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.

scholarly journals The Inorganic Composition of the Body Fluids of Three Marine Invertebrates

1939 ◽  
Vol 16 (4) ◽  
pp. 387-397
Author(s):  
JAMES D. ROBERTSON
Keyword(s):  
Marine Invertebrates ◽  
Sea Water ◽  
Dynamic Equilibrium ◽  
Body Fluids ◽  
The Body ◽  
Two Fluids ◽  
Physico Chemical ◽  
Decapod Crustacea ◽  
Before And After ◽  
Inorganic Composition

1. Analyses have been made of the body fluids of Echinus esculentus, and two decapod Crustacea, Homarus vulgaris and Cancer pagurus, before and after dialysis with sea water in which they were living. 2. The composition of the perivisceral fluid of Echinus is identical with that of sea water, complete physico-chemical equilibrium existing between the two fluids. 3. The blood plasmas of Homarus and Cancer are maintained in dynamic equilibrium with sea water. They contain more Na, K and Ca and less Cl, Mg and SO4 than sea water. 4. The antennary gland fluid of Cancer contains less Na, K, Ca and Cl and more Mg and SO4 than the blood plasma. 5. The importance of the antennary glands and the surface membranes in regulating the inorganic composition of the blood is discussed.

scholarly journals The osmotic changes in some marine animals

1931 ◽  
Vol 107 (754) ◽  
pp. 606-624 ◽  
Keyword(s):  
Osmotic Pressure ◽  
Fresh Water ◽  
Marine Invertebrates ◽  
Sea Water ◽  
Body Fluids ◽  
The Body ◽  
Marine Animals

Since Bottazzi's (1897) first determinations of the osmotic pressure of the body fluids of various marine animals many researches have been performed by other authors, particularly in reference to the permeability of the membranes separating the body from its surroundings. Bottazzi (1897, 1906, 1908, b) investigated individuals belonging to very different groups of animals, and found that the osmotic pressure of the body fluids of marine invertebrates, and of elasmobranchs, is very similar to that of the surroundings, while the osmotic pressure of the blood of teleosts is quite different. Changing the osmotic pressure of the medium, the osmotic pressure of most marine invertebrates, and of elasmobranchs, was shown to change in the same direction (L. Fredericq, 1882, 1904; Quinton, 1897; Dakin, 1908) and to reach, finally, the value of the former. The blood of teleosts is much more independent of the medium, for it shown to change only about 30 percent, in concentration, on transferring the animals from sea water to fresh water or vice versa (Dakin, 1908; Dekhuyzen, 1904: Sumner, 1905); other authors, however (fredericq, 1904: Garrey, 1905) could not field even these variations.

Change of Weight of Marine Animals in Diluted Media

1932 ◽  
Vol 9 (1) ◽  
pp. 61-68
Author(s):  
K. HUKUDA
Keyword(s):  
Body Weight ◽  
Osmotic Pressure ◽  
Marine Invertebrates ◽  
Sea Water ◽  
Quantitative Agreement ◽  
Body Fluids ◽  
The Body ◽  
Marine Animals ◽  
Osmotic Swelling

1. Several species of marine invertebrates, and an elasmobranch, have been kept in diluted media. The increase of body weight so caused was compared with the resulting dilution of the body fluids. 2. The bounding membrane of the invertebrates was permeable to salts when the animals were immersed in diluted sea water. 3. The bounding membrane of the elasmobranch was semipermeable, i.e. permeable to water but not to solute. There is a close quantitative agreement between the osmotic swelling observed and the diminution of the osmotic pressure of the blood.

On the use of ammonium for buoyancy in squids

1979 ◽  
Vol 59 (2) ◽  
pp. 259-276 ◽  
Author(s):  
M. R. Clarke ◽  
E. J. Denton ◽  
J. B. Gilpin-Brown
Keyword(s):  
Developmental Stage ◽  
Sea Water ◽  
The Body ◽  
The Other ◽  
Neutral Buoyancy ◽  
Rich Solution ◽  
Almost All ◽  
Neutrally Buoyant

Squids (teuthoids) fall into two distinct groups according to their density in sea water. Squids of one group are considerably denser than sea water and must swim to stop sinking; squids in the other group are nearly neutrally buoyant. Analyses show that in almost all the neutrally buoyant squids large amounts of ammonium are present. This ammonium is not uniformly distributed throughout the body but is mostly confined to special tissues where its concentration can approach half molar. The locations of such tissues differ according to the species and developmental stage of the squid. It is clear that the ammonium-rich solution are almost isosmotic with sea water but of lower density and they are present in sufficient volume to provide the main buoyancy mechanism of these squids. A variety of evidence is given which suggests that squids in no less than 12 of the 26 families achieve near-neutral buoyancy in this way and that 14 families contain squids appreciably denser than sea water [at least one family contains both types of squid]. Some of the ammonium-rich squids are extremely abundant in the oceans.

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.

Distribution of Sodium, Potassium and Chloride in the Ophiuroid, Ophiocomina Nigra (Abildgaard)

1980 ◽  
Vol 60 (1) ◽  
pp. 163-170 ◽  
Author(s):  
Richard M. Pagett
Keyword(s):  
Sea Water ◽  
Vascular System ◽  
Ionic Composition ◽  
Surrounding Medium ◽  
Chloride Ion ◽  
Chloride Content ◽  
Sodium Concentration ◽  
The Body ◽  
Marine Habitats ◽  
Chloride Concentrations

Echinoderms are not generally considered to experience significant dilution of the surrounding medium in their usual marine habitats and so it is to be expected that, due to the absence of any obvious excretory organ, the ionic composition of the body fluid would be similar to that of the ambient sea water. In general this has been confirmed by previous workers for many species of echinoderm. Binyon (1966) lists the results of workers who have determined osmotic pressure and/or ionic concentrations in the perivisceral and/or ambulacral fluids of many echinoderms. With reference to the perivisceral fluid in asteroids there is usually a small excess of potassium (9–16%) which is maintained in the more euryhaline species and in those acclimatized to reduced salinity. Generally, the chloride content is similar to, or a little higher than, that in the surrounding sea water. In echinoids there is little difference in the potassium content and chloride concentrations with respect to sea water though there may be a small increase in the former ion. In the holothurians, there is little regulation of potassium ions. Such concentrations which have been determined for the chloride ion in this group are found to be a little higher than in sea water. The sodium concentration in the perivisceral fluids of echinoderms tends to be similar to, or slightly lower than, that in the surrounding sea water. However in the ambulacral fluids of the water vascular system it has been shown that the potassium concentration is 20–90% higher in some species of asteroids and echinoids (Robertson, 1949; Binyon, 1962,1966). The fluids of the water vascular system of echinoderms, analysed to date, have concentrations of sodium ions lower than in the ambient sea water. From the available evidence, there appears to be little difference between environmental and ambulacral chloride concentrations.

scholarly journals Adaptation to Changes of Salinity in the Polychaetes

1937 ◽  
Vol 14 (1) ◽  
pp. 56-70
Author(s):  
L. C. BEADLE
Keyword(s):  
Hydrostatic Pressure ◽  
Body Wall ◽  
Sea Water ◽  
Calcium Deficiency ◽  
Body Fluids ◽  
The Body ◽  
Concentration Curve ◽  
Body Volume ◽  
Weight Curve ◽  
Body Wall Muscles

1. Nereis diversicolor collected from the same locality at different times showed smaller weight increases in dilute sea water (25 per cent) during the winter than during the summer months. 2. In spite of great variations in the weight curve, the body fluid concentration curve was very constant. 3. The maintenance of hypertonic body fluids and the regulation of body volume are largely unconnected. 4. The lowering of the weight curve below that theoretically expected from the concentration curve cannot be attributed to passive salt loss through the body surface. It is suggested that this is due to the removal of fluid through the nephridia under the hydrostatic pressure produced by the contraction of the body wall muscles. 5. Animals previously subjected to dilute sea water, when placed in water isotonic with the body fluids, will increase the concentration of the latter. This result is more marked when the internal hydrostatic pressure is high. 6. The results suggest that the osmotic regulatory mechanism involves the removal by the nephridia of fluid hypotonic to the body fluids. But no direct evidence for this is available. 7. Calcium deficiency and cyanide in dilute sea water cause an increase of weight and ultimately inhibit the maintenance of hypertonic body fluids. Both these effects are reversible. 8. The mechanism by which body fluids are maintained hypertonic to the external medium is not sufficiently developed to be of survival value in the locality in which the animals were found. 9. The control of body volume is probably of greater importance. 10. The majority of the extra oxygen consumption in dilute sea water is not the result of osmotic work. It is suggested that it may be due to work done by the body wall muscles in resisting swelling.

Gnathia pilosus sp. nov. (Crustacea, Isopoda, Gnathiidae) from the East Coast of South Africa

Zootaxa ◽  
2008 ◽  
Vol 1894 (1) ◽  
pp. 23-41 ◽  
Author(s):  
KERRY A. HADFIELD ◽  
NICO J. SMIT ◽  
ANNEMARIÉ AVENANT-OLDEWAGE
Keyword(s):  
South Africa ◽  
South African ◽  
East Coast ◽  
Sea Water ◽  
The Body ◽  
The Other ◽  
African Species ◽  
Intertidal Fish ◽  
Fish Hosts ◽  
Intertidal Fishes

The larvae of gnathiid isopods are known to parasitise a large variety of intertidal fish worldwide. In South Africa, the larvae of Gnathia africana Barnard, 1914, have been recorded from various intertidal fish hosts along the cold West and South Coasts. The warmer East Coast, however, has not previously been sampled for gnathiids. From March 2006 to February 2007, intertidal fishes were collected on the East Coast using hand held nets and kept in aerated tanks until the gnathiids completed their feeding. Once fed, the gnathiids were kept alive in 50 ml bottles with fresh sea water till moulting occurred. Results indicated that all the East Coast intertidal gnathiids were from the same species and new to science, and subsequently described as Gnathia pilosus sp. nov. The G. pilosus male and female can be clearly distinguished from other South African species in having numerous tubercles and setae covering the cephalosome and pereon which are not as pronounced in the other species. The G. pilosus larva can also be distinguished from the other South African species by the triangular-shaped cephalosome and numerous sensory pits covering the body.

Do crocodiles co-opt their sense of "touch" to "taste"? A possible new type of vertebrate sensory organ

2007 ◽  
Vol 28 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Kate Jackson ◽  
Daniel Brooks
Keyword(s):  
Osmotic Pressure ◽  
Sea Water ◽  
Water Solution ◽  
Body Fluids ◽  
The Body ◽  
Sensory Organ ◽  
Chemical Information ◽  
Sensory Organs ◽  
New Type ◽  
Sense Of Touch

AbstractWe recount here two experiments carried out which suggest the existence of the first described integumentary osmoreceptor of its kind in a vertebrate. Domed pressure receptors, present on the cranial scales of alligators have previously been demonstrated to convey the sensation of "touch" when flattened by pressure. Here we find that morphologically similar domed sensory organs present on the post-cranial scales of crocodylid but not alligatorid crocodilians flatten when exposed to increased osmotic pressure, such as that experienced when swimming in sea water hyper-osmotic to the body fluids. When contact between the integument and the surrounding sea water solution is blocked, crocodiles are found to lose their ability to discriminate salinities. We propose that the flattening of the sensory organ in hyper-osmotic sea water is sensed by the animal as "touch", but interpreted as chemical information about its surroundings.

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