![]() ![]() 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. Oremus said the Solomon Island hunters understand the risk of exploiting the population.Differences - Similarities - Dolphin versus Porpoise comparison chart ![]() “The teeth and meat are also sold for cash.” “The main objective of the hunt is to obtain dolphin teeth that are used in wedding ceremonies,” Oremus said. The hunters maneuver the canoes into a U-shape around the dolphins, using sound as an acoustic barrier to drive them toward shore where they are killed. When dolphins are found, the hunters used rounded stones to create a clapping sound underwater. In drive-hunting, the hunters operate in close coordination from 20 to 30 traditional canoes. During the first three months of that year, villagers killed more than 1,500 spotted dolphins, 159 spinner dolphins, and 15 bottlenose dolphins. Oremus and co-author John Leqata, a research officer with the Ministry of Fisheries and Marine Resources, visited Fanalei in March of 2013 to document the impact on the population, and examine detailed records of the kills. ![]() » It is also troubling that teeth are increasing in cash value, apparently creating a commercial incentive for hunting dolphins,” Baker said. “In other parts of the world, however, the targeting of dolphins and other small cetaceans appears to be increasing as coastal fishing stocks decline. “In the Solomon Islands, the hunting is as much about culture as economic value,” said Scott Baker, associate director of the Marine Mammal Institute at Oregon State University and co-author on the study. Dolphin Habitat and Environmental Threatsįrom 1976 to 2013, more than 15,000 dolphins were killed by villagers in Fanalei alone, where a single dolphin tooth can fetch the equivalent of 70 cents - an increase in value of five times just in the last decade. ![]()
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