Many Things Under a Rock

David Scheel / W.W. Norton & Company, Inc. / 307 pages

“Devilfish,” “old skin covering,” “many things under a rock”—octopus names are as varied and creative as the creatures themselves. As Many Things Under a Rock: The Mysteries of Octopuses reveals, these inquisitive, intelligent animals are capable of throwing things at each other, re-growing severed limbs, rapidly changing color to blend in with their surroundings, standing guard (in the case of some large males) over their communities, and displaying empathy—toward each other, and perhaps even humans. 

As predators, octopuses consume dozens of varied species, using a combination of hardened beaks to smash, toothed tongue-like organs to drill, suckers to pry open, and paralyzing saliva to immobilize. As prey, they evade hunters (like sea otters and moray eels) by hiding in dens, moving quietly through dense cover, shifting the times when they are active to when their predators are not, and altering the color and texture of their skin—and even the shapes of their bodies—to obscure their outlines and mimic nearby objects. These abilities are all the more impressive for an animal that receives no parental care or guidance after hatching from an egg (mother octopuses take meticulous care of their eggs, but die shortly after the eggs hatch), leads a generally solitary existence, and must perfect an impressive array of skills within a typical lifespan of a few years or less.

In page-turning detail, Dr. David Scheel, a behavioral ecologist and professor of marine biology at Alaska Pacific University, shares his observations of octopuses over a 25-year career of studying them around the world, particularly in the coastal waters near his home in Anchorage, Alaska. Woven throughout are Indigenous stories and legends of octopuses as sea monsters, warrior combatants, and even members of human families. 

Importantly, Scheel explains why octopuses—highly curious and mostly asocial species (which may even attack and kill each other when confined in cramped, stressful quarters)—are profoundly ill-suited to be commercially farmed for human food. Instead, in light of warming sea temperatures and other threats, the focus must remain on preserving wild octopus populations and their habitats. 

In the end, readers will agree that these remarkable creatures are far more than the horn-like protrusions above their eyes, the skin that accounts for so much of their bodies, or the eight limbs (each with semi-autonomous nervous systems) dangling in a den under a rock. They are one of the most complex and captivating beings in the sea.