The bottle-nose dolphin has a pronounced beak, high dorsal fin, and broad tail flukes.
These dolphins are approximately 1.2m (4ft) long at birth and grow to a maximun size of 3 to 4m (10to 13ft).
A dolphin breaks the surface of the water every few minutes while swimming to breath through a blow hole on the top of its head.
Under water,a dolphin communcates with whistles emitted in single-toned squels to convey alarm, sexual excitement, and perhaps other emotional states.
Dolphins inhabit all the worlds oceans, using their streamlined bodies to reach under water speeds of 40km/h (25mph).
This swimming ability coupled with sharp teeth enables dolphins to capture fish and squid, their principal prey.
Dolphins are sleek and powerful swimmers found in all seas.
There are at least 32 species of dolphins.
Dolphins once were hunted commercially, especially for the small quantity of valuable oil extracted from parts of the head and used to lubricate delicate watch mechanisms.
Cheaper oils have now been found from other sources, and dolphins are no longer hunted for this reason.
Many dolphins, however become accidentally trapped and drowned in tuna nets between 1959 and 1972 an estimated 4.8 million dolphins dies in this way.
Under pressure from animal activists and United States consumers, both domestic and international tuna canners have refused to accept shipments from fishing fleets that do not protect dolphins.
Concerns has also been expressed about the treatment of dolphins on display in public aquariums and in (swim with the dolphins) programs.
The marine mammal protection act of 1972, amended in 1988 and 1992, was passed to prevent explitation of dolphins and related aquatic animals.
The national marine fisheries service is the principal regulatory agency.
