The method of echolocation in dolphins is the same as the sonar used on boats to detect schools of fish or the ultrasound scanners used in hospitals to check unborn babies. The extraordinary sensory mechanism of echolocation allows dolphins to find flatfish and crustaceans completely buried in the sand. They can also catch fast-swimming prey in total darkness. The short and repetitive clicks, estimated at less than one millisecond in duration, can temporarily stun a fish, allowing the dolphin to easily grasp it. It was fishermen who first described the fishing methods of dolphins after seeing them effortlessly picking fluttering fish, which they had previously stunned, from the surface Echolocation in dolphins is not the principal means by which dolphins communicate, except for the larger odontocetes, like the sperm whales, who use echolocation for communication and their clicks are longer and repeated less often.
Dolphins communicate with their own language in the form of whistles.
Studies of dolphin whistles within the same species revealed that different groups will have their own whistle dialect. Furthermore each individual will have a signature whistle or voice print that dolphin probably use to recognize each other. Vocalization in dolphins is still, however, poorly understood and will require many more years of research. Stenella originates from the Greek word stenos meaning narrow, which is a common characteristics of the beaks of all Stenella. Frontalis refers to the prominent forehead of this dolphin.