Porpoises are a unique type of cetacean that are in the family Phocoenidae. Porpoises are generally small animals (no species grows longer than about 8 feet) with robust bodies, blunt snouts and spade-shaped teeth. Having spade-shaped teeth is a characteristic that makes them different from dolphins, who have cone-shaped teeth, and generally are larger and have longer, more tapered snouts. Like dolphins, porpoises are toothed whales (odonotocetes).
Most porpoises are shy, and many species are not well-known. Many references list 6 porpoise species, but the following species list is based on the species list of 7 porpoise species developed by the Society for Marine Mammalogy's taxonomy committee.
The harbor porpoise (Phocoena phocoena) is also called the common porpoise. This is probably one of the most well-known porpoise species. Like other porpoise species, harbor porpoises have a stocky body and blunt snout. They are a small cetacean that grows to about 4-6 feet long and can weigh 110-130 pounds. Female harbor porpoises are larger than males.
Harbor porpoises have a dark gray coloration on their back and a white underside, with mottled flanks. They have a stripe that runs from their mouth to the flippers, and a small, triangular dorsal fin.
These porpoises are fairly widely distributed, and live in cold waters in the North Pacific and North Atlantic Oceans and the Black Sea. Harbor porpoises are generally found in small groups in both inshore and offshore waters.
The vaquita, or Gulf of California harbor porpoise (Phocoena sinus) is the smallest cetacean, and one of the most endangered. These porpoises have a very small range - they live only in inshore waters off the northern end of the Gulf of California, off the Baja Peninsula in Mexico. It is estimated there are only about 250 of these porpoises in existence.
Vaquitas grow to about 4-5 feet in length and 65-120 pounds in weight. They have a dark gray back and lighter gray underside, black ring around their eye, and black lips and chin. As they grow older, they lighten in color. They are a shy species that may stay underwater for a long time, making sightings of this small toothed whale even more difficult.
The Dall's porpoise (Phocoenoides dalli) is the speedster of the porpoise world. It is one of the fastest cetaceans - in fact, it swims so quickly that it creates a "rooster tail" as it swims in speeds up to 30 mph.
Unlike most porpoise species, Dall's porpoises may be found in large groups that have been seen in the thousands. They may also be found with other whale species, including white-sided dolphins, pilot whales and baleen whales.
Dall's porpoises have a striking coloration made up of a dark gray to black body with white patches. They also have white pigmentation on their tail and dorsal fin. These fairly large porpoises can grow to 7-8 feet in length. They are found in warm temperate to subarctic, deep waters of the Pacific Ocean, from the Bering Sea to Baja California Mexico.
Burmeister's porpoise (Phocoena spinipinnis) is also known as the black porpoise. Its name came from Hermann Burmeister, who described the species in the 1860's.
The Burmeister's porpoise is another species that is not very well-known, but they are thought to grow to a maximum length of 6.5 feet and weight of 187 pounds. Their back is brownish-gray to dark gray, and they have a light underside, and a dark gray stripe that runs from their chin to the flipper, which is wider on the left side. Their dorsal fin is set far back on their body and has small tubercles (hard bumps) on its leading edge.
Burmeister's porpoises are found off eastern and western South America.
The spectacled porpoise (Phocoena dioptrica) is not well known. Much of what is known about this species is from stranded animals, many which have been found on the southern tip of South America.
The spectacled porpoise has distinctive coloration that deepens with age. Juveniles have light gray backs and light gray undersides, while adults have white undersides and black backs. Their name comes from the dark circle around their eye, which is surrounded by white.
Not much is known about the behavior, growth or reproduction of this species, but they are thought to grow to about 6 feet in length and about 250 pounds in weight.
6. Indo-Pacific Finless Porpoise
The Indo-Pacific finless porpoise (Neophocaena phocaenoides) was originally called the finless porpoise. This species was divided into two species (the Indo-Pacific finless porpoise and narrow-ridged finless porpoise fairly recently when it was discovered that the two species are incapable of breeding. This species appears to be more wide-ranging and live in more tropical waters than the narrow-ridged finless porpoise.
These porpoises live in shallow, coastal waters in the northern Indian, and western Pacific Oceans (click here to see a range map).
Indo-Pacific finless porpoises have a ridge on their back, rather than a dorsal fin. This ridge is covered with small, hard bumps called tubercles. They are dark gray to gray with a lighter underside. They grow to a maximum of about 6.5 feet in length and 220 pounds in weight.
7. Narrow-Ridged Finless Porpoise
The narrow-ridged finless porpoise (Neophocaena asiaeorientalis) is thought to have two subspecies:
- Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis), which is thought to live only in fresh water, and is found in the Yangtze River, Poyang and Dongting lakes and their tributaries, the Gan Jiang and the Xiang Jiang Rivers.
- East Asian finless porpoise (Neophocaena asiaeorientalis sunameri ) which lives in coastal waters off Taiwan, China, Korea and Japan
This porpoise has a ridge on its back rather than a dorsal fin, and like the ridge of the Indo-Pacific finless porpoise, it is covered with tubercles (small, hard bumps). It is a darker gray than the Indo-Pacific finless porpoise.