pool populated by a few thousand stars into a sparkling sea filled with ten times the

number. And today, with the help of bigger and better telescopes, we know that our home

galaxy - the Milky Way - is an ocean of as many as 400 billion stars.

However, telescopes can’t help us peer into the watery oceans here on Earth, so to count

their inhabitants, we've used fish trawls to drag them up into the light - and then

- more often than not - onto our plates. But now we don't have to fish fish in order

to count fish. In 2010, Spanish researchers sailed around the world with an ultra high-powered

SONAR, shooting sound waves into the depths and using the reflected signals to spot inhabitants.

While previous net counts had given us a global estimate of about 300 trillion fish, the fish-o-scope

method revealed that our oceans are home to roughly ten times that number.

One reason previous counts were so much lower seems to be that fish actively hide from approaching

trawls. In one study, scientists took a SONAR scan while dragging an open net through the

water behind them, and check this out: so many fish got out of the way that their relative

absence highlights the whole path of the trawl. We don’t know exactly how they manage to

avoid the nets, but deep-ocean dwellers like the fangtooth, lantern fish, and stoplight

loosejaw, all of which were especially undercounted by fish trawls, may take warning cues from

their neighbors flashing bioluminescent spots. Another deep water fish, the finger-sized

bristlemouth, turns out to be the most populous vertebrate on our planet. There are an estimated

quadrillion bristlemouths swimming the world’s oceans. That’s a few thousand fish for every

star in the Milky Way. Hi, Emily here. I'd like to thank Audible.com

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