scholarly journals Slow Discontinuous Ventilation in the Namib Dune-sea Ant Camponotus Detritus (Hymenoptera, Formicidae)

1990 ◽  
Vol 151 (1) ◽  
pp. 71-82 ◽  
Author(s):  
JOHN R. LIGHTON
Keyword(s):  
Body Size ◽  
Gas Exchange ◽  
Water Loss ◽  
Ventilation Rate ◽  
Co2 Production ◽  
Namib Desert ◽  
Ventilation Frequency ◽  
Loss Rates

Data on discontinuous ventilation phenomena in Camponotus detritus (Emery), an ant from the hyper-arid Namib Desert, are described and compared to equivalent data from two mesic insects, including Camponotus vicinus (Mayr). Although rate of CO2 production (Vco2 and body size were equivalent in C. detritus and C. vicinus, the ventilation rate of C. detritus was fourfold lower, significantly reducing predicted respiratory water loss rates. Ventilation rate was presumably modulated by Vco2, and low ventilation frequency was maintained in part by significant gas exchange during the fluttering-spiracle phase of the ventilation cycle, which is generally characterized by low rates of respiratory water loss.

scholarly journals Gas exchange patterns and water loss rates in the Table Mountain cockroach, Aptera fusca (Blattodea: Blaberidae)

2013 ◽  
Vol 216 (20) ◽  
pp. 3844-3853 ◽  
Author(s):  
B. Groenewald ◽  
C. S. Bazelet ◽  
C. P. Potter ◽  
J. S. Terblanche
Keyword(s):  
Gas Exchange ◽  
Water Loss ◽  
Table Mountain ◽  
Exchange Patterns ◽  
Loss Rates

scholarly journals Responses to Acute Aquatic Hypoxia in Larvae of the Frog Rana Berlandieri

1983 ◽  
Vol 104 (1) ◽  
pp. 79-95 ◽  
Author(s):  
MARTIN E. FEDER
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Body Size ◽  
Gas Exchange ◽  
Total Oxygen ◽  
Oxygen Loss ◽  
Anuran Larvae ◽  
Ventilation Frequency ◽  
Gill Ventilation ◽  
Rana Berlandieri

The oxygen consumption of larvae of the frog Rana berlandieri Baird was reduced during exposure to aquatic hypoxia at 25°C, and under severe hypoxia the larvae lost oxygen to the water. The larvae responded to aquatic hypoxia by increasing aerial oxygen consumption and lung ventilatory frequency, and also by altering their heart rate and gill ventilation frequency. Under severe or prolonged aquatic hypoxia without access to air, Rana larvae accumulated lactate. When prevented from breathing air, the larvae were unable to compensate fully by increasing their aquatic oxygen consumption. Body size or the interaction of body size and oxygen partial pressure significantly affected the aerial oxygen consumption, the total oxygen consumption and gill ventilation frequency, but did not affect other aspects of larval gas exchange. Anuran larvae resemble air-breathing fishes in some responses to aquatic hypoxia (e.g. increased dependence upon aerial oxygen uptake and changes in ventilatory frequencies), but are unusual in some ways (e.g. oxygen loss to the water). The interactions of body size and hypoxia are not sufficient to explain why so many anuran larvae without lungs are small.

scholarly journals Water Costs of Gas Exchange by a Speckled Cockroach and a Darkling Beetle

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 632
Author(s):  
Waseem Abbas ◽  
Philip C. Withers ◽  
Theodore A. Evans
Keyword(s):  
Body Size ◽  
Gas Exchange ◽  
Metabolic Rate ◽  
Water Loss ◽  
Evaporative Water ◽  
Factors Affecting ◽  
Darkling Beetle ◽  
Terrestrial Insects ◽  
Exchange Patterns ◽  
Respiratory Cost

Respiratory water loss during metabolic gas exchange is an unavoidable cost of living for terrestrial insects. It has been suggested to depend on several factors, such as the mode of gas exchange (convective vs. diffusive), species habitat (aridity), body size and measurement conditions (temperature). We measured this cost in terms of respiratory water loss relative to metabolic rate (respiratory water cost of gas exchange; RWL/V˙CO2) for adults of two insect species, the speckled cockroach (Nauphoeta cinerea) and the darkling beetle (Zophobas morio), which are similar in their mode of gas exchange (dominantly convective), habitat (mesic), body size and measurement conditions, by measuring gas exchange patterns using flow-through respirometry. The speckled cockroaches showed both continuous and discontinuous gas exchange patterns, which had significantly a different metabolic rate and respiratory water loss but the same respiratory water cost of gas exchange. The darkling beetles showed continuous gas exchange pattern only, and their metabolic rate, respiratory water loss and respiratory cost of gas exchange were equivalent to those cockroaches using continuous gas exchange. This outcome from our study highlights that the respiratory water cost of gas exchange is similar between species, regardless of gas exchange pattern used, when the confounding factors affecting this cost are controlled. However, the total evaporative water cost of gas exchange is much higher than the respiratory cost because cuticular water loss contributes considerably more to the overall evaporative water loss than respiratory water. We suggest that the total water cost of gas exchange is likely to be a more useful index of environmental adaptation (e.g., aridity) than just the respiratory water cost.

scholarly journals Respiratory Strategies in Relation to Ecology and Behaviour in Three Diurnal Namib Desert Tenebrionid Beetles

Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1036
Author(s):  
Frances D. Duncan
Keyword(s):  
Gas Exchange ◽  
Water Loss ◽  
Evaporative Cooling ◽  
Respiratory Physiology ◽  
Metabolic Rates ◽  
Beetle Species ◽  
Water Droplets ◽  
Namib Desert ◽  
Flow Through

The respiratory physiology of three diurnal ultraxerophilous tenebrionid beetles inhabiting either the dune slipface or gravel plain in the Namib Desert was investigated. The role of the mesothoracic spiracles and subelytral cavity in gas exchange was determined by flow-through respirometry. All three species exhibited the discontinuous gas exchange cycles with a distinct convection based flutter period and similar mass specific metabolic rates. There was variation in their respiration mechanics that related to the ecology of the species. The largest beetle species, Onymacris plana, living on the dune slipface, has a leaky subelytral cavity and used all its spiracles for gas exchange. Thus, it could use evaporative cooling from its respiratory surface. This species is a fog harvester as well as able to replenish water through metabolising fats while running rapidly. The two smaller species inhabiting the gravel plains, Metriopus depressus and Zophosis amabilis, used the mesothoracic spiracles almost exclusively for gas exchange as well as increasing the proportional length of the flutter period to reduce respiratory water loss. Neither species have been reported to drink water droplets, and thus conserving respiratory water would allow them to be active longer.

Gas exchange and hatchability of chicken eggs incubated at simulated high altitude

1985 ◽  
Vol 58 (2) ◽  
pp. 416-418 ◽  
Author(s):  
A. H. Visschedijk
Keyword(s):  
Gas Exchange ◽  
Sea Level ◽  
Ventilation Rate ◽  
Co2 Production ◽  
Optimal Conditions ◽  
Simulated Altitude ◽  
Level Control ◽  
Natural Conditions ◽  
Simulated High Altitude ◽  
Chicken Eggs

Chicken eggs laid at sea level were incubated at sea level (control conditions), at a simulated altitude of 5.5 km without any further measures (natural conditions), and at a simulated altitude of 5.7 km at optimal incubator gas composition (optimal conditions). Under optimal conditions the incubator relative humidity was 70% throughout incubation, the gas mixture supplied to the incubator contained 45% O2–55% N2, and the ventilation rate was reduced to 6% of control in order to maintain the normal air-space gas tensions and to compensate for the increased eggshell conductance at altitude. The embryos that developed under control conditions showed a normal CO2 production with 94% hatchability of fertile eggs. Under natural conditions at altitude all embryos died within a few days. Optimal conditions resulted in an almost normal gas exchange and in an improvement of hatchability from 0 to 81% of fertile eggs.

SPIRACULAR CONTROL OF RESPIRATORY WATER LOSS IN FEMALE ALATES OF THE HARVESTER ANT POGONOMYRMEX RUGOSUS

1993 ◽  
Vol 179 (1) ◽  
pp. 233-244
Author(s):  
J. R. B. Lighton ◽  
D. A. Garrigan ◽  
F. D. Duncan ◽  
R. A. Johnson
Keyword(s):  
Real Time ◽  
Water Loss ◽  
Water Conservation ◽  
Strong Support ◽  
Co2 Production ◽  
Pogonomyrmex Rugosus ◽  
Real Time Measurement ◽  
Cuticular Permeability ◽  
Measured Water ◽  
Loss Rates

It has been suggested that the discontinuous ventilation cycle (DVC) observed in many insects, including all ants described to date, is an adaptation to reduce respiratory water loss. To test this hypothesis, it is necessary to measure respiratory water loss as a percentage of total water loss and to estimate what sustained rates of water loss would be in the absence of spiracular control. We used two independent techniques to measure real-time water loss rates in female alates of Pogonomyrmex rugosus. The first measured water vapor emission and CO2 production simultaneously using dual- wavelength infrared absorbance analysis (DWIRAA). The second measured water loss gravimetrically. Real-time measurement allowed the separation of cuticular water loss rates (interburst) from water loss rates during the ventilation phase (burst) of the DVC. Cuticular permeability of P. rugosus female alates was only 27 ng h-1 cm-2 Pa-1, one-third of that reported for workers of the same species and the lowest yet reported for ants. Partly because of this low cuticular permeability, respiratory water loss represented a greater percentage of overall water loss (13 %) than has generally been reported for other insects. The DWIRAA and gravimetric techniques gave equivalent results. Peak rates of water loss during the burst phase were 2.8-fold higher than cuticular water loss rates alone (7.68 mg g-1 h-1 versus 2.77 mg g-1 h-1 at 25°C). This is a conservative estimate of water loss rates in the absence of spiracular control. Contrary to findings in certain other insects that suggest a negligible role for respiratory water loss, we find that, in an insect that employs the DVC and has low cuticular permeability, overall water loss rates rise several-fold in the absence of direct spiracular control. Our findings lend strong support to the water conservation hypothesis for the role of the DVC. In at least some insects, respiratory water loss rates can reach magnitudes significant enough, relative to other routes of water loss, for strong selective pressure to act on them.

Sign in / Sign up

Export Citation Format

Share Document