Potassium metabolism and the accumulation of 137Caesium by decapod Crustacea

1962 ◽  
Vol 42 (2) ◽  
pp. 199-241 ◽  
Author(s):  
G. W. Bryan ◽  
Eileen Ward
Keyword(s):  
Body Surface ◽  
Soft Tissues ◽  
Sea Water ◽  
The Body ◽  
Limiting Factor ◽  
Freshwater Crayfish ◽  
Marine Animals ◽  
Decapod Crustacea ◽  
Concentration Factors ◽  
Potassium Metabolism

SUMMARYThe accumulation of 137Cs from sea water has been examined in relation to potassium metabolism in the lobster Homarus vulgaris and in the prawn Palaemon serratus. In unfed animals 137Cs is taken up and lost far more slowly than 42K. Although all the inactive K in the animals can be exchanged with 42K, higher whole-animal concentration factors are reached for 137Cs (about eight for lobsters and twenty-five for prawns). This is because both species have higher plasma/medium ratios for 137Cs than K at equilibrium despite the selective excretion of 137Cs. Also, except for the hepatopancreas in lobsters and fed prawns, all soft tissues can probably attain higher tissue/plasma ratios for 137Cs than inactive K.Uptake of both isotopes has also been studied in the freshwater crayfish Austropotamobius pallipes pallipes. In crayfish in o-i % sea water 137Cs is not concentrated to the same extent as K by whole animals (50-200 for 137Cs against about 4500 for K). Although the situation between plasma and tissues resembles that in the marine animals, 137Cs cannot be accumulated in the plasma to the same degree as K. Crayfish selectively excrete 137Cs in the urine relative to K at a lower concentration than in the plasma.In the accumulation of 137Cs by all species, muscle is the principal limiting factor in uptake and loss, but with 42K the body surface becomes more limiting.Experiments on the absorption of 137Cs from food in prawns and freshwater crayfish have been carried out. In prawns in a constant environment, feeding is probably less important than uptake over the body surface while in crayfish feeding is probably much more important.

The accumulation of 137Cs by brackish water invertebrates and its relation to the regulation of potassium and sodium

1963 ◽  
Vol 43 (2) ◽  
pp. 541-565 ◽  
Author(s):  
G. W. Bryan
Keyword(s):  
New Media ◽  
Brackish Water ◽  
Sea Water ◽  
Indirect Evidence ◽  
The Body ◽  
Limiting Factor ◽  
Wide Range ◽  
Concentration Factors ◽  
The Relationship ◽  
Potamopyrgus Jenkinsi

The relationship between the ability of brackish water invertebrates to regulate Na and K and the extent to which the radioactive fission product 137Cs can be accumulated has been studied.The brackish water isopod Sphaeroma hookeri and the gastropod Potamopyrgus jenkinsi have been acclimatised to a wide range of sea-water dilutions. Unfed Sphaeroma can survive in sea-water concentrations of 100–2·5%, while Potamopyrgus can live fairly indefinitely in concentrations of 50–0·1%. Measurements of Na and K in the whole animals of both species and in the blood of Sphaeroma have been made. Salt movements are quite rapid and acclimatization to new media is achieved by both species in less than 10 h. Concentration factors for inactive K in particular increase to high values in the more dilute media.Uptake of the isotopes 42K and 137Cs from solution has been examined in both species over a range of sea-water concentrations. All of the body K is exchangeable with 42K and in Sphaeroma exchange of 42K between the blood and tissues is so rapid that the body surface appears to be the limiting factor in the uptake of the isotope. Both species exchange 42K more rapidly in the higher concentrations of sea water and one reason for this may be the existence of an exchange diffusion component of exchange which increases as the salinity of the medium is raised. Indirect evidence suggests that the excretion of 42K in urine is probably not an important factor in exchange.

scholarly journals The accumulation of radioactive caesium in crabs

1961 ◽  
Vol 41 (3) ◽  
pp. 551-575 ◽  
Author(s):  
G. W. Bryan
Keyword(s):  
Body Surface ◽  
Natural Environment ◽  
Sea Water ◽  
Carcinus Maenas ◽  
The Body ◽  
Limiting Factor ◽  
A Value ◽  
Cancer Pagurus ◽  
The Relationship ◽  
Accuracy Rates

SUMMARYThe accumulation of 134Cs and 42K from artificial sea water has been followed in crabs of the following species, viz. Carcinus maenas, Portunus puber, P. depurator, Polybius henslowi, Cancer pagurus and Corystes. cassivelaunm. In all cases 134Cs is taken up far more slowly than 42K but at equilibrium a higher concentration factor is attained by 134Cs. In Carcinus a value of about 8 is found for 134Cs and about 4 for 42K. Uptake of 134Cs in Carcinus is not affected by feeding on inactive food over a period of 1000 h. The relationship between the rates of uptake of the two isotopes is not the same in the different species and it is concluded that it would not be possible to predict with any accuracy rates of uptake for 134Cs in other species of crabs from the results of short 42K experiments.Uptake of 134Cs was followed in the blood and tissues of Carcinus and Cancer, and muscle is the principal limiting factor in the attainment of equilibrium by whole animals. Uptake of 42K by tissues has also been followed and in all species nearly all the inactive K appears to be readily exchangeable. At equilibrium in all species plasma/sea water and tissue/plasma 134Cs ratios nearly always exceed those for inactive K. The tissue/plasma 134Cs ratios in Carcinus are about twice those for K and the significance of this has been discussed.Loss of both isotopes in whole Carcinus is a slower process than uptake.Isotope accumulation takes place mainly across the body surface in unfed animals, but uptake of 134Cs from food is very rapid and complete and would considerably enhance the attainment of equilibrium in a natural environment.Selective excretion of 134Cs relative to K has been found in Carcinus, Cancer and Portunus puber.

Calcium Balance at the Premoult Stage of the Freshwater Crayfish Austropotamobius Pallipes (Lereboullet)

1974 ◽  
Vol 61 (1) ◽  
pp. 27-34
Author(s):  
PETER GREENAWAY
Keyword(s):  
Body Surface ◽  
The Body ◽  
Ionized Calcium ◽  
Freshwater Crayfish ◽  
Calcium Balance ◽  
Electrochemical Gradient ◽  
Austropotamobius Pallipes

The premoult stage in Austropotamobius pallipes is characterized by a net loss of calcium which increases from D0 to a maximum of 0.83 µmoles/g/h at D4. The concentration of ionized calcium in the haemolymph does not increase during the premoult stage although there is an increase in complexed calcium. The electrochemical gradient across the body surface is similar to that at the intermoult stage and favours calcium outflux. Possible routes for calcium net loss have been discussed and a mechanism for elimination of calcium has been proposed.

Sodium Regulation and Adaptation to Fresh Water in Gammarid Crustaceans

1968 ◽  
Vol 48 (2) ◽  
pp. 359-380
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Body Weight ◽  
Fresh Water ◽  
Body Surface ◽  
Sea Water ◽  
Sodium Concentration ◽  
The Body ◽  
Outward Diffusion ◽  
Gammarus Zaddachi ◽  
Freshwater Habitats ◽  
Sodium Regulation

1. Sodium uptake and loss rates are given for three gammarids acclimatized to media ranging from fresh water to undiluted sea water. 2. In Gammarus zaddachi and G. tigrinus the sodium transporting system at the body surface is half-saturated at an external concentration of about 1 mM/l. and fully saturated at about 10 mM/l. sodium. In Marinogammarus finmarchicus the respective concentrations are six to ten times higher. 3. M. finmarchicus is more permeable to water and salts than G. zaddachi and G. tigrinus. Estimated urine flow rates were equivalent to 6.5% body weight/hr./ osmole gradient at 10°C. in M. finmarchicus and 2.8% body weight/hr./osmole gradient in G. zaddachi. The permeability of the body surface to outward diffusion of sodium was four times higher in M. finmarchicus, but sodium losses across the body surface represent at least 50% of the total losses in both M. finmarchicus and G. zaddachi. 4. Calculations suggest that G. zaddachi produces urine slightly hypotonic to the blood when acclimatized to the range 20% down to 2% sea water. In fresh water the urine sodium concentration is reduced to a very low level. 5. The process of adaptation to fresh water in gammarid crustaceans is illustrated with reference to a series of species from marine, brackish and freshwater habitats.

Zinc Regulation in the Lobster Homarus Gammarus: Importance of Different Pathways of Absorption and Excretion

1986 ◽  
Vol 66 (1) ◽  
pp. 175-199 ◽  
Author(s):  
G. W. Bryan ◽  
L. G. Hummerstone ◽  
Eileen Ward
Keyword(s):  
Sea Water ◽  
Carcinus Maenas ◽  
The Body ◽  
Shore Crab ◽  
Freshwater Crayfish ◽  
Uptake Mechanism ◽  
Major Pathway ◽  
Homarus Gammarus ◽  
Wide Range ◽  
Body Concentration

Zinc is one of the most important of the essential trace metals and more than 90 zinc-containing enymes and proteins have been discovered: furthermore, zinc increases the activity of many other enzymes (Vallee, 1978). It is not surprising, therefore, that in some groups of animals the body concentration is regulated against fluctuations in intake. Decapod crustaceans comprise one such group, although the ways in which regulation is achieved vary from species to species. In the freshwater crayfish, Austropotamobius pallipes, excretion in the faeces is a major pathway for removing zinc (Bryan, 1967a) whereas in the shore crab Carcinus maenas losses over the body surface also assume considerable importance (Bryan, 1966). On the other hand, preliminary work on the lobster Homarus gammarus (formerly H. vulgaris) suggests that in this species urinary excretion plays a major role in regulation (Bryan, 1964). The present work continues the study of zinc regulation in lobsters and its main aims are: (1) to measure rates of absorption from sea water over a wide range of concentrations and study the uptake mechanism; (2) to examine absorption from the stomach under different conditions; (3) to determine the relative importance of different pathways for the removal of zinc in response to various levels of intake.

Osmoregulation in the Larva of the Marine Caddis Fly, Philanisus Plebeius (Walk.) (Trichoptera)

1972 ◽  
Vol 57 (3) ◽  
pp. 821-838
Author(s):  
JOHN P. LEADER
Keyword(s):  
Sodium Chloride ◽  
Osmotic Pressure ◽  
Body Surface ◽  
Sea Water ◽  
Electrical Potential ◽  
Chloride Ion ◽  
Chloride Ions ◽  
The Body ◽  
Electrical Potential Difference ◽  
Caddis Fly

1. The larva of Philanisus plebeius is capable of surviving for at least 10 days in external salt concentrations from 90 mM/l sodium chloride (about 15 % sea water) to 900 mM/l sodium chloride (about 150 % sea water). 2. Over this range the osmotic pressure and the sodium and chloride ion concentrations of the haemolymph are strongly regulated. The osmotic pressure of the midgut fluid and rectal fluid is also strongly regulated. 3. The body surface of the larva is highly permeable to water and sodium ions. 4. In sea water the larva is exposed to a large osmotic flow of water outwards across the body surface. This loss is replaced by drinking the medium. 5. The rectal fluid of larvae in sea water, although hyperosmotic to the haemolymph, is hypo-osmotic to the medium, making it necessary to postulate an extra-renal site of salt excretion. 6. Measurements of electrical potential difference across the body wall of the larva suggest that in sea water this tissue actively transports sodium and chloride ions out of the body.

The Relative Losses of Sodium in the Urine and Across the Body surface in the Amphipod, Gammarus Duebeni

1965 ◽  
Vol 42 (1) ◽  
pp. 59-69
Author(s):  
A. P. M. LOCKWOOD
Keyword(s):  
Body Surface ◽  
Sea Water ◽  
Average Rate ◽  
The Body ◽  
High Rate ◽  
Water Turnover ◽  
Urine Production ◽  
Sodium Loss ◽  
And Diffusion ◽  
Total Sodium

1. The relative contributions of urine production and diffusion across the body surface to the loss of sodium from the body of the amphipod Gammarus duebeni have been investigated. 2. When the urine is isotonic to the blood some 80% of the total sodium loss is via the urine. 3. As the gradient between blood and medium is increased in dilute media production of urine hypotonic to the blood counteracts the tendency for sodium loss to increase. 4. In consequence, the average rate of sodium uptake at the body surface by animals acclimatized to 2% sea water needs to be only about twice that of animals acclimatized to 50% sea water. 5. It is suggested that the conservation of ions within the body by the production of hypotonic urine is likely to be found to be a common feature of the smaller brackish water crustacea, especially those with a high rate of water turnover.

Metabolism of zinc in the mussel, Mytilus edulis (L.): a combined ultrastructural and biochemical study

1980 ◽  
Vol 60 (3) ◽  
pp. 575-590 ◽  
Author(s):  
Stephen G. George ◽  
Brian J. S. Pirie
Keyword(s):  
Mytilus Edulis ◽  
Soft Tissues ◽  
Sea Water ◽  
Biochemical Study ◽  
The Body ◽  
Zinc Metabolism ◽  
High Molecular Weight Complex ◽  
Multicompartmental Model ◽  
Body Tissues ◽  
Granular Amoebocytes

The uptake, transport, storage and excretion of zinc has been studied in Mytilus edulis. Zinc accumulates in the soft tissues in proportion to its concentration in sea water whilst the concentration in the haemolymph is little above that in the environment. Uptake is via the gut, mantle and gills. The zinc is transported from the gills and gut (t½ ≈ 8 days) via the haemolymph, either as a high molecular weight complex or in the granular amoebocytes, to the kidney. Most of the body zinc is present in the granular amoebocytes (which are found in all the body tissues) or in the gut and kidney. The kidney forms the major storage organ for many trace metals, containing 30% of the body zinc and a concentration of about 1000 μg/g. Zinc is localized as insoluble granules in membranelimited vesicles occupying some 20% of the cell volume. Excretion of zinc is by defaecation, exocytosis of the kidney granules into the urine and diapedesis of the amoebocytes. A multicompartmental model for zinc metabolism which correlates the ultrastructural and kinetic data is proposed.

scholarly journals Ionic Regulation in Some Marine Invertebrates

1949 ◽  
Vol 26 (2) ◽  
pp. 182-200
Author(s):  
JAMES D. ROBERTSON
Keyword(s):  
Marine Invertebrates ◽  
Sea Water ◽  
Protein Complexes ◽  
Ionic Composition ◽  
Body Fluids ◽  
The Body ◽  
The Other ◽  
Tissue Fluid ◽  
Ionic Regulation ◽  
Decapod Crustacea

1. Analyses have been made of the ionic composition of the body fluids of some twenty marine invertebrates belonging to five phyla. The body fluids were again analysed after dialysis in collodion sacs against samples of the original sea water in which the animals had been kept. Comparison of the two analyses in terms of weight of water gives a true measure of ionic regulation by taking into account such factors as the Donnan equilibrium and the formation of calcium-protein complexes in those animals with significant concentrations of protein in their blood. 2. Some ionic regulation is found in all the animals examined, but it is most pronounced in the cephalopod Mollusca and the decapod Crustacea. 3. The mesogloeal tissue fluid of the jelly-fish Aurelia showed the following composition (expressed as percentage of concentration in the dialysed fluid): Na 99%, K 106%, Ca 96%, Mg 97%, Cl 104%, SO4 47%. This regulation seems to be brought about by elimination of sulphate and accumulation of potassium by the epithelia bounding the mesogloea, with resultant alteration in the remaining ions in conformity with osmotic equilibrium between the jelly and sea water. 4. In the echinoderms studied only potassium is regulated, values in the perivisceral fluid not exceeding 111% being found, with higher values in the ambulacral fluid. Polychaetes regulated potassium (up to 126%) and sometimes reduced sulphate (92%). 5. Regulation extends to all ions in the decapod Crustacea. In six species the range was Na 104-113%, K 77-128%, Ca 108-131%, Mg 14-97% Cl 98-104%, SO4 32-99%. There is a series Lithodes, Cancer, Carcinus, Palinurtis, Nephrops and Homarus in which magnesium falls from 97 to 14%; the series is roughly in accordance with increase of activity. Analyses given of the secretion from the antennary glands emphasize the importance of these organs in controlling the composition of the blood. They eliminate magnesium, sulphate, and sometimes calcium, and conserve the other ions. 6. Lamellibranchs and gastropods accumulate potassium and calcium, and eliminate sulphate to a small degree. Range of values in six species was Na 97-101%, K 107-155%, Ca 103-112%, Mg 97-103%, Cl 99-101%, SO4 87-102%. 7. Considerable ionic regulation exists in the Cephalopoda, ranges being Na 95-98%, K 152-219%, Ca 94-107%, Mg 102-103%, Cl 101-104%, SO4 29-81%. In Eledone and Sepia differential excretion by renal organs is an important factor in this. Sulphate and sodium are eliminated in quantities greater than would be present in an ultrafiltrate of the plasma, tending to lower these values, whereas the other ions are excreted in proportions below those of an ultrafiltrate, tending to elevate their concentrations in the blood. 8. The ratio of equivalents Na+K/Ca+Mg in the body fluids of these marine invertebrates remains at the sea-water figure of 3.8 in Aurelia, echinoderms, anneli worms, and lamellibranchs, but decreases in the gastropods and cephalopods to 3.5. In the decapod Crustacea, owing principally to reduction of magnesium, it increases from 3.8 in Lithodes to 9 and 12 in the Palinura and Astacura genera.

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