...dolphins often leap clear of the water when travelling at speed. This is because the density of water is much greater than that of air and they are able to travel faster by leaping out of the water.
...whale and dolphin mothers ‘suckle’ their young underwater! Mothers have muscular mammary glands and ‘squirt’ their milk into the calf’s mouth, to ensure that the calf takes in as much of the energy rich milk as possible.
...on average, a whale or dolphin will eat four to five percent of its body weight in food per day. That means that a 100 ton blue whale will eat almost five tons of krill per day, or that a 200kg bottlenose dolphin will eat 10kg of fish per day!
...newborn cetacean calves ‘suckle’ three to four times each hour and will suckle from their mothers for six months or more.
...when right whales and humpback whalesbreach (leap out of the water), seagulls can often be seen darting in to pick up pieces of skin that become dislodged from the breaching whales. Presumably this is an easy source of food for seagulls.
...whales and dolphins don’t sleep in the way humans do. Although we don’t know how they sleep, some scientists believe they sleep with half the brain asleep and half the brain awake, keeping them aware of danger.
...all whales and dolphins have the remains of the pelvis, but it is reduced to two small bones at the rear of the animal.
...the ‘strapped-toothed whale’ is so called because in mature males there are only two teeth in the bottom jaw and these completely ‘strap’ the upper jaw, preventing it from opening more than a few centimetres. How these animals eat is unknown, but it may be that they stun their prey with high intensity sound.
...some cetaceans can dive to depths of more than a kilometre and stay there for more than an hour.
...common dolphins, which are often seen off South Africa’s east coast, can occur in schools of several thousand. The biggest school on record was estimated to consist of about 15,000 dolphins!
...because whales and dolphins are streamlined to swim in water, they do not have external organs. This makes it almost impossible to tell the sex of a whale or dolphin when watching them on the sea surface.
...there are probably types of cetaceans that are as yet unknown. For example, the Longman's beaked whale is only known from skulls washed ashore in Somalia and Australia. It has never been seen alive!
...the Orca, is the fastest swimmer of all the cetaceans and can reach speeds of more than 50 km/h (30 mph) while hunting.
...some cetaceans can dive to depths of more than one kilometre (0.6 mi) and stay there for more than an hour.
...newborn cetacean calves do not have the skills to swim for long periods or to accelerate away from danger, so they swim in the slipstream of their mothers, enabling the mother to protect her calf.
...all cetaceans have a blubber layer — a layer of fat under the skin. In most dolphins, this layer is about one quarter to one third of the total body weight, but in southern right whales nearly half of its weight (up to 50 tons) will be blubber.
...the male narwhal's tusk can be up to 3.5 metres in length which is over the size of an average female without a horn and weigh up to 10 kilograms.
...male narwhal(e)s tusk is the canine growing through the lip. Sometimes, the male will have 2 tusks but their number is small. Female narwhal(e) rarely have a tusk and if they do, it must be smaller than the males. Also,there is only 1 recorded case of a duel horned female narwhal(e)
...observations of cetaceans date back to at least the classical period in Greece, when fisherpeople made notches on the dorsal fins of dolphins entangled in nets in order to tell them apart years later.
...groups of bottlenose dolphins around the Australian Pacific have displayed basic tool use by wrapping pieces of sponge around their beaks to prevent abrasions. This is a display of a cognitive process similar to that of great apes.
...Qi Qi was the name of one of several captive Baijis held at the Wuhan Institute in China in an attempt to rescue the species.
...the Beaked whales (genus Ziphidae) contain over twenty species of small whales, and are the least known of all cetaceans.
...The ear bone called the hammer (malleus) in cetaceans is fused to the walls of the bone cavity where the ear bones are, making hearing in air nearly impossible. Instead sound is transmitted through their jaws and skull bones.
...cetaceans with pointed beaks have good binocular vision, but others, such as the Sperm Whale cannot see directly in front or behind.