Divide into two groups: toothed cetaceans (eg dolphins belong here), with whalebone that cetaceans (whales). In the same way as terrestrial mammals, cetaceans breathe with lungs, nursing their pups, but by developing strategies and special well adapted aquatic environment.Adaptation has significant consequences.
Whales have become huge: most of them, the blue whale, has an average of 26 meters and weighing 150 tons. Huge dimensions were developed because the water temperature is much lower than that of the whales body, so also other aquatic animals would lose a lot of heat, and arrive quickly to hypothermia.
But as the body is greater, the more weight relative to body surface mica.Ca is therefore gives relatively large animals in the water less heat than the small. To remove the risks of living in cold waters, whales have gained some tremendous size during evolution. Their whole conformation serves to save energy. Fat layer that are endowed help keep body temperature constant at 36-37 degrees C.
If the Greenland whale, the body fat can have up to 50 inches thick. Fat is not fixed but the muscles underneath, but has a considerable mobility, almost gliding over the muscular layer. Body of whale huge advances easily in water because the body is not producing huge whirlpools, saving a lot of energy. Fat is stored in the liver and bones is deposited a large amount of oil.
Feeding: In spite of huge size, the whales do not eat very much food. Because body conformation designed to save energy, they do not need to eat too much. They feed on small animals and plant-plankton organisms. It is the richest food source for marine mammals. Planctonii are microscopic, but can not fully satisfy the food needs of the whale.
Fanoanele: In order to be satisfied with plankton, whales during evolution have been endowed with some band called faloane. These in turn ends with some brush-shaped extensions, functioning as a sieve. Of the tons of water entered the mouth, they retain only plankton. Fanoanele folds originate from the floor of the mouth, no teeth. Different species of whales have developed their own whalebone out so that they retain the various components of the plankton, thus sharing resources between them food.
Cetaceans that have whalebone lunghi and thin, like a blue whale, the water retaining microcrustaceele. Whales that feed more than surface water, need greater whalebone. In this category, the Greenland whale whale of Vizcaya. Blue whale, whale or whale innotatoare northern latitude with each taking a huge water gua "attacking" the bottom or side millions of microorganisms.
Cape whale must be very big and strong to withstand the weight fanoanelor huge volume of water and is flitrata. Head length of Vizacaya whale (whale light) represent 40% of total body length, and cervical vertebrae are fused together in order to maintain body weight. All whale species live a migratory life. Crawl reguralitate roads between the polar waters, cold waters rich in food and tropical, suitable for raising chickens.
Whales give birth every 2-3 years. During birth, the dam is surrounded by several "midwives" who will help to keep the newborn to the surface to respira.puiul will suck breast milk and has a very large increase growth. Adult whales in tropical waters have not enough food. They hunger until the arrival of summer, when the insulating layer of chicken fat is thick enough to survive in cold waters where they feed.
Whales belong to the suborder Mysticeti order Cetacea. They are grouped into three families, which in turn are divided into five genera and ten species in total.
Whales smooth (not innotatoarea dorsal furrow and throaty) Greenlandic 1.Balena-(balaeria misticetus), the average length is 17 m, weight 60-80 tonnes of Vizacaya 2.Balena-(B. glacialis) length of 15 m, weight of 50-55 tons; 3.Balena sp-(Capers marginata), the average length of 5 meters, weighing 3 to 3.5 tonnes.
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