Who has never dreamed of seeing a whale up close? There are many reasons to marvel at these beautiful animals. Is it because since childhood we learned that they are the largest animals in the world? Is it because despite being mammals they live in the ocean? Is it because of their terrifying songs?
In any case, if you are someone who has always admired whales, or if you want to learn about them to start admiring them, in this article on our site, we are going to comment on some of thecharacteristics of whales that most surprise us.
What are whales?
First of all, it is important to clarify that despite their similarity to fish, Whales are mammals In addition, this group of species It belongs, together with the dolphins, to the group of cetaceans. However, they differ from dolphins by forming the mysticete group. The characteristics of whales that differentiate them from dolphins are mainly to have keratin beards that originate in the palater, instead of teeth, and to present in the top of head two spiracles (nostrils) instead of one.
For example, the orca, wrongly called the killer whale, is actually a dolphin, and we can verify it, since it has teeth and not baleen. To know how tall a whale is or how much whales weigh, it should be taken into account that these data can vary greatly depending on which whale we are talking about, since there are about 14 different species of whales Here we explain the Types of whales.
The smallest species is the pygmy right whale (Caperea marginata) which measures around 6 meters in its adult state and the largest species of whale is the blue whale (Balaenoptera musculus) which can reach measure up to 30 meters This leads us to ask "how much does a blue whale weigh?". Well, the weight of a blue whale is between 50 and 150 tons, and in 1947 a female weighing 190 tons was recorded.
Evolution of whales
Due to their aquatic way of life, whales might be thought to be more closely related evolutionarily to fish than to land mammals. However, cetaceans are actually descendants of the artiodactyl group, which includes camels, cattle, sheep, hippopotamuses, oxen, and wild boars, among other mammals terrestrial. In fact, they are particularly closely related to hippos.
It is believed that 50 million years ago, the Archaeoceti group originated, the ancestor of today's cetaceans, which included animals that spent part of their lives on land and another part of their lives in the water. Current cetaceans originated approximately 30 million years ago, and in the Oligocene (25-40 million years ago) baleen whales (whales) were differentiated from odontocetes (dolphins), based on their different feeding methods.
So, if they are mammals and live underwater, how do whales breathe? Well, whales perform pulmonary respiration by generating the entry and exit of air through the spiracles, which are the nostrils located on the top of the skull. Discover all the information related to this point in this other article: "How do whales breathe?".
Types of whales
There are four families of Mysticetes differentiated by the characteristics of the whales that make them up:
Balaenidae Whales
They are whales that have no dorsal fin and have smooth ventral skin. Also, his lower jaw is extremely arched. This family includes four species:
- Greenland whale (Balaena mysticetus).
- Basque whale (Eubalaena glacialis).
- North Pacific Right Whale (Eubalaena japónica).
- Southern Right Whale (Eubalaena australis).
Balaenopteridae Whales
This group of whales are called fin whales. They have a dorsal fin well back on the body and deep furrows in the skin below the throat that extend behind the pectoral fins. This family integrates 7 or 8 species, among which are:
- Humpback whale (Megaptera novaeangliae).
- Blue whale (Balaenoptera musculus).
- Fin whale (Balaenoptera physalus).
Eschrichtiidae Whales
Currently there is only one species belonging to this family: the gray whale (Eschrichtius robustus). This species is characterized by not having a dorsal fin and having two short furrows on the skin below the throat.
Cetotheriidae Whales
This family is also represented by a single species: the pygmy right whale (Caperea marginata), which looks similar to the whales of the family Balaenidae, but it is much smaller and usually weighs about 3 tons.
Whale Habitats
Whales are cosmopolitan, so we can find them in the oceans and seas around the world. They are adapted to live in s alt water and carry out long migrations in search of food and more suitable temperatures depending on the season of the year.
They are usually found in places with warm temperatures, but they can also resist very low temperatures and can live in Antarctic and Arctic waters. In addition, they can be found both in the oceanic zone and in the neritic zone (near the coasts). In this way, answering the question "where do the whales live?", as you can see, is more complex than it seems.
Whale feeding
Whales feed on small and diverse organisms such as zooplankton, cephalopods, crustaceans and small fishThey can feed in three different ways. In all cases, they draw water in along with the food and use their baleen to filter it back out without letting the food escape.
- With your mouth open: One of the ways to feed is to swim slowly with your mouth open, letting whatever comes in cross your path.
- Moving the tongue: another way is the one used, for example, by the blue whale, which opens its mouth and makes downward movements with the tongue generating a pressure difference and sucking the water around it.
- In group: Without a doubt, the most interesting way of feeding the whales is that carried out by the humpback whale. These whales hunt in groups using a particular system called "bubble-feeding", whereby one whale produces bubbles by releasing air through its blowhole and the rest move under the school of fish, pushing them towards the bubbles. The bubbles work like a net that prevents the passage of fish. In this way the fish are trapped and gobbled up by the whales. For this team hunting system, the whales communicate with each other.
Here we explain in more depth, not only what whales eat, but what whales eat.
How do whales communicate?
Whales can make vocalizations by passing air through their larynx, which has folds that vibrate and make sounds. They use these vocalizations to communicate in different circumstances, both when hunting, like humpbacks, and for courtship or to locate themselves during migrations. Through these vocalizations, they can communicate over 1,000 km away
Whale Reproduction
Whales reproduce sexually. Both the ovaries in females and the testicles in males are located inside the abdominal cavity. When not erect, the penis is inside a genital pocket.
Males perform courtship to be selected by females, which may include vocalizations, movements or fights. They have internal fertilization and copulation is usually very fast. Pregnancy lasts between 10 and 12 months and as they are viviparous species, once the gestation period is over they give birth to live young. After giving birth, females feed their young for a year with milk produced in the mammary glands, which are lodged in slits on the sides of the genital opening.
For more information, you can read this other article on our site on How do whales reproduce?
Are whales endangered?
There are many whales that today are in danger of extinction or critical danger of extinction, thus cataloged by the Red List of Endangered Species of the International Union for Conservation of Nature (IUCN). This is due to different threats to which these species are exposed.
But why are whales in danger of extinction? Mainly, the problems of whale conservation are due to massive hunting, for economic and cultural purposes. However, they also face other threats such as climate change, pollution from toxic products released into the sea and collisions with ships. Finally, noise pollution in the oceans from ships and other human activities interferes with whales' acoustic communication, disrupting hunting, courtship, and migration events.
