Are Whales Dolphins?

No, whales are not considered dolphins, however they are very closely related to the dolphin and porpoise species.

In fact whales belong to the cetacean family which includes both dolphins and porpoises.

All three species are marine mammals and share many of the same traits which are present in almost all mammals.

Some of the traits these marine mammals have in common with each other and with land mammals includes:

  • Giving birth which involves a pregnancy/gestation period that can last anywhere from 9 – 17 months instead of laying eggs like fish do
  • Breathing air – All cetaceans receive air by breathing above the waters surface because they do not possess gills and would drown if they inhaled water.
  • Being warm-blooded – All mammals are warm-blooded including marine mammals such as whales, dolphins and porpoises.
  • Producing milk – All cetaceans produce milk to feed their young
  • Having hair – Although hair is a common characteristic of mammals not all species of cetacea have hair and the ones that do lose their hair shortly after birth

In some cases the term “whale” can be used as a blanket statement to also include dolphins and porpoises, but in most cases “for clarification purposes”  the term whale is not used to describe dolphins and porpoises in order to not confuse people about the 3 different suborders.

Baleen whale characteristics

Whales in general are much larger than dolphins and porpoises, and some species of whale have a trait that is unique only to whales which is the presence of baleen plates and bristles instead of teeth.

These whales which are referred to as baleen whales (sometimes they’re also referred to as the true whales) are the largest of the whale species and some species  (such as the blue whale) can grow to lengths of 70 ft. – 90 ft. long.

In order to capture their food baleen whales hunt using a method known as filter feeding.

Since baleen whales don’t have teeth (they have baleen plates with bristles) they cannot grab or bite their prey so they hunt by swimming towards their prey with their mouth open and engulf large amounts of small fish, krill, squid and various crustaceans.

They then expel the water out of their mouth using their tongue while successfully keeping their prey trapped in the baleen bristles.

The purpose of the baleen bristles is to act like a fence that keeps their prey from escaping while allowing water to easily pass through the bristles.

Toothed whale characteristics

In addition to baleen whales there are also some species of whale that have teeth.

These whales are referred to as toothed whales and are generally smaller than their baleen whale counterparts, with the exception of the sperm whale.

All species of dolphin and porpoise have teeth and are also grouped under the toothed whales suborder.

Dolphins are typically larger than porpoises and unlike porpoises which have a fused vertebrae around the neck region (which limits its ability to move its head in various directions) dolphins have a jointed vertebrae allowing for much more flexibility and greater visibility of its surroundings.

In fact some dolphins are able to turn their head a full 90 degrees in order to observe their environment while porpoises have very limited neck mobility.

When it comes to dentation porpoises have spade shaped teeth compared to dolphins which have cone-shaped teeth.

Echolocation abilities

Lastly, toothed whales are able to use echolocation which allows them to search for prey, navigate the ocean and remain alert of predators in dark environments where light is not present.

The echolocation of toothed whales works similar to sonar in that bounces sound waves off of solid objects and the returning echo creates a map of the environment allowing these marine mammals to observe their surroundings without the use of eyesight.

The echolocation of these marine mammals is significantly better than the technology often seen in submarines and creates a much more vivid image of the animals landscape.

While echolocation is known to be present among the toothed whale suborder researchers are unclear about the existence and extent of echolocation among baleen whales.

Part of the reason for this confusion has to do with the fact that the baleen whale suborder has two blowholes while toothed whale suborder only possesses one.

This has led marine biologists to assume that toothed whales developed one of their blowholes into an echolocation system to allow them to better absorb sound and detect objects in their surrounding, however the reason for this physiological difference remains unclear as other research has indicated that baleen whales may also be capable of echolocation, at least among one or two species of baleen whale.

Fun facts and Interesting Whale Names

1) The killer whale is the largest animal within the dolphin species.

These marine mammals are able to grow to lengths in excess of 30 ft. and weigh as much as 10 tons.

Although they are referred to as killer whales they are actually dolphins.

The name “killer whale” was given to these dolphins because of their large size and expansive diet which includes eating other marine mammals.

In fact aside from the false killer whale these marine mammals are one of the only known species of cetacean to consume other marine mammals.

2) Although the false killer whale is known to consume marine mammals and resembles the killer whale in terms of appearance they are not closely related to killer whales.

They are however also characterized as dolphins and obtained their name due to their close resemblance to the killer whale and because of their wide diet which as stated earlier includes marine mammals.

3) A third species of dolphin that carries the term “whale” in its name is the pilot whale.

These large marine mammals are the second largest animals within the dolphin family, however they are not known for consuming other marine mammals like the killer whale and false killer whale.

Instead these dolphins consume a diet consisting primarily of squid and various species of fish.