The secretion of hyperosmotic fluid by the rectum of a saline-water mosquito larva, Aedes taeniorhynchus

1975 ◽  
Vol 63 (2) ◽  
pp. 331-342 ◽  
Author(s):  
T. J. Bradley ◽  
J. E. Phillips
Keyword(s):  
Sea Water ◽  
Saline Water ◽  
Average Rate ◽  
Ionic Composition ◽  
Fluid Secretion ◽  
Osmotic Concentration ◽  
Aedes Taeniorhynchus ◽  
Osmotic Balance ◽  
Anal Papillae

1. Fourth-instar larvae of the mosquito A. taeniorhynchus (Wiedemann), when living in sea water, drink at a rate of 100 nl h(−1) larva(−1) and maintain ionic and osmotic levels in the haemolymph at about one-third those of the external medium. 2. Hyperosmotic urine is produced in the rectum by secretion of fluid having an osmotic concentration and ionic composition similar to that of sea water, with the exception that potassium levels are elevated 18-fold in the secretion. The average rate of fluid secretion observed was 19 nl h-1) larva(−1) with a maximum of 92 nl h(−1) larva(−1). 3. The concentration and volume of rectal secretion may be too low to account completely for osmotic balance. The possible role of anal papillae is discussed in this regard.

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.

Regulation of rectal secretion in saline-water mosquito larvae living in waters of diverse ionic composition

1977 ◽  
Vol 66 (1) ◽  
pp. 83-96 ◽  
Author(s):  
T. J. Bradley ◽  
J. E. Philips
Keyword(s):  
Chemical Composition ◽  
External Medium ◽  
Saline Water ◽  
Ionic Composition ◽  
Malpighian Tubules ◽  
Fluid Composition ◽  
Mosquito Larvae ◽  
Major Site ◽  
Osmotic Concentration ◽  
Anal Papillae

1. Larvae of the saline-water mosquito Aedes campestris were adapted to three waters, all having an osmotic concentration of 700 mOsm, but differing in ionic rations. The (Na+Mg) SO4 medium was much moretoxic than the NAHCO3 or the NaCl media. 2. Ionic and osmotic concentrations of haemolymph and rectal secretion were measured in larvae adapted to all three media. The ratio of ionic concentrations in the rectal secretion reflected those in the external medium to which the larvae had been adapted, with the exception of SO42-, which was possibly replaced by HCO3-in the secretion. These differences in rectal fluid composition persisted even though all ligated recta were bathed in the same artificial haemolymph. 3. The Malpighian tubules were found to be the major site of SO42- excretion. In media containing high levels of NA+, Mg2+, K+, Cl- and HCO3-, the rectum secreted a hyperosmotic fluid containing these ions at concentrations several times greater than those found in the haemolymph. 4. These data provide the basis for speculation on the functioning of anal papillae in waters of diverse chemical composition.

The location and mechanism of hyperosmotic fluid secretion in the rectum of the saline-water mosquito larvae Aedes taeniorhynchus

1977 ◽  
Vol 66 (1) ◽  
pp. 111-126
Author(s):  
T. J. Bradley ◽  
J. E. Phillips
Keyword(s):  
Saline Water ◽  
Fluid Secretion ◽  
Opposite Polarity ◽  
Posterior Segment ◽  
Transport Processes ◽  
Cell Border ◽  
Experimental Conditions ◽  
Ultrastructural Studies ◽  
Aedes Taeniorhynchus

1. Ligation between the anterior and posterior segments of the rectum in vitro was used to demonstrate that the posterior rectum is the site of hyperosmotic secretion to the lumen side. Observations were consistent with a reabsorptive function for the anterior rectum. These results support predictions from ultrastructural studies of these two segments. 2. The initial potential of the rectal lumen, relative to the haemocoel side, was of opposite polarity in the anterior (−10 mV) and posterior (+ 10 mV) segments and these values decreased to −2 and +6 mV respectively in ligated recta which had secreted for 2 h. 3. A comparison of these potential difference measurements with concentration differences developed across the rectal epithelium under the same experimental conditions indicates that Na+, K+, Mg2+, and Cl- are all actively transported by the posterior segment to the lumen side. 4. The influence of different haemolymph concentrations of Na+, K+, and Cl- on the potential differences across the basal cell border and across the whole rectal epithelium are reported. Based on this and previous data, we propose a model for the organization of transport processes within the single celltype present in the posterior rectal epithelium.

scholarly journals ADAPTATIONS TO A TERRESTRIAL EXISTENCE BY THE ROBBER CRAB BIRGUS LATRO

1993 ◽  
Vol 179 (1) ◽  
pp. 93-113
Author(s):  
H. H. Taylor ◽  
P. Greenaway ◽  
S. Morris
Keyword(s):  
Drinking Water ◽  
Sea Water ◽  
Ionic Composition ◽  
Free Water ◽  
Deionized Water ◽  
Drinking Rate ◽  
Ion Concentrations ◽  
Regulation Changes ◽  
Very High

Crabs supplied with deionized water (DIW) and food maintained constant haemolymph osmolality, [Na] and [Cl]. Drinking of 300, 600 or 1000 mosmol kg-1 sea water (300SW, 600SW, 1000SW) elevated Na and Cl concentrations, which restabilized by 12 days on the 300SW and 600SW regimens but continued to rise on the 1000SW regimen. [Ca] increased slightly on all regimens. [K] changed only on the 1000SW regimen. Haemolymph [Mg] was poorly regulated on all saline regimens, doubling after 47 days on the 1000SW regimen. Urine was always isosmotic to haemolymph, had twice the [K] and a lower [Ca]. Changes in urinary ion concentrations paralleled those in the haemolymph, indicating that the antennal organs are unimportant in ionic regulation. Changes in ionic composition of the branchially modified urine (P) reflected drinking water concentrations on a mole-for-mole basis (except for [Mg]), confirming the regulatory role of P. Water and ion budgets indicate reingestion of 70–90 % of filtered urine. Branchial ion uptake and reingestion allow variable reclamation of 70–99.9 % of filtered Na, Ca, Mg and Cl and 37–96 % of K. Crabs drank DIW daily (mean rate, 16.2 g kg-1 day-1) and released P intermittently (intervals ranged from less than 1 to more than 6 days; mean 5.8 g kg-1 day-1). Provision of 300SW and 600SW doubled drinking rate and trebled P output. Intense initial drinking of 1000SW (58.1 g kg-1 day-1) was not maintained. Return to DIW after 1000SW stimulated very high drinking rates initially (119 g kg-1 day-1). Birgus can vary P composition rapidly and widely (less than 100 mosmol kg-1 and 20 mmol l-1 [NaCl] to more than 1000 mosmol kg-1 and 500 mmol l-1 [NaCl] within 1 day) and sometimes produce P that is hyperosmotic to the haemolymph. Production of P hyperosmotic to the drinking water and increased drinking rate permit a gain of osmotically free water to balance evaporation when drinking 300SW and 600SW, but not 1000SW. Adjustments to the volume and composition of the P appear to be more important than ‘behavioural osmoregulation’.

Induction of Sulphate Transport and Hormonal Control of Fluid Secretion by Malpighian Tubules of Larvae of the Mosquito Aedes Taeniorhynchus

1978 ◽  
Vol 72 (1) ◽  
pp. 181-202 ◽  
Author(s):  
S.H. P. MADDRELL ◽  
J. E. PHILLIPS
Keyword(s):  
Sea Water ◽  
Fluid Secretion ◽  
Hormonal Control ◽  
Malpighian Tubules ◽  
High Rate ◽  
Sulphate Content ◽  
Thoracic Ganglia ◽  
Sulphate Transport ◽  
Aedes Taeniorhynchus ◽  
The Brain

1. 4th stage larvae of A. taeniorhynchus reared in sulphate-enriched sea water drink the medium at the same rate that they do when reared in sulphate-free sea water. They absorb into the haemolymph most of the water and nearly all of the sulphate from the ingested fluid. 2. Larvae are able to keep the concentration of sulphate in the haemolymph at levels well below that of the medium, even when this contains as much as 89 mM sulphate. 3. The Malpighian tubules of larvae reared in sulphate-containing waters soon develop an ability to transport sulphate. The rate of sulphate transport induced varies directly with the sulphate content of the water in which they are reared. This ability is not retained into the adult stage. 4. The rate of fluid secretion by isolated Malpighian tubules is increased by up to 20 times when they are exposed to saline containing 1.5 mM cyclic AMP or concentrations of 5-hydroxytryptamine higher than 10−6 5. Tubules isolated from unfed insects into stimulant-free saline secrete fluid only slowly, but similarly treated tubules from feeding insects initially secrete fluid very much faster. 6. Extracts of the brain and of the thoracic ganglia stimulate Malpighian tubules to secrete fluid at a high rate. The brain is about four times as rich a source of stimulant as is the chain of thoracic ganglia. Treatment of the surface of the structures in the head with K-rich saline leads to the release of a factor which stimulates fluid secretion by the Malpighian tubules. 7. The results suggest that the Malpighian tubules in larvae of A. taeniorhynchus are under the control of a diuretic hormone which is elaborated in the brain and possibly also in the thoracic ganglia and which reaches high levels in the circulating haemolymph of feeding animals. 8. The rate of sulphate transport by isolated Malpighian tubules is strongly affected by the rate of fluid secretion. This behaviour is compatible with a passive leak of transported sulphate from the lumen back into the haemolymph through the permeable wall of the tubule.

scholarly journals Mineral Nutrition, Growth, and Germination of Antirrhinum majus L. (Snapdragon) when Produced Under Increasingly Saline Conditions

HortScience ◽  
2008 ◽  
Vol 43 (3) ◽  
pp. 710-718 ◽  
Author(s):  
Christy T. Carter ◽  
Catharine M. Grieve
Keyword(s):  
Sea Water ◽  
Saline Water ◽  
Ionic Composition ◽  
Antirrhinum Majus ◽  
Plant Tissues ◽  
Slight Reduction ◽  
Cut Flowers ◽  
Quality Water ◽  
Total P

The conservation of quality water is of special concern, especially in California, as the need for quality water increases with a growing population. Reusing saline wastewaters to irrigate salt-tolerant floral crops provides a viable option to produce quality marketable cut flowers while conserving the highest quality water for other purposes. A completely randomized design with three replications was used to investigate the effects of five salinity treatments [2.5 (control), 5, 8, 11, 14 dS·m−1] and two water ionic compositions: concentrations of Colorado River water (CCRW) and dilutions of sea water (SWD), on the mineral uptake, germination, growth, and quality of two cultivars of Antirrhinum majus (‘Monaco Rose’ and ‘Apollo Cinnamon’). Seeds of both cultivars were sown in 30 greenhouse sand tanks. Leaves were collected 2 months after planting and analyzed for concentrations of Ca2+, Mg2+, Na+, Cl−, K+, total P, and total S. As salinity increased, Ca2+, Mg2+, Na+, Cl–, and total S increased in plant tissues, whereas K+ and total P decreased in plant tissues for both cultivars in both irrigation solutions. Leaf nutrient composition was related to the interactions of ions within the substrate solutions and their ability to compete for uptake at the site of root membranes. Phenotypic measurements, made when plants were harvested, showed only slight decreases as salinity increased. A 2 × 5 factorial design was used to determine the effects of water ionic composition and salinity on the germination of seeds. Four replicate Petri dishes each with 25 seeds were exposed to constant temperature (20 °C) and an 8-h dark : 16-h light photoperiod to promote germination. Germination was checked daily for 16 d. Snapdragons can be produced from seed when exposed to salinities up to 14 dS·m−1 using both SWD and CCRW ionic solutions for irrigation because germination remained at 92% or greater. Quality of the flowering stems was rated according to standards developed by the Society of American Florists. Marketable stems of both cultivars were produced in all treatments. Overall, quality of stems produced with saline waters ranging from 2.5 to 11 dS·m−1 was very high (“special”). Irrigation with more saline water (14 dS·m−1) resulted in a slight reduction in quality and stems were rated as “fancy” depending on the cultivar. Both cut flower cultivars can be produced for commercial use under saline conditions up to at least 14 dS·m−1.

Osmotic Balance in Hydrobia Ulv Ae and Potamopyrgus Jenkinsi (Gastropoda: Hydrobiidae)

1964 ◽  
Vol 41 (3) ◽  
pp. 665-677
Author(s):  
MARY E. TODD
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Freezing Point ◽  
Phenol Red ◽  
Ecological Groups ◽  
Experimental Conditions ◽  
Osmotic Concentration ◽  
Hydrobia Ulvae ◽  
Osmotic Balance ◽  
Potamopyrgus Jenkinsi

1. Osmotic balance was studied in Hydrobia ulvae and Potamopyrgus jenkinsi over the range 100% sea water to fresh water, by determining the freezing-point depression of the urine in the different solutions. 2. Hydrobia ulvae was slightly hyperosmotic from 100 to 50% sea water, and sometimes initially markedly hyperosmotic in 25% sea water at 5°C. The urine was always markedly hyperosmotic relative to fresh water, and the animals were withdrawn. Experiments with phenol red indicated that the tissues were not shut off from the medium. 3. Potamopyrgus jenkinsi was hyperosmotic from fresh water to 100% sea water. Osmotic balance in fresh water is maintained in part by the excretion of a urine hypo-osmotic relative to the blood. 4. There was some variation in the reaction of different ecological groups of Hydrobia ulvae and Potamopyrgus jenkinsi to the experimental conditions. 5. In the Hydrobiidae, whether transformed from a lower to a higher salinity or vice versa, survival outside the viable range was longer at 5°C. than at 15°C., although, within the range, activity occurred more rapidly at 15°C. 6. In fresh water, winter animals of both species had a higher osmotic concentration of the urine than summer animals, but no differences in osmotic concentration correlated with temperature were demonstrated.

scholarly journals The pattern of osmotic regulation in larvae of the mosquito Culiseta inornata

1984 ◽  
Vol 113 (1) ◽  
pp. 133-141 ◽  
Author(s):  
M. Garrett ◽  
T. J. Bradley
Keyword(s):  
Sea Water ◽  
Saline Water ◽  
Mosquito Species ◽  
Full Range ◽  
Chloride Ion ◽  
Malpighian Tubules ◽  
Osmotic Concentration ◽  
Culiseta Inornata

Larvae of Culiseta inornata (Williston) can survive and complete development in dilutions of sea water ranging from 50–700 mosmol kg-1. The larvae hyperregulate with regard to haemolymph osmotic concentration in dilute media (50–400 mosmol kg-1) and osmoconform when external salinities exceed 400 mosmol kg-1. This pattern of osmoregulation is distinct from that observed in freshwater and saline-water mosquito species. We propose that mosquitoes exhibiting this osmoregulatory pattern should be described as ‘brackish-water’ species. Larvae of Culiseta inornata are able closely to regulate both sodium and chloride ion concentrations in the haemolymph over the full range of salinities tested (50–750 mosmol kg-1). The Malpighian tubules produce an isosmotic, potassium-rich fluid. In vitro and in vivo sampling of rectal fluids demonstrates that rectal secretions are isosmotic or only slightly hyperosmotic to the haemolymph and the surrounding saline media, and that they are isotonic with regard to sodium.

scholarly journals Ion Concentration and Activity in the Haemolymph of Aedes Aegypti Larvae

1982 ◽  
Vol 101 (1) ◽  
pp. 143-151 ◽  
Author(s):  
H.A. EDWARDS
Keyword(s):  
Amino Acids ◽  
Aedes Aegypti ◽  
Sea Water ◽  
Total Concentration ◽  
Ionic Composition ◽  
Inorganic Ions ◽  
Ion Concentration ◽  
Salinity Range ◽  
Substantial Part ◽  
Osmotic Concentration

The ionic composition of the haemolymph was measured in fourth instar larvae of Aedes aegypti (reared in 0.30% sea water, the animals' natural salinity range). Inorganic ions and free amino acids form a substantial part of the haemolymph osmotic concentration. With increasing external osmotic pressure, there is an increase in the concentration of the amino acids, not the major inorganic cations. Measurements with ion-selective electrodes indicate that the activities of sodium, potassium and chloride can vary independently of their total concentration. The osmotic contribution of these inorganic ions is therefore not necessarily determined by their total concentration.

The Role of the Interaction between Fe(III) and Cell Surface in the Accumulation of 67Ga by Tumor Cells

1991 ◽  
Vol 30 (06) ◽  
pp. 290-293 ◽  
Author(s):  
P. Maleki ◽  
A. Martinezi ◽  
M. C. Crone-Escanye ◽  
J. Robert ◽  
L. J. Anghileri
Keyword(s):  
Cell Surface ◽  
Tumor Cells ◽  
Ionic Composition ◽  
Iron Complex ◽  
Iron Binding ◽  
Complex Time ◽  
Interaction Product ◽  
Thermodynamic Constant ◽  
Number Of Cells

The study of the interaction between complexed iron and tumor cells in the presence of 67Ga-citrate indicates that a phenomenon of iron-binding related to the thermodynamic constant of stability of the iron complex, and a hydrolysis (or anion penetration) of the interaction product determine the uptake of 67Ga. The effects of various parameters such as ionic composition of the medium, nature of the iron complex, time of incubation and number of cells are discussed.

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