Porpoise Facts

Porpoises are marine mammals and make up part of the cetacean species which also include dolphins and whales.

They are the smallest of the cetaceans growing between 5 – 8 ft. in length and weighing between 100 – 200 lbs. on average although it is possible for some porpoises to weigh in excess of 400 lbs.

Although they are able to dive deep (over 650 ft.) they usually stay at or near the surface of the water.

Porpoises can reach speeds in excess of 30 miles per hour.

They have a short lifespan when compared to other cetaceans and only live till around 10 – 20 years of age on average.

There are currently about 6 species of porpoises in existence today.


Porpoises hunt for food and navigate the ocean using echolocation.

They survive on a diet primarily consist of fish, squid, and crustaceans.

While porpoises are predators they prefer to hunt in shallow coastal waters and usually hunt for food near or at the surface of the water.

Due to the porpoises small size it requires frequent eating in order to maintain its energy and body heat as compared to some of the larger cetacean species that can reserve large amounts of energy which they store in their fat/blubber.

Physical Characteristics

Porpoises have a shorter, stockier build than dolphins and appear to have a rotund shape.

They have a small triangular-shaped dorsal fin.

The head is rounded and the neck is short and immobile.

Their mouths are short with spade shaped teeth.

Species such as the harbor porpoise have dark gray or dark brown coloring with a white belly.

Social Structure

Unlike some dolphin species, porpoises are typically shy and tend to avoid interacting with humans or boats.

They usually prefer to live in small groups of 10 or less but can grow to 25 or more during times of feeding or travel.

Porpoises aren’t nearly as energetic as dolphins and prefer to be more reserved when it comes to things such as leaping and jumping.

Due to the fact that porpoises stay to themselves it is hard for scientists to develop significant research on the topic of porpoises and their social structure.


Most female porpoises have offspring once every 1 - 3 years.

The average gestation period for a porpoise (the period between conception and birth) is about 10 – 11 months.

Porpoises usually mature between the ages of 3 – 5 and rarely live past 20.

10 Spectacular porpoise facts

  1. There are currently six known species of porpoise which include Burmeister’s porpoise, Dall’s porpoise, the Finless porpoise, the Harbor porpoise, the Spectacled porpoise and the Vaquita.
  2. Porpoises are marine mammals which means they are warm-blooded, give birth to live young, breathe air and produce milk to feed their children.
  3. These marine mammals are equipped with echolocation which allows them to navigate the ocean and search for food; even in complete darkness.
  4. The porpoise species makes up six of around eighty known species of cetacea. As stated earlier cetaceans include all species of whale, dolphin and porpoise.
  5. Porpoise are known to face threats from natural predators such as killer whales and sharks.
  6. These marine mammals (along with all cetacean) are a protected species and hunting them in certain countries is considered illegal and can lead to steep fines and jail time.
  7. Dall’s porpoise has been recorded swimming at speeds in excess of 32 mph making it one of the fastest known cetaceans in existence.
  8. The most popular and well-known species of porpoise is the harbor porpoise as they are abundant and often found swimming near the harbor and in coastal waters.
  9. The smallest species of porpoise is the Vaquita porpoise which measures in at around 5 ft. long. It is also one of the rarest species of known cetacea.
  10. Porpoises are extremely intelligent and are able to learn how to perform various tricks and complete specific tasks when taught by a trainer.