What's the difference between a small mouth cow and a big mouth cow?

1, the appearance is different: the starting point of dorsal fin on the back of small mouth cattle is particularly convex, dark brown or gray, while the head of big mouth cattle is large and wide, and the snout is blunt and round, grayish brown or light brown.

2. Different sizes: the adult fish with a small mouth is1.2m long and weighs 30kg, while the adult fish with a large mouth is 2.4m long and weighs 84kg..