What Do Fish Know? More Than You Can Ever Imagine

On my last trip to Little Cayman, a Nassau grouper and I danced back and forth, eye to eye. When I turned to leave, he moved in front of me, swimming backward, continuing the dance, eyeing my every move. Fish aren't fed here, so why is he interested in me? Why not the five other divers in the water, in which he shows no interest? If I lift my hand, he seems to look at it, but then he looks back at my face. When I chuck him under his chin, he stays close for a minute, but then backs off, keeping his distance. As I swim away, he stays by my side. What could that fish be thinking? Or feeling? Or is he thinking and feeling at all?

Thanks to Jonathan Balcombe's recently published book -- What a Fish Knows: the Inner Lives of Our Underwater Cousins -- I have learned the fish I encounter are no slouches, and perhaps nearly as complex as I. They think, remember, recognize -- damsel fish, for example, recognize the faces or color patterns of their neighbors -- decide, plan, and socialize as much as many mammals. Some fish even use tools. Their emotions range from stress to joy, and yes indeed, they feel pain, Balcombe shows.

As we have our complex lives, so do fish, forming relationships, parenting and creating social order. And these conclusions are not just speculation, for Balcombe has gathered scores of fascinating scientific experiments and observations to show us just how fish are on a parallel evolutionary track in their own liquid world.

If you're a serious scuba diver, inquisitive about the lives of the fish you swim with, this is your kind of book. You'll learn about bait ball behavior, shark stroking, stingray problem-solving, how fish deal with optical illusions or respond to music -- they can recognize the commonality between John Lee Hooker and blues artist Koko Taylor (No Kidding!) -- and how a grouper signals a moray, or a lionfish signals another lionfish, to pair up for hunting.

What Fish Know is a well-researched, well-written and fascinating read that will turn your beliefs about the underwater world upside-down. When you turn the last page, you'll have a new and profound appreciation of the magic we see when we swim with the fishes.

What Fish Knows retails for $27 hardbound and is available in Kindle. To get Amazon's best prices, click here and Undercurrent will get a commission for the sale of the book and anything else you buy while you are there. We contribute our Amazon proceeds to saving coral reefs.

- Ben Davison