Surprisingly dolphins aren’t fish! A dolphin is a mammal. Like every mammal the dolphin is warm blooded, isn’t born in eggs, and breathes air. A dolphin usually breathes once or twice a minute. A dolphin can hold its breath no longer than seven minutes but only if it is an emergency. Dolphins do have a tiny bit of hair! The only place there is hair is right next to the blowhole. Dolphins have blubber instead of fur. Blubber gives a dolphin their streamline shape. Blubber also is a cover that holds in heat. Dolphins’ teeth are usually made for grasping not chewing. If a dolphin needs to make its food into smaller pieces, it will grasp its food and throw it against the water. This makes it easier to eat the food.
There are 45 different types of dolphins. Some dolphins live in oceans and other types live in rivers. A trainer can sometimes tell the difference between each dolphin by their back fin. The bottlenose dolphin is the type of dolphin most known. Dolphins are related to many other mammals in the ocean. The killer whale is the biggest dolphin!
A dolphin’s average life span is probably 20 years or less; even though, dolphins have lived as long as 48 years. We can tell how old a dolphin is by looking at its teeth. Each year it grows a new layer of tissue on its teeth. When a dolphin dies, its teeth can be cut to see how old the dolphin was, like the rings on a tree.
Dolphins die in various ways. They can get an infection; have breathing problems, or get heart disease. They can be killed by predators such as sharks or killer whales. Sometimes people kill dolphins on purpose. They use the dolphin for meat, leather, and oil. Human pollution also kills dolphins. They are also caught in fishing nets when people try to catch tuna fish.
en.wikipedia.org/wiki/dolphin www.defenders.org www.dolphins-world.com/
Dolphin-
Robert A. Morris 2/19/2011 197 pgs.
Spinning with the Dolphins-
Meera Dolasia 5/22/2011 152 pgs.