  We use numerical simulations to study the development of gas/star offsets in
the tidal tails of merging galaxies. These offsets are shown to be a natural
consequence of the radially extended HI spatial distribution in disk galaxies,
coupled with internal dissipation in the gaseous component driven by the
interaction. This mechanism explains the observed gas/star offsets in
interacting galaxies without invoking interactions with a hot (unseen) gaseous
component.
