The oceans are home to an infinity of animal life and among this variety we find the whales, which belong to the group of marine mammals. The term whale is used to name various types of large cetaceans, including toothed and baleen animals. However, from a taxonomic point of view, its use is more restricted, since it really belongs to the Balaenidae family, which in turn is made up of two genera, Balaena and Eubalaena, the first having one species and the second three.
Now, have you ever wondered if all whales are baleen or are there toothed whales? Join us in this article on our site so you can find out if whales have teeth or not.
Do whales have teeth or baleen?
The term cetacean includes a group of aquatic mammals that is divided into baleen whales and odontocetes The former are characterized by having an arched jaw, so that on the palate and upper jaw there are long, flattened, stacked structures known as baleen, which are made of keratin and vary in number depending on the species. The barbs are used as a filter system to capture the animals and algae they feed on. The second, which are called odontocetes, do not have the structures described above, but have teeth that they use in a common way to take and process food.
Now, as we mentioned at the beginning of this article, there is a reduced number of true whales, which are:
- Greenland Whale (Balaena mysticetus)
- Southern Right Whale (Eubalaena australis)
- Glacial Right Whale (Eubalaena glacialis)
- Pacific Right Whale (Eubalaena japonica)
They all belong to the Balaenidae family and have baleen, therefore, they lack teeth, so their nutrition occurs by filtration. These animals ingest large quantities of water that congregate the different species that constitute their food. Next, the liquid passes through the baleen, where it is trapped, and later they expel the water to finally swallow the food.
But there are other cetaceans that are part of families other than the one mentioned above that are also usually named as whales and have baleen. Let's get to know these bearded marine mammals:
- Family Balaenopteridae: includes various species of fin whales, such as the fin whale (Balaenoptera physalus), the blue whale (Balaenoptera musculus) and the humpback whale (Megaptera novaeangliae).
- Family Eschrichtiidae: There is only one extant species, the gray whale (Eschrichtius robustus).
- Family Neobalaenidae: currently with only one living species, the pygmy right whale (Caperea marginata).
Why don't whales have teeth?
The evolution of species is, without a doubt, a complex process that occurs over long periods of time. The ancestors of the whales were land mammals that about 53 million years ago made their transition to the sea. Those ancestors had teeth, and it has been revealed [1] that current baleen cetaceans have teeth when in utero, but then lose them to develop baleen. The embryonic presence of these dental structures is evidence that ancient whales had teeth, and even some related species had both teeth and baleen.
Now, scientists estimate that there was a change in the type of feeding in those marine mammals that lived millions of years ago, from So they went from consuming large prey for which they needed teeth, to smaller prey that form zooplankton and phytoplankton, for which the presence of dental structures was not necessary, but rather required a filtration system such as the one provided by beards.
Are there whales with teeth?
As we have mentioned in this article, species considered taxonomically as true whales have no teethHowever, some other cetaceans of the group of odontocetes that have teeth are named toothed whales, although, we insist, they are not true whales.
Next, we show the so-called "toothed whales":
- Family Delphinidae: Common killer whale (Orcinus orca), strictly speaking, is really a large dolphin. The naming of various subspecies and even other species has been proposed.
- Family Physeteridae: an example is the common sperm whale (Physeter microcephalus).
Differences between baleen and toothed whales
The differences that exist between the species that are named as baleen whales and toothed whales are the following:
- Baleen whales grow to larger sizes than toothed whales. In fact, the largest mammal today is the fin whale known as the blue whale (Balaenoptera musculus).
- Baleen species are filter feeders, mainly small fish, as well as zoo and phytoplankton. For their part, those that have teeth are usually active hunters, which in addition to fish include another variety of marine animals.
- In terms of socialization, baleen whales tend to congregate in smaller numbers than toothed species.
- The group of mysticetes (baleen whales) have two nostrils or spiracles, while the odontocetes (toothed whales) only have one.
Finally, we want to comment that, despite the common feature of baleen whales in terms of filter feeding, species differ in the techniques they use to obtain the foodThus, for example, fin whales are usually swallow whales, so while they swim on the surface they keep their mouths open to capture food. The gray whale, on the other hand, is called a dredger, since it feeds on muddy bottoms. And the group of balenids are known as combers and take food while swimming submerged. Find out more about it in this other article: "What do whales eat?".
