Cetaceans are aquatic mammalian animals 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 nasal openings through which they breathe. Through these openings they expel air, which when condensed resembles a jet of water.
Cetaceans generally do not have hair: 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 have a length of about 25 meters. Due to hunting , the blue whale population declined for many years, until protection began in the mid-1960s.
The southern right whale , glacial right whale , and bowhead whale are other whale species that belong to the order Cetaceans.
Dolphins , dolphins , killer whales , belugas and porpoises are also cetaceans. All of these animals have common characteristics and, at the same time, multiple differences.
In addition to everything stated 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 ever existed on planet Earth. And it can measure 33 meters long, while the largest dinosaur known so far, the Dreadnoughtus schrani, was 26 meters long.
-The aforementioned blue whale has the capacity to ingest between 6 and 8 tons of food per day.
-The tongue of that aforementioned whale weighs the same as an elephant.
-The baby of a blue whale comes into the world with a size of 7 meters in length. He 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, for their part, are faster as they can reach 54 kilometers per hour.
-Dolphins, underwater, are capable of detecting all types of threats and even objects with a sonar system very similar to that possessed by 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 truly 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 killer whales, other marine mammals. The main threat to the subsistence of cetaceans, on the other hand, is humans .