Charge conjugation, particle <-> antiparticle, reverses electric charge. To be consistent, the electromagnetic field must reverse sign. But aside from that, it stays the same as before.
Elementary fermions have antiparticles that are distinct from them. Their main bound states are mesons (quark-antiquark) and baryons (quark-quark-quark). Baryons have separate antibaryons, but mesons can be their own antiparticles. They will be that if they are flavor-neutral: flavor-antiflavor.
A neutral pion is ((up,antiup) - (down,antidown))/sqrt(2)
a mixed state
An eta meson is a mixture of ((up,antiup) + (down,antidown))/sqrt(2) and (strange,antistrange)
A J/psi meson is (charm,anticharm)
An upsilon meson is (bottom,antibottom)