Respiratory Response to Varying Temperature
33
5
A. Qudemonsi
o
o
P ollitera
s. ct /otipes
10
20
30
40
Temperature COC)
Fig. 3.5. The dependence of respiration rate on temperature in three adult oribatids. (Stamoll et
al.1995)
Apart from minor differences, temperature dependence of the oxygen consumption of all animals studied displays major areas of similarity. The dependence of respiratory activity on temperature is skewed to the left. Critical
thermal points, up to which respiratory activity remains insensitive to changing temperature, lie within 8 and 13 °C. Below Tcrt mortality is zero, no development or metamorphosis into subsequent instars occurs, and the animals
hardly move. The temperature threshold for egg production lies above this
critical point (data from laboratory cultures). It seems that at lower temperatures energy is invested almost exclusively in maintenance. Between T crt and
TinI1 (the latter varying from 13 to 18°C), respiration rate increases rapidly.
Within this range, the effect of temperature on respiration is pronounced.
Afterwards, the respiration rate slows down until the optimal temperature
has been reached.
It is obvious that animals may balance their respiratory activity within different temperature ranges. Hence, existence is readily inferred of an energysaving mechanism operating throughout the gradient of temperature tolerance. At lower temperatures this mechanism results in higher energy investment for maintenance, whereas at higher temperatures it ensures higher
energy investment in production. From the optimal point up to the lethal
threshold, respiratory activity exhibits a precipitous decline. This temperature range is very narrow, indicating that arthropods are highly sensitive
beyond T opt temperatures.
It has been demonstrated that warm-adapted arthropods display lower
respiratory levels than cold-adapted arthropods (e.g. Block and Young 1978;
Dwarakanath et al. 1973; Gromysz-Kalkowska and Tracz 1983; Stamou 1986).
This statement does not hold true for Mediterranean species (Table 3.1)
33
5
A. Qudemonsi
o
o
P ollitera
s. ct /otipes
10
20
30
40
Temperature COC)
Fig. 3.5. The dependence of respiration rate on temperature in three adult oribatids. (Stamoll et
al.1995)
Apart from minor differences, temperature dependence of the oxygen consumption of all animals studied displays major areas of similarity. The dependence of respiratory activity on temperature is skewed to the left. Critical
thermal points, up to which respiratory activity remains insensitive to changing temperature, lie within 8 and 13 °C. Below Tcrt mortality is zero, no development or metamorphosis into subsequent instars occurs, and the animals
hardly move. The temperature threshold for egg production lies above this
critical point (data from laboratory cultures). It seems that at lower temperatures energy is invested almost exclusively in maintenance. Between T crt and
TinI1 (the latter varying from 13 to 18°C), respiration rate increases rapidly.
Within this range, the effect of temperature on respiration is pronounced.
Afterwards, the respiration rate slows down until the optimal temperature
has been reached.
It is obvious that animals may balance their respiratory activity within different temperature ranges. Hence, existence is readily inferred of an energysaving mechanism operating throughout the gradient of temperature tolerance. At lower temperatures this mechanism results in higher energy investment for maintenance, whereas at higher temperatures it ensures higher
energy investment in production. From the optimal point up to the lethal
threshold, respiratory activity exhibits a precipitous decline. This temperature range is very narrow, indicating that arthropods are highly sensitive
beyond T opt temperatures.
It has been demonstrated that warm-adapted arthropods display lower
respiratory levels than cold-adapted arthropods (e.g. Block and Young 1978;
Dwarakanath et al. 1973; Gromysz-Kalkowska and Tracz 1983; Stamou 1986).
This statement does not hold true for Mediterranean species (Table 3.1)