9,749
edits
Difference between revisions of "Antarctic midge"
added link to psychrophiles
Westarctica (talk | contribs) (Created page with "350px|thumb|Two Antarctic midges mating tail to tail '''''Belgica antarctica''''', the '''Antarctic midge''', is a species of flightless midge, e...") |
Westarctica (talk | contribs) (added link to psychrophiles) |
||
| (One intermediate revision by the same user not shown) | |||
| Line 1: | Line 1: | ||
[[File:Antarctic-midgee.jpg|350px|thumb|Two Antarctic midges mating tail to tail]] | [[File:Antarctic-midgee.jpg|350px|thumb|Two Antarctic midges mating tail to tail]] | ||
'''''Belgica antarctica''''', the '''Antarctic midge''', is a species of flightless midge, endemic to the continent of [[Antarctica]]. At 0.079–0.24 in long, it is the largest purely terrestrial animal on the continent, as well as its only insect. It also has the smallest known insect genome as of 2014, with only 99 million base pairs of nucleotides (and about 13,500 genes). | '''''Belgica antarctica''''', the '''Antarctic midge''', is a species of flightless midge, endemic to the continent of [[Antarctica]]. At 0.079–0.24 in long, it is the largest purely terrestrial animal on the continent, as well as its only insect. It also has the smallest known insect genome as of 2014, with only 99 million base pairs of nucleotides (and about 13,500 genes). | ||
This species is the [[National Symbols of Westarctica|national insect]] of [[Westarctica]]. | |||
==Tolerance to extreme cold== | ==Tolerance to extreme cold== | ||
The flightlessness of of the Antarctic midge may be an adaptation to prevent wind from blowing it into inhospitable areas. | The flightlessness of of the Antarctic midge may be an adaptation to prevent wind from blowing it into inhospitable areas. As a [[psychrophiles|psychrophile]], it can survive freezing, but despite air temperatures reaching as low as -40 °C, this insect will not be alive after temperature drops under -15 °C. This is less than other cold-adapted insects. The reason for this comparatively low freezing tolerance is due to thermal buffering: just burrowing at a depth of 1 cm, temperature is stable between 0 and -2 °C for 10 months out of 12, and it seldom goes lower than -7 °C all year round. [[Ice]] and snow cover also helps keeping the temperature stable. Freezing tolerance is enhanced by cold hardening. | ||
To adapt to the cold temperatures, the Antarctic midge accumulates trehalose, glucose, and erythritol. These compounds help the insect survive freezing by reducing the amount of ice that forms within the body. They also stabilize proteins and membranes, binding to them by means of hydrogen bonds. Heat shock proteins also help the tolerance to both high and low temperatures. | To adapt to the cold temperatures, the Antarctic midge accumulates trehalose, glucose, and erythritol. These compounds help the insect survive freezing by reducing the amount of ice that forms within the body. They also stabilize proteins and membranes, binding to them by means of hydrogen bonds. Heat shock proteins also help the tolerance to both high and low temperatures. | ||