The cetaceans are aquatic mammals that make up the order Cetacea. These living beings, which are characterized by their large size, do not have hind limbs, while the forelimbs became fins. Their bodies also end in a single horizontal fin.
In the upper sector of the head, cetaceans have the nasal openings through which they breathe. Through these openings they expel the air, which when condensed resembles a jet of water.
Cetaceans are generally hairless: a very thick layer of fat allows them to resist low temperatures. The vast majority of the nearly eighty recognized species of cetaceans are marine, although there are some species of dolphins that live in fresh water.
The largest animal that exists is a cetacean: the blue whale. These specimens usually weigh more than one hundred tons and are about 25 meters long. Due to hunting, the blue whale population declined for many years, until its protection began in the mid-1960’s.
The southern right whale, the glacial right whale and the Greenland whale are other species of whale that belong to the order of the cetaceans.
The dolphins, the dolphins, the whales, the beluga whales and porpoises are also cetaceans. All these animals have characteristics in common and, in turn, multiple differences.
In addition to all the above about cetaceans, it is worth knowing another series of relevant aspects about cetaceans such as the following:
-The blue whale is considered to be the largest animal that has existed on planet Earth. And it is that it can reach 33 meters long, while the largest dinosaur known to date, the Dreadnoughtus schrani, was 26 meters.
-The aforementioned blue whale has the capacity to eat between 6 and 8 tons of food per day.
-The tongue of that aforementioned whale weighs the same as an elephant.
-The calf of a blue whale comes to the world with a size of 7 meters in length. You will gain about 90 kilos daily.
-The fin whale can reach up to 45 kilometers per hour and can dive up to 200 meters deep in search of food. Dolphins, meanwhile, are faster as they can reach 54 kilometers per hour.
-Dolphins, underwater, are capable of detecting all kinds of threats and even objects with a sonar system very similar to that of bats. This is what is known as echolocation.
-The so-called spinner dolphins have the ability to jump out of the water up to 7 meters high.
-The capacity of a whale’s stomach is really impressive. Thus, if that of a cow is 209 liters, that of the aforementioned cetacean reaches 760 liters.
It should be noted that cetaceans are predators that feed on fish, cephalopods, plankton and, in the case of orcas, other marine mammals. The main threat to the subsistence of cetaceans, on the other hand, is humans.