Salt and Water Balance of the Spiny Lobster, Panulirus Argus: The Role of the Antennal Glands

1977 ◽  
Vol 70 (1) ◽  
pp. 221-230
Author(s):  
D. F. MALLEY
Keyword(s):  
Water Balance ◽  
Sea Water ◽  
Spiny Lobster ◽  
Water Levels ◽  
Panulirus Argus ◽  
Antennal Glands ◽  
Salt And Water Balance

1. Panulirus argus in full sea water differs from most other marine isosmotic decapods by regulating Cl− levels in the haemolymph slightly below those in sea water and by having haemolymph K+ levels similar to those in sea water. The species is typical in regulating haemolymph Na+ and Ca2+ above, and Mg2+ and SO42- below, sea-water levels of these ions. Its haemolymph Mg2+ and SO42- concentrations are amongst the lowest reported in marine decapods. 2. The antennal glands contribute to this regulation of Mg2+ SO42- and Cl− by producing urine with markedly, and approximately equally, elevated Mg2+ and SO42- levels, and slightly elevated Cl− levels, compared with those in the haemolymph. The antennal glands show a small tendency to conserve water. Note: Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6.

Salt and Water Balance of the Spiny Lobster Panulirus Argus: The Role of the Gut

1977 ◽  
Vol 70 (1) ◽  
pp. 231-245
Author(s):  
D. F. MALLEY
Keyword(s):  
Sea Water ◽  
Spiny Lobster ◽  
The Body ◽  
Digestive Juice ◽  
Urine Production ◽  
Minor Portion ◽  
Salt And Water Balance ◽  
A Minor ◽  
A Site

1. The rate of drinking of sea water averaged 1.5 ± 0.6 ml/kg body weight per 24 h and accounts for only a minor portion of the uptake of water required to balance estimated urine production. 2. Imbibed water and ions, except Ca2+, are absorbed or diffuse across the gut wall into the haemolymph. The gut appears to be a route of net loss of Ca2+, derived from digestive juice and sea water, from the body. 3. The gut does not appear to be a site of regulation of ionic levels in the haemolymph or a major site of water uptake. Note: Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6.

Salt and Water Balance in Salmon Smolts

1970 ◽  
Vol 52 (3) ◽  
pp. 553-564
Author(s):  
W. T. W. POTTS ◽  
MARGARET A. FOSTER ◽  
J. W. STATHER
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Sodium Pump ◽  
Sea Water ◽  
High Rate ◽  
Exchange Diffusion ◽  
Rapid Changes ◽  
Alternative Hypotheses ◽  
Salt And Water Balance

1. Salmon smolts adapted to sea water maintain a high rate of turnover of both sodium and chloride, but when adapted to fresh water the rate of turnover is low. 2. Only a small part of the influx takes place through the gut. 3. On immediate transfer from sea water to dilute sea water or to fresh water the influxes decline rapidly, but on transfer from fresh water to sea water the restoration of the fluxes takes place slowly. 4. The alternative hypotheses that the rapid changes are due to exchange diffusion or to rapid adjustments of the sodium pump are discussed.

Studies on Salt and Water Balance in Caddis Larvae (Trichoptera)

1961 ◽  
Vol 38 (3) ◽  
pp. 501-519 ◽  
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Water Balance ◽  
Sea Water ◽  
Salt Water ◽  
Chloride Concentration ◽  
Malpighian Tubule ◽  
Free Water ◽  
The Body ◽  
Chloride Uptake ◽  
Concentrated Solution ◽  
Salt And Water Balance

1. Limnephilus affinis larvae tolerate external salt concentrations up to at least 410 mM./l. NaCl (about 75% sea water) and survive for short periods in 470 mM./l. NaCl (about 85/ sea water). 2. The body wall is highly permeable to water, but relatively impermeable to sodium and chloride. Most of the sodium and chloride uptake from salt water occurs via the mouth. 3. The sodium and chloride levels in the haemolymph are powerfully regulated. Both are maintained strongly hypotonic against large external concentration gradients. 4. The Malpighian tubule-rectal system is very sensitive to changes in the haemolymph chloride level. The chloride concentration in the rectal fluid can be at least three times greater than the concentration in the haemolymph, and slightly greater than the concentration in the external medium. 5. The rectal fluid is hyper-osmotic to the haemolymph and to the medium at high external salt concentrations. 6. At external concentrations greater than about 200 mM./l. NaCl, water balance is maintained by regulating the haemolymph roughly iso-osmotic with the medium. This is partly achieved by increasing the non-electrolyte fraction in the haemolymph. A small quantity of osmotically free water is available to replace any osmotic loss. This can be obtained by drinking salt water and producing a concentrated solution of salts in the rectum.

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.

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