A new American study has unveiled the perfect shape for a mushroom's fleshy gills.

Nicholas Money from Miami University, Oxford, US and Dr Mark Fischer from the College of St Joseph, Cincinnati, US revealed the best possible structure for a mushroom's gill by using theoretical modelling, measurements and photographs.

Their research also uncovers why different mushrooms have different arrangements of fleshy gills under their caps.

Mushrooms are fruiting bodies produced by fungi and as they grow they spread the reproductive spores with the help of gills.

"Spores are catapulted from the gill surface, travel a short distance horizontally, and then fall vertically to be swept away by air currents swirling around the mushroom cap," the BBC quoted Money as saying.

Thereafter, spores start new fungal communities.

Talking about their research Money said: "We set out to design the perfect mushroom."

Gills arrangement in mushrooms is such that it aids in spore dispersal.

According to Money; "Mushrooms are masterpieces of natural engineering."

However, no natural mushroom has an optimal design.

He said; "We found that the most efficient arrangements in engineering terms do not occur in nature.

"A single gill organised as a tight spiral beneath the cap would work very well, and a 'venetian blind' type arrangement would be very effective too."

But none of the optimal arrangement takes place naturally.

Money explained; "Natural selection has sculpted various radial arrays of gills that work very well, or at least, work well enough to have allowed mushrooms to flourish for tens of millions of years."

If a mushroom increases its surface area 20 times it could increase the number of spores it releases by the same amount.

Money said; "Twenty billion spores is a lot more than 1 billion spores."

Scientists are also looking at the design of mushroom gills to better engineering designs.

Money pointed out; "There might be some ways in which the arrangements of gills in a mushroom could aid the design of heating or air-conditioning devices, or filters for purifying water."

The findings of the study have appeared the journal Mycological Research.