Whales are one of the most amazing animals on the planet, yet proportionally little is known about them. Some of the whale species are the longest-living mammals on Planet Earth, so much so that some of the individuals alive today could have been born in the 19th century.
In this article on our site we will discover how many types of whales there are, their characteristics, which whales are in danger of extinction and many more curiosities.
Characteristics of whales
Whales are a type of cetacean grouped in the suborder Mysticeti, characterized by having baleen on place of teeth, as have dolphins, killer whales, sperm whales or porpoises (suborder Odontoceti). They are marine mammals, fully adapted to aquatic life. His ancestor came from the mainland, an animal similar to today's hippopotamus.
The physical characteristics of these animals are what make them so suitable for underwater life. Their pectoral and dorsal fins allow them to keep their balance in the water and move through it. On the upper part of their body they have two holes or spiracles through which they take in the air they need to stay underwater for long periods of time. Cetaceans of the suborder Odontoceti have only one spiracle.
On the other hand, the thickness of their skin and the accumulation of fat under it helps them to keep their body temperature constant when descending in the water column. This, together with the cylindrical shape of their body, which provides hydrodynamic characteristics, and the microbiota that lives in their digestive tract through a mutualistic relationship, makes the whales explode when they die stranded on the beaches.
What characterizes this group are the beards they have instead of teeth and they use them to eat. When a whale takes a mouthful of prey-laden water, it closes its mouth and pushes the water out with its tongue, forcing it through the baleen and trapping the food. Then, with the tongue, it collects all the food and swallows it.
Most of them have a dark gray coloration on the back and white on the belly, in order to go better unnoticed in the water column. There are no types of white whales, only the beluga (Delphinapterus leucas), which is not a whale, but a dolphin. Likewise, the whales are classified into four families, with a total of 15 species, which we will see in the following sections.
Types of whales in the Balaenidae family
The Balenid family is made up of two distinct living genera, the Balaena genus and the Eubalaena genus, and three or four species, depending on whether we rely on morphological or molecular studies.
This family includes the longest-lived species of mammals They are characterized by having a very convex maxilla or lower jaw, outwards, which gives them that characteristic look. They do not have folds under their mouths that they can expand when they feed, so the shape of their jaw is what allows them to catch large amounts of water with food. This group of animals also lacks a dorsal fin. They are a relatively small type of whale, measuring between 15 and 17 meters, and are slow swimmers.
The Greenland whale (Balaena mysticetus), the only species of its genus, is one of the species most threatened by hunting of whales, is in danger of extinction according to the IUCN but only the subpopulations surrounding Greenland[1], in the rest of the world there is no concern about them, so that Norway and Japan continue the hunt. As a curious fact, it is thought to be the longest-lived mammal on the planet, being able to live more than 200 years.
In the southern hemisphere of the planet we find the southern right whale (Eubalaena australis), one of the types of whales in Chile, important fact because it was here where, in 2008, a decree declared them a natural monument, declaring the region «Whale Hunting Free Zone » It seems that in this region the abundance of this species has improved thanks to the ban on hunting, but death by entanglement in fishing nets continues. In addition, it has been proven that for a few years, the Dominican gulls (Larus dominicanus) have increased their population considerably and, unable to obtain food resources, devour the skin of the back of calves or young whales, many dying because of the wounds.
To the north of the Atlantic Ocean and in the Arctic inhabits the glacial right whale or Basque whale (Eubalaena glacialis), which receive this name because the Basques were once the main hunters of this animal, driving them almost to extinction.
The last species in this family is the North Pacific right whale (Eubalaena japonica), almost extinct due to illegal whaling of the Soviet State.
Types of whales in the family Balaenopteridae
The balenopterids or rorquals are a family of whales created by an English zoologist from the British Museum of Natural History in 1864. The The name fin whale derives from Norwegian and means "with grooves in the throat". This is the distinguishing feature of this type of whale. In the lower jaw they have folds that, when drinking water to feed, expand allowing them to take more at once; It would work in a similar way to the crop that some birds such as pelicans have. The number and length of the folds vary from species to species. To this group belong the largest known animals Their length varies between 10 and 30 meters.
Within this family we find two genera: the Balaenoptera genus, with 7 or 8 species, and the Megaptera genus, with a single species, the yubarta or humpback whale(Megaptera novaeangliae). This whale is a cosmopolitan animal, present in almost all seas and oceans. Their breeding area is tropical waters, where they migrate from cold waters. Together with the glacial right whale (Eubalaena glacialis), it is the one that most often gets entangled in fishing nets. It should be noted that hunting of humpback whales is only allowed in Greenland, where up to 10 per year can be hunted, and on the island of Bequia, 4 per year.
The fact that there are 7 or 8 species in this family is due to the fact that it is still unclear whether the species should be divided from tropical fin whalein two Balaenoptera edeni and Balaenoptera brydei. This whale is characterized by having three cranial crests. They can measure up to 12 meters in length and weigh 12,000 kilograms.
One of the types of whales in the Mediterranean is the fin whale (Balaenoptera physalus). It is the second largest whale in the world, after the blue whale or blue whale (Balaenoptera musculus), reaching 24 meters in length. This whale is easy to distinguish in the Mediterranean from other types of cetaceans such as the sperm whale (Physeter macrocephalus), because when submerged it does not show its tail fin, as the latter does.
The other species of whales in this family are:
- Northern whale (Balaenoptera borealis)
- minke whale (Balaenoptera acutorostrata)
- Merke whale (Balaenoptera bonaerensis)
- Omura's whale (Balaenoptera omurai)
Types of whales in the family Cetotheriidae
Until a few years ago it was believed that the ketotheriids became extinct at the beginning of the Pleistocene, although recent studies by The Royal Society have determined that there is a living species of this family, the pygmy right whale (Caperea marginata).
These whales live in the southern hemisphere, in warm water areas. There are few sightings of this species, most of the data comes from old captures by the Soviet Union or strandings. They are very small whales, about 6.5 meters long, they do not have folds in their throats, so their appearance is similar to the whales of the family Balaenidae. In addition, they have short dorsal fins, presenting only 4 fingers instead of 5 in their bone structure.
Types of whales in the family Eschrichtiidae
The scriptids are represented by a single species, the gray whale (Eschrichtius robustus). This whale is characterized by not having a dorsal fin and, instead, they have some kind of small humps. They have a arched face, unlike the rest of the whales that have a straight face. Baleen are shorter than in other whale species.
The gray whale is one of the types of whales in Mexico. They live from this area to Japan, where it is allowed to hunt them. These whales feed near the seabed, but on the continental shelf, so they tend to stay close to the coast.
Types of endangered whales
The International Whaling Commission (IWC) or International Whaling Commission (IWC) is an organization created in 1942 with the aim of regulating and prohibiting whalingDespite the efforts made and, although the situation of many species has improved, whaling continues to be one of the main causes of the disappearance of marine mammals.
Other problems are collision against large ships, accidental entanglements with fishing nets , contamination by DDT (an insecticide), pollution by plastics, climate change and the thaw , which destroys the populations of krill, the main food of many of the whales.
Currently endangered or critically endangered species are:
- Rorqual or blue whale (Balaenoptera musculus)
- The Chile-Peru southern right whale subpopulation (Eubalaena australis)
- Glacial Right Whale (Eubalaena glacialis)
- The subpopulation of Humpback Whale (Megaptera novaeangliae) of Oceania
- Rorqual or tropical whale of the Gulf of Mexico (Balaenoptera edeni)
- Antarctic Blue Whale (Balaenoptera musculus ssp. Intermedia)
- Northern whale (Balaenoptera borealis)
- Grey whale (Eschrichtius robustus)
