Osmotic Behaviour of the Fairy Shrimp Chirocephalus Diaphanus Prévost

1941 ◽  
Vol 18 (2) ◽  
pp. 110-114
Author(s):  
N. KESAVA PANIKKAR
Keyword(s):  
Osmotic Pressure ◽  
External Medium ◽  
Tap Water ◽  
Fairy Shrimp ◽  
Distilled Water ◽  
Osmotic Concentration ◽  
General Behaviour ◽  
Initial Rise ◽  
Osmotic Behaviour ◽  
Chirocephalus Diaphanus

The blood of Chirocephalus has a normal osmotic concentration equivalent to 0.44-0.5% NaCl in an external medium of 0.002% NaCl. The osmotic pressure falls rapidly when the animal is kept in glass-distilled water, but is fairly well maintained in tap water. There is an initial rise and a later return to normal even in hypotonic saline media, and this indicates active absorption of ions. The bracts are presumably the organs concerned in the salt absorption. The animal is unable to live in tap water or distilled water for more than 2-3 days without food and its general behaviour is thus markedly different from that of Daphnia.

Pheromones inhibit the hatching of diapausing Anostraca (Crustacea: Branchiopoda)

2007 ◽  
Vol 57 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Johan Mertens ◽  
Lynda Beladjal ◽  
Kristof Dierckens
Keyword(s):  
Osmotic Pressure ◽  
Abiotic Factors ◽  
Resting Eggs ◽  
Distilled Water ◽  
Fairy Shrimps ◽  
Branchipus Schaefferi ◽  
Chirocephalus Diaphanus

AbstractHatching of resting eggs of Streptocephalus torvicornis (Waga, 1942) and Branchipus schaefferi Fischer, 1834, two sympatric fairy shrimps, was tested using medium in which these two species and Chirocephalus diaphanus (Prévost, 1803) had been raised. The medium of adults inhibited the hatching of conspecific nauplii, even when diluted by 50% using distilled water. Streptocephalus torvicornis resting eggs hatch in the medium of C. diaphanus but not in the medium of B. schaefferi. Resting eggs of B. schaefferi hatched in low numbers in S. torvicornis medium, and in high numbers in that of C. diaphanus.There appears to be one or more substances associated with the presence of adults of conspecifics and sympatrics which exceed the influences of abiotic factors, such as light, pH, conductivity and osmotic pressure in fresh media. We propose that this substance(s) functions as a pheromone to inhibit further hatching once a population of adults is present.

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.

Osmotic relations of some metazoan parasites

Parasitology ◽  
1941 ◽  
Vol 33 (2) ◽  
pp. 214-223 ◽  
Author(s):  
N. Kesava Panikkar ◽  
Nora G. Sproston
Keyword(s):  
Osmotic Pressure ◽  
Sea Water ◽  
Tap Water ◽  
Blood Feeding ◽  
Metazoan Parasites ◽  
Blood Sucking ◽  
Experimental Media ◽  
Low Concentrations ◽  
Osmotic Behaviour ◽  
The Relationship

1. The osmotic behaviour of three parasites in normal and experimental media has been studied with a view to understanding the relationship with their hosts.2. Angusticaecum sp., a nematode frpm the intestine of the tortoise, is hypertonic in media of very low concentrations (1·1–1·3 % NaCl in tap water), but becomes isotonic in sea water and slightly hypertonic in 50 % sea water. Ligaturing experiments show that its cuticle is permeable to water and probably to salts.3. Lernaeocera branchialis, a blood-feeding copepod from Gadus spp., is hypotonic to the surrounding sea water so long as it remains attached to its host, its blood showing an osmotic pressure equivalent to 2·O–2·8 % NaCl. Isotonicity with the medium is established when the parasite is excised and kept alive. Hypotonicity of Lernaeocera is probably caused by the low osmotic pressure of the blood of its host (1·443 % NaCl in Gadus pollachius), to which it is permanently attached.4. Bopyrus squillarum, a blood-sucking isopod from Leander serratus, is isotonic or slightly hypotonic to sea water, the tendency towards hypotonicity being probably the result of the hypotonic nature of the blood of the host.5. The osmotic properties of Lerpaeocera and Bopyrus would suggest their ability to survive in dilute sea water, a fact which is supported by their occurrence on hosts living in inshore or estuarine habitats.

scholarly journals Fluid Secretion by the Malpighian Tubules of the Dragonfly Libellula Quadrimaculata

1985 ◽  
Vol 116 (1) ◽  
pp. 53-67 ◽  
Author(s):  
S. P. NICHOLLS
Keyword(s):  
Osmotic Pressure ◽  
External Medium ◽  
Salt Water ◽  
Tap Water ◽  
Fold Increase ◽  
Fluid Secretion ◽  
Malpighian Tubules ◽  
Secretion Rate ◽  
Thoracic Ganglia

Fluid secretion by the Malpighian tubules of Libellula quadrimaculata is unusual in that it is dependent on sodium and entirely independent of potassium in the external medium. It is suggested that this is due to the primitive, sodium-rich haemolymph of the Odonata. Similarities between these tubules and those of the millipede Glomeris marginata, which has a similar sodium-based haemolymph, support this view. Fluid secretion by the tubules is also dependent on the osmotic pressure of the external medium, declining considerably at higher osmotic pressures. However, there is no difference in the secretory rates of tubules isolated from larvae adapted to tap water, de-ionized water or salt water, even though there are large differences in the haemolymph osmotic pressure under these different conditions. This suggests some form of adaptation of the tubules in larvae from these different conditions. A factor which causes a five- to six-fold increase in the rate of secretion was present in the thoracic ganglia, and a slightly lower increase in secretion rate was recorded in larvae that had been feeding.

The effect of external salinity on drinking rate and rectal secretion in the larvae of the saline-water mosquito Aedes taeniorhynchus

1977 ◽  
Vol 66 (1) ◽  
pp. 97-110
Author(s):  
T. J. Bradley ◽  
J. E. Phillips
Keyword(s):  
Sea Water ◽  
External Medium ◽  
Narrow Range ◽  
Saline Water ◽  
Fluid Secretion ◽  
Osmotic Concentration ◽  
Drinking Rate ◽  
Aedes Taeniorhynchus ◽  
External Salinity ◽  
Kinetics Of

1. The drinking rate of the saline-water mosquito larva Aedes taeniorhyncus (100 nl.mg-1.h-1) is unaffected by the salinity of the external medium, but is directly proportional to the surface area of the animal. 2. Haemolymph Na+, Mg2+, K+, Cl-, SO42- and osmotic concentrations were measured in larvae adapted to 10%, 100% and 200% seawater and were found to be regulated within a narrow range. 3. With the exception of potassium, ionic concentrations in rectal secretion were found to increase with increasing concentrations of the sea water in which larvae were reared. 4. The osmotic concentration of rectal secretion was unaffected by changes in haemolymph osmotic concentration but did rise when sodium or chloride concentrations of the haemolymph were increased. High levels of these ions also stimulated the rate of fluid secretion. 5. Transport of chloride and sodium by the rectum exhibits the kinetics of allosteric rather than classical enzymes.

Regulation of rectal secretion in saline-water mosquito larvae living in waters of diverse ionic composition

1977 ◽  
Vol 66 (1) ◽  
pp. 83-96 ◽  
Author(s):  
T. J. Bradley ◽  
J. E. Philips
Keyword(s):  
Chemical Composition ◽  
External Medium ◽  
Saline Water ◽  
Ionic Composition ◽  
Malpighian Tubules ◽  
Fluid Composition ◽  
Mosquito Larvae ◽  
Major Site ◽  
Osmotic Concentration ◽  
Anal Papillae

1. Larvae of the saline-water mosquito Aedes campestris were adapted to three waters, all having an osmotic concentration of 700 mOsm, but differing in ionic rations. The (Na+Mg) SO4 medium was much moretoxic than the NAHCO3 or the NaCl media. 2. Ionic and osmotic concentrations of haemolymph and rectal secretion were measured in larvae adapted to all three media. The ratio of ionic concentrations in the rectal secretion reflected those in the external medium to which the larvae had been adapted, with the exception of SO42-, which was possibly replaced by HCO3-in the secretion. These differences in rectal fluid composition persisted even though all ligated recta were bathed in the same artificial haemolymph. 3. The Malpighian tubules were found to be the major site of SO42- excretion. In media containing high levels of NA+, Mg2+, K+, Cl- and HCO3-, the rectum secreted a hyperosmotic fluid containing these ions at concentrations several times greater than those found in the haemolymph. 4. These data provide the basis for speculation on the functioning of anal papillae in waters of diverse chemical composition.

Osmotic equilibria in fibroblasts in tissue culture measured by immersion refractometry

1958 ◽  
Vol 149 (934) ◽  
pp. 130-143 ◽  
Keyword(s):  
Water Content ◽  
Osmotic Pressure ◽  
Regression Line ◽  
Fluid Medium ◽  
Physiological Conditions ◽  
Chick Heart ◽  
Osmotic Behaviour ◽  
Osmotic Properties ◽  
Saline Medium

Volume-osmotic pressure relationships at equilibrium have been obtained in chick heart fibroblasts grown in slide-coverslip cultures in a fluid medium consisting of heparinized plasma and embryo extract. The refractive index of the fibroblast gives a direct measure of its solid concentration, and the volume is estimated as the reciprocal of concentration. The volume is found to be linearly related to the reciprocal of the osmotic pressure over a range from 130 to 587 m-osm, provided the measurements are carried out rapidly at 38°C. The isotonic water content of the cells derived from the gradient of the regression line on the basis of the simple Boyle-van’t Hoff Law was found to be less than actual water content obtained by direct refractometry, i. e. the value of Ponder’s ℛ was 0⋅94 (s. d. 0⋅04). In cultures grown in a simple saline medium and measured at 22°C the volume was related linearly to the reciprocal of the osmotic pressure only between the limits of 330 and 191 m-osm. Outside these limits the volume was greater than expected and this was attributed to alterations in the semi-permeable properties of the cell membrane. The value of Ponder’s ℛ in these cultures was 1⋅15. The importance of the quantity, ℛ, as applied to cells other than the erythrocyte, is indicated. The value, 0⋅94 (s. d. 0⋅04), obtained in fibroblasts under physiological conditions is not explicable on the basis of the probable osmotic properties in vitro of the cell proteins. The discrepancy is within the experimental error, but it may also be due to abnormal osmotic behaviour of the cell proteins resulting from some form of intermolecular structure in the cytoplasm.

Influence of Learning on Taste Preferences

1966 ◽  
Vol 19 (2) ◽  
pp. 445-446 ◽  
Author(s):  
Paul Thomas Young
Keyword(s):  
Tap Water ◽  
Taste Preferences ◽  
Distilled Water

Further discussion of the Schnorr and Brookshire study of the preference between distilled water and tap water, with comments and suggestions.

The area and volume of single human erythrocytes during gradual osmotic swelling to hemolysis

1970 ◽  
Vol 48 (6) ◽  
pp. 369-376 ◽  
Author(s):  
Peter B. Canham ◽  
David R. Parkinson
Keyword(s):  
Osmotic Pressure ◽  
Single Cells ◽  
Ringer Solution ◽  
Potassium Ion ◽  
Distilled Water ◽  
Red Cell ◽  
Dialysis Membrane ◽  
Osmotic Swelling ◽  
Cell Changes ◽  
Area And Volume

A double-chambered slide was designed for the microscope which would enable continuous viewing of cells hanging on edge in a Ringer solution which was gradually being reduced in osmotic pressure. This was achieved by putting a dialysis membrane between the cell chamber and a chamber containing distilled water. Photographs were taken at 1-min intervals of single cells on edge (revealing the biconcave profile) until the cells hemolyzed, usually within 30 min. The area and volume of revolution of each cell were calculated from measurements on photographic enlargements. No significant change in area occurs during the swelling series although the red cell changes gradually from biconcave to spherical and remains spherical for approximately 7 min before hemolyzing. This stability is best explained by a leakage of potassium ion from the cell prior to hemolysis (which has been reported by Seeman to be approximately 20%).

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