The amur ide, a fish species endemic to China's saline Dali Nur lake, is battling for survival as it undertakes its annual spawning migration upstream to find a habitable water for laying eggs.
Vast shoals of the small freshwater fish crowd together fighting their way against the flow on a perilous journey of up to 60 kilometers to spawn in the Gonggeer River, which is in the upper reaches of Dalai Nur.
Where there is an obstacle, the amur ide will jump up to half meter out of the water.
"The water in Dalai Nur has a much higher salinity and alkalinity compared with regular river water. And we found that the fish egg envelopes will soon shrink inside the lake water because of this hypertonic environment, and then there will be some developmental abnormalities like malformation. So in general, river water is critical for Amul ide fish -- it has to go into the river to breed," said Wang Ruifang, a professor of aquaculture at Inner Mongolia Agriculture University.
The fish migration also aids exhausted migratory birds that rely on them for nutrients after long flights, aguaculture experts say.
For the amur ide, this year's migration season lasts around a month and is nearing its end, according to local authorities. Efforts have been made by local environmental authorities to dredge rivers to ease their passage.
Amur ide embarks on perilous journey upstream for reproduction
