Bartolomé Island, better known as a textbook of geology because of its barren appearance, has actually got several interesting species of both fauna and flora to look out for. There are two beautiful beaches separated by a splash of green: a mangrove forest. The larger of the two beaches is an important turtle nesting area, and the poor hatchlings have innumerable perils to overcome before reaching adulthood. In fact, just a very small percentage ever makes it, the rest succumbing to such voracious predators as the white-tipped reef sharks that can be found circling in the shallows, especially at this time of year.

This is a great opportunity to admire the grace and speed of these magnificent animals. All sharks belong to the class Chondrichthyes, whose members have cartilage instead of bone, enabling their movements to be particularly flexible and smooth. White-tipped reef sharks have beautifully streamlined bodies, for leisurely, energy-efficient cruising and fast hunting. They are shallow-water benthic sharks, that often lie side by side in shallow caves. This dispels the myth that sharks have to keep moving in order to breathe. Most sharks, including this one, have external gills arranged in five pairs; however many of them have a pair of openings known as "spiracles" which are located behind the eyes, and help with breathing when the fish lies on the bottom. It is true though that deep-water, pelagic sharks have to keep moving in order to keep afloat, as they lack lungs and swim bladders, thus cannot control their buoyancy and would sink down into the abyss. There are several species of sharks in Galapagos, none of which is considered dangerous. The white-tipped reef shark is the one most often seen during snorkeling, glass-bottom boating, Zodiac cruising and occasionally even from land, as some of our astounded guests found out during a walk this morning! In the picture, we can clearly see the white coloration on the tips of both dorsal and caudal fins.