Big Pacific: The deep diving Marine Iguana

From pages 123-124 of Big Pacific:

With 97 percent of its reptiles and land mammals found nowhere else, the Galápagos archipelago has one of the highest levels of endemism — species unique to one place — on the planet. A prime example is the Marine iguana, a landliving reptile that forages underwater for marine algae and can dive more than 9 meters (30 feet) beneath the water’s surface to do so.

Unsurprisingly, this lizard has evolved adaptations to equip it for this amphibious lifestyle, including long claws and strong limbs that help it cling on to the rocks in coastal currents and wave wash.

The Marine iguana of the Galápagos is the only lizard in the world that dives for its food. The post-swim sunbathing they enjoy warms their reptilian bodies, which have been chilled by the cold Galápagos waters.

Although comfortable in the cool Pacific waters of the Galapagos, the iguanas cannot remain long in the water or their body temperature will drop too low. As reptiles they rely on external heat sources, so in between dips they warm themselves by sunbathing on the rocks, their dark skin helping them soak up the equatorial sun. This period of post-swimming lethargy is when they are most vulnerable to predation, but as the iguanas are characteristically aggressive their natural predators are few.

Their main threats appear to be introduced predators such as dogs and cats, and climatic events, such as El Niño, which increase the local water temperature and impact the growth of the algae on which the iguanas rely.

Big Pacific: Passionate, Voracious, Mysterious, Violent
By Rebecca Tansley

The Pacific Ocean covers one-third of Earth’s surface—more than all of the planet’s landmasses combined. It contains half of the world’s water, hides its deepest places, and is home to some of the most dazzling creatures known to science. The companion book to the spectacular five-part series on PBS produced by Natural History New Zealand, Big Pacific breaks the boundaries between land and sea to present the Pacific Ocean and its inhabitants as you have never seen them before.

Illustrated in full color throughout, Big Pacific blends a wealth of stunning Ultra HD images with spellbinding storytelling to take you into a realm teeming with exotic life rarely witnessed up close—until now. The book is divided into four sections, each one focusing on an aspect of the Pacific. “Passionate Pacific” looks at the private lives of sea creatures, with topics ranging from the mating behaviors of great white sharks to the monogamy of wolf eels, while “Voracious Pacific” covers hunting and feeding. In “Mysterious Pacific,” you will be introduced to the Pacific’s more extraordinary creatures, like the pufferfish and firefly squid, and explore some of the region’s eerier locales, like the turtle tombs of Borneo and the skull caves of Papua New Guinea. “Violent Pacific” examines the effects of events like natural disasters on the development of the Pacific Ocean’s geography and the evolution of its marine life.

Providing an unparalleled look at a diverse range of species, locations, and natural phenomena, Big Pacific is truly an epic excursion to one of the world’s last great frontiers.

Learn more by watching Big Pacific, airing Sundays on PBS Guam and CPTV Spirit. Watch the trailer below:


This post is part of a series, explore additional posts here<< Big Pacific: Palolo Worms, the sprawling spectacleBig Pacific — The Blue Whale >>