In the research tab I’ve got some parts saying to capture a siren and an acid worm. I’ve got both of them. I can go into my personnel section and look at them, but I can’t perform a vivisection. I did catch them both before actually doing the autopsy on them. So I assume it just doesn’t expect you to do that and doesn’t bother checking to see if you’ve got them already, only checking to see if you captured one after future missions.