The cetaceans are the marine animals most famous for their presence in ancient tales and legends.They are animals that have always aroused great interest on the part of the human being.These animals, in general, are great strangers that, little by little, are disappearing without, apparently , let's do nothing.
In this article of Animals and Pets Online we will talk about cetaceans, which are, their characteristics, where they live and other curiosities .Do you want to know more about these inhabitants of the sea depths? Keep reading!
What are cetaceans?
The order of the cetaceans is composed of two suborders, the myxicets, formed by the bearded whales, and that of the odontocetes, composed of cetaceans with teeth, such as sperm whales, dolphins and killer whales.
The evolution of the cetaceans has resulted in a similarity between these two living suborders, being the result of evolutionary convergence.The common structural characteristics between the two groups, such as body shape, position of the nostril or spiral over the head, the absence of vocal cords and the similar shape of the lungs suggests that these species have evolved from different ancestors to animals very similar to each other.
Therefore, cetacean mammals are lung animals that inhabit our seas and oceans, although certain species live in rivers.
Characteristics of cetaceans
Cetaceans are characterized by their anatomy, morphology, physiology and habitat.The main characteristics of cetaceans are:
- They exhibit an exceptionally wide range of body mass that influences oxygen storage and utilization capabilities.This prevents the appearance of hypoxia or lack of oxygen in your tissues.
- During diving, your heart draws blood to the brain, lungs and muscles to allow swimming and the continuous functioning of the body.
- The trachea is shorter than in terrestrial mammals and does not communicate with the esophagus.It is linked to the spiral, where they take and expel the air.
- They have large reservoirs of fat to prevent hypothermia when submerged at greater depths.
- The hydrodynamic shape of your body allows faster swimming and prevents the ravages of large pressure changes.
- They don't have vocal cords.Instead they have an organ called melon that u San to communicate or hunt for echolocation.
- They have a very thick skin whose outermost layer, epidermis, is continually renewed at great speed.
- At birth, the offspring have hair, but these disappear after a few months of life.
- The number of fins depends on the species, although all have pectoral and caudal fins.
- Some species have teeth, all of the same size and form.Others have beards, which you use to filter the water.
Where do cetaceans live?
The habitat of the cetaceans is the aquatic environment.Sinel, his skin would dry out and die.Some cetaceans live in circumpolar waters, for example the beluga ( Delphinapterus leucas ) or the Narwhal ( Monodon monoceros ), so they are adapted to low temperatures.Others have a more tropical distribution, such as the common calderon ( Globicephala melas ) and the tropical calderon ( Globicephala macrorhynchus ).
Some of these animals live in fresh water, they are very threatened species of cetaceans due, mainly, to the contamination of rivers, the construction of dams and the discriminated hunting The list of cetaceans living in rivers is:
- Bolivian dolphin ( Inia boliviensis )
- Araguaia river dolphin ( Inia araguaiaensis )
- Pink dolphin ( Inia geoffrensis )
- Silver dolphin ( Pontoporia blainvillei )
- Baiji ( Lipotes vexillifer )
- Indus Dolphin ( Minor Platanist )
- Delfin del Ganges ( Gangetica Platanist )
The vast majority of cetaceans make annual migrations from their feeding areas to their breeding areas.This is the moment when these animals are most unprotected.
In the image we can see a pink dolphin:
Types of cetaceans:
The cetaceans are classified into two large groups: the mycedets and the odontecets .
1.Misticetos
Mistycetes, commonly called whales, are less numerous and are characterized, mainly, by having beards instead of teeth.They are animals of an enormous size and usually live in cold waters.Some of their species have not been seen during the sightings of cetaceans for decades.The most common species of myceicets are:
- Pacific Right Whale ( Eubalaena japonica )
- Greenland whale ( Balaena mysticetus )
- Common whale ( Balaenoptera physalus )
- Blue whale ( Balaenoptera musculus )
- Humpback whale ( Megaptera novaeangliae )
- Gray whale ( Eschrichtius robustus )
- Pygmy right whale ( Caperea marginata )
In the picture we can see a common whale:
2.Odontocetos
Odontocetes are cetaceans with true teeth, in greater or lesser number.They are very numerous and include a good variety of species.They are all carnivorous animals .The best known species of odontocetes They are:
- Calderon common ( Globicephala melas )
- Southern dolphin ( Lagenorhynchus australis )
- Common killer whale ( Orcinus orca )
- Delfin listed ( Stenella coeruleoalba )
- Bottlenose or bottlenose dolphin ( Tursiops truncatus )
- Atlantic dolphin ( Lagenorhynchus acutus )
- Dark dolphin ( Lagenorhynchus obscurus )
- Common porpoise ( Phocoena phocoena )
- Vaquita marina ( Phocoena sinus )
- Eyeglass porpoise ( Dioptric Phocoena )
- Sperm whale ( Physeter macrocephalus )
- Pygmy sperm whale ( Kogia breviceps )
- Dwarf sperm whale ( Kogia sima )
- Zinio de Blainville ( Mesoplodon densirostris )
- Zifio of Gervais ( Mesoplodon europaeus )
- Zifio de Gray ( Mesoplodon grayi )
In the image we can observe a common calderon:
If you want to read more articles similar to Cetaceans-Meaning, Types and Features , we recommend that you enter our Curiosities section of the animal world.
Bibliography
- Geisler, JH,& ; Sanders, AE (2003).Morphological evidence for the phylogeny of Cetacea.Journal of Mammalian Evolution, 10 (1-2), 23-129.
- Noren, SR,&Williams, TM (2000 ).Body size and skeletal muscle myoglobin of cetaceans: adaptations for maximizing dive duration.Comparative Biochemistry and Physiology Part A: Molecular&Integrative Physiology, 126 (2), 181-191.
- Yablokov, AV (1965 ) Convergence or parallelism in the evolution of cetaceans.International Geology Review, 7 (8), 1461-1 468.
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