Which animal has the smallest heart?

Wednesday 6th April 2011
Submitted by samshead
KATY WILLIAMS, BURNTWOOD

Insects have hearts, although nothing like our familiar muscular mammalian hearts. These consist of a narrow tube along the insect’s back that pumps blood (or hemolymph) towards their head. This circulates fluid in an open system with no veins or arteries. The smallest insect is said to be the fairy fly (above), which is a type of wasp that’s less than 0.2 millimetres long. You’d need a microscope to see its heart.

GOT A QUESTION?

Scratching your head over a burning scientific conundrum? Submit your question and we'll get our esteemed panel of experts to answer it for you.

 

Why do we give flora and fauna Latin names?
previous qanda Article
Are near-death experiences just hallucinations?
next qanda Article
Q&A Tabs

Lobsters and other shellfish have harmful bacteria naturally present in their flesh. Once the lobster is dead, these bacteria can rapidly multiply and release toxins that may not be destroyed by...

Beard hair is quite different to head hair; it is coarser, curlier and doesn't fall out as we get older. Comparatively little work has been done on the genetics of human hair colour, but it is...

The powder is actually tiny scales made from modified hairs. Moths, like butterflies, belong to the order Lepidoptera, which means 'scale wing'. The scales are pigmented but they also contribute...

Phlegm is the mucous secretion of the respiratory passages. The cilia cells that line these passages are continually driving the phlegm upward to the throat, where it triggers the swallow reflex...

It depends on the temperature of the water. In cold water, the bacterial action that causes a body to bloat with gas may be so slowed that the body stays on the seabed. The skin will absorb water...

All female mammals have a clitoris, the sole purpose of which is to react to sexual stimulation, and presumably this stimulation has evolved to be pleasurable for most species. But establishing...

To create a sound, we have to set matter - whether it's a gas like air, a liquid or even a solid material - in regular motion, creating a wave of specific frequencies, which we hear as a sound of...

Mirrors don’t reverse left and right either – that’s just our interpretation of what happens. Your reflection in the mirror is actually reversed front to back – if you have...

Discovered by an American student named Gary Flandro in the mid-1960s, the slingshot manoeuvre usually involves spacecraft briefly 'coat-tailing' a planet orbiting the Sun, extracting some of the...

The ice disappears because the wind blows away water molecules that have evaporated or 'sublimed' from the ice, so the ice slowly shrinks in size. The molecules that escape are those with the...