Polypedilum vanderplanki
Encyclopedia
Polypedilum vanderplanki or the sleeping chironomid, is a diptera
n in the family Chironomidae
. It occurs in northern Nigeria
and Uganda
where its larvae grow in temporary pools of water that frequently dry out during the lifetime of P. vanderplanki larvae. Under these conditions, the larvae's body desiccates
to as low as 3% water content by weight. In the dehydrated state the larvae become impervious to many extreme environmental conditions, and can survive temperatures from 3 K
to up to 375 K, very high (7000 Gray
) levels of gamma-rays, and exposure to vacuum
. It is one of few metazoans that can withstand near complete desiccation (anhydrobiosis) in order to survive adverse environmental conditions. Slow desiccation (0.22 ml per day) enabled larvae to synthesize 38 μg trehalose/individual, and all of them recovered after rehydration, whereas larvae that were dehydrated 3 times faster accumulated only 6.8 μg trehalose/individual and none of them revived after rehydration.
Late Embryo Abundant (LEA), anti-oxidant, and heat-shock proteins may also be involved in survival.
Diptera
Diptera , or true flies, is the order of insects possessing only a single pair of wings on the mesothorax; the metathorax bears a pair of drumstick like structures called the halteres, the remnants of the hind wings. It is a large order, containing an estimated 240,000 species, although under half...
n in the family Chironomidae
Chironomidae
Chironomidae are a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae...
. It occurs in northern Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...
and Uganda
Uganda
Uganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by...
where its larvae grow in temporary pools of water that frequently dry out during the lifetime of P. vanderplanki larvae. Under these conditions, the larvae's body desiccates
Desiccation
Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic substance that induces or sustains such a state in its local vicinity in a moderately sealed container.-Science:...
to as low as 3% water content by weight. In the dehydrated state the larvae become impervious to many extreme environmental conditions, and can survive temperatures from 3 K
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
to up to 375 K, very high (7000 Gray
Gray (unit)
The gray is the SI unit of absorbed radiation dose of ionizing radiation , and is defined as the absorption of one joule of ionizing radiation by one kilogram of matter ....
) levels of gamma-rays, and exposure to vacuum
Vacuum
In everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...
. It is one of few metazoans that can withstand near complete desiccation (anhydrobiosis) in order to survive adverse environmental conditions. Slow desiccation (0.22 ml per day) enabled larvae to synthesize 38 μg trehalose/individual, and all of them recovered after rehydration, whereas larvae that were dehydrated 3 times faster accumulated only 6.8 μg trehalose/individual and none of them revived after rehydration.
Late Embryo Abundant (LEA), anti-oxidant, and heat-shock proteins may also be involved in survival.