The identification guide doesn't say much about them, it does mention they do look similar to Diamond sturgeon. They should have 29 gill rakers and 44 dorsal fin rays, but this is quite difficult to determine. Also, they should have the barbels located close to the mouth. Judging from the area they could very well be Yangtze sturgeon (Acipenser dabryanus), or possibly Diamond sturgeon but they do look a bit different to me than the Diamonds I'm used to seeing.