Most
Macrognathus species attain in length, but a few surpass this size, with the largest being
M. aral at up to .
Macrognathus are mostly similar to
Mastacembelus. However, they differ in a more modified
rostrum, which may be slightly to significantly larger and longer than those found in
Mastacembelus. This serves not only to find food but also to help gather food. ==In the aquarium==