Jonathan Balcombe / Scientific American / 304 pages
As a child, I enjoyed standing in the shallow water of creeks, lakes, rivers, and the ocean watching fish. Later, as a scuba diver, I plunged deeper, observing the behavior and interactions of a wide array of fish in their natural habitats. What a Fish Knows, by ethologist Jonathan Balcombe, however, took me on a whole new journey into the vast and astounding world of fish.
The reader is presented with fact upon fact, beginning with the very first paragraph, in which we are told there are 33,249 species of fish, in 564 families and 64 orders—more than the combined total of mammals, birds, reptiles, and amphibians. But it’s their behaviors that are most intriguing. For example, the archerfish can squirt water up to 10 feet to obtain an insect or spider to eat; up to 3 feet, their accuracy is nearly 100 percent. This “squirt gun” can be fired in a single shot or in machine-gun fashion, with the amount of water varied to suit the size of the prey. Accomplished archerfish may even aim at what the prey is standing on so as to knock the prey into the water instead of farther back on land. And archerfish can learn these skills by watching others.
Balcombe describes how fish communicate, experience a wide range of emotions, feel pleasure and pain, develop cooperative relationships, use tools, and demonstrate memory and an ability to complete complex tasks. For readers who may have underestimated fish, the book is a call to think more carefully about them.