Saharan silver ant
Encyclopedia
The Saharan silver ant (Cataglyphis bombycina) is a type of ant
that lives in the Sahara Desert.
Due to the extreme high temperatures of their habitat and the threat of predators
, the ants are active outside their nest for only a few minutes per day. The twin pressures of predation and temperature restrict the above-ground activity to a narrow temperature band between that at which the predatory lizard
ceases activity and the ant's own upper threshold.
The ants often traverse mid-day temperatures above 115°F
(46°C
) to scavenge corpses of heat-stricken animals. To cope with such high temperatures, the ant has several unique adaptations.
They have longer legs than other ants. This keeps their body away from the hot sand, and when traveling at full speed, they use only four of their six legs. This quadrupedal gait is achieved by raising the front pair of legs.
Keeping track of the position of the sun, the ants navigate
always know the direct route back to their nest, and thus can minimize their time spent in the heat. They produce heat shock proteins, but unlike other animals they do this not in direct response to heat. Instead they do this before leaving the nest, because they simply are not out in the heat long enough for the proteins to take effect. This protein allows cellular functions to continue even at very high body temperatures. If they did not produce the proteins in anticipation of the extreme heat, they would die before the proteins could have its effect.
In the words of one researcher, the production of this protein "does not reflect an acute response to cellular injury or protein denaturation, but appears to be an adaptive response allowing the organism to perform work at elevated temperatures during temperature changes too abrupt to give the animal an opportunity to benefit from de novo HSP synthesis," further "the few minutes duration of the foraging frenzy is too short for synthesis of these protective proteins after exposure to heat." This and other adaptations led to the ant being be called "one of the most heat-resistant animals known." Its critical thermal maximum
is 128.5°F (53.6°C)
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
that lives in the Sahara Desert.
Due to the extreme high temperatures of their habitat and the threat of predators
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
, the ants are active outside their nest for only a few minutes per day. The twin pressures of predation and temperature restrict the above-ground activity to a narrow temperature band between that at which the predatory lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
ceases activity and the ant's own upper threshold.
The ants often traverse mid-day temperatures above 115°F
Fahrenheit
Fahrenheit is the temperature scale proposed in 1724 by, and named after, the German physicist Daniel Gabriel Fahrenheit . Within this scale, the freezing of water into ice is defined at 32 degrees, while the boiling point of water is defined to be 212 degrees...
(46°C
Celsius
Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...
) to scavenge corpses of heat-stricken animals. To cope with such high temperatures, the ant has several unique adaptations.
They have longer legs than other ants. This keeps their body away from the hot sand, and when traveling at full speed, they use only four of their six legs. This quadrupedal gait is achieved by raising the front pair of legs.
Keeping track of the position of the sun, the ants navigate
Path integration
Path integration is the name given to the method thought to be used by animals for dead reckoning.Charles Darwin and J.J. Murphy first postulated an inertially-based navigation system in animals in 1873...
always know the direct route back to their nest, and thus can minimize their time spent in the heat. They produce heat shock proteins, but unlike other animals they do this not in direct response to heat. Instead they do this before leaving the nest, because they simply are not out in the heat long enough for the proteins to take effect. This protein allows cellular functions to continue even at very high body temperatures. If they did not produce the proteins in anticipation of the extreme heat, they would die before the proteins could have its effect.
In the words of one researcher, the production of this protein "does not reflect an acute response to cellular injury or protein denaturation, but appears to be an adaptive response allowing the organism to perform work at elevated temperatures during temperature changes too abrupt to give the animal an opportunity to benefit from de novo HSP synthesis," further "the few minutes duration of the foraging frenzy is too short for synthesis of these protective proteins after exposure to heat." This and other adaptations led to the ant being be called "one of the most heat-resistant animals known." Its critical thermal maximum
Critical thermal maximum
Critical thermal maximum, in zoology, is that temperature for a given species above which most individuals respond with unorganized locomotion, subjecting the animal to likely death...
is 128.5°F (53.6°C)