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Common Name:
Baiji or whitefin dolphin
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Palearctic. Baijis are found in China in the mouth of the Chang Jiang(Yangtze) to a point about 1900 km up the river, as well as in the middle and lower regions of the Quintangjiang River. |
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Mass: 135 to 230 kg The coloration of the Lipotes vexillifer is pale blue-grey in the dorsal region and white ventrally. Baiji have long, beaklike snouts that are upward-curving. There are 32-36 teeth per side of both the upper and lower jaws. The rostrum is bowed slightly upward and the eyes are situated high on the head. Lipotes vexillifer lacks hairs on the snout and has a blowhole that is longitudinal and elliptic. Baiji also have no fore-stomach but a three-compartment main stomach and the absence of a caecum. Furthermore, these creatures lack a maxillary crest and contact between the palatal portion of the maxillas. |
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Lipotes vexillifer's diet consists of mainly, if not entirely, fish. They use their long beaks to probe muddy bottoms for food. Their dives are short, lasting only 10-20 seconds. Baiji have poor eyesight but use a highly developed echolocation faculty to find food. These creatures seek food in the shallow water near sandbanks or close to the mouth of tributaries of the river. |
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Little is known about the reproductive activities of the Baiji. Ovulation in females is periodic and sperm density in males varies seasonally. The mating season peaks twice a year, in spring and in autumn. The gestation period estimates range from 6 to 12 months. They have 1 young per birth. Mothers carry their calves close to the left or right side of their bodies while swimming, diving, and coming up to breathe. Lipotes vexillifer reaches sexual maturity at 3-4 years of age and lives to be aproximately 25 years old. |
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Whitefin dolphins are usually found in pairs within a larger social unit of about 10 individuals. |
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Status: endangered. Lipotes vexillifer is probably the most endangered of all cetaceans. The total population is estimated at between 60 and 250 animals!!! It is the rarest whale in the world. There are three major factors that threaten Baiji survival: dams and floodgates that block fish migration in the river's tributaries and lakes, fisheries accidentally hooking dolphins, and boat propellers. Population numbers also declined through hunting and development of irrigation facilities. The heavy pollution and underwater noise characteristic of the Yangtze also affects the Baiji. These stresses, as well as lack of food, can inhibit reproduction. They are also killed by explosives used in fishing. Six baijis were killed by a single explosion meant to clear reefs near the city of Yaohu. China began providing legal protection in 1975, but this has not eliminated the accidental killing and the consequences of industrial development. The efforts to work on baiji preservation are urgent. Many programs are also being established to breed Lipotes vexillifer in captivity. Some captive breeding methods include artificial insemination and exogenous induction of ovulation. If you want to read an article about the Baiji's Conservation click here=) |
