Ionic Regulation in the Palaemonid Prawn Palaemon (=Leander) Serratus

1954 ◽  
Vol 31 (4) ◽  
pp. 601-613 ◽  
Author(s):  
G. PARRY
Keyword(s):  
Sea Water ◽  
External Medium ◽  
Inorganic Ions ◽  
Osmotic Regulation ◽  
Ionic Regulation ◽  
Blood Concentrations ◽  
Antennal Gland

1. Analyses have been made of the blood and urine of Palaemon serratus for the inorganic ions Na, K, Ca, Mg, Cl, SO4 the animals being kept in 50, 100 and 120% sea water. 2. When the animal is in 100% sea water the concentrations of ions in the blood, expressed as percentages of their concentrations in the medium (to the nearest 5%) are as follows: Na, K and Cl, 85% Ca, 105% Mg, 20% SO4 10%. 3. When the animal is in 50% sea water the corresponding figures are: Na and Cl, 105%K, 120%; Ca, 200%; Mg, 20%; SO4 10%. 4. When the animal is in 120% sea water the corresponding figures are: Na, K and Cl, 85% Ca, 115% Mg, 30% SO4 20%. 5. The concentrations of Na, K and Ca in the urine are always slightly (≤20%) less than their concentrations in the blood. The concentration of Cl is slightly greater in the urine than in the blood (10-20%) and the concentrations of Mg and SO4 are very much greater, by factors of up to 7 times. The relative concentrations of ions blood and urine do not change substantially with changes in the external medium. 6. The antennal gland, although it plays no part in purely osmotic regulation, is no doubt partly responsible for maintaining the low blood concentrations of Mg and SO4.

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.

Distribution of intracellular solutes in Arenicola marina (Polychaeta) equilibrated to diluted sea water

1977 ◽  
Vol 57 (4) ◽  
pp. 889-905 ◽  
Author(s):  
R. F. H. Freeman ◽  
T. J. Shuttleworth
Keyword(s):  
Osmotic Pressure ◽  
Free Amino ◽  
Body Fluid ◽  
Marine Invertebrates ◽  
Sea Water ◽  
External Medium ◽  
Inorganic Ions ◽  
Fluid Level ◽  
Arenicola Marina ◽  
Percentage Contribution

Recent studies on the osmotic responses of marine invertebrates to dilution of the external medium have tended to emphasize the osmotic and ionic regulation at the intracellular level rather than at blood/body fluid level. Even in those invertebrates, principally euryhaline crustaceans, possessing osmoregulatory mechanisms which enable them to maintain concentrations of the blood above those of dilute media, the regulation is not perfect, and there is some lowering of the blood concentration below the level exhibited in full-strength sea water (Lockwood, 1962). This requires the establishment of a new osmotic equilibrium between the intracellular solutes and those of the blood. The nature of the intracellular osmotic constituents is, however, strikingly different from those of the blood, even in those invertebrates which are stenohaline and purely marine in their distribution (Robertson, 1961). The osmotic pressure of the blood is due almost entirely to the same inorganic electrolytes as are present in sea water, although the percentage contribution of the various ions may differ. On the other hand these inorganic ions account for only about one third to one half of the intracellular osmotic pressure. The remainder is accounted for by organic solutes, most particularly free amino acids.

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.

The Formation of Urine by the Prosobranch Gastropod Mollusc Viviparus Viviparus Linn

1965 ◽  
Vol 43 (1) ◽  
pp. 39-54
Author(s):  
C. LITTLE
Keyword(s):  
Blood Pressure ◽  
Sea Water ◽  
External Medium ◽  
Tap Water ◽  
Pericardial Fluid ◽  
Blood Concentrations ◽  
Gastropod Mollusc ◽  
Urine Production ◽  
Viviparus Viviparus ◽  
Pericardial Pressure

1. The urine of Viviparus is hypotonic to the blood by about 30 mM./l. NaCl in tap water, and remains hypotonic in concentrations of up to 10% sea water. 2. The rate of production of urine is between 0·25 and 0·91 µl./g./min. in tap water at 19° C. The rate decreases in proportion to the decrease in osmotic difference between blood and external medium. Viviparus may be able to detect changes in salt concentration of the external medium and alter its rate of urine production accordingly. 3. Pericardial fluid is similar to blood in composition; the rate of flow of pericardial fluid through the reno-pericardial canal is proportional to the blood pressure; and when inulin is injected into the blood, concentrations in blood and pericardial fluid are approximately the same. For these reasons it is supposed that blood is filtered through the heart into the pericardium. 4. About 20 mM./l. NaCl, and probably some water, are reabsorbed in the kidney. Liquid is passed through the kidney by rhythmic contractions of the kidney musculature. Pericardial pressure does not influence the overall rate of urine production but blood pressure does have an effect. 5. About 5 mM./ NaCl, and probably a little water, are reabsorbed in the ureter.

Osmotic Regulation in the Crab-Eating Frog (Rana Cancrivora)

1961 ◽  
Vol 38 (3) ◽  
pp. 659-678 ◽  
Author(s):  
MALCOLM S. GORDON ◽  
KNUT SCHMIDT-NIELSEN ◽  
HAMILTON M. KELLY
Keyword(s):  
Fresh Water ◽  
External Medium ◽  
Short Circuit ◽  
Inorganic Ions ◽  
Short Circuit Current ◽  
Water Levels ◽  
Close Relative ◽  
Osmotic Regulation ◽  
Water Frogs ◽  
Nacl Concentration

1. The osmotic and ionic regulatory abilities of adults of the euryhaline crab-eating frog (Rana cancrivora) have been studied. Adult frogs tolerated environmental salinities as high as 28‰ at 30°C. Tadpoles of this form tolerated salinities as high as 39%‰ at the same temperature. 2. Changes in body weight of frogs following transfers to different environmental salinities indicate both that the skin of this frog is permeable to water and that these animals do not swallow large volumes of external medium, even in high salinities. 3. Above salinities of about 9%‰, plasma Δ rises with increasing environmental Δ. Plasma Δ is always higher than environmental Δ. Increases in plasma concentration above fresh-water levels are due partly to increased NaCl concentration (about 40%), partly to increased urea concentration (about 60%). Urea concentrations as high as 0.48 M (2.9%) have been measured. 4. Urinary Δ parallels plasma Δ, but is always lower than plasma Δ. Considerable quantities of urea are lost via the urine, even though urinary urea levels are below plasma levels. 5. Measurements of short-circuit current indicate that active uptake by the skin of inorganic ions continues in R. cancrivora acclimatized to high salinities. 6. R. cancrivora is no less susceptible to water loss by evaporation from the skin than are other amphibians. 7. In preference experiments R. cancrivora chooses salinities below 18%‰, but shows no strong preference for a particular salinity. 8. Similar observations on osmoregulatory mechanisms in a close relative of R. cancrivora, the tiger frog (R. tigerina), show that the latter species is similar to ordinary fresh-water frogs. 9. The striking physiological convergence between R. cancrivora and the elasmo-branch fishes is discussed, as are various possible implications of our data regarding nitrogen metabolism in tadpoles and kidney function in adult frogs.

Osmotic and Ionic Regulation in the Prosobranch Gastropod Mollusc, Viviparus Viviparus Linn

1965 ◽  
Vol 43 (1) ◽  
pp. 23-37
Author(s):  
C. LITTLE
Keyword(s):  
Amino Acids ◽  
Sea Water ◽  
External Medium ◽  
Ionic Composition ◽  
Ionic Regulation ◽  
Gastropod Mollusc ◽  
Normal Value ◽  
Viviparus Viviparus ◽  
Inorganic Composition ◽  
The Mean

1. The inorganic composition of the blood of Viviparus has been examined. The mean Δ is 40·9 mM./l. NaCl, and the blood Contains 34 mM./l. sodium, 1·2 mM./l. potassium, 5·7 mM./l. calcium, 31 mM./l. chloride, and 11 mM./ bicarbonate. The pH is 7·73. 2. When the concentration of the external medium is increased, Δ of the blood increases and in 20% sea water the blood is isosmotic with the external medium. Chloride is maintained in lower concentration in the blood than in the external medium. 3. The minimum concentrations of the external medium at which Viviparus can come to equilibrium are 0·006 mM./l sodium and 0.20 mM./l calcium. 4. After washing-out in de-ionized water Δ of the blood can be reduced to half its normal value. Chloride is reduced to about 5 mM./l. and is to some extent replaced by bicarbonate. 5. The ionic composition of the opercular muscle has been analysed. Much calcium is held in solid concretions. The ratios of internal:external potassium and chloride do not appear to obey a Donnan equilibrium. This matter is discussed. 6. The possibility is discussed that the concentration of amino acids in the cells increases when Δ of the blood is increased.

The Effects of Salinity on Herring After Metamorphosis

1961 ◽  
Vol 41 (1) ◽  
pp. 37-48 ◽  
Author(s):  
F. G. T. Holliday ◽  
J. H. S. Blaxter
Keyword(s):  
Salinity Tolerance ◽  
Blood Concentration ◽  
Sea Water ◽  
Freezing Point ◽  
Tolerance Range ◽  
Blood Concentrations

The salinity tolerance of herring 9-ca 24 cm in length was found to lie between 6‰0 and 40–45‰0.Determinations of changes in weight and blood concentration (by measurement of the freezing-point), when herring were transferred from one salinity to another, demonstrated that extensive changes occurred in the blood. Under these conditions the herring experienced and survived blood concentrations equivalent to salinites of 13–22·5‰. A recovery to near normal (δ0·95 ≡ 15·8‰) took place in all the salinities within the tolerance range.Badly descaled herring in sea water showed large increases in blood concentration before death.A study of the kidney of the herring indicated that the ability to withstand the low salinities for long periods probably rested in the high glomerular count of the kidney.The importance of damage to the skin for survival is discussed in relation to tagging experiments.The results are also discussed in relation to the evolution of the herring.

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.

The opening response of mussels (Mytilus edulis) exposed to rising sea-water concentrations

1981 ◽  
Vol 61 (3) ◽  
pp. 667-678 ◽  
Author(s):  
John Davenport
Keyword(s):  
Mytilus Edulis ◽  
Sea Water ◽  
External Medium ◽  
Mantle Cavity ◽  
Low Salinity ◽  
Medium Exchange ◽  
Mantle Edge

When exposed to water of low salinity specimens of Mytilus edulis L. keep their shell valves tightly closed; they do not gape periodically to test the external medium. Exchange of salts and water between the mantle cavity and the environment is thus minimized. Rising salinities are registered by diffusion of salts to the tentaculate portion of the inhalent siphon and not to any other portion of the mantle edge or to any more deeply located structures.

scholarly journals Aedes Aegypti: Energetics of Osmoregulation

1982 ◽  
Vol 101 (1) ◽  
pp. 135-141 ◽  
Author(s):  
H.A. EDWARDS
Keyword(s):  
Oxygen Consumption ◽  
Energy Cost ◽  
Sea Water ◽  
External Medium ◽  
Minimum Energy ◽  
Body Volume ◽  
Wet Weight ◽  
Minimum Energy Cost ◽  
Anal Papillae ◽  
Theoretical Minimum

1. Oxygen consumption of A. aegypti larvae, about 210 mul l g−1 tissue wet weight h−1, does not change when the salinity of the environment is changed. The number of mitochondria in the anal papillae, a salt-absorbing epithelium, increases as the external medium is diluted. There is no difference in oxygen consumption between isolated anal papillae in 0, 2 and 20% sea water. The papillae represent about 5% of body volume and their oxygen consumption is about 2% of the animal's total. The theoretical minimum energy cost of osmoregulation is four orders of magnitude smaller than the measured figure for the anal papillae alone. Osmoregulatory phenomena which would explain the recorded observations are discussed.

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