What a Fish Knows / Jonathan Balcombe

4 out of 5 stars

Do fishes think? Do they really have three-second memories? And can they recognize the humans who peer back at them from above the surface of the water? In What a Fish Knows, the myth-busting ethologist Jonathan Balcombe addresses these questions and more, taking us under the sea, through streams and estuaries, and to the other side of the aquarium glass to reveal the surprising capabilities of fishes. Although there are more than thirty thousand species of fish—more than all mammals, birds, reptiles, and amphibians combined—we rarely consider how individual fishes think, feel, and behave. Balcombe upends our assumptions about fishes, portraying them not as unfeeling, dead-eyed feeding machines but as sentient, aware, social, and even Machiavellian—in other words, much like us.

What a Fish Knows draws on the latest science to present a fresh look at these remarkable creatures in all their breathtaking diversity and beauty. Fishes conduct elaborate courtship rituals and develop lifelong bonds with shoalmates. They also plan, hunt cooperatively, use tools, curry favor, deceive one another, and punish wrongdoers. We may imagine that fishes lead simple, fleeting lives—a mode of existence that boils down to a place on the food chain, rote spawning, and lots of aimless swimming. But, as Balcombe demonstrates, the truth is far richer and more complex, worthy of the grandest social novel.

Highlighting breakthrough discoveries from fish enthusiasts and scientists around the world and pondering his own encounters with fishes, Balcombe examines the fascinating means by which fishes gain knowledge of the places they inhabit, from shallow tide pools to the deepest reaches of the ocean.

Fish get short shrift when we are thinking about animal behaviour. Consider the poor maligned gold fish, which is reputed to have an attention span of mere seconds. Incorrect, as it turns out—gold fish can learn tasks and retain that learning for months.

I’m not a diver. I can’t swim and water will always be a scary place for me, but I can see where this book would be very interesting to anyone who spends time in the underwater world. Fish are much more interesting that I gave them credit for. I’m a birder, after all, and so I’m a little biased (although I certainly know that the term “bird brain” is actually more of a compliment than an insult).

It’s difficult for us to imagine what a fish’s life is like—they live in a completely different medium than we do, have extra senses that we can’t fathom, and have unexpressive faces. I think that last point is the one that leads us to underestimate fishes—we value expressiveness over evidence, I think, because it’s something we’re good at.

If you are interested in matters of animal intelligence (and human judginess) I would recommend Franz de Waal’s excellent book Are We Smart Enough to Know How Smart Animals Are?.