How to distinguish the baiji, finless porpoise and Chinese white dolphin: look at its kiss and dorsal fin.

White dolphin, dark in body color, with dorsal fin near the back and lip about 30 cm long. Photo courtesy of Wuhan Baidolphin Protection Foundation

Recently, the China Biodiversity Conservation and Green Development Foundation (hereinafter referred to as the "Green Development Association") baiji expedition team reported that two suspected baiji dolphins were found in Wuhu section of the Yangtze River, and released related videos. The news that the baiji dolphin, which has been declared functionally extinct for ten years, reappears in the Yangtze River is all exciting.

Regrettably, some experts later judged according to the video that the expedition team photographed the finless porpoise instead of the baiji.

Finless porpoise, with dark body color, no dorsal fin and short lips. Photo courtesy of Wuhan Baidolphin Protection Foundation

At 8 o’clock in the morning on the 16th, Weibo, the official of the Green Development Association, sent a message again, saying that some experts believed that "the scientific research team may be able to see the target by combining various factors, but it is not very sure to take a large enough and clear photo".

The relevant staff of the Green Hair Association later told The Paper (www.thepaper.cn) that the experts who participated in the research and judgment of related videos have not yet given the final judgment, and it is not yet certain that the expedition team photographed the baiji.

How to distinguish white dolphin, finless porpoise and Chinese white dolphin? What are their respective characteristics? 

It is relatively easy to distinguish them from each other by the length of kisses.. On May 16th, an aquatic expert from Wuhan Baiji Dolphin Protection Foundation introduced to The Paper that the kiss of Baiji Dolphin was very obvious. The kiss length of adult baiji dolphins is generally about 30 cm, while that of Chinese white dolphins is generally less than 20 cm. The finless porpoise’s kiss is shorter and easier to identify.

Body color is also the key factor to distinguish them.The white dolphin’s body color has not changed much in its life, and its back is bluish gray and its abdomen is white. However, the body color of Chinese white dolphins changes obviously, and the back of their larvae is dark gray. When they grow up, the black gray on the back will gradually fade away, showing dark gray spots, and the background color will be bluish white. In adulthood, it will mainly be white, and with the change of water temperature, it will show different degrees of pink, while the abdomen will always be white. The finless porpoise is basically black and gray, and the color is the deepest among the three.

In addition, the dorsal fin of the baiji dolphin is closer to the back of the body and shorter; The dorsal fin of Chinese white dolphin is higher and closer to the middle of the back; The finless porpoise has no dorsal fin.

"The white dolphin lives in the Yangtze River. Because the water is turbid and its vision has basically deteriorated, its eyes are very small, as big as small mung beans; The Chinese white dolphins live in the sea, their eyesight is quite good, and their eyes are much bigger. " The expert said, "And from the perspective of posture, the white dolphin is more elegant and the Chinese white dolphin is stronger."

Ten years ago, the baiji dolphin was declared "functional extinction", which means that this large animal, which was once at the top of the energy pyramid and food chain of the Yangtze River ecosystem, has lost its position and function in the Yangtze River ecosystem and lost its ability to reproduce itself.

The living conditions of finless porpoises and Chinese white dolphins are also in jeopardy. On May 9th, the symposium on upgrading Yangtze finless porpoise to national first-class protected animals was held. The related technical report compiled by Institute of Aquatic Sciences of Chinese Academy of Sciences showed that the protection of Yangtze finless porpoise has entered the most critical period, and it may be the last chance to save the population at present.

Chinese white dolphin, the body color becomes lighter with age, the dorsal fin is higher near the middle, and the lip is shorter. Photo courtesy of Wuhan Baidolphin Protection Foundation

As one of the only two cetaceans in the list of national key protected wild animals (the other is the baiji), the news of Chinese white dolphin’s death has been exposed continuously since this year, and it has even been captured by fishermen and slaughtered in the street.

(Thanks to the World Conservation Union (IUCN) for its written materials and some pictures, and thanks to the Wuhan Baiju Dolphin Conservation Foundation for providing some pictures.)

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White dolphin

English name: Yangtze River Dolphin

Latin name: Lipotes vexillifer

Quantity: It has not been found since 2000.

Mammalia, Cetacea, Freshwater Dolphinidae and Baiji, also known as "aquatic pandas", are endemic to China. The national first-class protected animals are listed as "CR" in the Red List of IUCN Endangered Species. The body is spindle-shaped, the whole body skin is bare and hairless, with a long kiss. Mainly distributed in the middle and lower reaches of the Yangtze River, feeding on a variety of fish and other species. Due to the development of water conservancy projects, the habitat of Baiji dolphin has been lost or degraded, and the Baiji dolphin has not been found since 2000 due to ship traffic, accidental fishing and port construction.

The chinese white dolphin – sousa chinensis

English name: Indo-Pacific Humpbacked Dolphin

Latin name: Sousa chinensis

Quantity: about 1200-1300.

Mammals, Cetaceans, Dolphins, Dolphins. The national first-class protected animals are listed as "NT" by the IUCN Red List of Endangered Species. Chinese white dolphins are slender and spindle-shaped, with long and narrow beaks, which generally fade from primary dark gray to adult pink. Mainly distributed in the Indian Ocean, the east coast of India, China and Australia. In China, it is mainly distributed in the southeast coast, inhabiting the waters of continental shelf, and the water depth is less than 100m m. The population of Chinese white dolphins is still decreasing due to the loss of habitat and accidental catching of other fish.

Yangtze finless porpoise

English name: Yangtze Finless Porpoise

Latin name: neophocaena phocaenoides asiae orientalis

Quantity: 1000-1800

Mammalia, Cetaceae, porpoises and finless porpoises, commonly known as porpoises, are the only freshwater subspecies of finless porpoises endemic to China. The national second-class protected animals are listed as "VU" by the IUCN Red List of Endangered Species. Small size, blunt head, forehead bulge slightly forward; The snout is short and wide, the upper and lower jaws are almost the same length, the snout is short and wide, and the whole body is leaden or grayish white, which looks like a dolphin. The Yangtze finless porpoise is a unique freshwater dolphin, which is only found in the Yangtze River basin. Their intelligence level is similar to that of gorillas, and they generally lack dorsal fins. They eat fish and shrimp, but the ecological damage caused by overfishing makes it difficult for finless porpoises to find food. In some parts of the Yangtze River, the food chain of finless porpoises has been broken.

About IUCN and Red List of Endangered Species;

Founded in 1948, the International Union for Conservation of Nature (IUCN) provides relevant data, evaluation and analysis for the global nature conservation work, and provides knowledge and technical support to the public, non-governmental organizations and the private sector.

The Red List of Endangered Species was compiled in 1963 by the Species Survival Committee (SSC) in cooperation with several species assessment agencies. Assess the extinction risk of thousands of species every year and classify them into nine different protection levels. This directory collects information on threats, ecological needs, where to live, and protection actions to reduce or avoid species extinction, which has been widely accepted and applied around the world.

About Wuhan Baidolphin Conservation Foundation:

Wuhan Baiji Conservation Foundation (WBCF) was established on December 25th, 1996, and it is the first public fund for the protection of finless porpoises and their habitats in China.

Since 1997, the Foundation has participated in and supported all the large-scale finless porpoises’ investigation activities in 2006 and 2012, and promoted the protection projects of important habitats of finless porpoises, including Poyang Lake and Dongting Lake. At the same time, the Foundation strongly supports the participation in the ex-situ conservation project of the Yangtze finless porpoise in Tianezhou and Hewangmiao (integration embankment), laying the foundation for the Yangtze finless porpoise conservation project.