The Bajji (Lipotes vexillifer) was a freshwater dolphin found only in the Yangtze River in China. The Baiji population declined drastically in recent decades as China industrialized and made heavy use of the river for fishing, transportation, and hydroelectricity
The Baiji weighs 135 - 230 kg .Its length is up to 2.5 m in females and 2.3 m in males.
They are found in freshwater rivers and lakes. They usually live in the deeper sections, swimming to shallow water only to catch small fish.
6 years - females;
Approximately 4 years - males
10 - 11 months.
Normally breeds and gives birth in the first half of the year. The peak season appears to be February to April.
The inter birth interval is 2 years. There is a single young at birth.
Any available species of freshwater fish is eaten. The only selection criterion appears to be
Size must be smaller than 6.5 cm (2.5") in width. Both surface- and bottom-feeders are taken as prey.
Feeding activity is primarily diurnal. At night the baiji often rests in areas of very slow current. Baijis surface without splashing and breathe smoothly. Short breathing intervals of 10 - 30 sec alternate with a longer one of up to 200 sec.
Baijis generally live in small groups of 3 - 4 animals, which may come together to make up a larger social unit of 9 - 16 dolphins. A group may congregate in the quiet area of an eddy for 5 - 6 hours.
For More Information: http://www.animalinfo.org/rarest.htm