scholarly journals The Adaptation of Mosquito Larvae to Salt Water

1933 ◽  
Vol 10 (1) ◽  
pp. 27-36 ◽  
Author(s):  
V. B. WIGGLESWORTH
Keyword(s):  
Basement Membrane ◽  
Fresh Water ◽  
Mosquito Larva ◽  
Sea Water ◽  
Salt Water ◽  
Physiological Adaptation ◽  
Mosquito Larvae ◽  
Salt Solutions ◽  
Newly Hatched Larvae

Larvae of Aedes argenteus reared in fresh water are killed by 1.1 per cent. NaCl or by "sea water"1 isotonic with 1.3-1.4 per cent. NaCl. Newly hatched larvae are killed by 1.1 per cent. NaCl or "sea water" equivalent to 1.3 per cent. NaCl. By gradually increasing the concentration, larvae can be made resistant to 1.1 per cent. NaCl and to "sea water" equivalent to 1.75 percent. NaCl (50 per cent. sea water). The nature of the physiological adaptation in these larvae has been studied and the following conclusions reached: 1. The elastic strands in the cells of the gills become exaggerated, and these cells resist swelling in hypertonic salt solutions. 2. There are changes in the epithelium of the mid-gut so that: (a) the cells are no longer caused to swell up and become detached from the basement membrane; and (b) the mid-gut and caeca can absorb the salt fluid and so avoid the excessive distension which occurs in unadapted larvae. 3. It is possible that the Malpighian tubes excrete a more concentrated urine and that the reabsorptive activity of the rectum is increased. The mosquito larva appears to be homoiosmotic in both fresh water and in hypertonic salt water.

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.

THE OSMOREGULATORY ROLE OF THE THYROID GLAND IN THE STARRY FLOUNDER, PLATICHTHYS STELLATUS

1959 ◽  
Vol 37 (6) ◽  
pp. 997-1060 ◽  
Author(s):  
Cleveland P. Hickman Jr.
Keyword(s):  
Thyroid Gland ◽  
Fresh Water ◽  
Body Fluid ◽  
Sea Water ◽  
Salt Water ◽  
Standard Metabolic Rate ◽  
Energy Demands ◽  
Platichthys Stellatus ◽  
Fluid Concentration

Energy demands for osmotic regulation and the possible osmoregulatory role of the thyroid gland were investigated in the euryhaline starry flounder, Platichthys stellatus. Using a melting-point technique, it was established that flounder could regulate body fluid concentration independently of widely divergent environmental salinities. Small flounder experienced more rapid disturbances of body fluid concentration than large flounder after abrupt salinity alterations.The standard metabolic rate of flounder adapted to fresh water was consistently and significantly less than that of marine flounder. In supernormal salinities standard metabolic rate was significantly greater than in normal sea water. These findings agree with the theory that energy demands for active electrolyte transport are greater in sea water than fresh water.Thyroid activity was studied in flounder adapted to fresh water and salt water. Percentage uptake of radioiodine by the thyroid was shown to be an insensitive and inaccurate criterion for evaluating thyroid activity in different salinities because removal rates of radioiodine from the body and blood differed between fresh water and marine flounder. Using thyroid clearance of radioiodine from the blood as a measure of activity, salt-water flounder were shown to have much greater thyroid clearance rates and, hence, more active thyroid glands than flounder adapted to fresh water. The greater activity of the thyroid of marine flounder correlates with greater oxygen demands in sea water and suggests a direct or adjunctive osmoregulatory role of the thyroid gland of fish.

Studies on Salt-Water and Fresh-Water Anopheles gambiae on the East African Coast

1951 ◽  
Vol 41 (3) ◽  
pp. 487-502 ◽  
Author(s):  
R. C. Muirhead Thomson
Keyword(s):  
West Africa ◽  
Fresh Water ◽  
Sea Water ◽  
Salt Water ◽  
Dar Es Salaam ◽  
Limiting Factor ◽  
East African ◽  
East African Coast ◽  
African Coast ◽  
Gravid Females

The brackish water form of A. gambiae on the East African coast—and probably in Mauritius—is not the same as A. melas of West Africa.In salt-water gambiae a variable proportion of the females have an additional dark band on the palps, resembling 4-banded melas, but the remainder are indistinguishable from typical gambiae.Eggs and larvae of salt-water gambiae show no morphological differences from those of fresh-water gambiae, thereby differing from A. melas of West Africa.Larvae of the two forms show a clear-cut difference in reaction to sudden changes in salinity, and a simple test has been worked out whereby wild-caught females can be accurately identified by the reactions of their progeny.This physiological test has formed the basis of all work in comparing the incidence, habits, and infectivity of salt and fresh-water gambiae in Dar-es-Salaam.Exposed to equal chances of infection in the same village during 1947 and 1948, fresh-water gambiae had a sporozoite rate of 9·4 per cent. while that of salt-water gambiae was 0·8 per cent.About 4 per cent, of both forms were infected with filaria larvae, but monthly figures showed that infection rates in salt-water gambiae may rise to 22 per cent.Fresh-water gambiae show little tendency to leave African houses at dawn after feeding, whereas in salt-water gambiae over one-third of freshly blood-fed females leave the house at dawn.In fresh-water gambiae many half-gravid females leave the shelter of the house at dusk on the night after the blood feed. There is no marked difference in infectivity between those which leave the hut and those which remain indoors at this stage.Blood-fed and gravid females of fresh-water gambiae, funestus, and salt-water gambiae have been found in outdoor resting places, gravid females predominating in the case of the first two.Although larvae of salt-water gambiae can complete their development in pure sea water, in nature increasing salinity becomes a limiting factor before it reaches that of sea water, continuous breeding being no longer possible at salinities over 83 per cent. sea water.Salinity as a limiting factor explains the rather restricted breeding of salt-water gambiae on the coast, and suggests that certain coastal fresh-water swamps at Dar-es-Salaam could be cleared of all Anopheline breeding by salinifying with sea water.

Influence of salinity on ultrastructure of the secretory cells of the adenohypophyseal pars distalis in yearling coho salmon (Oncorhynchus kisutch)

1977 ◽  
Vol 55 (1) ◽  
pp. 183-198 ◽  
Author(s):  
Yoshitaka Nagahama ◽  
W. Craig Clarke ◽  
W. S. Hoar
Keyword(s):  
Freshwater Fish ◽  
Fresh Water ◽  
Coho Salmon ◽  
Sea Water ◽  
Salt Water ◽  
Light And Electron Microscopy ◽  
Secretory Cells ◽  
Plasma Sodium ◽  
Pars Distalis ◽  
Freshwater Environment

Six different types of secretory cells were identified by light and electron microscopy in the adenohypophyseal pars distalis of yearling coho salmon acclimated to fresh or salt water. Prolactin cells are markedly more active in the freshwater than the seawater fish; these cells exhibit definite functional activity 3 days after transfer from salt to fresh water, indicating an osmoregulatory role of prolactin in the freshwater environment. Plasma sodium showed a significant decline 6 h after transfer from sea water to fresh water and, even after 1 week, remained lower than in the fully acclimated freshwater fish. Corticotropic (ACTH) cells did not appear cytologically different in freshwater and seawater fish. GH cells, the most prominent cells in the proximal pars distalis, appear more numerous and more granulated in the seawater fish, suggesting an osmoregulatory involvement in young coho salmon. Putative thyrotropic (TSH) and putative gonadotropic cells (GTH) can be distinguished by differences in granulation; only one type of GTH cell is evident with ultrastructural features that differ from those of sexually mature salmon. Stellate, non-granulated cells occur in all regions of the adenohypophysis but more frequently in the prolactin follicles; they are much more prominent in the seawater than freshwater fish.

Lung changes and incidence of respiratory arrest in rats after aspiration of sea and fresh water

1961 ◽  
Vol 16 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Denis F. J. Halmagyi
Keyword(s):  
Body Weight ◽  
Fresh Water ◽  
Sea Water ◽  
Salt Water ◽  
Respiratory Arrest ◽  
Fluid Administration ◽  
Lung Weight ◽  
Intratracheal Administration ◽  
Cervical Vagotomy

Some effects of intratracheal administration of 0.1 ml/100 gm body weight of fresh and sea water were studied in intact and vagotomized rats. No local changes were seen in the lungs after fresh water inhalation. A marked increase in lung weight and intra-alveolar hemorrhages developed following the aspiration of sea water. Fatal respiratory arrest occurred in some cases of salt water and cold fresh water inhalation. Bilateral cervical vagotomy prior to the intratracheal fluid administration failed to affect the incidence of respiratory arrest. Submitted on November 30, 1959

Investigating Effects of Graphene Nanoinclusions for Improved Desalination Rates of Salt Water Under Solar Heat

2018 ◽  
Author(s):  
Vinay Patil ◽  
Aybala Usta ◽  
Muhammad M. Rahman ◽  
Ramazan Asmatulu
Keyword(s):  
Fresh Water ◽  
Produced Water ◽  
Sea Water ◽  
Salt Water ◽  
Inorganic Compounds ◽  
Single Layer ◽  
Cost Effective ◽  
Hexagonal Shape ◽  
Water Problem ◽  
The Many

The development of sustainable, cost-effective, reliable, efficient and stable materials and methods for continuous fresh water production is crucial for many regions of the world. Among the many other options, graphene nanoflakes seem to be good option to solve the global water problem due to their low energy cost and simple operational process to purify waste water. The produced water can be used for drinking, agriculture, gardening, medical, industrial and other purposes. Most of the nanofilter-based multifunctional fresh water systems do not require large infrastructures or centralized systems, and can be portable to remote regions for efficient water treatment. Graphene was discovered as a single-layer of isolated graphite atoms arranged in 2D hexagonal shape, making it the thinnest and strongest material known to date. Despite its intriguing mechanical, thermal and electrical properties, usage of graphene for different industries has not been investigated in detail. The present study investigated the availability and practical use of graphene inclusions for desalination of salt water to produce fresh water. In the present study, graphene was added to 3.5wt% salt water (similar to sea water) at different percentages. Graphene has a high absorption capability to convert solar energy into heat to enhance the evaporation rate of salt water. The graphene inclusions can also be used to remove bacteria, viruses, fungi, heavy metals and ions, complex organic and inorganic compounds, and other pathogens and pollutants present in various water sources (e.g., surface, ground water, and industrial water).

scholarly journals Biofiltration Efficiency of Algae Spirogyra hyalina to Reduce Salinity of Sea Water

2017 ◽  
Vol 1 (1) ◽  
pp. 9
Author(s):  
Ayub Wirabuana Putra
Keyword(s):  
Fresh Water ◽  
Dosage Form ◽  
Sea Water ◽  
Salt Water ◽  
Salinity Level ◽  
Powder Form ◽  
The Third ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Level Reduction

Algae Spyrogyra hyalina is one species of fresh water algae that is very easy to find in Indonesia. This species of algae known to have a lot of potential, which until now unknown. One potential that tried to explore in this research is the ability of these algae for decreasing the level of salt water salinity into fresh water. This research is an experiment with a completely randomized design (CRD), three treatments and three replications. Testing is done by performing algae arbsorbtion using three forms (powder, granule, and paper) with different biomass (1 g, 2 g, and 4gr). Preparations then coupled into a transparent pipe. The results showed the real effect of the decreased levels of salinity brine through the circuit. Filter with the powder forms with 4gr biomass has the highest salinity level reduction of 15%o,  then the dosage form of granules with biomass 4gr with decreased 5.23%o and the third dosage form of paper with 1 gram of biomass with a decrease of 4.23%o.Forms with other biomass have a decrease in the salinity level of not more than 4%o. Preparations with powder form and 4gr biomass can be used to reduce the salinity level in the salt water.

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>

A table shewing, to what degree air is compressible in sea water, at the depth of any number of feet from 1. to 33. feet or 5½ fathom, and thence for any number of 5½ fathoms, or 33. feet, to 324½ fathoms or 1947 feet-

1671 ◽  
Vol 6 (73) ◽  
pp. 2192-2195
Keyword(s):  
Fresh Water ◽  
Royal Society ◽  
Sea Water ◽  
Salt Water ◽  
High Water

Some Members of the Royal Society did with two different sorts of Instruments make divers Experiments for finding the Proportions of the Compression of Air under Water , in the Month of July , at sheerness , in the mouth of the River of Medway , at the time of high water, where the depth was then about 19 Fathom, and the proportion of the weight of the Salt-water to that of the same quantity of Fresh water, taken out of the river Thames , was as 41 to 42.

scholarly journals Studies in the life of Robert Boyle, F. R. S. Part II. Salt water freshened

1952 ◽  
Vol 9 (2) ◽  
pp. 196-216 ◽  
Keyword(s):  
Drinking Water ◽  
Fresh Water ◽  
Sea Water ◽  
Salt Water ◽  
Water Supplies ◽  
Chemical Examination ◽  
Robert Boyle ◽  
Adequate Supply

The problem of ensuring an adequate supply of good drinking water during lengthy voyages at sea is one that has received much attention through the ages. In particular the preparation of fresh water from seawater has been frequently attempted : it is mentioned by Pliny, and even receives consideration to-day. During the sixteenth, seventeenth and eighteenth centuries when so much enterprise was directed to the discovery of new worlds, navigators were put to much trouble to maintain supplies of drinking water of reasonable quality. It is understandable that any invention capable of satisfying this need would be of inestimable benefit ; that Robert Boyle should have taken an interest in the matter is not surprising. In 1674 he published a tract entitled Observations and Experiments about the Saltness of the Sea in which he reviewed past speculations on the cause of the sea’s salinity ; gave his own views on this subject ; referred to the difficulty experienced by seamen in maintaining fresh water supplies; dealt with the preparation of fresh water from sea-water by distillation, mentioning that this process had already been used aboard ship under conditions of extreme necessity by the navigator Sir Richard Hawkins; and finally reported the results of his own hydrostatical and chemical examination of sea-water.

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