I cannot identify one species, if you have any idea, please, answer. The host of this species is Ameiurus melas and Ameiurus (Ictalurus) nebulosus. The hooks are not visible, because they are in the body. I am going to dissect this example to see how look the hooks inside.
This guide (see attached file) mentions the hosts of described species of Acanthocephala. In addition, other documents indicate the presence of Leptorhynchoides thecatus on Ameiurus melas.