Janus VI colony personnel
List of Janus VI colony personnel.

Named
 Ed Appel
 Roberts
 
 Schmitter
 Vanderberg

Unnamed

Chemists  
These chemists were given the task of identifying the cause of the disintegration of the metal on miner's automatic machinery. According to Chief Vanderberg, there was no reason for their equipment to dissolve, and ultimately, "our chemists were unable to analyze the corrosive agent." ()

Engineers  
These engineers were civilians who lived on the planet Janus VI. A Horta was killing the miners in order to protect its eggs. They attacked a security team from the  that was trying to hold them back while Spock attempted to communicate with the creature. ()

Guard 1  

This colonist served as a guard in the area near the PXK pergium reactor in 2267. He was murdered by the mother Horta prior to her theft of the main circulating pump. ()

Guard 2  

This colonist guarded the office of Administrator Vanderberg in 2267. He lead Kirk, Spock, and McCoy into Vanderberg's officer upon their beam down to the station. ()

Guard 3  

This solitary guard stood outside the entrance to one of the building on the upper level of the facility. ()

Miners and maintenance engineers  
These fifty miners had already been butchered by the mother Horta as of 2267. According to Vanderberg, the first butchered were maintenance engineers sent down into the drifts to repair the corroded machinery, who were later found "burned to a crisp" and "seared almost out of existence." Vanderberg further explained that the deaths began moving towards the upper levels, with the last man having died two days prior to the arrival of the , three levels below the headquarters. In addition, five sentries assigned to guard the entrance of the mine, including Schmitter, were among the casualties. ()

Plant physician 
The plant physician concurred with Leonard McCoy's conclusion that Schmitter was the victim of chemical corrosion. ()

Unnamed Humans
Personnel lists