Sousa teuszii
Atlantic humpbacked dolphin

Sousa teuszii resides in Atlantic waters off the coast of Western Africa. The Atlantic humpback dolphin's range extends from Mauritania south to Angola. This range is the primary distinction between Sousa teuszii and its sister species Sousa chinensis, which is found in the Indian and Pacific oceans. (Evans 1987, Herman 1980, Nowak 1997)

Sousa teuszii lives in tropical waters close to the West African shorline. It is believed that they do not venture more than one or two kilometers away from the shore in an effort to avoid killer whale (/Orca orcinus/) predation. Killler whales attempt to find Sousa teuszii through echolocation and it is thought by some that, by remaining close to shore, Sousa teuszii remains relatively safe because land disrupts the echolocating abilities of the killer whale. When predators do near, the Atlantic humpack dolphin will seek refuge in reefs. Those dolphins that do move over deeper waters do so over sandy ocean floors. (Evans 1987, Herman 1980, Nowak 1997)

Due to the volatile political atmosphere in Angola and other parts of Western Africa, zoologists have not had much of an opportunity to thoroughly examine Sousa teuszii. Because of this many characteristics of the dolphin, such as mass, are based on few studied individuals.

The length of the Atlantic humpback dolphin is 120 cm to 250 cm

from head to fluke. There is no known sexual dimorphism. The humpback dolphin is known for its unusual dorsal fin. At approximately 15 cm in height, the dorsal fin is curved, as it is in most dolphins, however, instead of coming back directly to the dolphins back-side, the fin projects upward once again to create a "hump" behind the fin. A second, smaller hump, exists on the dorsal side just prior to the fluke. Sousa teuszii's pectoral fins are under 30 cm in length, and their flukes have a width of approximately 45 cm.

The coloration of Sousa teuszii darkens as individuals age. Younger dolphins are a light cream color, and as they get older, they become more gray.

Atlantic humpbacked dophins have 26 to 31 pairs of homodont, peg-like teeth in each jaw. They also have fewer vertebrae than their sister species. Tooth count and vertebrae, along with geographical location, are the major distinguishing characteristics between Sousa teuszii and Sousa chinensis. (Evans 1987, Herman 1980, Nowak 1997)

Sousa teuszii is a fairly solitary species, individuals often travel and feed alone. Groups are usually small, ranging in size from 2 to 10 dolphins. These dolphins are more likely to travel in groups when young and, as they get older, they then adopt a more solitary lifestyle.

Sousa teuszii is known to be slower than other Delphinidae. They may stay underwater for as much as three minutes, and when they do surface, they breathe while rolling. The Atlantic humpback dolphin is capable of jumping 120 cm out of the water.

The Atlantic humpback dolphin has some intriguing behavior characteristics that are common to most Delphinidae. Among these characteristics is the fact that their brain to body mass ratio is higher than most other mammals, which some biologists suggest provides a prediction of intelligence. Sousa teuszii uses echolocation for sensory purposes. It does not rely on its sense of smell, for this sense has been lost in Delphinidae. (Evans 1987, Herman 1980, Heyning 1995, Nowak 1997)

Atlantic humpback dolphins feed independently or in small groups. Their diet consists of fish such as sardines and mullet which they herd towards land. By herding their prey close to land, they create a situation in which there is little opportunity for escape. They may also feed upon some small crustaceans. (Evans 1987, Herman 1980, Nowak 1997)

Sousa teuszii can be a competitor with humans for fish along the shores of West Africa (Evans 1987).

Atlantic humpback dolphins are used by people in Mauritania as an aid in netting fish (see Conservation section) (Evans 1987).

Currently, not enough is known about Atlantic humpback dolphin populations to determine threats to this species.

While Sousa teuszii must compete for food with humans, and occasionally get stuck in fish nets, they are a quintessential example of co-operative living among humans and animals. As stated earlier, the Atlantic humpback dolphin herds fish towards shorelines. This is beneficial to humans who wish to catch fish. A level of co-operation has developed in Mauritania where fisherman beat upon the water with sticks. Dolphins cue to this signal and begin their herding process. Fisherman are then able to capture the herded fish. While the fish are in the nets the dolphins are able to eat freely. This co-operative feeding is an example of how animals may be thought of as a partner to humans; a manner of thinking which, if accepted by more people, may lead to the conservation of many more species. (Evans 1987, Nowak 1997, Simmonds 1996)

The taxonomy of Sousa teuszii is still a matter of some uncertainty. Some biologists believe it is a subspecies of Sousa chinensis. (Nowak 1997)