What a Fish Knows

The New York Times–bestselling "exploration of the world from a piscine perspective . . . makes a persuasive case that what fish know is quite a lot" (Elizabeth Kolbert, The New York Review of Books).

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, ethologist Jonathan Balcombe addresses these questions and more, revealing the surprising capabilities of fishes. Upending our assumptions about fishes, Balcombe portrays 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. 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.


Highlighting breakthrough discoveries from 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. Teeming with insights and exciting discoveries, What a Fish Knows will forever change how we see our aquatic cousins—the pet goldfish included.

Longlisted for the PEN/E.O. Wilson Literary Science Writing Award

"Balcombe vividly shows that fish have feelings and deserve consideration and protection like other sentient beings." —The Dalai Lama


"[An] exhaustively researched and elegantly written argument for the moral claims of ichthyofauna." —Nathan Heller, The New Yorker

"Engrossing." —Nature

"With the vivacious energy of a cracking good storyteller . . . Balcombe makes a convincing case." —Publishers Weekly