie on the freezing curve and allows them to diffuse in the vertical. In the interfacial region, the combination of these processes generates a lateral crystal growth, which continues until a horizontal ice sheet forms. Third, because of theTandsgradients in the sea water below this ice sheet, the horizontal sheet both migrates upwards and increases in thickness. From one-dimensional theoretical models of the first two phases, we find that the heat-transfer rates are 5–10 times those calculated for classic thermal diffusion.

Osmoregulation in Ligia Oceanica and Idotea Granulosa

1963 ◽  
Vol 40 (2) ◽  
pp. 381-392
Author(s):  
MARY E. TODD
Keyword(s):  
Blood Concentration ◽  
Sea Water ◽  
Freezing Point ◽  
Freezing Point Depression ◽  
External Concentration ◽  
Osmotic Concentration ◽  
Test Range ◽  
The Mean ◽  
The Difference ◽  
Idotea Granulosa

1. The osmoregulatory response of Ligia oceanica and Idotea granulosa to the range of the experimental variables was similar. They were both hyperosmotic relative to the medium and the difference between internal and external concentration increased as the salinity of the medium decreased. 2. In 100% sea water the osmotic concentration of the blood of Ligia oceanica was markedly above that of the medium, whereas in Idotea granulosa the blood was only marginally hyperosmotic. 3. In Ligia oceanica the blood concentration changed little in 100 and 75% sea water, but dropped significantly between 75 and 50% sea water, whereas blood concentration in Idotea granulosa dropped significantly throughout the test range of salinities. 4. The more efficient osmoregulation of Ligia oceanica in 25% sea water is reflected in the mean freezing-point depression of the blood, Δi = 1.65, compared with Δi = 0.90 in Idotea granulosa. 5. In both species the osmotic concentration of the blood was influenced by season, by temperature and by a temperature-salinity interaction. 6. Neither size nor sex of the animal influenced osmotic concentration of the blood.

Osmotic regulation in the embryo of the herring (Clupea harengus)

1965 ◽  
Vol 45 (2) ◽  
pp. 305-311 ◽  
Author(s):  
F. G. T. Holliday ◽  
M. Pattie Jones
Keyword(s):  
Sea Water ◽  
Freezing Point ◽  
Body Fluids ◽  
Clupea Harengus ◽  
Osmotic Regulation ◽  
Osmotic Concentration ◽  
Significant Change

Just before spawning the semen of the herring is isosmotic with the parent blood, the eggs are hyposmotic. Immediately the eggs are placed in sea water of salinities 5, 17·5, 35 and 50 %0 there is a change in the freezing-point of the yolk indicating that it has approached close to being isosmotic with the water. Changes in the freezing-point of the yolk during development indicate that the overgrowing embryo gradually regulates the osmotic concentration of the yolk, although full regulation is not achieved until after the closing of the blastopore. After this point there is no significant change in the freezing-point of the yolk or body fluids. Regulation is most probably brought about by the activity of the cells of the ectoderm.

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.

Osmotic Regulation in Mosquito Larvae

1950 ◽  
Vol 27 (2) ◽  
pp. 145-157 ◽  
Author(s):  
J. A. RAMSAY
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
External Medium ◽  
Freezing Point ◽  
Anterior Part ◽  
Osmotic Regulation ◽  
Opposite Process ◽  
Normal Environment ◽  
Different Parts

1. The processes of osmotic regulation in the larvae of Aedes aegypti and of A. detritus have been studied by determination of the freezing-point of samples of fluid collected from different parts of the gut. 2. In A. aegypti, kept in fresh water (its normal environment), the fluid passing down the intestine to the rectum is isotonic with the haemolymph. In the rectum it becomes strongly hypotonic before being eliminated. 3. In A. detritus, kept in sea water (its normal environment), the opposite process is observed, the fluid in the rectum becoming hypertonic to the haemolymph and approximately isotonic with the external medium before being eliminated. 4. In A. detritus, which is able to live in dilute media as well as in sea water, the only two specimens from fresh water available for examination were found to have the rectal fluid hypotonic to the haemolymph. 5. The ability of A. detritus, not possessed by A. aegypti, to produce an hypertonic fluid in the rectum is tentatively associated with a region in the anterior part of the rectum and lined with an epithelium distinctly different from that in the remainder of the rectum. This anterior region has not been found in A. aegypti.

Changes in Body Chloride, Density, and Water Content of Chum (Oncorhynchus keta) and Coho (O. kisutch) Salmon Fry when Transferred from Fresh Water to Sea Water

1951 ◽  
Vol 8b (3) ◽  
pp. 164-177 ◽  
Author(s):  
Virginia Safford Black
Keyword(s):  
Water Content ◽  
Fresh Water ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Sea Water ◽  
The Body ◽  
Oncorhynchus Keta ◽  
Normal Range ◽  
Experimental Conditions ◽  
Salmon Fry

Changes in body chloride, density and water content of chum and coho salmon fry were measured when these fish were transferred from fresh water to sea water, and the reverse. Both species tolerated 50% sea water (8–9‰ Cl). Chum fry survived direct transfer from fresh water to sea water (15–17‰ Cl), but showed a marked increase in body chloride during the first 12 hours, followed by a return to the normal range between 12 and 24 hours. Coho, however, died within the first 36 hours, after a 60% increase in chloride. Coho fry lost more water than chum fry after introduction to sea water. The density of both species approximated that of the water within an hour of transfer to the new medium. When returned to fresh water after 12 hours in sea water the body chloride, density, and water content of both species regained normal levels within 10 hours. Chum salmon go to sea as fry, whereas cohos remain in fresh water a year or more. Although coho fry seem capable of some adjustment to sea water after a preliminary period in 50% sea water, permanent acclimatization could not be demonstrated under the experimental conditions.

scholarly journals Irrigation management strategies through the combination of fresh water and desalinated sea water for banana crops in El Hierro, Canary Islands

2021 ◽  
Author(s):  
Sergio J. Álvarez-Méndez ◽  
Isidro Padrón-Armas ◽  
Jalel Mahouachi
Keyword(s):  
Fresh Water ◽  
Canary Islands ◽  
Sea Water ◽  
Irrigation Management ◽  
Management Strategies ◽  
Experimental System ◽  
Mineral Nutrient ◽  
Experimental Conditions ◽  
El Hierro ◽  
Banana Crops

Abstract The current lack of natural water resources, mainly due to the absence of sufficient precipitation and the deterioration of irrigation water (IW) quality, urges to search for alternative resources, especially in arid and semiarid areas. Desalination of sea water is well established in numerous regions where water is scarce. To investigate the effects of the combination of regular fresh water and desalinated sea water (DSW) on mineral nutrient changes in crops, an experimental system based on Musa acuminata AAA plants was performed in Frontera (El Hierro, Canary Islands). Data showed that banana crops irrigated with a mixture of fresh water and DSW exhibited an adequate nutritional status and did not suffer any injuries of salt ions (Na+ and Cl−) or B toxicity. Moreover, plants may tolerate higher concentrations of these elements and a major supply of the other essential micronutrients. The obtained results suggest that irrigating crops with a combination of fresh water and DSW is a good strategy to respond to the high water requirements, at least under the tested experimental conditions. This strategy could be very helpful in arid regions, as well as in other areas where precipitation is seasonal and scarce, like the Mediterranean or the Canaries.

Osmotic and Ionic Regulation in Scottish Brown Trout and Sea Trout (Salmo Trutta L.)

1959 ◽  
Vol 36 (2) ◽  
pp. 253-260
Author(s):  
MALCOLM S. GORDON
Keyword(s):  
Fresh Water ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Sea Water ◽  
Freezing Point ◽  
Water Levels ◽  
Acid Base Balance ◽  
Serum Samples ◽  
Water Stream ◽  
Sea Trout

1. Adult brown trout (Salmo trutta L.) of both sea-run (sea trout) and fresh-water stream (brown trout) forms were captured in the vicinity of Aberdeen and acclimatized to full-strength sea water for periods of up to 5 months. 2. Blood serum samples from these fish were analysed for freezing-point depression, chloride, sodium and potassium concentrations. 3. The patterns of regulation of these concentrations are very nearly the same in both forms. Brown trout and sea trout, at least in eastern Scotland, thus appear to be virtually identical in osmotic and ionic regulatory abilities. However, there is a possibility that there is a difference between the two forms with respect to mechanisms controlling blood acid-base balance. 4. The patterns of regulation shown by Scottish fish are the same as those shown by American hatchery fish treated similarly. The different populations of the species seem not to have diverged significantly from one another in this regard after many generations of more or less complete genetic isolation. 5. The species Salmo trutta is strongly homoiosmotic. Internal concentrations are either unchanged or increase by less than 10% above fresh-water levels with long-term acclimatizations to half and full sea water. The brown trout is the first salmonid species known to regulate so well.

2. Inquiry whether Sea Water has its Maximum Density at some degrees above its freezing point, after the manner of fresh water

1845 ◽  
Vol 1 ◽  
pp. 203-204
Author(s):  
Hope
Keyword(s):  
Fresh Water ◽  
Short Range ◽  
Sea Water ◽  
Freezing Point ◽  
Maximum Density ◽  
Considerable Importance ◽  
General Law

Dr Hope stated that it has been considered a matter of considerable importance in the reasonings of geologists and hydrographers respecting some oceanic phenomena, whether sea water obeys at all temperatures the general law of expansion by heat, and contraction by cold, or, after the manner of fresh water, observes the anomalous course of contracting by heat, and expanding by cold, during a short range of temperature near its congealing point.

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