Human sperm swim more like otters than eels, study finds

For more than 300 years, most scientists have assumed that sperm
“swim” through fluids by wriggling their tails back and forth like
eels to propel themselves forward. But according to a new
paper
in Science Advances, this is actually an optical
illusion—the result of viewing the creatures from above with 2D
microscopes. New observations with 3D microscopy have revealed that
human sperm actually roll as they swim, like otters, essentially
corkscrewing themselves forward.

“With over half of infertility caused by male factors,
understanding the human sperm tail is fundamental to developing
future diagnostic tools to identify unhealthy sperm,”
said co-author Hermes Gadelha
from the University of
Bristol.

The honor of directly observing the first sperm rests with
Antonie van
Leeuwenhoek
, a 17th-century Dutch draper with a side interest
in science—specifically, building microscopes and coming up with
innovative manufacturing methods to make better lenses for said
microscopes. Only a few of his microscopes have survived, but they
are capable of magnifying small objects up to 275 times, and
historians believe some of his instruments could have achieved
magnifications as high as 500 times.

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Source: FS – All – Science – News
Human sperm swim more like otters than eels, study
finds