The Indo-Pacific finless porpoise (Neophocaena phocaenoides) is an aquatic marine mammal found throughout most of the Indian Ocean, as well as the tropical and subtropical Pacific from Indonesia north to the Taiwan Strait. Finless porpoises are the only porpoises to lack a true dorsal fin. Although similar in appearance to dolphins, porpoises are more closely related to narwhals and belugas than to the true dolphins.
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DiurnalDiurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
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CarnivoreA carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of a...
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PiscivoresA piscivore is a carnivorous animal that eats primarily fish. Piscivorous is equivalent to the Greek-derived word ichthyophagous. Fish were the die...
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MolluscivoreA molluscivore is a carnivorous animal that specializes in feeding on molluscs such as gastropods, bivalves, brachiopods, and cephalopods. Known mo...
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AquaticAn aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract ...
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PrecocialPrecocial species are those in which the young are relatively mature and mobile from the moment of birth or hatching. Precocial species are normall...
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PredatorPredators are animals that kill and eat other organisms, their prey. Predators may actively search for or pursue prey or wait for it, often conceal...
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NatatorialNatatorial animals are those adapted for swimming. Some fish use their pectoral fins as the primary means of locomotion, sometimes termed labriform...
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ViviparousAmong animals, viviparity is the development of the embryo inside the body of the parent. The term 'viviparity' and its adjective form 'viviparous'...
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CongregatoryCongregatory animals tend to gather in large numbers in specific areas as breeding colonies, for feeding, or for resting.
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PolygynyPolygyny is a mating system in which one male lives and mates with multiple females but each female only mates with a single male.
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Generally solitaryGenerally solitary animals are those animals that spend their time separately but will gather at foraging areas or sleep in the same location or sh...
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Not a migrantAnimals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
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starts withThe flippers of this porpoise are moderately large, reaching up to 20% of the total body length. Adults are typically a uniform, light grey colour, although some may have lighter patches of skin around the mouth or darker patches in front of the flippers. Newborn calves of the central and eastern subspecies are mostly black with grey around the dorsal ridge area, becoming fully grey after four to six months. However, newborn calves of the western subspecies are a light creamy grey and become darker as they age.
Indo-Pacific finless porpoises live in the coastal waters of Asia, especially around Indonesia, Malaysia, India, and Bangladesh. At the western end, their range includes the length of the western coast of India and continues up into the Persian Gulf. On the eastern edge of their range, they are found throughout the Indonesian archipelago and range north to the Taiwan Strait. Finless porpoises are also one of the species protected at Sundarbans National Park. They inhabit estuaries, shallow bays, mangroves, and rivers. They prefer waters with a sandy or soft bottom.
Indo-Pacific finless porpoises are diurnal. They spend their time singly or as a mother/calf pair or two adults, and in schools of 3 or more individuals. They are not as energetic and showy as dolphins. They do not ride bow waves, and in some areas appear to be shy of boats. Although they don't make acrobatics in the water, finless porpoises are believed to be very active swimmers. They typically swim just beneath the surface of the water and roll to one side when surfacing to breathe. This rolling movement disturbs very little water on the surface, so they are often overlooked when rising to breathe. Surfacing generally lasts for one minute, as they take 3 to 4 quick successive breaths, then quickly submerge into the water. They often surface a great distance from the point where they dive beneath the water's surface. Dives lasting over 4 minutes have been recorded, and a common pattern of behavior is to take one long dive, followed by two shorter ones. Finless porpoises make both high-frequency clicking sounds and longer, low-frequency tones, the latter perhaps being for communication, rather than echolocation. The clicks are narrow-band, with peaks of over 100 kHz.
Indo-Pacific finless porpoises are carnivores (piscivores, molluscivores) and eat fish, crustaceans, and cephalopods. They also consume some plant material, including leaves, rice, and eggs deposited on vegetation.
Finless porpoises are polygynous, which means that one male mates with multiple females. They breed in late spring and early summer. The young are born in spring, summer, or winter, depending on the geographic locality, after a gestation period of 10 to 11 months. Newborn finless porpoises are reported to be 72 to 84 cm (28 to 33 in) in length. It has been claimed that young calves cling to the denticulated area of skin on their mother's back and are carried by her as she swims, but there is no clear evidence of this happening. Calves are weaned when they are 6-15 months old. Young males become reproductively mature at 4 to 6 years of age, and females at 6 to 9 years.
Large numbers of Indo-Pacific finless porpoises are killed by entanglement in gill nets. The other big danger to the species is environmental degradation. They also suffer from hunting, human disturbance, live capture for display, collisions with boats, and noise and chemical pollution.
The IUCN Red List and other sources don’t provide the number of the Indi-Pacific finless porpoise total population size. Currently, this species is classified as Vulnerable (VU) on the IUCN Red List and its numbers today are decreasing.