- Saharan silver ant
Taxobox| name = Saharan silver ant
regnum =Animal ia
phylum =Arthropod a
classis =Insect a
ordo =Hymenoptera
subordo =Apocrita
superfamilia =Vespoidea
familia = Formicidae
genus = "Cataglyphis "
species = "C. bombycina"
binomial = "Cataglyphis bombycina"
binomial_authority = Roger, 1859The Saharan silver ant ("Cataglyphis bombycina") is a type of
ant that lives in theSahara Desert .Because of the extremely high temperatures of their environment, and the threat of predators, they are only active a few minutes a day. [ [http://www.nature.com/nature/journal/v357/n6379/abs/357586a0.html Desert ants on a thermal tightrope] ] 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. [http://books.google.com/books?id=ZZaVjVWUaXIC&pg=PA160&lpg=PA160&dq=%22Cataglyphis+bombycina%22&source=web&ots=EhC9akL1lV&sig=KedT3XcobtHHN0USvYdC7oT_lAw&hl=en#PPA160,M1 Gullen, P: "The Insects: An Outline of Entomology", page 160. Blackwell Publishing, 2005] ] They often traverse mid-day temperatures upwards of 115°F (46°C) to scavenge the corpses of heat-stricken animals. [ [http://query.nytimes.com/gst/fullpage.html?res=9E0CE0D9133DF933A05755C0A964958260&sec=&spon=&pagewanted=2 Life at the Extremes: Ants Defy Desert Heat] ]To cope with such high temperatures, although for only a short time, the ant has several unique adaptations. They have longer legs than other ants to keep 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. [ [http://jeb.biologists.org/cgi/reprint/192/1/107.pdf Zollikofer, C: "Stepping Patterns in Ants - Influence of Body Morphology", "Journal of Experimental Biology", 192(94):100] ] They navigate by the sun to find the shortest route back to their nest, in order to minimize time spent in the heat. [ [http://www.youtube.com/watch?v=w9KDM4C1kVg The Amazing Cataglyphis Ant] ] They produce
heat shock proteins , not in direct response to heat, like other animals, but rather before leaving the nest because they are not out in the heat long enough for the proteins to take effect. This protein allows cellular functions to continue at very high body temperatures, but if they did not produce the proteins in anticipation of the extreme heat, they would die before they took 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," [http://jap.physiology.org/cgi/content/full/83/5/1413 Moseley, P: "Heat shock proteins and heat adaptation of the whole organism", "Journal of Applied Physiology", 83(97):1413-1417] ] further "the few minutes duration of the foraging frenzy is too short for synthesis of these protective proteins after exposure to heat." [http://books.google.com/books?id=ZZaVjVWUaXIC&pg=PA160&lpg=PA160&dq=%22Cataglyphis+bombycina%22&source=web&ots=EhC9akL1lV&sig=KedT3XcobtHHN0USvYdC7oT_lAw&hl=en#PPA160,M1 Gullen, P: "The Insects: An Outline of Entomology", page 160. Blackwell Publishing, 2005] ] This and other adaptations led it to be called "one of the most heat-resistant animals known." Its critical thermal maximum is 128.5°F (53.6°C) [http://books.google.com/books?id=B4_Wz7inaT4C&pg=PA162&lpg=PA162&dq=%22Cataglyphis+bombycina%22&source=web&ots=axOFCe5ZHL&sig=wM0ZGkQuftSfocKvqlv47MOuljM&hl=en#PPA168,M1 Chown, S: "Insect Physiological Ecology: Mechanisms and Patterns", page 162. Oxford University Press, 2004] ]Notes
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