Osmoregulation in Ligia Oceanica and Idotea Granulosa

1963 ◽  
Vol 40 (2) ◽  
pp. 381-392
Author(s):  
MARY E. TODD

1. The osmoregulatory response of Ligia oceanica and Idotea granulosa to the range of the experimental variables was similar. They were both hyperosmotic relative to the medium and the difference between internal and external concentration increased as the salinity of the medium decreased. 2. In 100% sea water the osmotic concentration of the blood of Ligia oceanica was markedly above that of the medium, whereas in Idotea granulosa the blood was only marginally hyperosmotic. 3. In Ligia oceanica the blood concentration changed little in 100 and 75% sea water, but dropped significantly between 75 and 50% sea water, whereas blood concentration in Idotea granulosa dropped significantly throughout the test range of salinities. 4. The more efficient osmoregulation of Ligia oceanica in 25% sea water is reflected in the mean freezing-point depression of the blood, Δi = 1.65, compared with Δi = 0.90 in Idotea granulosa. 5. In both species the osmotic concentration of the blood was influenced by season, by temperature and by a temperature-salinity interaction. 6. Neither size nor sex of the animal influenced osmotic concentration of the blood.

Author(s):  
F. G. T. Holliday ◽  
J. H. S. Blaxter

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.


2021 ◽  
Author(s):  
Jon F. Went ◽  
Jeanette D. Wheeler ◽  
François J. Peaudecerf ◽  
Nadine Borduas-Dedekind

<p>Cloud formation represents a large uncertainty in current climate predictions. In particular, ice in mixed-phase clouds requires the presence of ice nucleating particles (INPs) or ice nucleating macromolecules (INMs). An influential population of INPs has been proposed to be organic sea spray aerosols in otherwise pristine ocean air. However, the interactions between INMs present in sea water and their freezing behavior under atmospheric immersion freezing conditions warrants further research to constrain the role of sea spray aerosols on cloud formation. Indeed, salt is known to lower the freezing temperature of water, through a process called freezing point depression (FPD). Yet, current FPD corrections are solely based on the salt content and assume that the INMs’ ice nucleation abilities are identical with and without salt. Thus, we measured the effect of salt content on the ice nucleating ability of INMs, known to be associated with marine phytoplankton, in immersion freezing experiments in the Freezing Ice Nuclei Counter (FINC) (Miller et al., AMTD, 2020). We measured eight INMs, namely taurine, isethionate, xylose, mannitol, dextran, laminarin, and xanthan as INMs in pure water at temperatures relevant for mixed-phase clouds (e.g. 50% activated fraction at temperatures above –23 °C at 10 mM concentration). Subsequently, INMs were analyzed in artificial sea water containing 36 g salt L<sup>-1</sup>. Most INMs, except laminarin and xanthan, showed a loss of ice activity in artificial sea water compared to pure water, even after FPD correction. Based on our results, we hypothesize sea salt has an inhibitory effect on the ice activity of INMs. This effect influences our understanding of how INMs nucleate ice as well as challenges our use of FPD correction and subsequent extrapolation to ice activity under mixed-phase cloud conditions.</p>


2021 ◽  
Author(s):  
Snezana M Jovicic

Abstract Background: Understanding the effect of pre-analytical factors is important for data quality of bio-specimens and health status. The study examines the effect of 9-days fluid intake and 2-time sampling on concentration changes of 7-Urine and 17-Blood variables. Material and Method: SPSS software v23.0 applies to data processing. The group of 23 healthy subjects divide based on water intake and gender. Results: A statistically significant difference(p<0.01) between 1st/2nd sampling is confirmed for Freezing point depression, Sodium, Potassium, Creatinine Urea and Urate in Urine and Urea, Urate, Glucose, Hematocrit, Thrombocyte in Blood. The difference between water intake after 1st sampling is confirmed (p<0.01) for Freezing point depression, Sodium, Urate and(p<0.05) for Potassium(p<0.05), Chloride(p<0.05), Creatinine(p<0.05), Urate, Urea in Urine and Potassium(p<0.01) and Chloride(p<0.05) in Blood. Difference between gender exists for Urea(p<0.05) in Urine after 2nd sampling and Urate(P<0.01), Glucose(p<0.01/0.05), Ht(p<0.01/0.05) after 1st and 2nd sampling and MCHC(p<0.01) after 2nd sampling in Blood samples.Conclusion: Water intake increases blood and urine biomarker range after sampling.


2020 ◽  
Vol 4 (5) ◽  
pp. 951-956
Author(s):  
Miftahul Walid ◽  
Hozairi ◽  
Madukil Makruf

In this research, an analysis was carried out to develop a measuring instrument for seawater density in salt production using a microcontroller (Arduino Uno) and YL-69 sensor, this sensor was commonly used to measure soil moisture. The experimental method was used in this research to produce initial data in the form of resistance and seawater density values, then calculations are carried out using statistical methods to find equations and produce a constant variable that connects the resistance and seawater density values. The equation was used to compile the algorithm into Arduino Uno. As for the results of this research,  From six experiments conducted, two experiments produced the same sea water density value between the actual and the predicted, namely the 2nd and 5th experiments, while for other experiments there was a difference between the actual and predicted values, however, it was not too significant, the difference occurs between the value range 0 ~ 1, to determine the level of error, use the Mean Square Error (MSE) with an error level of = 0.5 and Mean Absolute Error (MAE) with an error level of = 0.6. The contribution of this research is an algorithm that can predict the density value (baume) based on the resistance value obtained from the YL 69 sensor.


1941 ◽  
Vol 12 (3) ◽  
pp. 315-321 ◽  
Author(s):  
R. Aschaffenburg ◽  
P. L. Temple

The results of regular determinations of the freezing-point and solids-not-fat content of the milk of three Shorthorn cows over a period of more than six months are reported.The known constancy of the freezing-point depression was confirmed, the Δ values deviating generally by less than 2% and, in the most extreme case, by no more than 3·5% from the mean of 0·546 ± 0·002° C. No evidence was found of any influence of the state of lactation on the freezing-point depression, but a slight but definite decrease persisting for some weeks occurred at the time of year at which ample supplies of spring pasture became available to the animals.


The responses of a number of barnacles to a wide range of salinity have been studied by observation of the activity and measurement of the depression of freezing point of the blood. In active barnacles of the species Elminius modestus, Balanus balanoides, B. crenatus, B. improvisus, B. hameri, B. balanus and Chthamalus stellatus the blood concentration conforms with changes in the external salinity. The concentration of the blood tends to remain slightly hyperosmotic to the fluid in the mantle cavity, and to the medium. With sudden changes of external salinity the blood concentration conforms within a few hours if cirral activity is maintained. When placed in such low salinities that activity is inhibited, E. modestus, B. balanoides, B. crenatus, B. improvisus, B. balanus and C. stellatus close the opercular valves with the result that the blood and mantle cavity fluid are maintained for some time at a level initially considerably hyperosmotic to the medium, but the blood is still only slightly hyperosmotic to the fluid remaining in the mantle cavity. There is no permanent control, and in time the blood concentration approximates to the external level. E. modestus, B. balanoides and B. improvisus from low salinity estuarine habitats, and B. crenatus after gradual reduction of salinity in the laboratory over a matter of days, exhibit tolerance to lower salinities than do specimens of the same species obtained from, or acclimated to normal salinities. Salinity acclimation is typical of osmoconformers lacking specific organs for effective regulation. It is concluded that the barnacles here tested are osmoconformers, able to adjust to small changes of environmental salinity by tissue acclimation, but evading too severe salinity changes by withdrawing into the protection of the shell. The deep sea B. hameri , however, does not close up when immersed in dilute sea water, and appears to be relatively stenohaline with limited ability to acclimate to low salinity. The intertidal E. modestus and B. balanoides , and the low-tidal to sublittoral B. crenatus , are tolerant, after experimental or natural acclimation, of salinities down to 14 to 17 ‰. The estuarine B. improvisus can, with gradual acclimation, be induced to be active in a salinity of about 2 ‰ . This species is remarkably tolerant of dilution of the blood, and its distribution into regions of low salinity is evidently due to a wide tissue resistance and not to any ability to regulate.


1975 ◽  
Vol 53 (9) ◽  
pp. 1207-1212 ◽  
Author(s):  
Patricia I. Tones ◽  
U. T. Hammer

Results of freezing point depression determinations of haemolymph show that first instars, third instars, and adults of Trichocorixa verticalis interiores have well-developed powers of osmoregulation and can hyporegulate in saline water. This species can osmoregulate equally well at 13, 20, and 25 °C but the mean tolerance limit decreases as the temperature increases. T. verticalis interiores is also tolerant to changes in ionic composition. The osmoregulation of this species is similar to that of Sigara stagnalis rather than most Corixidae which are unable to hyporegulate. T. verticalis interiores was collected quantitatively from six athalassic saline lakes which were selected to represent a wide range of salinities. The maximum adult population and conductivity and ionic composition of the water are reported for each lake.


Geophysics ◽  
1976 ◽  
Vol 41 (4) ◽  
pp. 700-711 ◽  
Author(s):  
H. D. Valliant ◽  
J. Halpenny ◽  
R. Beach ◽  
R. V. Cooper

A simultaneous test of a LaCoste and Romberg and a Graf‐Askania sea gravimeter was made over the Halifax Gravity Test Range aboard CSS Hudson in 1972. The test consisted of a total of 33 traverses over precisely located and calibrated test profiles established for this purpose. If errors are defined as the difference between surface and underwater values compared on a common datum, the mean LaCoste gravimeter error observed during a traverse varied from run‐to‐run to form a near normal distribution with mean of 1.8 mgal and standard deviation of 1.0 mgal. The corresponding statistics for the Askania are 2.1 mgal and 3.4 mgal, respectively, with the distribution markedly skew. The data were correlated with three components of accelerations as measured by the LaCoste and Romberg inertial platform. No significant correlation was evident for the LaCoste meter. Some correlation for the Graf‐Askania data, to which crosscoupling corrections are not normally applied, was observed.


Author(s):  
F. G. T. Holliday ◽  
M. Pattie Jones

Just before spawning the semen of the herring is isosmotic with the parent blood, the eggs are hyposmotic. Immediately the eggs are placed in sea water of salinities 5, 17·5, 35 and 50 %0 there is a change in the freezing-point of the yolk indicating that it has approached close to being isosmotic with the water. Changes in the freezing-point of the yolk during development indicate that the overgrowing embryo gradually regulates the osmotic concentration of the yolk, although full regulation is not achieved until after the closing of the blastopore. After this point there is no significant change in the freezing-point of the yolk or body fluids. Regulation is most probably brought about by the activity of the cells of the ectoderm.


Author(s):  
S. K. Eltringham

SUMMARYFreezing-point measurements were made of blood samples taken from specimens of the marine wood-boring isopod Limnoria that had been exposed to sea water of various salinities for 2-3 days. Most of the work was done with L. (L.) tripunctata Menzies, but some preliminary experiements were carried out with L. (L.) lignorum (Rathke) and L. (L.) quadripunctata Holthuis.It was found that the freezing point of the blood averaged 0·17°C above that of the external of medium in both hyp- and hyperosmotic environments. In the absence of any obvious factor which could explain this discrepancy, it is assumed that Limnoria has a certain degree of control over its blood concentrations.Further experiments showed that the blood concentration fell as soon as the animal was introduced to the reduced salinity and levelled off at the hyperosmotic value within a few hours. There was some evidence of a periodicity in the osmoregulation.The possible energetics of osmoregulation in Limnoria are discussed and it is concluded that the amount of energy utilized in the process is unlikely to make any significant inroad into the energy resources available for boring activity.


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