Lizards are superbly adapted to a desert existence. Tough skin prevents injuries in spiny, rocky environments and acts as a barrier to moisture loss. Sharp toenails are perfect for scrambling and climbing. The pinto chuckwalla (pictured) is perhaps the most colorful and largest of all chuckwallas and may grow to 25 inches in length. We observed several of these gentle herbivores on our morning walks at San Esteban. Chuckwallas sleep and hide beneath rocks and will gulp air to puff up in response to disturbances by potential predators. When wedged in place, it is very difficult to budge them. Native people at times used a crooked stick tipped with a tiny arrowhead to puncture an inflated lizard, so they could remove it for food.
While we explored the island, our Undersea Specialist scuba dived and returned to the Sea Bird with a few fascinating and fanciful creatures. The inset photo shows a Spanish Shawl, a 2- to 3-inch long nudibranch. This gastropod is a type of shell-less snail. The colorful extensions on the animal's back increase the skin's surface area to facilitate gas exchange. Some nudibranchs ingest the untriggered stinging cells of cnidarians (anemones and their relatives) and store them within these structures to deter predators. The beautiful creature was returned to its home, and we sailed on for other activities.
