Book review: The Extreme Life of the Sea - marine wonders explored
The Extreme Life of the Sea
by Stephen Palumbi and Anthony Palumbi
Princeton University Press
Only the strong survive, it is said, but The Extreme Life of the Sea makes a good case for the ugly, the strange and the efficient.
Oceans are full of "extreme" creatures, surviving in the face of extraordinary challenges. In recent decades, scientists and their submersibles have shown us some of the animals that glide along in the depths, their lamplike eyes and freaky self-created light cloaked by the frigid, bone-crushing pressure.
But canny survivors are more familiar to us than we realise; even otters and starfish pull off pretty amazing stuff, thanks to their biological limitations and their harsh environments. Marine scientist Stephen Palumbi and his son, writer Anthony Palumbi, present these contrasts in an engaging blend. Stanford professor Stephen serves up the heavier science of DNA and physiology, seasoned with a sprightly narrative, some scene-setting and humour from novelist Anthony.
Extreme Life uses Guinness Record-like chapters to discuss the smallest, the deepest, the shallowest and the coldest marine life forms. I'd award a ribbon for "Most likely to become a sci-fi star" to the zombie bone worm, whose Latin name, Osedax mucofloris, translates as "bone-eating snot flower".
This "flower" is related to the giant tube worm. But it doesn't feed on microscopic organisms floating by, like its worm cousin. Osedax has drill-like tendrils that pock the bones of whale skeletons that hit the bottom of the ocean with tiny holes, so it can extract the lipids. The lipids are then turned to useful fuel by the Osedax's onboard bacteria.
All this takes place inside what the Palumbis describe as a fingernail-sized mass that "looks like nothing so much as the contents of a tissue after a sneeze". But wait, there's more: all the adult snot flowers are female. Males remain in a larval state.
Certainly much cuter, but no less challenged, are sea otters. They need to live in the chilly Pacific because the kelp forests are a rich habitat for shellfish, urchins and snails. But grazing that cold-water buffet comes at a high metabolic cost. The otters have no insulating blubber and their luxurious pelt, while certainly a help, can't do the whole job of keeping them warm.
To stay alive in such cold water, they've developed a metabolism that runs like a locomotive. A 60-pound (27kg) otter will eat a quarter of its body weight every day or it will die.
And consider the starfish, scattered across the intertidal zone. It preys on barnacles and mussels, which can just close up when the tide goes out. Because the starfish can't, it has a way to get groceries and run (well, more like mosey): it will hunker down over a patch of barnacles and rip them off the rocks, with the gripper feet near its central mouth quickly shovelling in the grub. The starfish's digestive system then begins working, as its owner creeps away, beating low tide.
If that seems banal, the Palumbis offer plenty of strangeness. Meet the Pompeii worm, whose head tolerates 40 degrees Fahrenheit (4 degrees Celsius) seawater while its tail is comfortably anchored near hydrothermal vents on the ocean floor, where it's about 120 degrees F.
They describe a key thing about clownfish that Finding Nemo left out: all clownfish are born male. The largest in the colony will switch sex, becoming a Nemette, capable of laying many eggs for the Nemos to fertilise. If she dies, the next Nemo takes "her" place. "In retrospect," the authors write with the candour and humour typical of the book, "the producers at Disney probably made the right call."