Types of Porpoises - Characteristics of Porpoise Species

Porpoises are aquatic mammals, belonging within the group of cetaceans known as odontocetes, also known as toothed-whales. This group is a parvorder which also includes dolphins and whales. However, the animals we call porpoises all correspond to the Phocoenidae family. Within this family, the smallest species of cetaceans are found.

Porpoises and dolphins are commonly confused due to their similar appearance, as well as the fact they are taxonomically linked. However, both groups diverge in the final point of classification, belonging to different families (Delphinidae for the latter and Phocoenidae for the former).

Take a look at our article on the types of river dolphins around the world to learn more.

Porpoises are relatively small individuals, when compared to other cetaceans. The size range can vary according to the species. Generally porpoises measure between 1.5 to 2 meters in length, although individuals can be found below or above these measurements. In terms of weight, they range from about 50 to 220 kg (110 to 485 lbs) approximately.

They are sexually dimorphic animals in relation to the size of the females, which are usually larger than the males. The body is similar to a torpedo shape and they have a single blowhole, an orifice important for respiration. This is similar to how dolphins breathe.

Although the skull is somewhat similar to that of dolphins, porpoises have certain protrusions that differentiate it. The facial shape extends backwards, which gives the peculiar feature to the head. The result is a bulging structure, devoid of ears, which protrudes from the back.

Their jaws are short, so they do not have the elongated shape that characterizes dolphins. They have many teeth, with the peculiarity that the end of the mouth does not completely cover their dental structures. This provides the impression that they are always smiling.

With the exception of the genus Neophocaena, all porpoises have a dorsal fin which tends to be small and triangular or with a pointed shape. They also have two forward fins, plus the tail. The Neophocaena is known as the finless porpoise as they lack a dorsal fin.

Porpoises are usually of a uniform gray color, but there are also some with a marked gray, black and white coloration. Their body is covered with a thick layer of fat that helps them with thermoregulation, in addition to serving as protection against predation in some cases.

Although their eyes are not large in relation to their body size, they have good vision acuity. In addition, they have the sense of echolocation. As with other cetaceans, this is highly developed and allows them to locate and know the surrounding environment. They do so by relying on the emission of high frequency sounds known as clicks.

There are three genera of porpoises, which contain a total of seven species. Below we reveal what they are, as well as provide information on where they live and whether they are marine animals in danger of extinction:

Genus Neophocaena:

In this there are two species of porpoises:

• Finless porpoise (Neophocaena phocaenoides): a species that lives in the waters of eastern countries such as Bangladesh, Cambodia, India, Iran, Singapore, Thailand and the United Arab Emirates, among others. It is found in shallow waters of coasts, mangroves and estuaries. It is considered in a vulnerable state.
• Narrow-ridged finless porpoise (Neophocaena asiaeorientalis): this species is native to China, Japan and the Republic of Korea. It inhabits coastal areas, mangroves and large rivers. It is classified as critically endangered.

Genus Phocoena:

It is the genus that groups the largest number of porpoise species, with a total of four:

• Harbor porpoise (Phocoena phocoena): has a wide distribution, occupying some regions in America, Europe and Asia. They are generally found in shallow coastal waters, estuaries, and certain channels. It is considered in the category of least concern.
• Vaquita (Phocoena sinus): this species of porpoise is endemic to Mexico and inhabits shallow and generally turbid marine waters. It is classified in critical danger of extinction.
• Spectacled porpoise (Phocoena dioptrica): found in cold, temperate and sub-antarctic waters of the southern hemisphere, with sightings in countries such as Argentina, Australia, Brazil, Chile, Uruguay, among others. It is considered in the category of least concern. They have noticeably stark markings with black on their top and white underneath.
• Burmeister's porpoise (Phocoena spinipinnis): its distribution range occupies Argentina, Brazil, Chile, Peru and Uruguay. It lives in shallow and coastal marine waters, but also in channels, algae areas and is capable of submerging up to a depth of 1000 m. It is considered in the category of near threatened.

Genus Phocoenoides:

This genus groups a single species of porpoise:

• Dall's porpoise (Phocoenoides dalli): is distributed mainly in the northern Pacific Ocean, occupying countries such as Canada, Japan, Republic of Korea, Mexico, Russia and the United States. This species has deep marine waters as its habitat, which have cold temperatures below 18 ºC. It is classified as of least concern.

Although porpoises are different animals to dolphins, they are related. To learn more check out our article on 10 fun facts about dolphins.

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