Today we had another incredible experience, and the snorkeling around Turtle Rock became a highlight for most of us. It was very impressive to see a numerous group of fish of different sizes, colors and shapes; however the presence of the white tip reef sharks and the spotted eagle ray in the area made a big difference in terms of adrenaline consumption.
With more than 20,000 species, fish are by far the most numerous group of all vertebrates. They are also the earliest group of backboned animals, having evolved in the seas almost 500 million years ago.
More than half of all living vertebrates are fish and it is probably a safe assumption to say that well over half of all extinct vertebrates were fish.
Sharks and rays are part of the class Chondrichthyes. They have a skeleton made up of cartilage rather than bone, and so are generally referred to as the cartilaginous fishes. Sharks evolved from a group of bony fish ancestors during the Silurian period. All living chondrichchthyans have internal fertilization, and produce a low number of large yolky eggs relative to bony fishes. They have a range of reproductive strategies varying from simple oviparity (egg-laying) to advanced viviparity (live-bearing) where the embryos are nourished via placenta analogous to that in mammals.
At the end of the snorkeling each one of us retained the grace of the eagle ray flying through the water with their beautiful wings.
