The Kalduu had transparent bodies, with four tentacles that extended below their hemispherical body. They breathed carbon dioxide and exhaled oxygen. Kalduu reproduced by fission. As they lacked vocal cords, Kalduu communicated telepathically. They could form a group mind if two or more Kalduu were within 60 meters of one another. This could be extended to their hosts, which were most often Ropagu, with whom they had a long-standing friendship. Kalduu ate airborne bacteria as well as germs and viruses from their hosts.
The Kalduu and the Ropagu had a symbiotic relationship. The Ropagu benefited from the medicinal abilities of the Kalduu while they were able to feed on the infections of their hosts.
They were able to stop the Ropagu civil wars. They bonded with the minds of Ropagu leaders during a period of conflict and filled their heads with peaceful thoughts. This influenced the Ropagu into a state of harmonious coexistence.
- Twin Stars of Kira
- Alien Encounters