Yangtze cowfish, an endangered subspecies of the finless porpoise in the Yangtze River, is found dead alongside the bank of the Dongting Lake, northeastern Hunan province, China. The number of cowfish is declining by 6.3 percent on average each year, and its present population is around 1,000 in China. [Photo/Xinhua]

The number of cowfish is declining by 6.3 percent on average each year, and its present population is around 1,000 in China. [Photo/Xinhua]

The number of cowfish is declining by 6.3 percent on average each year, and its present population is around 1,000 in China. [Photo/Xinhua]

A pregnant Yangtze cowfish, an endangered subspecies of the finless porpoise in the Yangtze River, is found dead alongside the bank of the Dongting Lake, northeastern Hunan province, China. The number of cowfish is declining by 6.3 percent on average each year, and its present population is around 1,000 in China. [Photo/Xinhua]

The number of cowfish is declining by 6.3 percent on average each year, and its present population is around 1,000 in China. [Photo/Xinhua]

Experts dissect a Yangtze cowfish to do the research. The number of cowfish is declining by 6.3 percent on average each year, and its present population is around 1,000 in China. [Photo/Xinhua]

Yangtze cowfish, an endangered subspecies of the finless porpoise in the Yangtze River, is found dead in Yueyang, Hunan province, China. The number of cowfish is declining by 6.3 percent on average each year, and its present population is around 1,000 in China. [Photo/Xinhua]

A dead Yangtze cowfish is still smelling. The number of cowfish is declining by 6.3 percent on average each year, and its present population is around 1,000 in China. [Photo/Xinhua]