They are among the few species in the world that can identify themselves in a mirror. They have large, complex brains and are self-aware like humans. Porpoises can act in a coordinated fashion even when they are hundreds of feet apart, using echolocation for finding prey and staying together in a pod, but do not use it to communicate as often as dolphins do.ĭolphins and porpoises are highly intelligent. Their grouping behavior does not result in stable associations, but ephemeral relationships that change as individuals join or leave.

Porpoises are relatively shy and are seen alone or in groups containing a few individuals. Dolphins coordinate hunts and communicate for other reasons by combining whistles, clicks, and ultrasonic sounds. Where food is abundant, 'superpods' exceeding 1,000 dolphins have been observed. Social Behavior of Dolphins and Porpoisesĭolphins tend to live in pods, or groups, of up to a dozen individuals. Gestation periods are very similar, between 7 and 12 months, with 1-2 calves born, though most often only one. Pair bonding is more frequently observed in dolphins, often for life. Mating seasons for both species tend to be short, with dominant males having multiple mates. Males of both species have two genital openings on their ventral side, while females have four: two for their sex organs and two for lactation, with teats found inside the body. Vocalizations are more extensive and frequent with dolphins, and can travel longer distances than those recorded for porpoises. Neither dolphins nor porpoises rely much on their sense of smell. The small external ear opening is about two inches behind the eye in both animals.

This dorsal fin, along with the tail flukes, is made of collagen, a fibrous connective tissue similar to cartilage.īoth dolphins and porpoises use echolocation for navigating underwater, finding food, avoiding predators, and communicating with other members of their species. Click to enlarge.īeyond the pectoral fins, the dorsal, or back, fin provides stability as the dolphin and porpoise move quickly through water (up to 25 mph). The flippers on dolphins and porpoises contain finger-like digits. Scientists theorize that these bones come from dolphins' and porpoises' land-dwelling ancestors some 50 million years ago. These fins actually contain the same number of bones as a human arm and end in five digits that are structured similarly to fingers. Of the three types of fins found on dolphins and porpoises, only the pectoral fins (flippers), which are used for stopping and steering underwater, contain bones. Dolphins and porpoises even have hair, but nearly all of it is lost shortly after birth. And, like almost all mammals, they give live birth to their young and nurse their offspring. On average, porpoises, which are more darkly-colored than dolphins, are between 5 and 8 feet long.īoth species breathe air from blowholes at the top of their head. The orca, or killer 'whale,' which is actually a dolphin, genetically, can be up to 35 feet long, for example, and the Hector's dolphin of New Zealand is sometimes smaller than 4 feet. Up close, one can distinguish the two by their teeth: dolphins have cone-shaped teeth, but porpoises have flat or spade-shaped teeth.ĭolphins and porpoises vary in size, with dolphins generally being the larger of the two animals. Dolphins usually have a “beak” that makes them appear 'long-nosed,' while porpoises do not have a beak and thus appear more 'flat-faced.' The dorsal fins on dolphins are usually curved or hooked, while those on porpoises are more triangular in shape. Externally, one can tell the difference between the two animals by looking at the head and dorsal fins. The primary differences between dolphins and porpoises are anatomical. Porpoises have small, rounded heads and blunt jaws instead of beaks. Porpoises are only found in the Pacific OceanĪ porpoise's dorsal fin is generally triangular, somewhat like sharks.ĭolphins have a round, bulbous 'melon' in the head and elongated jaws that often form a distinct beak. Porpoises are marine mammals related to whales and dolphins. Porpoises have flattened, spade-shaped teeth.ĭolphins are marine mammals closely related to whales and porpoises. Porpoises are usually smaller (1.5 - 2.5 m) but stouter than dolphins. Differences - Similarities - Dolphin versus Porpoise comparison chart

Dolphin fish vs.dolphin