The Evaporation of Water from Woodlice and the Millipede Glomeris

1951 ◽  
Vol 28 (1) ◽  
pp. 91-115
Author(s):  
E. B. EDNEY
Keyword(s):  
Water Vapour ◽  
Water Loss ◽  
Average Rate ◽  
Temperature Tolerance ◽  
Effect Of Temperature ◽  
Absolute Amount ◽  
Absolute Size ◽  
Saturation Deficit ◽  
Dry Air ◽  
Rate Of Evaporation

1. Comparative studies have been made on seven woodlice and the millipede Glomeris to determine: (i) the site of water loss, (ii) the effect of temperature and humidity on the rate of evaporation of water, (iii) the effect of humidity on their upper temperature tolerance, and (iv) their capacity to regain water after desiccation. 2. An apparatus was constructed in which several animals can be exposed simultaneously but separately to a slowly moving stream of air of any required humidity and temperature. 3. There is no difference between the sexes as regards rate of water loss, and no difference was found in this respect between living and dead animals for exposures up to 1 hr. 4. In Armadillidium and Porcellio the pleopodal area loses water some ten to twenty times faster per unit area than the dorsal or ventral surface (some five times only in Ligia), but the absolute amount of water lost per unit time by the pleopods is less than that from either of the other areas mentioned. 5. Tables and graphs are given showing the rate of loss of water in mg./cm.2/hr. in dry air at various temperatures for each species studied, both for 15 min. and 1 hr. exposures. These show a linear relationship between rate of evaporation and saturation deficit except for Armadillidium and Glomeris above 40° C. (where the rate falls off), and Ligia. Reasons for these exceptions are suggested: curling in the first two, absolute size in the last. 6. The animals studied can be placed in a series as regards rate of loss of water, from Ligia (which shows the greatest rate) through Philoscia, Oniscus, Porcellio, Cyclisticus and Armadillidium nasatum to A. vulgare, which shows the lowest rate of loss. Oniscus, Porcellio and Cylisticus do not differ very greatly from one another in this respect. Glomeris loses water less rapidly than the majority of species of woodlice if exposed for 15 min., but, because the average rate of loss from woodlice falls if they are exposed for an hour, Glomeris appears to lose more rapidly than they do for an hour's exposure. 7. The highest temperature tolerated by woodlice for short exposures (15 min. or 1 hr.) does not vary greatly with humidity--temperatures are somewhat above 40° C. for 15 min. exposures--it is slightly higher at 50% R.H., due to a cooling effect, than in dry or saturated air; but for 24 hr. exposures, the animals die of desiccation and consequently the highest tolerable temperature is very much lower in dry air than in moist. These findings are also true, but to a less marked extent, of Glomeris. 8. The species can be arranged in a series as regards temperature tolerance which corresponds with the rate of evaporation series, A. vulgare having the highest temperature tolerance, Ligia the lowest. 9. After exposure to desiccation for 45 min. in dry air, or for 23 hr. in 50% R.H., both at room temperature, no species could live or recover weight if subsequently kept at 95% R.H. Armadillidium (but no others) could live and recover weight by absorption of water vapour if kept at 98% R.H., and all species could live and recover weight if kept in saturated air. Only living animals recovered weight by absorption of water vapour or liquid water. Animals which died after a period in the ‘recovery’ dishes always lost water very rapidly before doing so. The power to recover water from air at 98% R.H., possessed by Armadillidium, is limited by relative humidity not by saturation deficit. 10. The above results are discussed and the need for microclimatic data is stressed.

On the Behaviour of Wireworms of the Genus Agriotes Esch. (Coleoptera, Elateridae)

1943 ◽  
Vol 20 (1) ◽  
pp. 43-53
Author(s):  
A. D. LEES
Keyword(s):  
Water Loss ◽  
The Other ◽  
Sudden Increase ◽  
Great Activity ◽  
Moist Air ◽  
Steep Gradient ◽  
Dry Air ◽  
Constant Rate ◽  
Rate Of Evaporation ◽  
Humidity Range

1. The general humidity behaviour, the humidity receptors and the orientation mechanisms have been studied in the larvae of Agriotes. 2. Wireworms avoid dry air, the intensity of avoidance being greatest when the alternatives are close to saturation . Within this humidity range a difference of 7.5 % R.H. in the alternative chamber (at 17 ° C.) is sufficient to ensure the successful avoidance of the lower humidity by nearly every individual, while statistically significant reactions are obtained with differences as small as 0.5 % R.H. At lower ranges of humidity the same differences yield progressively less intense reactions; at low humidities the response is entirely eliminated. 3. The intensity of the reaction is in better accord with the humidity differences when these are expressed as saturation deficiencies rather than as relative humidities. This suggests that the reaction is initiated by the evaporation of water (‘evapori-meter’ receptor) and not by the operation of receptors which function hygrometrically (‘hygrometer’ receptors). 4. The humidity ‘receptors’ lie on the head. Amputation experiments indicate that the relevant sites of evaporation are distributed between the antennae, maxillary and labial palps; the structure of these appendages is compatible with such a function;- on the other hand, sensilla which might conceivably have a hygroscopic function are absent. 5. Orientation is achieved by the operation of two mechanisms. First, larvae are more active in dry than in moist air (low hygro-kinesis); secondly, larvae show a directed response to low humidities (klinotaxis); this is displayed as a powerful backward recoil if the wireworm crosses a steep gradient from moist into dry air. No tropo-tactic component is involved. The failure of the reaction at low humidities is explained by the great activity of the larvae which interferes with the operation of the klino-tactic mechanism. It is suggested that the kinesis is maintained by a relatively constant rate of water loss from the head appendages, while the klino-taxis is initiated by any sudden increase in the rate of evaporation. 6. The behaviour can readily be correlated with the humidity conditions prevailing in the soil; the necessity for such a sensitive response is possibly dictated by the permeability of the cuticle which renders wireworms peculiarly liable to water loss in unsaturated atmospheres.

The Body Temperature of Woodlice

1951 ◽  
Vol 28 (3) ◽  
pp. 271-280
Author(s):  
E. B. EDNEY
Keyword(s):  
Body Temperature ◽  
Water Vapour ◽  
High Temperatures ◽  
Air Temperature ◽  
Water Loss ◽  
Evaporation Rate ◽  
The Body ◽  
Steady Temperature ◽  
Dry Air ◽  
Temperature Depression

1. Measurements by means of thermocouples, accurate to 0.1°C., were made of the body temperature of the woodlice Armadillidium, Porcellio, Oniscus and Ligia, and of the cockroach Blatta, both alive and dead, in a stream of saturated or dry air at both 20 and 37°C. 2. No difference in temperature depression was found between living and dead woodlice, and in all the animals used there was, after equilibration, no difference greater than 0.1°C. between the air temperature and body temperature if the air were saturated with water vapour. 3. In dry air, the body temperature of all the animals except Ligia settled down after at most 25 min. to a steady temperature which was lower than that of the surrounding air. The body temperature of Ligia continued to rise slowly for at least 2 hr., though remaining well below that of the environment. 4. After 30 min. in dry air at 20 and 37°C. respectively, mean temperature depressions (of at least three readings at each temperature for each species) were, in degrees centigrade: Ligia, 2.6 and 6.8; Oniscus, 1.5 and 2.7; Parcellio, 0.4 and 1.3; Armadillidium, 0.5 and 1.8; and the cockroach Blatta, 0.7 and 2.4. The order of the species in this respect is substantially the same as their order in respect of evaporation rate, which was established previously. 5. Certain anomalies which appear when these figures are compared with previously established figures for insects are probably the result of differences in permeability of the integument and in the site of water loss. The ability to evaporate water rapidly, and thus to cool the body, may be of survival value when woodlice are exposed to high temperatures for short periods, particularly in littoral forms which may well have been intermediate in the evolution of terricolous from maricolous isopods.

Mucus glycoconjugate secretion in cool and hypertonic solutions

1997 ◽  
Vol 272 (6) ◽  
pp. L1121-L1125 ◽  
Author(s):  
T. M. Dwyer ◽  
J. M. Farley
Keyword(s):  
Average Rate ◽  
Transient Increase ◽  
Productive Cough ◽  
Submucosal Gland ◽  
Basal Secretion ◽  
Cold Air ◽  
Dry Air ◽  
Gland Cells ◽  
Hypertonic Solutions ◽  
Exercise Induced

For sensitive individuals, exercise-induced asthma is triggered by cold and dry air and is often accompanied by a productive cough. In this study, we determined whether cold solutions and/or solutions of increased tonicity directly caused an increase in glycoconjugate (GC) secretion. To test this, we used isolated swine tracheal submucosal gland cells (TSGCs) and measured the rate of GC secretion at 37 and 32 degrees C in isotonic solutions and in solutions made hypertonic by 30 mosM. TSGCs were isolated under conditions that minimized the rate of GC secretion and were perfused with medium 199 equilibrated with 5% CO2 to a pH of 7.4. A lectin-based assay was used to specifically detect GC present in each 2-min fraction of the perfusate. Basal secretion was 3.1-fold greater at 32 degrees C (n = 3) than at 37 degrees C (n = 4; P < 0.05). At 37 degrees C, increasing perfusate osmolarity by 30 mosM increased the average rate of secretion by 41 +/- 11% (n = 4; P < 0.05); return to isotonic perfusate caused a 4.5 +/- 1.8-fold transient increase in secretion (n = 4; P < 0.05) that was complete within 10 min. At 32 degrees C, changing tonicity of the perfusate had no significant effect but returning to isotonic perfusate caused a 2.3 +/- 0.7-fold transient increase in secretion (n = 3; P < 0.05). Thus key stimuli that trigger obstruction of airflow (cold and increased osmolarity) can also directly stimulate GC secretion in the airway. Such increased secretions may contribute to the productive cough observed in some individuals in response to cold air.

Water Relationships of Aphis Fabae Scop. During Tethered Flight

1961 ◽  
Vol 38 (1) ◽  
pp. 175-180
Author(s):  
A. J. COCKBAIN
Keyword(s):  
Body Weight ◽  
Relative Humidity ◽  
Water Loss ◽  
Total Body Weight ◽  
Aphis Fabae ◽  
Limiting Factor ◽  
Saturation Deficit ◽  
Tethered Flight ◽  
C 23 ◽  
Total Body

1. Water content varies from 64 to 73% of the total body weight and 72-76% of the fatless body weight of 24 hr. old unflown alatae of Aphis fabae. 2. Water loss during flight may be attributed to evaporation and excretion. A mean of 0.07 mg. water is lost per aphid during a 6 hr. tethered fligh a 25-26° C. and 57-82% R.H., corresponding to c. 9% body weight; at least 66% of the loss (c. 1% body weight/hr.) is by evaporation. 3. Excretion during fligh is not affected by relative humidity differences over the range 41-75% at 25%26° C., but the relative amounts of water lost during prolonged flight are inversely related to relative humidity, because of the effect of humidity on evaporation. 4. Proportion of water in he body does no change significantly during tethered fligh. Mean percentage water to total body weight increases from c. 68-69% during 6 hr.; mean percentage water to fatless body weight decreases from c. 74 to 73%. 5. Water loss is evidently not a limiting factor to fligh in atmospheres of saturation deficit less than c. 23 mm. Hg.

scholarly journals Temperature-dependent seminal recovery in the southern king crab Lithodes santolla

2019 ◽  
Vol 6 (3) ◽  
pp. 181700 ◽  
Author(s):  
Katrin Pretterebner ◽  
Luis Miguel Pardo ◽  
Kurt Paschke
Keyword(s):  
Fishery Management ◽  
Climate Change Scenario ◽  
Temperature Tolerance ◽  
Effect Of Temperature ◽  
Change Scenario ◽  
Southern Chile ◽  
Temperature Dependent ◽  
Fishery Resource ◽  
Recovery Index ◽  
Distributional Limit

Male-biased fishery management can provoke depletion of seminal reserves, which is the primary cause of sperm limitation. Therefore, identifying factors which contribute to the vulnerability to depletion of seminal reserves is a priority. The present study aimed to determine the effect of temperature on the recovery rate of sperm and seminal reserves after their depletion in Lithodes santolla , an important fishery resource in southern Chile. Sperm and seminal reserves were not fully recovered within 30 days. Temperature significantly affected seminal recovery: after 30 days the recovery index increased to 40% and 21% at 9°C and 12°C, respectively. The twice as fast seminal recovery at 9°C may be explained by the zone of origin of the individuals in this study (northern distributional limit), and 12°C may be close to the threshold of temperature tolerance. Lithodes santolla populations subject to intense male-only fisheries may be vulnerable to depletion of seminal reserves and a climate change scenario could additionally aggravate the risk of seminal depletion in L. santolla in its northern distributional limit.

Effect of breathing dry air on structure and function of airways

1986 ◽  
Vol 61 (1) ◽  
pp. 312-317 ◽  
Author(s):  
J. C. Van Oostdam ◽  
D. C. Walker ◽  
K. Knudson ◽  
P. Dirks ◽  
R. W. Dahlby ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Connective Tissue ◽  
Water Loss ◽  
Structure And Function ◽  
Maximum Response ◽  
Response Curves ◽  
Loose Connective Tissue ◽  
Dry Air ◽  
And Function ◽  
Breathing Room

We compared the effect of breathing dry air (0.70 mg H2O/l) with that of breathing room air (8.62 mg H2O/l) in guinea pigs anesthetized with urethane. The data showed that breathing dry air caused a reduction of extravascular water (EVW) in the trachea (P less than 0.01) but not the lung. Structural analysis showed that this water loss occurred from the loose connective tissue of the submucosa. Histamine dose response curves performed on the animals showed that breathing dry air caused an increase in the maximum response (delta max RL) (P less than 0.01) without changing either the dose required to produce 50% of the delta max RL or the ratio of delta max RL to this dose. We conclude that breathing dry air produces an acute reduction of EVW of the loose connective tissue of the airways and an increase in the maximum response to histamine.

EFFECT OF TEMPERATURE, NITROGEN FERTILIZATION AND MOISTURE STRESS ON GROWTH, ASSIMILATE DISTRIBUTION AND MOISTURE USE BY MANITOU SPRING WHEAT

1979 ◽  
Vol 59 (3) ◽  
pp. 603-626 ◽  
Author(s):  
C. A. CAMPBELL ◽  
H. R. DAVIDSON
Keyword(s):  
Spring Wheat ◽  
Leaf Blade ◽  
Dry Matter ◽  
Average Rate ◽  
Moisture Stress ◽  
Effect Of Temperature ◽  
Dry Matter Accumulation ◽  
N Accumulation ◽  
Early Stress ◽  
Dough Stage

The effects of early moisture stress [tillering (Tg) to last leaf visible (LLV)], late moisture stress [LLV to anthesis (AN)], and three rates of N fertilizer (44, 88 and 132 kg N/ha) on the development and moisture use characteristics of spring wheat (Triticum aestivum L. ’Manitou’) were determined under simulated irrigation in the growth chamber at day/night temperatures of 27 °C/12 °C (T27/12) and 22 °C/12 °C (T22/12). Plant height was unaffected by N and by early stress, but was reduced by late stress. Number of tillers increased until LLV, then decreased sharply and remained constant to maturity. More tillers were initiated at T27/12 than at T22/12, but by maturity there was little difference. Leaf blade photosynthetic area reached its maximum at LLV, while the non-leaf blade photosynthetic area reached its maximum at AN and constituted 75% of the total photosynthetic area at the milk dough stage. Heads comprised no more than 9% of the photosynthetic area at any time. Total plant matter accumulated sigmoidally, but at T27/12 and low N rates, plants lost total dry weight after the milk dough stage. Dry matter of the vegetative plant parts increased until the milk dough stage, then stems in particular, and roots to a lesser extent, lost weight. Head weight increased linearly at about 17.5 mg/head/day. Dry matter accumulation was directly proportional to N applied, inversely related to temperature, temporarily retarded by early stress and markedly reduced by late stress. Although stems were the dominant vegetative dry matter sink, leaves were the dominant N sink. A combination of high temperature, high N and moisture stress resulted in a temporary loss of N from the plants between LLV and the milk dough stage. As maturation proceeded, N assimilates appeared to move from leaves to roots into stems and thence into heads. The average rate of N accumulation in the heads was 0.22 and 0.27 mg/head/day at T22/12 and T27/12, respectively. Some N was lost by denitrification. The amount and rate of evapotranspiration were directly proportional to N applied and in general inversely related to moisture stress. The rate of moisture use was generally more rapid at T27/12, but the amount used was no different from that at T22/12. Plants stressed early recovered and used water at the same rate as unstressed plants, but plants stressed late did not recover.

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