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These wonderful creatures live in deep tropical and warm temperate waters in both the southern and northern hemisphere. People in Torbay have been lucky enough to see one or two jump out of the water. They are not thought to migrate over large waters and they are only seen swimming close to the shore.
An adult Risso's dolphin is quite distinctive. You can tell whether or not they are adults or infants depending on their size and scarring. Adult dolphins have a lot of scars because of their experiences throughout their lives. Their heads, unlike the bottlenose dolphin, are quite flat. (The sperm whale has a similar shaped head.) The dolphin varies greatly in colour. Usually, they are a mixture of grey and brown but they can be a blend of blue and grey as well. Although it is highly unusual, in some cases they can be bright white, however, this all depends on their age and what type of injuries it has had to face during its life. The mouth is slanted upwards and, inside of it, there are usually no more than seven pairs of teeth.
The dorsal fin is tall and curved, with a visible point at the tip of it, which is similar to its flippers. The tail is immense in size and weight and has powerful flukes on its tip. Risso's dolphin can grow to approximately 2.8m - 3.85m. They can weigh up to a phenomenal 500 kg and swim in schools of 3 to 50 individuals. No cases of over 150 dolphins of this breed have ever been sighted in the same place at the same time.
Their main diet is octopus and squid, which are called cephalopods. They also eat seaweed when they are young. They start to eat sea animals in their fourth or fifth years.
Over the last few years, Risso's dolphin have been plagued by mankind. Many have been killed because of the immense pressure of gill nets, pair trawling and drift nets. The fishermen who use the nets do not wish to shorten the dolphins' lifespans in any way - they are after fish that they wish to catch and sell - but nonetheless a lot of dolphins die by accident. They are, however, extremely common in warmer, tropical waters.
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