scholarly journals ROUTES OF TRANSPIRATORY WATER LOSS IN A DRYHABITAT TENEBRIONID BEETLE

1991 ◽  
Vol 157 (1) ◽  
pp. 425-437 ◽  
Author(s):  
KARL ERIK ZACHARIASSEN
Keyword(s):  
East Africa ◽  
Water Permeability ◽  
Water Loss ◽  
Air Humidity ◽  
Evaporative Water ◽  
Dry Air ◽  
Dominant Component ◽  
Tenebrionid Beetle ◽  
Abdominal Surface ◽  
Respiratory Gases

Routes of evaporative water loss in the tenebrionid beetle Phrynocolus petrosus Gerstaecker from dry savanna in East Africa were investigated. The humidity of the air surrounding the abdomen, the air surrounding the head and pronotum and the air inside the subelytral cavity was varied independently, and the effects on organismal rate of water loss were observed. The rate of organismal water loss dropped when the humidity around the head and pronotum and inside the subelytral cavity increased. Saturation of these air compartments, which both exchange respiratory gases with the tracheae through the spiracles, reduced the organismal rate of water loss by more than 80%, even when the large abdominal surface was surrounded by dry air. The results indicate that the transcuticular water loss makes up only about 20% of the total transpiratory water loss in these beetles, i.e. transcuticular water permeability is very low. The results also indicate that the average air humidity inside the subelytral cavity of normal intact beetles is close to saturation. Water loss from the subelytral chamber is reduced accordingly, and appears to make up less than 10% of the total transpiratory water loss. The water loss over the pronotal spiracles amounts to about 70%, and is thus the dominant component of transpiratory water loss in these beetles.

The Evaporation of Water from Helix Aspersa

1964 ◽  
Vol 41 (4) ◽  
pp. 759-769
Author(s):  
JOHN MACHIN
Keyword(s):  
Water Content ◽  
Water Loss ◽  
Vapour Pressure ◽  
Freezing Point ◽  
Muscular Activity ◽  
Helix Aspersa ◽  
Distilled Water ◽  
Atmospheric Conditions ◽  
Evaporative Water ◽  
Dry Air

1. Observations of intact specimens of Helix aspersa together with experiments with isolated skin preparations are described. 2. Under normal atmospheric conditions increases in haemocoelic pressure, probably due to general muscular activity, are sufficient to maintain the superficial mucous coating of the skin. 3. Under conditions of rapid water loss more intense muscular undulations serve to spread mucus which collects in the grooves to more exposed areas of the skin. 4. The water content, the rate of water loss in dry air, the equilibrium in saturated air and depression of freezing point of isolated mucus samples have been measured. 5. The vapour pressure of mucus has been shown to be within 0.4% of that of distilled water under the same conditions. 6. The significance of the above findings is discussed in relation to evaporative water loss and water uptake of an intact snail.

scholarly journals Airway Surface Liquid Osmolality Measured Using Fluorophore-Encapsulated Liposomes

2001 ◽  
Vol 117 (5) ◽  
pp. 423-430 ◽  
Author(s):  
Sujatha Jayaraman ◽  
Yuanlin Song ◽  
A.S. Verkman
Keyword(s):  
Epithelial Cells ◽  
Water Loss ◽  
Airway Epithelial Cells ◽  
Evaporative Water Loss ◽  
Airway Surface Liquid ◽  
Airway Epithelial ◽  
Evaporative Water ◽  
Dry Air ◽  
Surface Liquid ◽  
Sulforhodamine 101

The airway surface liquid (ASL) is the thin layer of fluid coating the luminal surface of airway epithelial cells at an air interface. Its composition and osmolality are thought to be important in normal airway physiology and in airway diseases such as asthma and cystic fibrosis. The determinants of ASL osmolality include epithelial cell solute and water transport properties, evaporative water loss, and the composition of secreted fluids. We developed a noninvasive approach to measure ASL osmolality using osmotically sensitive 400-nm-diam liposomes composed of phosphatidylcholine/cholesterol/polyethylene glycol-phosphatidylcholine (1:0.3:0.08 molar ratio). Calcein was encapsulated in the liposomes at self-quenching concentrations (30 mM) as a volume-sensitive marker, together with sulforhodamine 101 (2 mM) as a volume-insensitive reference. Liposome calcein/sulforhodamine 101 fluorescence ratios responded rapidly (<0.2 s) and stably to changes in solution osmolality. ASL osmolality was determined from calcein/sulforhodamine 101 fluorescence ratios after addition of microliter quantities of liposome suspensions to the ASL. In bovine airway epithelial cells cultured on porous supports at an air–liquid interface, ASL thickness (by confocal microscopy) was 22 μm and osmolality was 325 ± 12 mOsm. In anesthetized mice in which a transparent window was created in the trachea, ASL thickness was 55 μm and osmolality was 330 ± 36 mOsm. ASL osmolality was not affected by pharmacological inhibition of CFTR in airway cell cultures or by genetic deletion of CFTR in knockout mice. ASL osmolality could be increased substantially to >400 mOsm by exposure of the epithelium to dry air; the data were modeled mathematically using measured rates of osmosis and evaporative water loss. These results establish a ratio imaging method to map osmolality in biological compartments. ASL fluid is approximately isosmolar under normal physiological conditions, but can become hyperosmolar when exposed to dry air, which may induce cough and airway reactivity in some patients.

Adaptations of carabid beetles to dry habitats in East Africa

1986 ◽  
Vol 2 (2) ◽  
pp. 127-138 ◽  
Author(s):  
Johan Andersen ◽  
Karl Erik Zachariassen ◽  
Geoffrey M. O. Maloiy ◽  
John M. Z. Kamau
Keyword(s):  
Body Weight ◽  
Body Size ◽  
East Africa ◽  
Water Loss ◽  
Carabid Beetles ◽  
Temperate Species ◽  
Humid Atmosphere ◽  
Dry Air ◽  
Relative Water ◽  
Tropical Areas

ABSTRACTThe rates of water loss and humidity preference of carabids from dry tropical habitats have been studied and compared with corresponding data from temperate carabids and tropical tenebrionids. Within each group of beetles the rate of relative water loss decreases with increasing body size. Carabids from dry tropical areas have rates of water loss which are lower than those of temperate species, but considerably higher than the values for tenebrionids from dry tropical habitats. Small temperate carabids can stay in dry air for only a few hours, whereas large tropical tenebrionids may survive for weeks without becoming critically dehydrated. Given the choice between a dry and a humid atmosphere, well hydrated beetles of all groups will initially choose the dry atmosphere. Most temperate carabids will switch to humid atmosphere after a few hours and tropical carabids after 1–3 days, whereas tropical tenebrionids may remain in dry air for almost 3 weeks. The temperate carabids are very sensitive to dehydration and will shift to a humid atmosphere when dehydrated by only 2–5%. Tropical carabids and tenebrionids will shift first when they are dehydrated by 7–20% of their body weight in a hydrated state, implying that these beetles are considerably less sensitive to water loss than temperate carabids.

Metabolism, Respiration and Evaporative Water Loss in the Australian Hopping-Mouse Notomys Alexis (Rodentia: Muridae).

1979 ◽  
Vol 27 (2) ◽  
pp. 195 ◽  
Author(s):  
PC Withers ◽  
AK Lee ◽  
RW Martin
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Tidal Volume ◽  
Water Loss ◽  
Minute Volume ◽  
Evaporative Water Loss ◽  
Moist Air ◽  
Evaporative Water ◽  
Ambient Temperatures ◽  
Dry Air

Resting oxygen consumption and total evaporative water loss were determined for N. alexis at ambient temperatures of 20, 28 and 33 deg C in dry air. The minimum rate of oxygen consumption was 0.61 ml min-1 at 33 deg C, and minimum total evaporative water loss was 4.75% body mass day-1 at 28 deg C. Respiration frequency, tidal volume and respiratory minute volume were determined for N. alexis at ambient temperatures of 20, 28 and 33 deg C in air of low or high relative humidity. Minimum values were obtained at 28 deg C and low RH for respiratory minute volume and tidal volume, and at 28 deg C and high RH for respiratory frequency. Expired air temperature of N. alexis at these temperatures was lower than or similar to ambient for mice in air of low RH, but was higher than or similar to ambient at high RH. Respiratory evaporative water loss, calculated from the previous data, was greatest for mice in dry air at 33 deg C, and least in moist air at 33 deg C. Cutaneous evaporative water loss made up about 40-60% of the total evaporative water loss for mice in dry air. The rates of total evaporative water loss were clearly reflected in the manner of body temperature regulation at high ambient temperatures. Hopping-mice in moist air at 28 and 33 deg C became hyperthermic, whereas mice in dry air showed only slight increases in body temperature. The significance of these data to hopping-mice in the field was discussed.

Studies on the water economy of some Australian frogs.

1965 ◽  
Vol 13 (2) ◽  
pp. 317 ◽  
Author(s):  
MR Warburg
Keyword(s):  
High Temperatures ◽  
Water Uptake ◽  
Water Loss ◽  
Vapour Pressure ◽  
Arid Regions ◽  
Vapour Pressure Deficit ◽  
Evaporative Water ◽  
Dry Air ◽  
Reduced Water ◽  
Semi Arid

The rate of evaporative water loss of several species of frog found in Australia and their ability to survive at high temperatures were studied at various temperatures in both dry and in humid air, and at constant vapour pressure deficit. The species studied were: Bufonidae, Bufo marinus (L.); Leptodactylidae, Crinia signifera Girard, Pseudophryne bibroni Gunther, Limnodynastes tasmaniensis Gunther, L. dorsalis (Gray), L. ornatus (Gray), Neobatrachus pictus Peters, N. centralis (Parker); Hylidae, Hyla ewingi (Dumeril & Bibron) and H. rubella Gray. To a certain extent, the trend for increased adaptation to terrestrial conditions follows the trend for reduced water loss. The rate of water uptake after dehydration is greatest in the burrowing frogs inhabiting arid and semi-arid regions. Survival at high temperatures in dry air was found to be a good criterion for judging the degree of adaptation of these frogs to life in arid regions.

Shell Resistance and Evaporative Water Loss from Bird Eggs: Effects of Wind Speed and Egg Size

1981 ◽  
Vol 54 (2) ◽  
pp. 195-202 ◽  
Author(s):  
James R. Spotila ◽  
Christina J. Weinheimer ◽  
Charles V. Paganelli
Keyword(s):  
Wind Speed ◽  
Water Loss ◽  
Egg Size ◽  
Evaporative Water Loss ◽  
Evaporative Water ◽  
Bird Eggs

Scaling of Evaporative Water Loss in Marsupials

1986 ◽  
Vol 59 (1) ◽  
pp. 1-9 ◽  
Author(s):  
David S. Hinds ◽  
Richard E. MacMillen
Keyword(s):  
Water Loss ◽  
Evaporative Water Loss ◽  
Evaporative Water
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