Explore the world of dolphins!

What's in a name?

Dolphin comes from the Greek delphin and in fact the common dolphin's latin name is Delphinus delphis.
Porpoise derives from the Latin phrase porcus, which means hog and piscis meaning fish, literally meaning sea pig. The porpoise's relationship to a pig is found in many names, for example, in South America it is known as chancho mariono which means sea pig and in Germany it is called meerschweinalso meaning sea pig.

Why do some whales and dolphins have a dorsal fin?

The dorsal or back fin stabilises the mammal in the same way as a keel on a sailboat stabilises a boat. Most dolphins have a dorsal fin, but in some it has been reduced to just a series of bumps. In some it has been lost altogether such as in the narwhal, which is another species of porpous.

How well do dolphins see?
D olphins have excellent vision, both in the water and in the air. The only species of dolphins with reduced vision are the river dolphins found in the Amazon, Ganges and Indus rivers. Here the eye is simply a slit 2-3 mm in diameter.

What is Sounding?
Sounding is a word used when dolphins dive down deeply into the water, usually to look for food.

What is Breaching?
Breaching is when dolphins launch their bodies out of the water almost vertically. They then descend onto their backs with a huge crash.

How deep can dolphins dive?
Most dolphins spend most of their time swimming in 100 metres of water because this is where food is most plentiful. A captive bottlenose dolphin was trained by the US Navy to dive as deeply as 535 meters.

What is a Blow?
A blow is an outward breath of a dolphin and is explosive! Sometimes the species can be identified by their blows. Often the blows are 5-6 metres high and are visible for several miles. An experienced observer can estimate the size of the individual by the height of the blow.

Do Dolphins sleep?
D olphins do not sleep in the same way that we do and the reason for this is that when they sleep they stop breathing. So they can only sleep or doze for short periods.
However, they can also go into a semi-sleep mode where one half of the brain switches off but they continue to surface for breaths.

How do Dolphins make sounds?
This isn't an easy question to answer, because dolphins don't have vocal cords like humans do. In dolphins the low frequency whistle sounds they make are thought to be produced by their larynges, and the high-pitched clicks by the complex structure in their foreheads. Recent studies carried out with the bottlenose dolphins in Cardigan Bay in West Wales have shown that they have their own accent and that their whistle is slightly different from other dolphins from western Ireland, for example!