The planet appears to be cold, dark and lifeless, but nevertheless supports a breathable atmosphere, water and presumably food. Before the sinister Animus took control of the planet, Vortis was covered in a flowerforest, which the Menoptra hoped would return. Many years later after the Animus was apparently vanquished, Vortis drifted into the neighboring Rhumos system and was fought over by the Rhumons, who considered it a disputed territory. The Animus had also survived, until the intervention of a time traveller once more brought peace to the troubled world.
Species of Vortis
Menoptra
Resembling giant, humanoid butterflies and able to achieve space flight with their wings alone, the Menoptra were the original masters of Vortis until the Animus inveigled itself within the minds of the Zarbi. The Menoptra fled to Pictos, one of the moons of Vortis, eventually planning an invasion. Those that were captured were either killed or forced to work, once their wings had been removed by the Zarbi. That their attempt to retake their home world was a success was largely down to the efforts of the aforementioned party of time travellers.
Optera
In an apparent example of emerging speciation, some of the Menoptra fled underground, adapting to a subterranean environment and calling themselves the Optera. This species have lost the ability to fly, and resemble upright caterpillars, indicating that they had evolved through neoteny. They also have larger eyes than their Menoptra brethren. However, they have numerous arms and appear to 'hop' in a stylised way. With the Animus defeated, they appeared to believe that future generations of Optera would redevelop flight.
Venom Grubs
Unlike the other bipedal species of Vortis, Venom Grubs crawl along the ground. They were used as mobile weapons by the Zarbi, able to shootvenom from their snouts that proved fatal to all it touched. The Grubs were rendered harmless once the Zarbi were freed from the Animus's influence. Venom Grubs were mentioned in the 2005 episode Boom Town, where it is implied that they are used to punish disobedient Slitheen.
Zarbi
The Zarbi resemble giant ants, and according to the Menoptra have been used as cattle in the planet's history. These insectoids lackintelligence, and so were easily enslaved by the malevolent Animus and used against the Menoptra. When the Animus's evil influence was lifted through the intervention of a mysterious time traveller and his human companions, the Zarbi returned to their docile state. According to the novelisation of The Web Planet, the Zarbi reproduce through the "Zarbi Supremo", who acts like a queen bee. The Supremo also appeared in the 1966 Doctor Who Annual.