Sperm whales are the biggest animals on the Earth that have teeth. They are carnivores, which means they eat meat. Although sperm whales can be found in all oceans, they prefer the waters with high squid populations, which are the main diet. A sperm whale can eat up to 1,500 kg of food each day. Sperm whales are big animals. The males can grow up to 18 meters long and weigh up to 54,000 kg while the females are a bit smaller with a length of 12 meters and a weight of 17,000 kg. A female sperm whale give birth to one calf every five to seven years after a gestation period of fourteen to nineteen months. The life span of sperm whales can be up to sixty or seventy years. It is interesting to know that they also have the largest brain of any mammals. Sperm whale populations are at risk due to hunting and their accidental entrapment in fishing nets.
Dolphins are not fish. They are mammals that live in the water. Dolphins are among the most intelligent animals on Earth. Although they can be found in all the oceans in the world, dolphins prefer coastal waters and bays. The size of dolphins varies greatly. The smallest dolphin is just about 50 kg in weight and 1.2 m in length while the largest one can weigh up to 8,200 kg and is 10 m long. Dolphins are carnivores and they eat mainly fish. A female dolphin gives birth to one calf every 2 years after a gestation period of eleven to twelve months. A dolphin can normally live from twenty-five to sixty-five years and some species of dolphins can even live longer. Dolphin populations are at risk due to the pollution of their habitat and accidental entrapment in fishing net