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Re: Frozen Planet
Posted: Wed Nov 02, 2011 9:27 pm
by Susie
Do caterpillars have a heart?
Re: Frozen Planet
Posted: Wed Nov 02, 2011 10:41 pm
by MikeOxon
Susie wrote:Do caterpillars have a heart?
In effect, yes. Although insects do not have veins and arteries, they do have a muscle which moves the haemolymph (blood) around the body cavity. For more information, see
http://insects.about.com/od/morphology/ ... tomy_4.htm
I was fascinated to learn of a caterpillar which spends 14 years with an annual cycle of being frozen solid!
Mike
Re: Frozen Planet
Posted: Wed Nov 02, 2011 11:39 pm
by Dave McCormick
I was fascinated to learn of a caterpillar which spends 14 years with an annual cycle of being frozen solid!
Me too, never knew anything could survive basically shutting down to the point of death then coming alive after warming up, cryopreservation?
Re: Frozen Planet
Posted: Thu Nov 03, 2011 8:08 am
by Lee Hurrell
As with last week's I essentially watched for an hour with mouth agape, awestruck.
Rewinding bits every now and again (did he say 14 years!?; they won't touch land for 5 years!? etc).
Stunning.
LH
Re: Frozen Planet
Posted: Thu Nov 03, 2011 10:48 am
by MikeOxon
Once again, evolutionary mechanisms leave us awestruck!
My wife showed me a textbook on insect entomology (Gullan & Cranston), which describes the amazing array of mechanisms that enable insects to survive Arctic conditions. Apparently, there is a Himalayan glacier midge which remains active at an air temperature of -16°C !
There are ice-nucleating agents, which allow 'safe' freezing of the blood, gut, and some other areas. Other agents gradually dehydrate cell contents, so that these cannot freeze. Antifreeze proteins may also be produced, to provide protection throughout the freezing and thawing processes.
The tenacity of life in extreme conditions is utterly amazing.
Mike